/*
	PsychGetGLErrorListString()
	
*/ 
psych_bool PsychGetGLErrorListString(const char **errorListStr)
{
	#define MAX_GL_ERROR_LIST_LEN			2048
	#define MAX_GL_ERROR_LIST_DELTA_LEN		256
	static char	errorListString[MAX_GL_ERROR_LIST_LEN];
	char	*errorNameStr;
	int		currentIndex, deltaStrLen, nextCurrentIndex;
    GLenum	glError;
    psych_bool	isError=FALSE;

    // Skip this routine with "no error" return status, if kPsychAvoidCPUGPUSync
    // is set as conserveVRAM setting by usercode:
    *errorListStr = NULL;
    if (PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync) return(FALSE);
	
	currentIndex=0;
    for(glError=glGetError(); glError!=GL_NO_ERROR; glError=glGetError()){
		errorNameStr=PsychGetGLErrorNameString(glError);
		deltaStrLen=strlen(errorNameStr)+2;  //2 chars: comma and space
		nextCurrentIndex=currentIndex+deltaStrLen;
		if(nextCurrentIndex >= MAX_GL_ERROR_LIST_LEN)
			PsychErrorExitMsg(PsychError_internal,"string memory overflow");
		if(isError)
			sprintf(&(errorListString[currentIndex]), " ,%s", errorNameStr);
		else
			sprintf(&(errorListString[currentIndex]), "%s", errorNameStr);
		currentIndex=nextCurrentIndex;
		isError=TRUE;		
	}
	if(isError)
		*errorListStr=errorListString;
	else
		*errorListStr=NULL;
	return(isError);
}
Ejemplo n.º 2
0
/*
 * PsychOSFlipWindowBuffers() -- OS-X swapbuffers call.
 */
void PsychOSFlipWindowBuffers(PsychWindowRecordType *windowRecord)
{	
	CGLError			cglerr;
    psych_bool oldStyle = (PsychPrefStateGet_ConserveVRAM() & kPsychUseOldStyleAsyncFlips) ? TRUE : FALSE;
    
	// Execute OS neutral bufferswap code first:
	PsychExecuteBufferSwapPrefix(windowRecord);
	
    // Trigger the "Front <-> Back buffer swap (flip) (on next vertical retrace)":
    if ((cglerr = CGLFlushDrawable((oldStyle || PsychIsMasterThread()) ? windowRecord->targetSpecific.contextObject : windowRecord->targetSpecific.glswapcontextObject))) {
		// Failed! This is an internal OpenGL/CGL error. We can't do anything about it, just report it:
		printf("PTB-ERROR: Doublebuffer-Swap failed (probably during 'Flip')! Internal OpenGL subsystem/driver error: %s. System misconfigured or driver/operating system bug?!?\n", CGLErrorString(cglerr));
	}
}
Ejemplo n.º 3
0
/* PsychOSSetVBLSyncLevel - Enable or disable synchronization of bufferswaps to
 * onset of vertical retrace. This is the OS-X version...
 */
void PsychOSSetVBLSyncLevel(PsychWindowRecordType *windowRecord, int swapInterval)
{
    CGLError	error;
    GLint myinterval = (GLint) swapInterval;
    psych_bool oldStyle = (PsychPrefStateGet_ConserveVRAM() & kPsychUseOldStyleAsyncFlips) ? TRUE : FALSE;
    
	// Store new setting also in internal helper variable, e.g., to allow workarounds to work:
	windowRecord->vSynced = (swapInterval > 0) ? TRUE : FALSE;
	
    error=CGLSetParameter((oldStyle || PsychIsMasterThread()) ? windowRecord->targetSpecific.contextObject : windowRecord->targetSpecific.glswapcontextObject, kCGLCPSwapInterval, &myinterval);
    if (error) {
        if (PsychPrefStateGet_Verbosity()>1) printf("\nPTB-WARNING: FAILED to %s synchronization to vertical retrace!\n\n", (swapInterval>0) ? "enable" : "disable");
    }
    
    error=CGLGetParameter((oldStyle || PsychIsMasterThread()) ? windowRecord->targetSpecific.contextObject : windowRecord->targetSpecific.glswapcontextObject, kCGLCPSwapInterval, &myinterval);
    if (error || (myinterval != (GLint) swapInterval)) {
        if (PsychPrefStateGet_Verbosity()>1) printf("\nPTB-WARNING: FAILED to %s synchronization to vertical retrace (System ignored setting)!\n\n", (swapInterval>0) ? "enable" : "disable");
    }
}
Ejemplo n.º 4
0
PsychError SCREENPreference(void)  
{

	PsychArgFormatType		arg1Type;
	char					*preferenceName, *newFontName;
	const char				*tableCreator, *oldDefaultFontName;
	Boolean					preferenceNameArgumentValid, booleanInput, ignoreCase, tempFlag, textAlphaBlendingFlag, suppressAllWarningsFlag;
	int						numInputArgs, i, newFontStyleNumber, newFontSize, tempInt;
	double					returnDoubleValue, inputDoubleValue;
	
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous or missing arguments
	PsychErrorExit(PsychCapNumInputArgs(3));			
	PsychErrorExit(PsychRequireNumInputArgs(1));		   
	PsychErrorExit(PsychCapNumOutputArgs(1));
	
	numInputArgs=PsychGetNumInputArgs();
	arg1Type=PsychGetArgType(1);
	preferenceNameArgumentValid=FALSE;
	
	//Cases which require both a window pointer or screen number and preference name.  Argument 1 is the wposn and argument 2 is the preference name.
	if( numInputArgs >= 2 && (PsychIsScreenNumberArg(1) || PsychIsScreenNumberArg(1)) && PsychGetArgType(2)==PsychArgType_char ){
		PsychAllocInCharArg(2, kPsychArgRequired, &preferenceName);
		//preferences which require window pointer or screen number argument which we DO NOT support  
		for(i=0;i<kPsychNumUnsupportedMacVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//insert here conditionals  to act on prefernces which accept a window pointer or screen number argument which we DO support.
		PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}

	//Cases which do not require a wposn.  Argument 1 is the preference name.  if present Argument 2 is the new value
	if(arg1Type==PsychArgType_char){
		PsychAllocInCharArg(1, kPsychArgRequired, &preferenceName);
		//Preferernces which we do not support and which do not require a wposn
		for(i=0;i<kPsychNumUnsupportedMacNonVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacNonVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//Preferences which we do support
		if(PsychMatch(preferenceName, "IgnoreCase")){
			ignoreCase=!PsychIsPsychMatchCaseSensitive();
			PsychCopyOutFlagArg(1, kPsychArgOptional, ignoreCase);
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
				PsychSetPsychMatchCaseSenstive(!booleanInput);			
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Tick0Secs")){
			if(PsychCopyInDoubleArg(2, kPsychArgOptional, &inputDoubleValue) && inputDoubleValue==PsychGetNanValue())
				PsychEstimateGetSecsValueAtTickCountZero();
			returnDoubleValue=PsychGetEstimatedSecsValueAtTickCountZero();
			PsychCopyOutDoubleArg(1, kPsychArgOptional, returnDoubleValue);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableVersion")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double)PsychPrefStateGet_PsychTableVersion());
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableCreator")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			tableCreator=PsychPrefStateGet_PsychTableCreator();
			PsychCopyOutCharArg(1, kPsychArgOptional, tableCreator);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Process")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double)getpid());
			preferenceNameArgumentValid=TRUE;


		}else 
		if(PsychMatch(preferenceName, "DefaultFontName")){
			PsychPrefStateGet_DefaultFontName(&oldDefaultFontName);
			PsychCopyOutCharArg(1, kPsychArgOptional, oldDefaultFontName);
			if(numInputArgs==2){
				PsychAllocInCharArg(2, kPsychArgRequired, &newFontName);
				PsychPrefStateSet_DefaultFontName(newFontName);
			}
			preferenceNameArgumentValid=TRUE;
			
		}else 
		if(PsychMatch(preferenceName, "DefaultFontStyle")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextStyle());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontStyleNumber);
				PsychPrefStateSet_DefaultTextStyle(newFontStyleNumber);
			}
			preferenceNameArgumentValid=TRUE;
		}else
		if(PsychMatch(preferenceName, "DefaultTextYPositionIsBaseline")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextYPositionIsBaseline());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextYPositionIsBaseline(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DefaultFontSize")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextSize());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontSize);
				PsychPrefStateSet_DefaultTextSize(newFontSize);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DebugMakeTexture")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DebugMakeTexture());
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
				PsychPrefStateSet_DebugMakeTexture(tempFlag);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SkipSyncTests")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_SkipSyncTests());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_SkipSyncTests(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VisualDebugLevel")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VisualDebugLevel());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_VisualDebugLevel(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VBLTimestampingMode")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VBLTimestampingMode());
			if(numInputArgs==2){
                            PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
                            PsychPrefStateSet_VBLTimestampingMode(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "ConserveVRAM")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_ConserveVRAM());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_ConserveVRAM(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Verbosity")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_Verbosity());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_Verbosity(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "EmulateOldPTB")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_EmulateOldPTB());
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
					PsychPrefStateSet_EmulateOldPTB(tempFlag);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Enable3DGraphics")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_3DGfx());
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
					PsychPrefStateSet_3DGfx(tempFlag);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "TextAlphaBlending")){
				textAlphaBlendingFlag=PsychPrefStateGet_TextAlphaBlending();
				PsychCopyOutFlagArg(1, kPsychArgOptional, textAlphaBlendingFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_TextAlphaBlending(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SuppressAllWarnings")){
				suppressAllWarningsFlag=PsychPrefStateGet_SuppressAllWarnings();
				PsychCopyOutFlagArg(1, kPsychArgOptional, suppressAllWarningsFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_SuppressAllWarnings(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}
	
	if(!preferenceNameArgumentValid)
		PsychErrorExitMsg(PsychError_user, "Invalid arguments to preferences command");
		
	return(PsychError_none);
}
Ejemplo n.º 5
0
PsychError SCREENOpenWindow(void) 

{
    int						screenNumber, numWindowBuffers, stereomode, multiSample, imagingmode;
    PsychRectType 			rect, screenrect;
    PsychColorType			color;
    PsychColorModeType  	mode; 
    boolean					isArgThere, settingsMade, didWindowOpen, useAGL;
    PsychScreenSettingsType	screenSettings;
    PsychWindowRecordType	*windowRecord;
    double dVals[4];
    PsychDepthType			specifiedDepth, possibleDepths, currentDepth, useDepth;
	int dummy1;
	double dummy2, dummy3, dummy4;
	Boolean EmulateOldPTB = PsychPrefStateGet_EmulateOldPTB();
    
	//just for debugging
    //if (PSYCH_DEBUG == PSYCH_ON) printf("Entering SCREENOpen\n");

    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};

    //cap the number of inputs
    PsychErrorExit(PsychCapNumInputArgs(8));   //The maximum number of inputs
    PsychErrorExit(PsychCapNumOutputArgs(2));  //The maximum number of outputs

    //get the screen number from the windowPtrOrScreenNumber.  This also checks to make sure that the specified screen exists.  
    PsychCopyInScreenNumberArg(kPsychUseDefaultArgPosition, TRUE, &screenNumber);
    if(screenNumber==-1)
        PsychErrorExitMsg(PsychError_user, "The specified onscreen window has no ancestral screen."); 

    /*
      The depth checking is ugly because of this stupid depth structure stuff.  
      Instead get a descriptor of the current video settings, change the depth field,
      and pass it to a validate function wich searches a list of valid video modes for the display.
      There seems to be no point in checking the depths alone because the legality of a particular
      depth depends on the other settings specified below.  Its probably best to wait until we have
      digested all settings and then test the full mode, declarin an invalid
      mode and not an invalid pixel size.  We could notice when the depth alone is specified 
      and in that case issue an invalid depth value.
     */  

    //find the PixelSize first because the color specifier depends on the screen depth.  
    PsychInitDepthStruct(&currentDepth);  //get the current depth
    PsychGetScreenDepth(screenNumber, &currentDepth);
    PsychInitDepthStruct(&possibleDepths); //get the possible depths
    PsychGetScreenDepths(screenNumber, &possibleDepths);

    #if PSYCH_SYSTEM == PSYCH_OSX || PSYCH_SYSTEM == PSYCH_WINDOWS
       // MK Experimental Hack: Add the special depth values 64 and 128 to the depth struct. This should 
       // allows for 16 bpc, 32 bpc floating point color buffers on the latest ATI and NVidia hardware.
	   // "Should" means: It doesn't really work with any current driver, but we leave the testcode in
	   // in the hope for future OS and driver releases ;-)
       // Unfortunately at this point of the init sequence, we are not able
       // to check if these formats are supported by the hardware. Ugly ugly ugly...
       PsychAddValueToDepthStruct(64, &possibleDepths);
       PsychAddValueToDepthStruct(128, &possibleDepths);
    #endif

//    #if PSYCH_SYSTEM == PSYCH_OSX || PSYCH_SYSTEM == PSYCH_LINUX
		// On MacOS/X and Linux with ATI Radeon X1000/HD2000/HD3000 hardware and the special
		// kernel support driver installed, we should be able to configure the hardwares
		// framebuffers into ABGR2101010 mode, ie. 2 bits alpha, 10 bpc for red, green, blue.
		// This needs support from the imaging pipeline, or manually converted stimuli, as
		// the GPU doesn't format pixel data properly, only the CRTC scans out in that format.
		// Anyway, allow this setting on OS/X and Linux:
		
		// Update: Some FireGL cards (2008 and later) claim to support this on MS-Windows. Enable
		// this option on Windows as well, so it is at least testable:
		PsychAddValueToDepthStruct(30, &possibleDepths);
//    #endif


    PsychInitDepthStruct(&specifiedDepth); //get the requested depth and validate it.  
    isArgThere = PsychCopyInSingleDepthArg(4, FALSE, &specifiedDepth);

    PsychInitDepthStruct(&useDepth);
    if(isArgThere){ //if the argument is there check that the screen supports it...
        if(!PsychIsMemberDepthStruct(&specifiedDepth, &possibleDepths))
            PsychErrorExit(PsychError_invalidDepthArg);
        else
            PsychCopyDepthStruct(&useDepth, &specifiedDepth);
    }else //otherwise use the default
        PsychCopyDepthStruct(&useDepth, &currentDepth);

    // Initialize the rect argument to the screen rectangle:
    PsychGetScreenRect(screenNumber, rect); 	//get the rect describing the screen bounds.  This is the default Rect.  

    // Override it with a user supplied rect, if one was supplied:
    isArgThere=PsychCopyInRectArg(kPsychUseDefaultArgPosition, FALSE, rect );
    if (IsPsychRectEmpty(rect)) PsychErrorExitMsg(PsychError_user, "OpenWindow called with invalid (empty) rect argument.");

	if (PSYCH_SYSTEM == PSYCH_OSX) {
		// OS/X system: Need to decide if we use a Carbon window + AGL
		// or a fullscreen context with CGL:
		
		// Default to AGL, switch to CGL if below constraints are met:
		useAGL = TRUE;
	
		// Window rect provided which has a different size than screen?

		// We do not use windowed mode if the provided window rectangle either
		// matches the target screens rectangle (and therefore its exact size)
		// or its screens global rectangle.
		PsychGetScreenRect(screenNumber, screenrect);
		if (PsychMatchRect(screenrect, rect)) useAGL=FALSE;
		PsychGetGlobalScreenRect(screenNumber, screenrect);
		if (PsychMatchRect(screenrect, rect)) useAGL=FALSE;

		// Override for use on f$%#$Fd OS/X 10.5.3 - 10.5.6 with NVidia GF 8800 GPU's:
		if (PsychPrefStateGet_ConserveVRAM() & kPsychUseAGLCompositorForFullscreenWindows) useAGL = TRUE;
	}
	else {
		// Non OS/X system: Do not use AGL ;-)
		useAGL = FALSE;
	}
	
    //find the number of specified buffers. 

    //OS X:	The number of backbuffers is not a property of the display mode but an attribute of the pixel format.
    //		Therefore the value is held by a window record and not a screen record.    

    numWindowBuffers=2;	
    PsychCopyInIntegerArg(5,FALSE,&numWindowBuffers);
    if(numWindowBuffers < 1 || numWindowBuffers > kPsychMaxNumberWindowBuffers) PsychErrorExit(PsychError_invalidNumberBuffersArg);

    // MK: Check for optional spec of stereoscopic display: 0 (the default) = monoscopic viewing.
    // 1 == Stereo output via OpenGL built-in stereo facilities: This will drive any kind of
    // stereo display hardware that is directly supported by MacOS-X.
    // 2/3 == Stereo output via compressed frame output: Only one backbuffer is used for both
    // views: The left view image is put into the top-half of the screen, the right view image
    // is put into the bottom half of the screen. External hardware demangles this combi-image
    // again into two separate images. CrystalEyes seems to be able to do this. One looses half
    // of the vertical resolution, but potentially gains refresh rate...
    // Future PTB version may include different stereo algorithms with an id > 1, e.g., 

    // anaglyph stereo, interlaced stereo, ...

    stereomode=0;
    PsychCopyInIntegerArg(6,FALSE,&stereomode);
    if(stereomode < 0 || stereomode > 10) PsychErrorExitMsg(PsychError_user, "Invalid stereomode provided (Valid between 0 and 10).");
	if (stereomode!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, stereo display functions are not supported in OS-9 PTB emulation mode.");

    multiSample=0;
    PsychCopyInIntegerArg(7,FALSE,&multiSample);
    if(multiSample < 0) PsychErrorExitMsg(PsychError_user, "Invalid multisample value provided (Valid are positive numbers >= 0).");
	if (multiSample!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, anti-aliasing functions are not supported in OS-9 PTB emulation mode.");

	imagingmode=0;
    PsychCopyInIntegerArg(8,FALSE,&imagingmode);
    if(imagingmode < 0) PsychErrorExitMsg(PsychError_user, "Invalid imaging mode provided (See 'help PsychImagingMode' for usage info).");
	if (imagingmode!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, imaging pipeline functions are not supported in OS-9 PTB emulation mode.");
	
	// We require use of the imaging pipeline if stereomode for dualwindow display is requested.
	// This makes heavy use of FBO's and blit operations, so imaging pipeline is needed.
	if (stereomode==kPsychDualWindowStereo) {
		// Dual window stereo requested, but imaging pipeline not enabled. Enable it:
		imagingmode|= kPsychNeedFastBackingStore;
		if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Trying to enable imaging pipeline for dual-window stereo display mode...\n");
	}
	
    //set the video mode to change the pixel size.  TO DO: Set the rect and the default color  
    PsychGetScreenSettings(screenNumber, &screenSettings);    
    PsychInitDepthStruct(&(screenSettings.depth));
    PsychCopyDepthStruct(&(screenSettings.depth), &useDepth);

    // Here is where all the work goes on:

    // If the screen is not already captured then to that:
    if(!PsychIsScreenCaptured(screenNumber) && !useAGL) {
        PsychCaptureScreen(screenNumber);

		// We disable the call to PsychSetScreenSettings here: Its not useful, as it
		// could only change color depth - which is something we don't want to do anyway here.
		// If people want to change displays settings, they should use Screen('Resolution') instead,
		// which is a more clever interface to PsychSetScreenSettings().
		
        // settingsMade=PsychSetScreenSettings(screenNumber, &screenSettings);
        //Capturing the screen and setting its settings always occur in conjunction
        //There should be a check above to see if the display is captured and openWindow is attempting to chang
        //the bit depth
    }

#if PSYCH_SYSTEM == PSYCH_WINDOWS
    // On M$-Windows we currently only support - and therefore require >= 30 bpp color depth.
    if (PsychGetScreenDepthValue(screenNumber) < 30) {
		// Display running at less than 30 bpp. OpenWindow will fail on M$-Windows anyway, so let's abort
		// now.

		// Output warning text:
        printf("PTB-ERROR: Your display screen %i is not running at the required color depth of at least 30 bit.\n", screenNumber);
        printf("PTB-ERROR: The current setting is %i bit color depth..\n", PsychGetScreenDepthValue(screenNumber));
        printf("PTB-ERROR: This will not work on Microsoft Windows operating systems.\n");
        printf("PTB-ERROR: Please use the 'Display settings' control panel of Windows to change the color depth to\n");
        printf("PTB-ERROR: 32 bits per pixel ('True color' or 'Highest' setting) and then retry. It may be neccessary\n");
        printf("PTB-ERROR: to restart Matlab after applying the change...\n");
        fflush(NULL);

		// Release the captured screen:
		PsychRestoreScreenSettings(screenNumber);
		PsychReleaseScreen(screenNumber);

        // Reset master assignment to prepare possible further dual-window config operations:
		sharedContextWindow = NULL;

		// Abort with Matlab error:
		PsychErrorExitMsg(PsychError_user, "Insufficient color depth setting for display device (smaller than 30 bpp).");
    }

#endif

    //if (PSYCH_DEBUG == PSYCH_ON) printf("Entering PsychOpenOnscreenWindow\n");
    PsychCopyDepthStruct(&(screenSettings.depth), &useDepth);
	
	// Create the onscreen window and perform initialization of everything except
	// imaging pipeline and a few other special quirks. If sharedContextWindow is non-NULL,
	// the new window will share its OpenGL context ressources with sharedContextWindow.
	// This is typically used for dual-window stereo mode. Btw. If imaging pipeline is really
	// active, we force multiSample to zero: This way the system backbuffer / pixelformat
	// is enabled without multisampling support, as we do all the multisampling stuff ourselves
	// within the imaging pipeline with multisampled drawbuffer FBO's...
    didWindowOpen=PsychOpenOnscreenWindow(&screenSettings, &windowRecord, numWindowBuffers, stereomode, rect, ((imagingmode==0 || imagingmode==kPsychNeedFastOffscreenWindows) ? multiSample : 0), sharedContextWindow);
    if (!didWindowOpen) {
        if (!useAGL) {
			PsychRestoreScreenSettings(screenNumber);
			PsychReleaseScreen(screenNumber);
		}

		// Reset master assignment to prepare possible further dual-window config operations:
		sharedContextWindow = NULL;

        // We use this dirty hack to exit with an error, but without printing
        // an error message. The specific error message has been printed in
        // PsychOpenOnscreenWindow() already..
        PsychErrMsgTxt("");
    }

    // Sufficient display depth for full alpha-blending and such?
    if (PsychGetScreenDepthValue(screenNumber) < 24) {
        // Nope. Output a little warning.
        printf("PTB-WARNING: Your display screen %i is not running at 24 bit color depth or higher.\n", screenNumber);
        printf("PTB-WARNING: The current setting is %i bit color depth..\n", PsychGetScreenDepthValue(screenNumber));
        printf("PTB-WARNING: This could cause failure to work correctly or visual artifacts in stimuli\n");
        printf("PTB-WARNING: that involve Alpha-Blending. It can also cause drastically reduced color resolution\n");
        printf("PTB-WARNING: for your stimuli! Please try to switch your display to 'True Color' (Windows)\n");
        printf("PTB-WARNING: our 'Millions of Colors' (MacOS-X) to get rid of this warning and the visual artifacts.\n");
        fflush(NULL);
    }
    
	// Define clear color: This depends on the color range of our onscreen window...
    isArgThere=PsychCopyInColorArg(kPsychUseDefaultArgPosition, FALSE, &color); //get from user
    if(!isArgThere) PsychLoadColorStruct(&color, kPsychIndexColor, PsychGetWhiteValueFromWindow(windowRecord)); //or use the default
    PsychCoerceColorMode(&color);

	// Special setup code for dual window stereomode:
	if (stereomode == kPsychDualWindowStereo) {
		if (sharedContextWindow) {
			// This is creation & setup of the slave onscreen window, ie. the one
			// representing the right-eye view. This window doesn't do much. It
			// is not used or referenced in the users experiment script. It receives
			// its final image content during Screen('Flip') operation of the master
			// onscreen window, then gets flipped in sync with the master window.
			
			// Ok, we already have the slave window open and it shares its OpenGL context
			// with the master window. Reset its internal reference to the master:
			windowRecord->slaveWindow = NULL;
			
			// Reset imagingmode for this window prior to imaging pipeline setup. This
			// window is totally passive so it doesn't need the imaging pipeline.
			imagingmode = 0;
						
			// Assign this window to the master window as a slave:
			sharedContextWindow->slaveWindow = windowRecord;
			
			// Reset master assignment to prepare possible further dual-window config operations:
			sharedContextWindow = NULL;

			// Activate the IdentitiyBlitChain for the slave window and add a single identity blit
			// operation to it: This is needed in PsychPreFlipOperations() for final copy of stimulus
			// image into this slave window:
			PsychPipelineAddBuiltinFunctionToHook(windowRecord, "IdentityBlitChain", "Builtin:IdentityBlit", INT_MAX, "");
			PsychPipelineEnableHook(windowRecord, "IdentityBlitChain");

			if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Created master-slave window relationship for dual-window stereo display mode...\n");

			// Special config finished. The master-slave combo should work from now on...
		}
		else {
			// This is initial setup & creation of the master onscreen window, ie. the one
			// representing the left-eye view and doing all the heavy work, acting as a
			// proxy for both windows.
			
			// Not much to do here. Just store its windowRecord as a reference for creation
			// of the slave window. We'll need it for that purpose...
			sharedContextWindow = windowRecord;
		}
	}

	// Set special half-width flag for window if we are either in a dual-display/dual-view stereo mode or if
	// if is requested as part of the imagingMode flag. This will cause PTB 2D drawing routines and window size
	// query routines etc. to return an effective window width or window rect only half the real width.
	if (windowRecord->stereomode==kPsychFreeFusionStereo || windowRecord->stereomode==kPsychFreeCrossFusionStereo || (imagingmode & kPsychHalfWidthWindow)) {
		windowRecord->specialflags = windowRecord->specialflags | kPsychHalfWidthWindow;
		imagingmode = imagingmode & (~kPsychHalfWidthWindow);
	}

	// Similar handling for windows of half the real height, except that none of our built-in stereo modes requires these,
	// so this is only done on request from external code via the imagingmode flag kPsychHalfHeightWindow.
	// One use of this is when using interleaved line stereo mode (PsychImaging(...'InterleavedLineStereo')) where windows
	// only have a useable net height of half their physical height:
	if (imagingmode & kPsychHalfHeightWindow) {
		windowRecord->specialflags = windowRecord->specialflags | kPsychHalfHeightWindow;
		imagingmode = imagingmode & (~kPsychHalfHeightWindow);
	}

	// Initialize internal image processing pipeline if requested:
	PsychInitializeImagingPipeline(windowRecord, imagingmode, multiSample);
	
	// On OS-X, if we are in quad-buffered frame sequential stereo mode, we automatically generate
	// blue-line-sync style sync lines for use with stereo shutter glasses. We don't do this
	// by default on Windows or Linux: These systems either don't have stereo capable hardware,
	// or they have some and its drivers already take care of sync signal generation.
	if ((PSYCH_SYSTEM == PSYCH_OSX) && (windowRecord->stereomode==kPsychOpenGLStereo)) {
		if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Enabling internal blue line sync renderer for quad-buffered stereo...\n");
		PsychPipelineAddBuiltinFunctionToHook(windowRecord, "LeftFinalizerBlitChain", "Builtin:RenderStereoSyncLine", INT_MAX, "");
		PsychPipelineEnableHook(windowRecord, "LeftFinalizerBlitChain");		
		PsychPipelineAddBuiltinFunctionToHook(windowRecord, "RightFinalizerBlitChain", "Builtin:RenderStereoSyncLine", INT_MAX, "");
		PsychPipelineEnableHook(windowRecord, "RightFinalizerBlitChain");		
	}

	// Activate new onscreen window for userspace drawing: If imaging pipeline is active, this
	// will bind the correct rendertargets for the first time:
	PsychSetDrawingTarget(windowRecord);

    // Set the clear color and perform a backbuffer-clear:
    PsychConvertColorToDoubleVector(&color, windowRecord, windowRecord->clearColor);
	PsychGLClear(windowRecord);

    // Mark end of drawing op. This is needed for single buffered drawing:
    PsychFlushGL(windowRecord);

    // Make sure no OpenGL errors happened up to this point:
    PsychTestForGLErrors();

    // If we are in logo-startup mode (former blue-screen mode) and double-buffering
    // is enabled, then do an initial bufferswap & clear, so the display starts in
    // the user selected background color instead of staying at the blue screen or
    // logo display until the Matlab script first calls 'Flip'.
    if ((PsychPrefStateGet_VisualDebugLevel()>=4) && numWindowBuffers>=2) {
      // Do immediate bufferswap by an internal call to Screen('Flip'). This will also
	  // take care of clearing the backbuffer in preparation of first userspace drawing
	  // commands and such...
	  PsychFlipWindowBuffers(windowRecord, 0, 0, 0, 0, &dummy1, &dummy2, &dummy3, &dummy4);
      // Display now shows background color, so user knows that PTB's 'OpenWindow'
      // procedure is successfully finished.
    }

    PsychTestForGLErrors();

    //Return the window index and the rect argument.
    PsychCopyOutDoubleArg(1, FALSE, windowRecord->windowIndex);

	// rect argument needs special treatment in stereo mode:
	PsychMakeRect(&rect, windowRecord->rect[kPsychLeft], windowRecord->rect[kPsychTop],
					windowRecord->rect[kPsychLeft] + PsychGetWidthFromRect(windowRecord->rect)/((windowRecord->specialflags & kPsychHalfWidthWindow) ? 2 : 1),
					windowRecord->rect[kPsychTop] + PsychGetHeightFromRect(windowRecord->rect)/((windowRecord->specialflags & kPsychHalfHeightWindow) ? 2 : 1));

    PsychCopyOutRectArg(2, FALSE, rect);

    return(PsychError_none);   
}
PsychError SCREENBeginOpenGL(void)
{
    static char useString[] = "Screen('BeginOpenGL', windowPtr [, sharecontext=0]);";
    static char synopsisString[] = "Prepare window 'windowPtr' for OpenGL rendering by external OpenGL code. "
		"This allows to use OpenGL drawing routines other than the ones implemented "
        "in Screen() to draw to a Psychtoolbox onscreen- or offscreen window via execution of "
        "OpenGL commands. Typical clients of this function are mogl (Richard F. Murrays OpenGL for Matlab wrapper), "
        "the new Eyelink-Toolbox and third party Matlab Mex-Files which contain OpenGL rendering routines. "
        "You *have to* call this command once before using any of those external drawing commands for the window. "
        "After drawing, you *must* switch back to PTB's rendering via the Screen('EndOpenGL', windowPtr); command. "
		"Normally, you won't provide the optional flag 'sharecontext', so PTB will automatically isolate the OpenGL "
		"state of your code from its internal state. However, if you provide sharecontext=1, then PTB will allow "
		"your code to use and affect PTBs internal context. Only do this if you really know what you're doing! "
		"If you provide sharecontext=2 then PTB will give you your own private context, but it will synchronize "
		"the state of that context with its internal state - Seldomly needed, but here for your convenience. "
		"The context state isolation is as strict as possible without seriously affecting performance and functionality: "
		"All OpenGL context state is separated, with two exceptions: The framebuffer binding (if any) is always synchronized "
		"with PTB (and reset to zero when calling 'EndOpenGL' or another Screen command) to allow external code to transparently "
		"render into PTBs internal framebuffers - Needed for the imaging pipeline to work. Ressources like textures, display lists, "
		"FBOs, VBOs, PBOs and GLSL shaders are shared between PTB and your code as well for efficiency reasons. Both types of "
		"ressource sharing shouldn't be a problem, because either you are a beginner or advanced OpenGL programmer and won't use "
		"those facilities anyway, or you are an expert user - in which case you'll know how to prevent any conflicts easily.";

    static char seeAlsoString[] = "EndOpenGL SetOpenGLTexture GetOpenGLTexture moglcore";	

    PsychWindowRecordType	*windowRecord;
	GLint fboid, coltexid, ztexid, stexid;
	
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(2));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(1));    // Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
	// Already in userspace mode?
	if (PsychIsUserspaceRendering()) PsychErrorExitMsg(PsychError_user, "Tried to call Screen('BeginOpenGL'), but userspace rendering is already active! Missing or mismatched Screen('EndOpenGL')? Check your code.");
	
	// (Optional) context sharing flag provided?
	sharecontext = 0;
	PsychCopyInIntegerArg(2, FALSE, &sharecontext);
	if (sharecontext<0 || sharecontext>2) PsychErrorExitMsg(PsychError_user, "Invalid value for 'sharecontext' provided. Not in range 0 to 2.");
	
	// Master override: If context isolation is disabled then we use the PTB internal context...
	if (PsychPrefStateGet_ConserveVRAM() & kPsychDisableContextIsolation) sharecontext = 1;
	
    // Set it as drawing target: This will set up the proper FBO bindings as well:
    PsychSetDrawingTarget(windowRecord);

	// Store it as a reference for later 'EndOpenGL' call:
	preswitchWindowRecord = windowRecord;

	// Userspace wants its own private rendering context, optionally updated to match PTBs internal state?
	if (sharecontext == 0 || sharecontext == 2) {
		// Yes. This is the normal case for 3D rendering. MOGLs and PTBs contexts are separated to
		// increase robustness, only ressources like textures, display lists, PBO's, VBO's, FBO's
		// and GLSL shaders are shared, but not the current renderstate.
		
		// Make sure 3D rendering is globally enabled, otherwise this is considered a userspace bug:
		if (PsychPrefStateGet_3DGfx()==0) PsychErrorExitMsg(PsychError_user, "Tried to call 'BeginOpenGL' for external rendering, but 3D rendering not globally enabled! Call 'InitializeMatlabOpenGL' at the beginning of your script!!");
		
		// Query current FBO binding. We need to manually transfer this to the userspace context, so
		// it can render into our window:
		if (glBindFramebufferEXT) {
			fboid = 0;
	 		glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &fboid);
			if (fboid>0) {
				// Query attachments of FBO:
 				glGetFramebufferAttachmentParameterivEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME_EXT, &coltexid);
 				glGetFramebufferAttachmentParameterivEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME_EXT, &ztexid);
 				glGetFramebufferAttachmentParameterivEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME_EXT, &stexid);
			}
		}
		
		// Flush our context before context switch:
		glFlush();
		
		// Unbind possible FBOs, so system FB is active in our context:
		if (glBindFramebufferEXT && (fboid > 0)) {
			glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
			glFlush();
		}
		
		// Switch to userspace context for this window, optionally sync state with PTBs context:
		PsychOSSetUserGLContext(windowRecord, (sharecontext==2) ? TRUE : FALSE);
		
		// All following ops apply to the usercontext, not our internal context:
		
		// Manually establish proper FBO binding for userspace. This will get reset automaticaly on back-transition
		// inside PsychSetGLContext on its first invocation. If we are in non-imaging mode then there's nothing to do.
		if (glBindFramebufferEXT && (fboid > 0)) {
			if (!glIsFramebufferEXT(fboid)) {
				// Special case: Need to bind a special FBO and the underlying OpenGL driver is faulty,
				// i.e. it doesn't share FBO names accross our OpenGL contexts as it should according to
				// spec.: We manually create a clone of our internal FBO - Create an FBO in the userspace
				// context with the same FBO handle, then manually reattach the proper attachments...					
				if (PsychPrefStateGet_Verbosity()>1) printf("PTB-WARNING: Faulty graphics driver - FBO sharing doesn't work properly, trying work-around. Update your drivers as soon as possible!\n");
				
				glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fboid);
				glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_RECTANGLE_EXT, coltexid, 0);
				glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_TEXTURE_RECTANGLE_EXT, ztexid, 0);
				glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_STENCIL_ATTACHMENT_EXT, GL_TEXTURE_RECTANGLE_EXT, stexid, 0);
				if (GL_FRAMEBUFFER_COMPLETE_EXT != glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT)) {
					// Game over :(
					PsychErrorExitMsg(PsychError_internal, "Graphics driver malfunction: Failed to clone PTBs internal FBO for userspace GLContext inside SCREENBeginOpenGL as part of workaround code! Upgrade your gfx-drivers!!");
				}
				// If we reach this point, then the workaround for the worst OS in existence has worked.
			}
			else {
				// Need to bind a special FBO and the system works correctly - no workaround needed. Just bind it in new context:
				glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fboid);
			}
		}

        // Is this the first time that the userspace rendering context of this
        // onscreen window is selected for real userspace rendering?
        if (windowRecord->needsViewportSetup && PsychIsOnscreenWindow(windowRecord)) {
            // Yes. Need to perform one-time setup actions for this context:
            windowRecord->needsViewportSetup = FALSE;
            
            // Need to setup glViewPort, scissor rectangle, projection and modelview
            // matrices to values that match the windows client rectangle. We need to
            // do this here because some imaging pipeline display modes, e.g, stereomodes
            // for top-bottom stereo or dualview stereo may have altered the useable client
            // rendering area after the context was initially created. OpenGL spec states that
            // at least the viewport and scissor rectangles are set to the full client window
            // area at first bind of a context to its drawable, so we emulate this here on first
            // 'BeginOpenGL' to avoid unpleasant surprises for unsuspecting users:
            PsychSetupView(windowRecord, FALSE);        
        }        
		
		// Running without imaging pipeline and a stereo mode is active?
		if ((windowRecord->stereomode) > 0 && !(windowRecord->imagingMode & kPsychNeedFastBackingStore)) {
			// Perform setup work for stereo drawbuffers in fixed function mode:
			PsychSwitchFixedFunctionStereoDrawbuffer(windowRecord);
		}        
	}
	else {
		// Userspace shares context with PTB. Let's disable possibly bound GLSL shaders:
		PsychSetShader(windowRecord, 0);
	}

	// Check for GL errors:
    PsychTestForGLErrors();
    
	// Set the userspace flag:
	PsychSetUserspaceGLFlag(TRUE);

	// Ready for userspace rendering:
	return(PsychError_none);
}
PsychError SCREENEndOpenGL(void)
{
    static char useString[] = "Screen('EndOpenGL', windowPtr);";
    static char synopsisString[] =  "Finish OpenGL rendering by external OpenGL code, prepare 2D drawing into window 'windowPtr'.\n"
                                    "This is the counterpart to Screen('BeginOpenGL'). Whenever you used Screen('BeginOpenGL') to enable "
                                    "external OpenGL drawing from Matlab, you *must* call Screen('EndOpenGL') when you're finished with a "
                                    "window, either because you want to draw into a different window, or you want to use a Screen command. "
                                    "Psychtoolbox will abort your script if you omit this command. ";
    static char seeAlsoString[] = "BeginOpenGL SetOpenGLTexture GetOpenGLTexture moglcore";	
    
    PsychWindowRecordType	*windowRecord;
    GLenum error;
	GLint fboid;
    
    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString,seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //check for superfluous arguments
    PsychErrorExit(PsychCapNumInputArgs(1));        // The maximum number of inputs
    PsychErrorExit(PsychRequireNumInputArgs(1));    // Number of required inputs.
    PsychErrorExit(PsychCapNumOutputArgs(0));       // The maximum number of outputs
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
	
	// In userspace mode?
	if (!PsychIsUserspaceRendering()) PsychErrorExitMsg(PsychError_user, "Tried to call Screen('EndOpenGL'), but userspace rendering is already disabled! Missing or mismatched Screen('BeginOpenGL')? Check your code.");

    // Check for OpenGL errors in external code:
    if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync) && ((error=glGetError())!=GL_NO_ERROR)) {
        printf("PTB-ERROR: Some of your external OpenGL code executed between last invocation of Screen('BeginOpenGL') and\n");
        printf("PTB-ERROR: Screen('EndOpenGL') produced an OpenGL error condition. Please check your code. The reported GL\n");
        printf("PTB-ERROR: error was: %s\n\n", (const char*) gluErrorString(error));

		// Reset further error state for this context:
		while (glGetError()!=GL_NO_ERROR);
		
		// Abort script:
        PsychErrorExitMsg(PsychError_user, "Failure in external OpenGL code.");
    }

	// Reset userspace rendering flag:
	PsychSetUserspaceGLFlag(FALSE);
	
	// Switch to our windows own OpenGL context and enable it as drawingtarget:

    // MK: Note to self at 31. July 2012, after thinking about this for > 1 hour:
    // The fboid and preswitchWindowRecord code looks redundant and as if it could
    // get replaced by a simple PsychSetDrawingTarget(NULL) call in 'BeginOpenGL', to
    // let the PsychSetDrawingTarget(windowRecord); call below do all the work, but
    // *this is not the case* !!! Do not touch it! It is good as it is.
    //
    // Reason: The intermediate switching Voodoo is needed if PTB is used with the
    // imaging pipeline (partially) disabled for at least one of the participating
    // windows. We need the global currentRenderTarget to stay what it is aka 
    // preswitchWindowRecord, and not turn to NULL while 3D rendering, because
    // we must not trigger the transition logic from NULL to windowRecord in the call to
    // PsychSetDrawingTarget(windowRecord); -- This would trigger a restore operation of
    // the framebuffer as it was pre-BeginOpenGL from the shadow framebuffer backup textures,
    // thereby undoing all the rendering work between BeginOpenGL and EndOpenGL.
    //
    // The only way we could get safely rid of this logic would be to always have the imaging
    // pipeline enabled on all windows -- to make OpenGL 2.1 with FBO extension and all other
    // required extensions mandatory for use of PTB. Iow., we would drop support for all GPU's
    // older than about OpenGL-3 / Direct3D-10 and would accept a significant memory overhead
    // for using all the FBO backing and FBO blitting even in use cases where enabling the
    // full pipeline has no benefit whatsoever. This would be a bad tradeoff, saving a fraction
    // of a millisecond here (potentially) while wasting dozens of MB VRAM+RAM and adding 1
    // millisecond overhead and increased hardware spec requirements to any PTB script.
    //
    // Ok, we *can* skip it if sharecontext flag has been set to 1 to (ab)use the Screen() 2D internal
    // OpenGL rendering context for 3D userspace rendering. In that case no actual context switching
    // or change of framebuffer FBO bindings or any kind of framebuffer shadow backup-restore happens,
    // so the whole 'BeginOpenGL' -> 'EndOpenGL' call sequence is mostly a no-op. The only thing done
    // is setting the 2D drawingtarget at 'Begin/EndOpenGL' time if needed, to get the buffer bindings
    // and viewports / scissors / matrices et al. correct, setting of the userspace flag, and some
    // glGetError() error checking if not disabled by usercode.
    if (sharecontext == 0 || sharecontext == 2) {
        // Current state: Userspace context bound, possibly with a FBO binding active.
        // Internal drawingtarget is still set properly in our internal inactive context,
        // but possible FBO bindings are not set.
        //
        // Wanted intermediate state: Unbind FBO in userspace context, unbind userspace context.
        // Bind internal context, preserve its drawingtarget, but restore possible FBO
        // bindings for that drawingtarget.

        // Query current FBO binding in userspace context. We need to manually transfer this back to the PTB context, so
        // it can render into our window:
        if (glBindFramebufferEXT) {
            fboid = 0;
            glGetIntegerv(GL_FRAMEBUFFER_BINDING_EXT, &fboid);
        }
        
        // Bind OpenGL context of pre-userspacerendering-switch-state:
        // This implicitely flushes the old context and unbinds any FBO's if neccessary
        // before the transition:
        PsychSetGLContext(preswitchWindowRecord);
        
        // Rebind possible old FBOs:
        if (glBindFramebufferEXT && (fboid > 0)) {
            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fboid);
        }

        // Reset error state for our internal context:
        if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) while (glGetError()!=GL_NO_ERROR);
    }
    
	// Current intermediate state: Preswitch state restored, ie. the OpenGL context and
	// FBO bindings (and as part of context state all viewport/matrix/scissor setups etc.)
	// are set as it was before 'BeginOpenGL' was called. The drawingtarget is also the
	// same.
	
    // Avoid a no-op call to PsychSetDrawingTarget() as it would still perform a redundant no-op context-switch
    // causing a bit of overhead:
    if (windowRecord != preswitchWindowRecord) {
        // This call binds our internal OpenGL context for the requested 'windowRecord' and sets up the windowRecord for drawing:
        // It's a no-op if preswitch windowRecord == the requested windowRecord. Otherwise a standard context switch and drawing
        // target switch will occur:
        PsychSetDrawingTarget(windowRecord); 

        // Reset error state for our internal context:
        if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) while (glGetError()!=GL_NO_ERROR);
    }
    
    // Reset preswitch record and state:
	preswitchWindowRecord = NULL;
    sharecontext = 0;
    
	// Ready for internal rendering:
    return(PsychError_none);
}
Ejemplo n.º 8
0
PsychError SCREENPreference(void)  
{

	PsychArgFormatType		arg1Type;
	char					*preferenceName, *newFontName;
	const char				*tableCreator, *oldDefaultFontName;
	psych_bool				preferenceNameArgumentValid, booleanInput, ignoreCase, tempFlag, textAlphaBlendingFlag, suppressAllWarningsFlag;
	int						numInputArgs, i, newFontStyleNumber, newFontSize, tempInt, tempInt2, tempInt3, tempInt4;
	double					returnDoubleValue, inputDoubleValue;
	double					maxStddev, maxDeviation, maxDuration;
	int						minSamples;
    double                  *dheads = NULL;

	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous or missing arguments
	PsychErrorExit(PsychCapNumInputArgs(5));			
	PsychErrorExit(PsychRequireNumInputArgs(1));		   
	PsychErrorExit(PsychCapNumOutputArgs(4));
	
	numInputArgs=PsychGetNumInputArgs();
	arg1Type=PsychGetArgType(1);
	preferenceNameArgumentValid=FALSE;
	
	//Cases which require both a window pointer or screen number and preference name.  Argument 1 is the wposn and argument 2 is the preference name.
	if( numInputArgs >= 2 && (PsychIsScreenNumberArg(1) || PsychIsScreenNumberArg(1)) && PsychGetArgType(2)==PsychArgType_char ){
		PsychAllocInCharArg(2, kPsychArgRequired, &preferenceName);
		//preferences which require window pointer or screen number argument which we DO NOT support  
		for(i=0;i<kPsychNumUnsupportedMacVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//insert here conditionals  to act on prefernces which accept a window pointer or screen number argument which we DO support.
		PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}

	//Cases which do not require a wposn.  Argument 1 is the preference name.  if present Argument 2 is the new value
	if(arg1Type==PsychArgType_char){
		PsychAllocInCharArg(1, kPsychArgRequired, &preferenceName);
		//Preferernces which we do not support and which do not require a wposn
		for(i=0;i<kPsychNumUnsupportedMacNonVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacNonVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//Preferences which we do support
		if(PsychMatch(preferenceName, "IgnoreCase")){
			ignoreCase=!PsychIsPsychMatchCaseSensitive();
			PsychCopyOutFlagArg(1, kPsychArgOptional, ignoreCase);
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
				PsychSetPsychMatchCaseSenstive(!booleanInput);			
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Tick0Secs")){
			if(PsychCopyInDoubleArg(2, kPsychArgOptional, &inputDoubleValue) && inputDoubleValue==PsychGetNanValue())
				PsychEstimateGetSecsValueAtTickCountZero();
			returnDoubleValue=PsychGetEstimatedSecsValueAtTickCountZero();
			PsychCopyOutDoubleArg(1, kPsychArgOptional, returnDoubleValue);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableVersion")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double)PsychPrefStateGet_PsychTableVersion());
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableCreator")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			tableCreator=PsychPrefStateGet_PsychTableCreator();
			PsychCopyOutCharArg(1, kPsychArgOptional, tableCreator);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Process")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double) (psych_int64) getpid());
			preferenceNameArgumentValid=TRUE;


		}else 
		if(PsychMatch(preferenceName, "DefaultFontName")){
			PsychPrefStateGet_DefaultFontName(&oldDefaultFontName);
			PsychCopyOutCharArg(1, kPsychArgOptional, oldDefaultFontName);
			if(numInputArgs==2){
				PsychAllocInCharArg(2, kPsychArgRequired, &newFontName);
				PsychPrefStateSet_DefaultFontName(newFontName);
			}
			preferenceNameArgumentValid=TRUE;			
		}else 
		if(PsychMatch(preferenceName, "TextEncodingLocale")){
			PsychCopyOutCharArg(1, kPsychArgOptional, PsychGetUnicodeTextConversionLocale());
			if(numInputArgs==2){
				PsychAllocInCharArg(2, kPsychArgRequired, &newFontName);
				if (!PsychSetUnicodeTextConversionLocale(newFontName)) PsychErrorExitMsg(PsychError_user, "Setting the 'TextEncodingLocale' failed, most likely because you provided an invalid/unknown locale setting string.");
			}
			preferenceNameArgumentValid=TRUE;			
		}else 
		if(PsychMatch(preferenceName, "DefaultFontStyle")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextStyle());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontStyleNumber);
				PsychPrefStateSet_DefaultTextStyle(newFontStyleNumber);
			}
			preferenceNameArgumentValid=TRUE;
		}else
		if(PsychMatch(preferenceName, "OverrideMultimediaEngine")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_UseGStreamer());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_UseGStreamer(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else
		if(PsychMatch(preferenceName, "DefaultTextYPositionIsBaseline")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextYPositionIsBaseline());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextYPositionIsBaseline(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "TextAntiAliasing")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextAntiAliasing());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextAntiAliasing(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "TextRenderer")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextRenderer());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextRenderer(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DefaultFontSize")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextSize());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontSize);
				PsychPrefStateSet_DefaultTextSize(newFontSize);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DebugMakeTexture")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DebugMakeTexture());
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
				PsychPrefStateSet_DebugMakeTexture(tempFlag);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SkipSyncTests")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_SkipSyncTests());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_SkipSyncTests(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VisualDebugLevel")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VisualDebugLevel());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_VisualDebugLevel(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VBLTimestampingMode")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VBLTimestampingMode());
			if(numInputArgs>=2){
                            PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
                            PsychPrefStateSet_VBLTimestampingMode(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SyncTestSettings")){
			PsychPrefStateGet_SynctestThresholds(&maxStddev, &minSamples, &maxDeviation, &maxDuration);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, maxStddev);
			PsychCopyOutDoubleArg(2, kPsychArgOptional, minSamples);
			PsychCopyOutDoubleArg(3, kPsychArgOptional, maxDeviation);
			PsychCopyOutDoubleArg(4, kPsychArgOptional, maxDuration);
			if(numInputArgs>=2){
							PsychCopyInDoubleArg( 2, kPsychArgOptional, &maxStddev);
                            PsychCopyInIntegerArg(3, kPsychArgOptional, &minSamples);
							PsychCopyInDoubleArg( 4, kPsychArgOptional, &maxDeviation);
							PsychCopyInDoubleArg( 5, kPsychArgOptional, &maxDuration);
							PsychPrefStateSet_SynctestThresholds(maxStddev, minSamples, maxDeviation, maxDuration);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VBLEndlineOverride")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VBLEndlineOverride());
			if(numInputArgs>=2){
                            PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
                            PsychPrefStateSet_VBLEndlineOverride(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else
			if(PsychMatch(preferenceName, "DefaultVideocaptureEngine")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VideoCaptureEngine());
				if(numInputArgs==2){
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					PsychPrefStateSet_VideoCaptureEngine(tempInt);
				}
			preferenceNameArgumentValid=TRUE;
		}else
			if(PsychMatch(preferenceName, "WindowShieldingLevel")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_WindowShieldingLevel());
				if(numInputArgs==2){
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					PsychPrefStateSet_WindowShieldingLevel(tempInt);
				}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "ConserveVRAM") || PsychMatch(preferenceName, "Workarounds1")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_ConserveVRAM());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_ConserveVRAM(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Verbosity")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_Verbosity());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_Verbosity(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "FrameRectCorrection")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_FrameRectCorrection());
					if(numInputArgs==2){
						PsychCopyInDoubleArg(2, kPsychArgRequired, &inputDoubleValue);
						PsychPrefStateSet_FrameRectCorrection(inputDoubleValue);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "EmulateOldPTB")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_EmulateOldPTB());
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
					PsychPrefStateSet_EmulateOldPTB(tempFlag);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Enable3DGraphics")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_3DGfx());
				if(numInputArgs==2){
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					PsychPrefStateSet_3DGfx(tempInt);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "TextAlphaBlending")){
				textAlphaBlendingFlag=PsychPrefStateGet_TextAlphaBlending();
				PsychCopyOutFlagArg(1, kPsychArgOptional, textAlphaBlendingFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_TextAlphaBlending(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SuppressAllWarnings")){
				suppressAllWarningsFlag=PsychPrefStateGet_SuppressAllWarnings();
				PsychCopyOutFlagArg(1, kPsychArgOptional, suppressAllWarningsFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_SuppressAllWarnings(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SynchronizeDisplays")){
				if(numInputArgs >= 2) {
					// This is a special call: It currently doesn't set a preference setting,
					// but instead triggers an instantaneous synchronization of all available
					// display heads, if possible. We may have a more clever and "standard" interface
					// interface for this later on, but for first tests this will do.
					// Syncmethod is hard-coded to 0 -> Use whatever's available to sync.
					// timeout for retries is 5.0 seconds.
					// Acceptable residual offset is +/- 2 scanlines.
					// Returns the real residual offset after sync.
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					if (!PsychCopyInIntegerArg(3, kPsychArgOptional, &tempInt3)) {
                        // No screenId specified: Resync default screen or whatever...
                        tempInt2 = 0;
                        if (PsychSynchronizeDisplayScreens(&tempInt2, NULL, &tempInt, tempInt, 5.0, 2)!=PsychError_none) PsychErrorExitMsg(PsychError_user, "Sync failed for reasons mentioned above.");
                    } else {
                        // Specific screenId provided: Resync crtc's associated with this screenId if possible:
                        tempInt2 = 1;
                        if (PsychSynchronizeDisplayScreens(&tempInt2, &tempInt3, &tempInt, tempInt, 5.0, 2)!=PsychError_none) PsychErrorExitMsg(PsychError_user, "Sync failed for reasons mentioned above.");
                    }
                    
					PsychCopyOutDoubleArg(1, kPsychArgOptional, tempInt);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "ScreenToHead")){
				// screenId is required:
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				if (tempInt < 0 || tempInt >= PsychGetNumDisplays() || tempInt >= kPsychMaxPossibleDisplays) PsychErrorExitMsg(PsychError_user, "Invalid screenId provided. Out of valid range!");

				// Return old mappings for this screenId:
                for (tempInt2 = 0; (tempInt2 < kPsychMaxPossibleCrtcs) && (PsychPrefStateGet_ScreenToHead(tempInt, tempInt2) >= 0); tempInt2++);
                PsychAllocOutDoubleMatArg(1, kPsychArgOptional, 2, tempInt2, 1, &dheads);
                
                tempInt4 = 0;
                for (tempInt3 = 0; tempInt3 < tempInt2; tempInt3++) {
                    dheads[tempInt4++] = (double) PsychPrefStateGet_ScreenToHead(tempInt, tempInt3);
                    dheads[tempInt4++] = (double) PsychPrefStateGet_ScreenToCrtcId(tempInt, tempInt3);
                }
                
                // Optionally retrieve and set new mappings for this screenId:
				if(numInputArgs>=3) {
					// Set new headId for screenId:
					PsychCopyInIntegerArg(3, kPsychArgRequired, &tempInt2);
					if (tempInt2 < 0) PsychErrorExitMsg(PsychError_user, "Invalid negative headId provided!");

					// Set new crtcId for screenId:
					PsychCopyInIntegerArg(4, kPsychArgRequired, &tempInt3);
					if (tempInt3 < 0) PsychErrorExitMsg(PsychError_user, "Invalid negative crtcId provided!");

                    // Assign primary head by default (index 0), but allow optionally others as well:
                    tempInt4 = 0;
					PsychCopyInIntegerArg(5, kPsychArgOptional, &tempInt4);
					if (tempInt4 < 0 || tempInt4 >= kPsychMaxPossibleCrtcs) PsychErrorExitMsg(PsychError_user, "Invalid rankId provided! Too many heads for one screen!");

					PsychPrefStateSet_ScreenToHead(tempInt, tempInt2, tempInt3, tempInt4);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}
	
	if(!preferenceNameArgumentValid)
		PsychErrorExitMsg(PsychError_user, "Invalid arguments to preferences command");
		
	return(PsychError_none);
}
Ejemplo n.º 9
0
PsychError SCREENMakeTexture(void) 
{
    size_t								ix, iters;
    PsychWindowRecordType				*textureRecord;
    PsychWindowRecordType				*windowRecord;
    PsychRectType						rect;
    psych_bool							isImageMatrixBytes, isImageMatrixDoubles;
    int									numMatrixPlanes, xSize, ySize;
    unsigned char						*byteMatrix;
    double								*doubleMatrix;
    GLuint								*texturePointer;
    GLubyte								*texturePointer_b;
	GLfloat								*texturePointer_f;
    double								*rp, *gp, *bp, *ap;
    GLubyte								*rpb, *gpb, *bpb, *apb;
    int									usepoweroftwo, usefloatformat, assume_texorientation, textureShader;
    double								optimized_orientation;
    psych_bool							bigendian;
	psych_bool							planar_storage = FALSE;

    // Detect endianity (byte-order) of machine:
    ix=255;
    rpb=(GLubyte*) &ix;
    bigendian = ( *rpb == 255 ) ? FALSE : TRUE;
    ix = 0; rpb = NULL;

    if(PsychPrefStateGet_DebugMakeTexture())	//MARK #1
        StoreNowTime();
    
    //all subfunctions should have these two lines.  
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
    
    //Get the window structure for the onscreen window.  It holds the onscreein GL context which we will need in the
    //final step when we copy the texture from system RAM onto the screen.
    PsychErrorExit(PsychCapNumInputArgs(7));   	
    PsychErrorExit(PsychRequireNumInputArgs(2)); 	
    PsychErrorExit(PsychCapNumOutputArgs(1)); 
    
    //get the window record from the window record argument and get info from the window record
    PsychAllocInWindowRecordArg(kPsychUseDefaultArgPosition, TRUE, &windowRecord);
    
    if((windowRecord->windowType!=kPsychDoubleBufferOnscreen) && (windowRecord->windowType!=kPsychSingleBufferOnscreen))
        PsychErrorExitMsg(PsychError_user, "MakeTexture called on something else than a onscreen window");
    
	// Get optional texture orientation flag:
	assume_texorientation = 0;
	PsychCopyInIntegerArg(6, FALSE, &assume_texorientation);
	
	// Get optional texture shader handle:
	textureShader = 0;
	PsychCopyInIntegerArg(7, FALSE, &textureShader);
	
    //get the argument and sanity check it.
    isImageMatrixBytes=PsychAllocInUnsignedByteMatArg(2, kPsychArgAnything, &ySize, &xSize, &numMatrixPlanes, &byteMatrix);
    isImageMatrixDoubles=PsychAllocInDoubleMatArg(2, kPsychArgAnything, &ySize, &xSize, &numMatrixPlanes, &doubleMatrix);
    if(numMatrixPlanes > 4)
        PsychErrorExitMsg(PsychError_inputMatrixIllegalDimensionSize, "Specified image matrix exceeds maximum depth of 4 layers");
    if(ySize<1 || xSize <1)
        PsychErrorExitMsg(PsychError_inputMatrixIllegalDimensionSize, "Specified image matrix must be at least 1 x 1 pixels in size");
    if(! (isImageMatrixBytes || isImageMatrixDoubles))
        PsychErrorExitMsg(PsychError_user, "Illegal argument type");  //not  likely. 

	// Is this a special image matrix which is already pre-transposed to fit our optimal format?
	if (assume_texorientation == 2) {
		// Yes. Swap xSize and ySize to take this into account:
		ix = (size_t) xSize;
		xSize = ySize;
		ySize = (int) ix;
		ix = 0;
	}

	// Build defining rect for this texture:
    PsychMakeRect(rect, 0, 0, xSize, ySize);

    // Copy in texture preferred draw orientation hint. We default to zero degrees, if
    // not provided.
    // This parameter is not yet used. It is silently ignorerd for now...
    optimized_orientation = 0;
    PsychCopyInDoubleArg(3, FALSE, &optimized_orientation);
    
    // Copy in special creation mode flag: It defaults to zero. If set to 1 then we
    // always create a power-of-two GL_TEXTURE_2D texture. This is useful if one wants
    // to create and use drifting gratings with no effort - texture wrapping is only available
    // for GL_TEXTURE_2D, not for non-pot types. It is also useful if the texture is to be
    // exported to external OpenGL code to simplify tex coords assignments.
    usepoweroftwo=0;
    PsychCopyInIntegerArg(4, FALSE, &usepoweroftwo);

    // Check if size constraints are fullfilled for power-of-two mode:
    if (usepoweroftwo & 1) {
		for(ix = 1; ix < (size_t) xSize; ix*=2);
		if (ix != (size_t) xSize) {
			PsychErrorExitMsg(PsychError_inputMatrixIllegalDimensionSize, "Power-of-two texture requested but width of imageMatrix is not a power of two!");
		}
		
		for(ix = 1; ix < (size_t) ySize; ix*=2);
		if (ix != (size_t) ySize) {
			PsychErrorExitMsg(PsychError_inputMatrixIllegalDimensionSize, "Power-of-two texture requested but height of imageMatrix is not a power of two!");
		}
    }

	// Check if creation of a floating point texture is requested? We default to non-floating point,
	// standard 8 bpc textures if this parameter is not provided.
	usefloatformat = 0;
    PsychCopyInIntegerArg(5, FALSE, &usefloatformat);
	if (usefloatformat<0 || usefloatformat>2) PsychErrorExitMsg(PsychError_user, "Invalid value for 'floatprecision' parameter provided! Valid values are 0 for 8bpc int, 1 for 16bpc float or 2 for 32bpc float.");
	if (usefloatformat && !isImageMatrixDoubles) {
		// Floating point texture requested. We only support this if our input is a double matrix, not
		// for uint8 matrices - converting them to float precision would be just a waste of ressources
		// without any benefit for precision.
		PsychErrorExitMsg(PsychError_user, "Creation of a floating point precision texture requested, but uint8 matrix provided! Only double matrices are acceptable for this mode.");
	}

    //Create a texture record.  Really just a window record adapted for textures.  
    PsychCreateWindowRecord(&textureRecord);						//this also fills the window index field.
    textureRecord->windowType=kPsychTexture;
    // MK: We need to assign the screen number of the onscreen-window, so PsychCreateTexture()
    // can query the size of the screen/onscreen-window...
    textureRecord->screenNumber=windowRecord->screenNumber;
    textureRecord->depth=32;
    PsychCopyRect(textureRecord->rect, rect);
    
	// Is texture storage in planar format explicitely requested by usercode? Do the gpu and its size
	// constraints on textures support planar storage for this image?
	// Can a proper planar -> interleaved remapping GLSL shader be generated and assigned for this texture?
	if ((usepoweroftwo == 4) && (numMatrixPlanes > 1) && (windowRecord->gfxcaps & kPsychGfxCapFBO) && !(PsychPrefStateGet_ConserveVRAM() & kPsychDontCacheTextures) &&
		(ySize * numMatrixPlanes <= windowRecord->maxTextureSize) && PsychAssignPlanarTextureShaders(textureRecord, windowRecord, numMatrixPlanes)) {
		// Yes: Use the planar texture storage fast-path.
		planar_storage = TRUE;
		if (PsychPrefStateGet_Verbosity() > 6) printf("PTB-DEBUG: Using planar storage for %i layer texture of size %i x %i texels.\n", numMatrixPlanes, xSize, ySize);
	}
	else {
		planar_storage = FALSE;
		if (PsychPrefStateGet_Verbosity() > 7) printf("PTB-DEBUG: Using standard storage for %i layer texture of size %i x %i texels.\n", numMatrixPlanes, xSize, ySize);
	}

    //Allocate the texture memory and copy the MATLAB matrix into the texture memory.
	if (usefloatformat || (planar_storage && !isImageMatrixBytes)) {
		// Allocate a double for each color component and pixel:
		textureRecord->textureMemorySizeBytes = sizeof(double) * (size_t) numMatrixPlanes * (size_t) xSize * (size_t) ySize;		
	}
    else {
		// Allocate one byte per color component and pixel:
		textureRecord->textureMemorySizeBytes = (size_t) numMatrixPlanes * (size_t) xSize * (size_t) ySize;
    }

	// We allocate our own intermediate conversion buffer unless this is
	// creation of a single-layer luminance8 integer texture from a single
	// layer uint8 input matrix and client storage is disabled. In that case, we can use a zero-copy path:
	if ((isImageMatrixBytes && (numMatrixPlanes == 1) && (!usefloatformat) && !(PsychPrefStateGet_ConserveVRAM() & kPsychDontCacheTextures)) ||
		(isImageMatrixBytes && planar_storage)) {
		// Zero copy path:
		texturePointer = NULL;
	}
	else {
		// Allocate memory:
		if(PsychPrefStateGet_DebugMakeTexture()) StoreNowTime();
		textureRecord->textureMemory = malloc(textureRecord->textureMemorySizeBytes);
		if(PsychPrefStateGet_DebugMakeTexture()) StoreNowTime();
		texturePointer = textureRecord->textureMemory;
	}
	
    // Does script explicitely request usage of a GL_TEXTURE_2D power-of-two texture?
    if (usepoweroftwo & 1) {
      // Enforce creation as a power-of-two texture:
      textureRecord->texturetarget=GL_TEXTURE_2D;
    }

	// Now the conversion routines that convert Matlab/Octave matrices into memory
	// buffers suitable for OpenGL:
	if (planar_storage) {
		// Planar texture storage, backed by a LUMINANCE texture container:

		// Zero-Copy possible? Only for uint8 input -> uint8 output:
		if (texturePointer == NULL) {
			texturePointer = (GLuint*) byteMatrix;
			textureRecord->textureMemory = texturePointer;
			// Set size to zero, so PsychCreateTexture() does not free() our
			// input buffer:
			textureRecord->textureMemorySizeBytes = 0;
			
			// This is always a LUMINANCE8 texture, backing our planar uint8 texture:
			textureRecord->depth = 8 * numMatrixPlanes;
			textureRecord->textureexternaltype   = GL_UNSIGNED_BYTE;
			textureRecord->textureexternalformat = GL_LUMINANCE;
			textureRecord->textureinternalformat = GL_LUMINANCE8;
		}
		else {
			// Some cast operation needed from double input format.
			// We always cast from double to float, potentially with
			// normalization and/or checking of value range.
			textureRecord->textureexternalformat = GL_LUMINANCE;

			if (usefloatformat) {
				// Floating point or other high precision format:
				textureRecord->depth = ((usefloatformat == 1) ? 16 : 32) * numMatrixPlanes;
				textureRecord->textureexternaltype = GL_FLOAT;
				textureRecord->textureinternalformat = (usefloatformat == 1) ? GL_LUMINANCE_FLOAT16_APPLE : GL_LUMINANCE_FLOAT32_APPLE;
				
				// Override for missing floating point texture support: Try to use 16 bit fixed point signed normalized textures [-1.0 ; 1.0] resolved at 15 bits:
				if ((usefloatformat == 1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) textureRecord->textureinternalformat = GL_LUMINANCE16_SNORM;

				// Perform copy with double -> float cast:
				iters = (size_t) xSize * (size_t) ySize * (size_t) numMatrixPlanes;
				texturePointer_f = (GLfloat*) texturePointer;
				for(ix = 0; ix < iters; ix++) {
					*(texturePointer_f++) = (GLfloat) *(doubleMatrix++);
				}
				iters = (size_t) xSize * (size_t) ySize;
			}
			else {
				// 8 Bit format, but from double input matrix -> cast to uint8:
				textureRecord->depth = 8 * numMatrixPlanes;
				textureRecord->textureexternaltype = GL_UNSIGNED_BYTE;
				textureRecord->textureinternalformat = GL_LUMINANCE8;

				iters = (size_t) xSize * (size_t) ySize * (size_t) numMatrixPlanes;
				texturePointer_b = (GLubyte*) texturePointer;
				for(ix = 0; ix < iters; ix++) {
					*(texturePointer_b++) = (GLubyte) *(doubleMatrix++);
				}
				iters = (size_t) xSize * (size_t) ySize;
			}
		}
	}
	else if (usefloatformat) {
		// Conversion routines for HDR 16 bpc or 32 bpc textures -- Slow path.
		// Our input is always double matrices...
		iters = (size_t) xSize * (size_t) ySize;

		// Our input buffer is always of GL_FLOAT precision:
		textureRecord->textureexternaltype = GL_FLOAT;
		texturePointer_f=(GLfloat*) texturePointer;
		
		if(numMatrixPlanes==1) {
			for(ix=0;ix<iters;ix++){
				*(texturePointer_f++)= (GLfloat) *(doubleMatrix++);  
			}
			textureRecord->depth=(usefloatformat==1) ? 16 : 32;

			textureRecord->textureinternalformat = (usefloatformat==1) ? GL_LUMINANCE_FLOAT16_APPLE : GL_LUMINANCE_FLOAT32_APPLE; 
			textureRecord->textureexternalformat = GL_LUMINANCE;

			// Override for missing floating point texture support: Try to use 16 bit fixed point signed normalized textures [-1.0 ; 1.0] resolved at 15 bits:
			if ((usefloatformat==1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) textureRecord->textureinternalformat = GL_LUMINANCE16_SNORM;
		}

		if(numMatrixPlanes==2) {
			rp=(double*) ((size_t) doubleMatrix);
			ap=(double*) ((size_t) rp + (size_t) iters * sizeof(double));

			for(ix=0;ix<iters;ix++){
				*(texturePointer_f++)= (GLfloat) *(rp++);  
				*(texturePointer_f++)= (GLfloat) *(ap++);  
			}
			textureRecord->depth=(usefloatformat==1) ? 32 : 64;
			textureRecord->textureinternalformat = (usefloatformat==1) ? GL_LUMINANCE_ALPHA_FLOAT16_APPLE : GL_LUMINANCE_ALPHA_FLOAT32_APPLE; 
			textureRecord->textureexternalformat = GL_LUMINANCE_ALPHA;

			// Override for missing floating point texture support: Try to use 16 bit fixed point signed normalized textures [-1.0 ; 1.0] resolved at 15 bits:
			if ((usefloatformat==1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) textureRecord->textureinternalformat = GL_LUMINANCE16_ALPHA16_SNORM;
		}
		
		if(numMatrixPlanes==3) {
			rp=(double*) ((size_t) doubleMatrix);
			gp=(double*) ((size_t) rp + (size_t) iters * sizeof(double));
			bp=(double*) ((size_t) gp + (size_t) iters * sizeof(double));

			for(ix=0;ix<iters;ix++){
				*(texturePointer_f++)= (GLfloat) *(rp++);  
				*(texturePointer_f++)= (GLfloat) *(gp++);  
				*(texturePointer_f++)= (GLfloat) *(bp++);  
			}
			textureRecord->depth=(usefloatformat==1) ? 48 : 96;
			textureRecord->textureinternalformat = (usefloatformat==1) ? GL_RGB_FLOAT16_APPLE : GL_RGB_FLOAT32_APPLE; 
			textureRecord->textureexternalformat = GL_RGB;

			// Override for missing floating point texture support: Try to use 16 bit fixed point signed normalized textures [-1.0 ; 1.0] resolved at 15 bits:
			if ((usefloatformat==1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) textureRecord->textureinternalformat = GL_RGB16_SNORM;
		}
		
		if(numMatrixPlanes==4) {
			rp=(double*) ((size_t) doubleMatrix);
			gp=(double*) ((size_t) rp + (size_t) iters * sizeof(double));
			bp=(double*) ((size_t) gp + (size_t) iters * sizeof(double));
			ap=(double*) ((size_t) bp + (size_t) iters * sizeof(double));

			for(ix=0;ix<iters;ix++){
				*(texturePointer_f++)= (GLfloat) *(rp++);  
				*(texturePointer_f++)= (GLfloat) *(gp++);  
				*(texturePointer_f++)= (GLfloat) *(bp++);  
				*(texturePointer_f++)= (GLfloat) *(ap++);  
			}			
			textureRecord->depth=(usefloatformat==1) ? 64 : 128;
			textureRecord->textureinternalformat = (usefloatformat==1) ? GL_RGBA_FLOAT16_APPLE : GL_RGBA_FLOAT32_APPLE; 
			textureRecord->textureexternalformat = GL_RGBA;

			// Override for missing floating point texture support: Try to use 16 bit fixed point signed normalized textures [-1.0 ; 1.0] resolved at 15 bits:
			if ((usefloatformat==1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) textureRecord->textureinternalformat = GL_RGBA16_SNORM;
		}		
		// End of HDR conversion code...
	}
    else {
		// Standard LDR texture 8 bpc conversion routines -- Fast path.
		iters = (size_t) xSize * (size_t) ySize;

		// Improved implementation: Takes 13 ms on a 800x800 texture...
		if(isImageMatrixDoubles && numMatrixPlanes==1){
			texturePointer_b=(GLubyte*) texturePointer;
			for(ix=0;ix<iters;ix++){
				*(texturePointer_b++)= (GLubyte) *(doubleMatrix++);  
			}
			textureRecord->depth=8;
		}
		
		// Improved version: Takes 3 ms on a 800x800 texture...
		// NB: Implementing memcpy manually by a for-loop takes 10 ms! This is a huge difference.
		// -> That's because memcpy on MacOS-X is implemented with hand-coded, highly tuned Assembler code for PowerPC.
		// -> It's always wise to use system-routines if available, instead of coding it by yourself!
		if(isImageMatrixBytes && numMatrixPlanes==1) {
			if (texturePointer) {
				// Need to do a copy. Use optimized memcpy():
				memcpy((void*) texturePointer, (void*) byteMatrix, iters);
				
				//texturePointer_b=(GLubyte*) texturePointer;
				//for(ix=0;ix<iters;ix++){
				//	*(texturePointer_b++) = *(byteMatrix++);  
				//}
			}
			else {
				// Zero-Copy path. Just pass a pointer to our input matrix:
				texturePointer = (GLuint*) byteMatrix;
				textureRecord->textureMemory = texturePointer;
				// Set size to zero, so PsychCreateTexture() does not free() our
				// input buffer:
				textureRecord->textureMemorySizeBytes = 0;
			}

			textureRecord->depth=8;
		}
		
		// New version: Takes 33 ms on a 800x800 texture...
		if(isImageMatrixDoubles && numMatrixPlanes==2){
			texturePointer_b=(GLubyte*) texturePointer;
			rp=(double*) ((size_t) doubleMatrix);
			ap=(double*) ((size_t) rp + (size_t) iters * sizeof(double));
			for(ix=0;ix<iters;ix++){
				*(texturePointer_b++)= (GLubyte) *(rp++);  
				*(texturePointer_b++)= (GLubyte) *(ap++);  
			}
			textureRecord->depth=16;
		}
		
		// New version: Takes 20 ms on a 800x800 texture...
		if(isImageMatrixBytes && numMatrixPlanes==2){
			texturePointer_b=(GLubyte*) texturePointer;
			rpb=(GLubyte*) ((size_t) byteMatrix);
			apb=(GLubyte*) ((size_t) rpb + (size_t) iters);
			for(ix=0;ix<iters;ix++){
				*(texturePointer_b++)= *(rpb++);  
				*(texturePointer_b++)= *(apb++);  
			}
			textureRecord->depth=16;
		}
		
		// Improved version: Takes 43 ms on a 800x800 texture...
		if(isImageMatrixDoubles && numMatrixPlanes==3){
			texturePointer_b=(GLubyte*) texturePointer;
			rp=(double*) ((size_t) doubleMatrix);
			gp=(double*) ((size_t) rp + (size_t) iters * sizeof(double));
			bp=(double*) ((size_t) gp + (size_t) iters * sizeof(double));
			for(ix=0;ix<iters;ix++){
				*(texturePointer_b++)= (GLubyte) *(rp++);  
				*(texturePointer_b++)= (GLubyte) *(gp++);  
				*(texturePointer_b++)= (GLubyte) *(bp++);  
			}
			textureRecord->depth=24;
		}
		
		// Improved version: Takes 25 ms on a 800x800 texture...
		if(isImageMatrixBytes && numMatrixPlanes==3){
			texturePointer_b=(GLubyte*) texturePointer;			
			rpb=(GLubyte*) ((size_t) byteMatrix);
			gpb=(GLubyte*) ((size_t) rpb + (size_t) iters);
			bpb=(GLubyte*) ((size_t) gpb + (size_t) iters);
			for(ix=0;ix<iters;ix++){
				*(texturePointer_b++)= *(rpb++);  
				*(texturePointer_b++)= *(gpb++);  
				*(texturePointer_b++)= *(bpb++);  
			}
			textureRecord->depth=24;
		}
		
		// Improved version: Takes 55 ms on a 800x800 texture...
		if(isImageMatrixDoubles && numMatrixPlanes==4){
			texturePointer_b=(GLubyte*) texturePointer;			
			rp=(double*) ((size_t) doubleMatrix);
			gp=(double*) ((size_t) rp + (size_t) iters * sizeof(double));
			bp=(double*) ((size_t) gp + (size_t) iters * sizeof(double));
			ap=(double*) ((size_t) bp + (size_t) iters * sizeof(double));
			if (bigendian) {
				// Code for big-endian machines like PowerPC:
				for(ix=0;ix<iters;ix++){
					*(texturePointer_b++)= (GLubyte) *(ap++);  
					*(texturePointer_b++)= (GLubyte) *(rp++);  
					*(texturePointer_b++)= (GLubyte) *(gp++);  
					*(texturePointer_b++)= (GLubyte) *(bp++);  
				}
			}
			else {
				// Code for little-endian machines like Intel Pentium:
				for(ix=0;ix<iters;ix++){
					*(texturePointer_b++)= (GLubyte) *(bp++);  
					*(texturePointer_b++)= (GLubyte) *(gp++);  
					*(texturePointer_b++)= (GLubyte) *(rp++);  
					*(texturePointer_b++)= (GLubyte) *(ap++);  
				}
			}
			
			textureRecord->depth=32;
		}
		
		// Improved version: Takes 33 ms on a 800x800 texture...
		if(isImageMatrixBytes && numMatrixPlanes==4){
			texturePointer_b=(GLubyte*) texturePointer;			
			rpb=(GLubyte*) ((size_t) byteMatrix);
			gpb=(GLubyte*) ((size_t) rpb + (size_t) iters);
			bpb=(GLubyte*) ((size_t) gpb + (size_t) iters);
			apb=(GLubyte*) ((size_t) bpb + (size_t) iters);
			if (bigendian) {
				// Code for big-endian machines like PowerPC:
				for(ix=0;ix<iters;ix++){
					*(texturePointer_b++)= *(apb++);  
					*(texturePointer_b++)= *(rpb++);  
					*(texturePointer_b++)= *(gpb++);  
					*(texturePointer_b++)= *(bpb++);  
				}
			}
			else {
				// Code for little-endian machines like Intel Pentium:
				for(ix=0;ix<iters;ix++){
					*(texturePointer_b++)= *(bpb++);  
					*(texturePointer_b++)= *(gpb++);  
					*(texturePointer_b++)= *(rpb++);  
					*(texturePointer_b++)= *(apb++);  
				}
			}
			
			textureRecord->depth=32;
		}
	} // End of 8 bpc texture conversion code (fast-path for LDR textures)
    
	// Override for missing floating point texture support?
	if ((usefloatformat==1) && !(windowRecord->gfxcaps & kPsychGfxCapFPTex16)) {
		// Override enabled. Instead of a 16bpc float texture with 11 bit linear precision in the
		// range [-1.0 ; 1.0], we use a 16 bit signed normalized texture with a normalized value
		// range of [-1.0; 1.0], encoded with 1 bit sign and 15 bit magnitude. These textures have
		// an effective linear precision of 15 bits - better than 16 bpc float - but they are restricted
		// to a value range of [-1.0 ; 1.0], as opposed to 16 bpc float textures. Tell user about this
		// replacement at high verbosity levels:
		if (PsychPrefStateGet_Verbosity() > 4)
			printf("PTB-INFO:MakeTexture: Code requested 16 bpc float texture, but this is unsupported. Trying to use 16 bit snorm texture instead.\n");
		
		// Signed normalized textures supported? Otherwise we bail...
		if (!(windowRecord->gfxcaps & kPsychGfxCapSNTex16)) {
			printf("PTB-ERROR:MakeTexture: Code requested 16 bpc floating point texture, but this is unsupported by this graphics card.\n");
			printf("PTB-ERROR:MakeTexture: Tried to use 16 bit snorm texture instead, but failed as this is unsupported as well.\n");
			PsychErrorExitMsg(PsychError_user, "Creation of 15 bit linear precision signed normalized texture failed. Not supported by your graphics hardware!");
		}
		
		// Check value range of pixels. This will not work for out of [-1; 1] range values.
		texturePointer_f=(GLfloat*) texturePointer;
		iters = iters * (size_t) numMatrixPlanes;
		for (ix=0; ix<iters; ix++, texturePointer_f++) {
			if(fabs((double) *texturePointer_f) > 1.0) {
				// Game over!
				printf("PTB-ERROR:MakeTexture: Code requested 16 bpc floating point texture, but this is unsupported by this graphics card.\n");
				printf("PTB-ERROR:MakeTexture: Tried to use 16 bit snorm texture instead, but failed because some pixels are outside the\n");
				printf("PTB-ERROR:MakeTexture: representable range -1.0 to 1.0 for this texture type. Change your code or update your graphics hardware.\n");
				PsychErrorExitMsg(PsychError_user, "Creation of 15 bit linear precision signed normalized texture failed due to out of [-1 ; +1] range pixel values!");
			}
		}
	}

	// This is a special workaround for bugs in FLOAT16 texture creation on Mac OS/X 10.4.x and 10.5.x.
	// The OpenGL fails to properly flush very small values (< 1e-9) to zero when creating a FLOAT16
	// type texture. Instead it seems to initialize with trash data, corrupting the texture.
	// Therefore, if FLOAT16 texture creation is requested, we loop over the whole input buffer and
	// set all values with magnitude smaller than 1e-9 to zero. Better safe than sorry...
	if ((usefloatformat==1) && (windowRecord->gfxcaps & kPsychGfxCapFPTex16)) {
		texturePointer_f=(GLfloat*) texturePointer;
		iters = iters * (size_t) numMatrixPlanes;
		for(ix=0; ix<iters; ix++, texturePointer_f++) if(fabs((double) *texturePointer_f) < 1e-9) { *texturePointer_f = 0.0; }
	}

    // The memory buffer now contains our texture data in a format ready to submit to OpenGL.
    
	// Assign parent window and copy its inheritable properties:
	PsychAssignParentWindow(textureRecord, windowRecord);

    // Texture orientation is zero aka transposed aka non-renderswapped.
    textureRecord->textureOrientation = ((assume_texorientation != 2) && (assume_texorientation != 3)) ? 0 : 2;
    
	// This is our best guess about the number of image channels:
	textureRecord->nrchannels = numMatrixPlanes;

	if (planar_storage) {
		// Setup special rect to fake PsychCreateTexture() into creating a luminance
		// texture numMatrixPlanes times the height (in rows) of the texture, to store the
		// numMatrixPlanes layers concatenated to each other.
		if (textureRecord->textureOrientation == 0) {
			// Normal case: Transposed storage.
			PsychMakeRect(&(textureRecord->rect[0]), 0, 0, xSize * numMatrixPlanes, ySize);
		}
		else {
			// Special case: Non-transposed or isotropic storage:
			PsychMakeRect(&(textureRecord->rect[0]), 0, 0, xSize, ySize * numMatrixPlanes);
		}
		
		// Create planar texture:
		PsychCreateTexture(textureRecord);

		// Restore rect and clientrect of texture to effective size:
		PsychMakeRect(&(textureRecord->rect[0]), 0, 0, xSize, ySize);
		PsychCopyRect(textureRecord->clientrect, textureRecord->rect);
		
		textureRecord->specialflags = kPsychPlanarTexture;
	}
	else {
		// Let's create and bind a new texture object and fill it with our new texture data.
		PsychCreateTexture(textureRecord);
		
		// Assign GLSL filter-/lookup-shaders if needed:
		PsychAssignHighPrecisionTextureShaders(textureRecord, windowRecord, usefloatformat, (usepoweroftwo & 2) ? 1 : 0);
	}
	
	// User specified override shader for this texture provided? This is useful for
	// basic image processing and procedural texture shading:
	if (textureShader!=0) {
		// Assign provided shader as filtershader to this texture: We negate it so
		// that the texture blitter routines know this is a custom shader, not our
		// built in filter shader:
		textureRecord->textureFilterShader = -1 * textureShader;
	}
	
    // Texture ready. Mark it valid and return handle to userspace:
    PsychSetWindowRecordValid(textureRecord);
    PsychCopyOutDoubleArg(1, FALSE, textureRecord->windowIndex);
	
	// Swapping the texture to upright orientation requested?
	if (assume_texorientation == 1) {
		// Transform sourceRecord source texture into a normalized, upright texture if it isn't already in
		// that format. We require this standard orientation for simplified shader design.
		PsychSetShader(windowRecord, 0);
		PsychNormalizeTextureOrientation(textureRecord);
	}
	
	// Shall the texture be finally declared "normally oriented"?
	// This is either due to explicit renderswapping if assume_textureorientation == 1,
	// or because it was already pretransposed in Matlab/Octave if assume_textureorientation == 2,
	// or because user space tells us the texture is isotropic if assume_textureorientation == 3.
	if (assume_texorientation > 0) {
		// Yes. Label it as such:
		textureRecord->textureOrientation = 2;
	}
    
    if(PsychPrefStateGet_DebugMakeTexture()) 	//MARK #4
        StoreNowTime();
    
    return(PsychError_none);
}
Ejemplo n.º 10
0
PsychError SCREENPreference(void)  
{

	PsychArgFormatType		arg1Type;
	char					*preferenceName, *newFontName;
	const char				*tableCreator, *oldDefaultFontName;
	Boolean					preferenceNameArgumentValid, booleanInput, ignoreCase, tempFlag, textAlphaBlendingFlag, suppressAllWarningsFlag;
	int						numInputArgs, i, newFontStyleNumber, newFontSize, tempInt, tempInt2, tempInt3;
	double					returnDoubleValue, inputDoubleValue;
	
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString,seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};
	
	//check for superfluous or missing arguments
	PsychErrorExit(PsychCapNumInputArgs(3));			
	PsychErrorExit(PsychRequireNumInputArgs(1));		   
	PsychErrorExit(PsychCapNumOutputArgs(1));
	
	numInputArgs=PsychGetNumInputArgs();
	arg1Type=PsychGetArgType(1);
	preferenceNameArgumentValid=FALSE;
	
	//Cases which require both a window pointer or screen number and preference name.  Argument 1 is the wposn and argument 2 is the preference name.
	if( numInputArgs >= 2 && (PsychIsScreenNumberArg(1) || PsychIsScreenNumberArg(1)) && PsychGetArgType(2)==PsychArgType_char ){
		PsychAllocInCharArg(2, kPsychArgRequired, &preferenceName);
		//preferences which require window pointer or screen number argument which we DO NOT support  
		for(i=0;i<kPsychNumUnsupportedMacVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//insert here conditionals  to act on prefernces which accept a window pointer or screen number argument which we DO support.
		PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}

	//Cases which do not require a wposn.  Argument 1 is the preference name.  if present Argument 2 is the new value
	if(arg1Type==PsychArgType_char){
		PsychAllocInCharArg(1, kPsychArgRequired, &preferenceName);
		//Preferernces which we do not support and which do not require a wposn
		for(i=0;i<kPsychNumUnsupportedMacNonVideoPreferences;i++){
			if(PsychMatch(preferenceName, unsupportedMacNonVideoPreferenceNames[i]))
				PsychErrorExit(PsychError_unsupportedOS9Preference);
		}
		//Preferences which we do support
		if(PsychMatch(preferenceName, "IgnoreCase")){
			ignoreCase=!PsychIsPsychMatchCaseSensitive();
			PsychCopyOutFlagArg(1, kPsychArgOptional, ignoreCase);
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
				PsychSetPsychMatchCaseSenstive(!booleanInput);			
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Tick0Secs")){
			if(PsychCopyInDoubleArg(2, kPsychArgOptional, &inputDoubleValue) && inputDoubleValue==PsychGetNanValue())
				PsychEstimateGetSecsValueAtTickCountZero();
			returnDoubleValue=PsychGetEstimatedSecsValueAtTickCountZero();
			PsychCopyOutDoubleArg(1, kPsychArgOptional, returnDoubleValue);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableVersion")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double)PsychPrefStateGet_PsychTableVersion());
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "PsychTableCreator")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			tableCreator=PsychPrefStateGet_PsychTableCreator();
			PsychCopyOutCharArg(1, kPsychArgOptional, tableCreator);
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "Process")){
			if(numInputArgs==2)
				PsychErrorExit(PsychError_extraInputArg);
			PsychCopyOutDoubleArg(1, kPsychArgOptional, (double)getpid());
			preferenceNameArgumentValid=TRUE;


		}else 
		if(PsychMatch(preferenceName, "DefaultFontName")){
			PsychPrefStateGet_DefaultFontName(&oldDefaultFontName);
			PsychCopyOutCharArg(1, kPsychArgOptional, oldDefaultFontName);
			if(numInputArgs==2){
				PsychAllocInCharArg(2, kPsychArgRequired, &newFontName);
				PsychPrefStateSet_DefaultFontName(newFontName);
			}
			preferenceNameArgumentValid=TRUE;
			
		}else 
		if(PsychMatch(preferenceName, "DefaultFontStyle")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextStyle());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontStyleNumber);
				PsychPrefStateSet_DefaultTextStyle(newFontStyleNumber);
			}
			preferenceNameArgumentValid=TRUE;
		}else
		if(PsychMatch(preferenceName, "DefaultTextYPositionIsBaseline")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextYPositionIsBaseline());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextYPositionIsBaseline(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "TextAntiAliasing")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextAntiAliasing());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextAntiAliasing(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "TextRenderer")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_TextRenderer());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_TextRenderer(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DefaultFontSize")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DefaultTextSize());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &newFontSize);
				PsychPrefStateSet_DefaultTextSize(newFontSize);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
		if(PsychMatch(preferenceName, "DebugMakeTexture")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_DebugMakeTexture());
			if(numInputArgs==2){
				PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
				PsychPrefStateSet_DebugMakeTexture(tempFlag);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SkipSyncTests")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_SkipSyncTests());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_SkipSyncTests(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VisualDebugLevel")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VisualDebugLevel());
			if(numInputArgs==2){
				PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
				PsychPrefStateSet_VisualDebugLevel(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VBLTimestampingMode")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VBLTimestampingMode());
			if(numInputArgs>=2){
                            PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
                            PsychPrefStateSet_VBLTimestampingMode(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "VBLEndlineOverride")){
			PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VBLEndlineOverride());
			if(numInputArgs>=2){
                            PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
                            PsychPrefStateSet_VBLEndlineOverride(tempInt);
			}
			preferenceNameArgumentValid=TRUE;
		}else
			if(PsychMatch(preferenceName, "DefaultVideocaptureEngine")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_VideoCaptureEngine());
				if(numInputArgs==2){
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					PsychPrefStateSet_VideoCaptureEngine(tempInt);
				}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "ConserveVRAM") || PsychMatch(preferenceName, "Workarounds1")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_ConserveVRAM());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_ConserveVRAM(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Verbosity")){
					PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_Verbosity());
					if(numInputArgs==2){
						PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
						PsychPrefStateSet_Verbosity(tempInt);
					}
			preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "EmulateOldPTB")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_EmulateOldPTB());
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
					PsychPrefStateSet_EmulateOldPTB(tempFlag);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "Enable3DGraphics")){
				PsychCopyOutDoubleArg(1, kPsychArgOptional, PsychPrefStateGet_3DGfx());
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &tempFlag);
					PsychPrefStateSet_3DGfx(tempFlag);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "TextAlphaBlending")){
				textAlphaBlendingFlag=PsychPrefStateGet_TextAlphaBlending();
				PsychCopyOutFlagArg(1, kPsychArgOptional, textAlphaBlendingFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_TextAlphaBlending(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SuppressAllWarnings")){
				suppressAllWarningsFlag=PsychPrefStateGet_SuppressAllWarnings();
				PsychCopyOutFlagArg(1, kPsychArgOptional, suppressAllWarningsFlag);
				if(numInputArgs==2){
					PsychCopyInFlagArg(2, kPsychArgRequired, &booleanInput);
					PsychPrefStateSet_SuppressAllWarnings(booleanInput);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			if(PsychMatch(preferenceName, "SynchronizeDisplays")){
				if(numInputArgs==2){
					// This is a special call: It currently doesn't set a preference setting,
					// but instead triggers an instantaneous synchronization of all available
					// display heads, if possible. We may have a more clever and "standard" interface
					// interface for this later on, but for first tests this will do.
					// Syncmethod is hard-coded to 0 -> Use whatever's available to sync.
					// timeout for retries is 5.0 seconds.
					// Acceptable residual offset is +/- 2 scanlines.
					// Returns the real residual offset after sync.
					PsychCopyInIntegerArg(2, kPsychArgRequired, &tempInt);
					tempInt2 = 0;
					if (PsychSynchronizeDisplayScreens(&tempInt2, NULL, &tempInt, tempInt, 5.0, 2)!=PsychError_none) PsychErrorExitMsg(PsychError_user, "Sync failed for reasons mentioned above.");
					PsychCopyOutDoubleArg(1, kPsychArgOptional, tempInt);
				}
				preferenceNameArgumentValid=TRUE;
		}else 
			PsychErrorExit(PsychError_unrecognizedPreferenceName);
	}
	
	if(!preferenceNameArgumentValid)
		PsychErrorExitMsg(PsychError_user, "Invalid arguments to preferences command");
		
	return(PsychError_none);
}
Ejemplo n.º 11
0
/*
    PsychOSOpenOnscreenWindow()
    
    Creates the CGL pixel format and the CGL context objects and then instantiates the context onto the screen.
    
    -The pixel format and the context are stored in the target specific field of the window recored.  Close
    should clean up by destroying both the pixel format and the context.
    
    -We mantain the context because it must be be made the current context by drawing functions to draw into 
    the specified window.
    
    -We maintain the pixel format object because there seems to be now way to retrieve that from the context.
    
    -To tell the caller to clean up PsychOSOpenOnscreenWindow returns FALSE if we fail to open the window. It 
    would be better to just issue an PsychErrorExit() and have that clean up everything allocated outside of
    PsychOpenOnscreenWindow().
    
    MK: The new option 'stereomode' allows selection of stereo display instead of mono display:
    0 (default) ==  Old behaviour -> Monoscopic rendering context.
    >0          ==  Stereo display, where the number defines the type of stereo algorithm to use.
    =1          ==  Use OpenGL built-in stereo by creating a context/window with left- and right backbuffer. This is
                    the only mode of interest here, as it requires use of a stereo capable OpenGL pixelformat. All other
                    stereo modes are implemented by PTB itself in a platform independent manner on top of a standard mono
                    context.
*/
psych_bool PsychOSOpenOnscreenWindow(PsychScreenSettingsType *screenSettings, PsychWindowRecordType *windowRecord, int numBuffers, int stereomode, int conserveVRAM)
{
    CGOpenGLDisplayMask             displayMask;
    CGLError                        error;
    CGDirectDisplayID               cgDisplayID;
    CGLPixelFormatAttribute         attribs[40];
    int                             attribcount;
    GLint                           numVirtualScreens;
    GLenum                          glerr;
    PsychRectType                   screenrect;
    int                             i;
    int                             windowLevel;
    long                            scw, sch;
    void*                           cocoaWindow = NULL;

    // Map screen number to physical display handle cgDisplayID:
    PsychGetCGDisplayIDFromScreenNumber(&cgDisplayID, screenSettings->screenNumber);
    displayMask = CGDisplayIDToOpenGLDisplayMask(cgDisplayID);

    // NULL-out Cocoa window handle, so this is well-defined in case of error:
    windowRecord->targetSpecific.windowHandle = NULL;

    // Retrieve windowLevel, an indicator of where non-CGL / non-fullscreen windows should
    // be located wrt. to other windows. -2 = Allow regular window manager control of stacking
    // order, visibility etc., -1 = Invisible/hidden, 0 = Behind everything else, occluded by
    // everything else. 1 - 999 = At layer 'windowLevel' -> Occludes stuff on layers "below" it.
    // 1000 - 1999 = At highest level, but partially translucent / alpha channel allows to make
    // regions transparent. Range 1000 - 1499 = transparent for mouse and keyboard, alpha 0-99.99%,
    // 1500-1599 = opaque for mouse and keyboard, alpha 0-99.99%, 2000 or higher: Above everything,
    // fully opaque, occludes everything, a typical fullscreen onscreen window. 2000 is the default.
    windowLevel = PsychPrefStateGet_WindowShieldingLevel();

    // Window rect provided which has same size as screen?
    // We do not use windowed mode if the provided window rectangle either
    // matches the target screens rectangle (and therefore its exact size)
    // or its screens global rectangle. In such cases we use CGL for better
    // low level control and to exclude the desktop compositor from interfering:
    PsychGetScreenRect(screenSettings->screenNumber, screenrect);
    if (PsychMatchRect(screenrect, windowRecord->rect)) windowRecord->specialflags |= kPsychIsFullscreenWindow;

    PsychGetGlobalScreenRect(screenSettings->screenNumber, screenrect);
    if (PsychMatchRect(screenrect, windowRecord->rect)) windowRecord->specialflags |= kPsychIsFullscreenWindow;

    if ((windowRecord->specialflags & kPsychIsFullscreenWindow) && (PsychPrefStateGet_Verbosity() > 3)) {
        printf("PTB-INFO: Always using Cocoa for fullscreen windows to work around graphics driver bugs in OSX.\n");
        printf("PTB-INFO: Presentation timing precision is not yet known for this configuration on most machines. Check your results.\n");
    }

    // Display for fullscreen window not captured? Timing precision is unclear in this mode. In theory the compositor should disable
    // itself for fullscreen windows on modern OSX versions. If it really does that, who knows?
    if ((windowRecord->specialflags & kPsychIsFullscreenWindow) && (PsychPrefStateGet_ConserveVRAM() & kPsychUseAGLCompositorForFullscreenWindows)) {
        // Force a window rectangle that matches the global screen rectangle for that windows screen:
        PsychCopyRect(windowRecord->rect, screenrect);

        // Warn user about what's going on:
        if (PsychPrefStateGet_Verbosity()>1) printf("PTB-INFO: No display capture / compositor lockout for fullscreen window. Timing precision is unknown.\n");
    }

    if ((windowRecord->specialflags & kPsychGUIWindow) && (PsychPrefStateGet_Verbosity() > 3)) {
        printf("PTB-INFO: Onscreen window is configured as regular GUI window.\n");
    }

    // Create onscreen Cocoa window of requested position and size:
    if (PsychCocoaCreateWindow(windowRecord, windowLevel, &cocoaWindow)) {
        printf("\nPTB-ERROR[CreateNewWindow failed]: Failed to open Cocoa onscreen window\n\n");
        return(FALSE);
    }

    // Transparent window requested?
    if ((windowLevel >= 1000) && (windowLevel < 2000)) {
        // Setup of global window alpha value for transparency. This is premultiplied to
        // the individual per-pixel alpha values if transparency is enabled by Cocoa code.
        //
        // Levels 1000 - 1499 and 1500 to 1999 map to a master opacity level of 0.0 - 1.0:
        PsychCocoaSetWindowAlpha(cocoaWindow, ((float) (windowLevel % 500)) / 499.0);
    }

    // Show it! Unless a windowLevel of -1 requests hiding the window:
    if (windowLevel != -1) PsychCocoaShowWindow(cocoaWindow);

    // If usercode wants a black startup screen then we add a pause of 0.5 seconds here
    // before proceeding. This will avoid a white flash at window open time, which might
    // be something the user wanted to avoid. Why does this help or is needed at all?
    // Nobody knows, but this is Apples ridiculous toy OS, so why even ask such questions?
    if (PsychPrefStateGet_VisualDebugLevel() < 4)
        PsychYieldIntervalSeconds(0.5);

    // Level zero means: Place behind all other windows:
    if (windowLevel == 0) PsychCocoaSendBehind(cocoaWindow);

    // Levels 1 to 999 define window levels for the group of the window.
    // A level of -2 would leave this to the system:
    if (windowLevel > 0 && windowLevel < 1000) PsychCocoaSetWindowLevel(cocoaWindow, windowLevel);

    // Is the target display captured for a fullscreen window?
    if (PsychIsScreenCaptured(screenSettings->screenNumber)) {
        // Yes. Make sure our window is above the shielding window level:
        PsychCocoaSetWindowLevel(cocoaWindow, (int) CGShieldingWindowLevel());
    }

    // Store window handle in windowRecord:
    windowRecord->targetSpecific.windowHandle = cocoaWindow;

    // Store vblank startline aka true height of physical display screen in pixels:
    PsychGetScreenPixelSize(screenSettings->screenNumber, &scw, &sch);
    windowRecord->VBL_Startline = (int) sch;

    // Define pixelformat attributes for OpenGL contexts:

    // No pixelformat attribs to start with:
    attribcount = 0;

    attribs[attribcount++]=kCGLPFADisplayMask;
    attribs[attribcount++]=displayMask;

    // 10 bit per component integer framebuffer requested (10-10-10-2)?
    if (windowRecord->depth == 30) {
        // Request a 10 bit per color component framebuffer with 2 bit alpha channel:
        printf("PTB-INFO: Trying to enable 10 bpc, 30 bit integer framebuffer...\n");
        attribs[attribcount++]=kCGLPFANoRecovery;
        attribs[attribcount++]=kCGLPFAMinimumPolicy;
        attribs[attribcount++]=kCGLPFAColorSize;
        attribs[attribcount++]=10*3;
        attribs[attribcount++]=kCGLPFAAlphaSize;
        attribs[attribcount++]=2;
    }

    // 11 bit per component integer framebuffer requested (11-11-10-0)?
    if (windowRecord->depth == 33) {
        // Request a ~ 11 bit per color component framebuffer without alpha channel:
        printf("PTB-INFO: Trying to enable 11 bpc, 32 bit integer framebuffer...\n");
        attribs[attribcount++]=kCGLPFANoRecovery;
        attribs[attribcount++]=kCGLPFAMinimumPolicy;
        attribs[attribcount++]=kCGLPFAColorSize;
        attribs[attribcount++]=32;
        attribs[attribcount++]=kCGLPFAAlphaSize;
        attribs[attribcount++]=0;
    }

    // 16 bit per component integer framebuffer requested (16-16-16-16)?
    if (windowRecord->depth == 48) {
        // Request a 16 bit per color component framebuffer:
        printf("PTB-INFO: Trying to enable 16 bpc, 64 bit integer framebuffer...\n");
        attribs[attribcount++]=kCGLPFANoRecovery;
        attribs[attribcount++]=kCGLPFAMinimumPolicy;
        attribs[attribcount++]=kCGLPFAColorSize;
        attribs[attribcount++]=16*3;
        attribs[attribcount++]=kCGLPFAAlphaSize;
        attribs[attribcount++]=16;
    }

    // 16 bit per component, 64 bit framebuffer requested (16-16-16-16)?
    if (windowRecord->depth == 64) {
        // Request a floating point framebuffer in 16-bit half-float format, i.e., RGBA = 16 bits per component.
        printf("PTB-INFO: Trying to enable 16 bpc float framebuffer...\n");
        attribs[attribcount++]=kCGLPFAColorFloat;
        attribs[attribcount++]=kCGLPFAMinimumPolicy;
        attribs[attribcount++]=kCGLPFAColorSize;
        attribs[attribcount++]=16*3;
        attribs[attribcount++]=kCGLPFAAlphaSize;
        attribs[attribcount++]=16;
    }

    // 32 bit per component, 128 bit framebuffer requested (32-32-32-32)?
    if (windowRecord->depth == 128) {
        // Request a floating point framebuffer in 32-bit float format, i.e., RGBA = 32 bits per component.
        printf("PTB-INFO: Trying to enable 32 bpc float framebuffer...\n");
        attribs[attribcount++]=kCGLPFAColorFloat;
        attribs[attribcount++]=kCGLPFAMinimumPolicy;
        attribs[attribcount++]=kCGLPFAColorSize;
        attribs[attribcount++]=32*3;
        attribs[attribcount++]=kCGLPFAAlphaSize;
        attribs[attribcount++]=32;
    }

    // Possible to request use of the Apple floating point software renderer:
    if (conserveVRAM & kPsychUseSoftwareRenderer) {
        #ifndef kCGLRendererGenericFloatID
        #define kCGLRendererGenericFloatID    0x00020400
        #endif

        attribs[attribcount++]=AGL_RENDERER_ID;
        attribs[attribcount++]=kCGLRendererGenericFloatID;
    }

    // Support for 3D rendering requested?
    if (PsychPrefStateGet_3DGfx()) {
        // Yes. Allocate a 24-Bit depth and 8-Bit stencilbuffer for this purpose:
        attribs[attribcount++]=kCGLPFADepthSize;
        attribs[attribcount++]=24;
        attribs[attribcount++]=kCGLPFAStencilSize;
        attribs[attribcount++]=8;
        // Alloc an accumulation buffer as well?
        if (PsychPrefStateGet_3DGfx() & 2) {
            // Yes: Alloc accum buffer, request 64 bpp, aka 16 bits integer per color component if possible:
            attribs[attribcount++]=kCGLPFAAccumSize;
            attribs[attribcount++]=64;
        }
    }

    if(numBuffers>=2){
        // Enable double-buffering:
        attribs[attribcount++]=kCGLPFADoubleBuffer;
        if ((conserveVRAM & kPsychDisableAUXBuffers) == 0) {
            // Allocate one or two (for mono vs. stereo display) AUX buffers for "don't clear" mode of Screen('Flip'):
            // Not clearing the framebuffer after "Flip" is implemented by storing a backup-copy of
            // the backbuffer to AUXs before flip and restoring the content from AUXs after flip.
            // Unless the imaging pipeline is active, which doesn't need AUX buffers due to internal
            // storage of fb content in its drawbufferFBO's:
            attribs[attribcount++]=kCGLPFAAuxBuffers;
            attribs[attribcount++]=(stereomode==kPsychOpenGLStereo || stereomode==kPsychCompressedTLBRStereo || stereomode==kPsychCompressedTRBLStereo) ? 2 : 1;
        }
    }

    // If stereo display output is requested with OpenGL native stereo, request a stereo-enabled rendering context.
    // This is deprecated since 10.11 El Capitan, and in fact does no longer work - OpenGL quad buffered stereo is
    // dead on 10.11 on all tested GPU's from Intel, NVidia, AMD.
    if(stereomode==kPsychOpenGLStereo) {
        attribs[attribcount++] = kCGLPFAStereo;
    }

    // Multisampled Anti-Aliasing requested?
    if (windowRecord->multiSample > 0) {
        // Request a multisample buffer:
        attribs[attribcount++]= kCGLPFASampleBuffers;
        attribs[attribcount++]= 1;
        // Request at least multiSample samples per pixel:
        attribs[attribcount++]= kCGLPFASamples;
        attribs[attribcount++]= windowRecord->multiSample;
    }

    // Finalize attribute array with NULL.
    attribs[attribcount++]=(CGLPixelFormatAttribute)NULL;

    // Init to zero:
    windowRecord->targetSpecific.pixelFormatObject = NULL;
    windowRecord->targetSpecific.glusercontextObject = NULL;
    windowRecord->targetSpecific.glswapcontextObject = NULL;

    // Try to find matching pixelformat:
    error = CGLChoosePixelFormat(attribs, &(windowRecord->targetSpecific.pixelFormatObject), &numVirtualScreens);

    // No valid pixelformat found and stereo format requested?
    if ((error || (windowRecord->targetSpecific.pixelFormatObject == NULL)) && (stereomode == kPsychOpenGLStereo)) {
        // Yep: Stereo may be the culprit. Remove the stereo attribute by overwriting it with something
        // that is essentially a no-op, specifically kCGLPFAAccelerated which is supported by all real
        // renderers that might end up in this code-path:
        for (i = 0; i < attribcount && attribs[i] != kCGLPFAStereo; i++);
        attribs[i] = kCGLPFAAccelerated;
        
        // Retry query of pixelformat without request for native OpenGL quad-buffered stereo. If we succeed, we're
        // sort of ok, as the higher-level code will fallback to stereomode kPsychFrameSequentialStereo - our own
        // homegrown frame-sequential stereo support, which may be good enough.
        error = CGLChoosePixelFormat(attribs, &(windowRecord->targetSpecific.pixelFormatObject), &numVirtualScreens);
        if (error || (windowRecord->targetSpecific.pixelFormatObject == NULL)) {
            windowRecord->targetSpecific.pixelFormatObject = NULL;
            printf("\nPTB-ERROR[ChoosePixelFormat failed: %s]: Disabling OpenGL native quad-buffered stereo did not help. Moving on...\n\n", CGLErrorString(error));
        }
    }

    // Now try if choosing a matching format for a lower multisample mode helps to get unstuck:
    if (windowRecord->multiSample > 0) {
        if (windowRecord->targetSpecific.pixelFormatObject==NULL && windowRecord->multiSample > 0) {
            // Failed. Probably due to too demanding multisample requirements: Lets lower them...
            for (i = 0; i < attribcount && attribs[i] != kCGLPFASamples; i++);
            while (windowRecord->targetSpecific.pixelFormatObject == NULL && windowRecord->multiSample > 0) {
                attribs[i+1]--;
                windowRecord->multiSample--;
                error = CGLChoosePixelFormat(attribs, &(windowRecord->targetSpecific.pixelFormatObject), &numVirtualScreens);
            }

            if (windowRecord->multiSample == 0 && windowRecord->targetSpecific.pixelFormatObject == NULL) {
                // Ok, multisampling is now at zero and we still don't succeed. Disable multisampling completely:
                for (i=0; i<attribcount && attribs[i]!=kCGLPFASampleBuffers; i++);
                attribs[i+1] = 0;
                printf("\nPTB-ERROR[ChoosePixelFormat failed: %s]: Disabling multisample anti-aliasing did not help. Moving on...\n\n", CGLErrorString(error));
            }
        }
    }

    // Try choosing a matching display configuration again and create the window and rendering context:
    // If one of these two fails, then the installed gfx hardware is not good enough to satisfy our
    // requirements, or we have massive ressource shortage in the system. -> Screwed up anyway, so we abort.
    if (windowRecord->targetSpecific.pixelFormatObject == NULL) error = CGLChoosePixelFormat(attribs, &(windowRecord->targetSpecific.pixelFormatObject), &numVirtualScreens);
    if (error) {
        printf("\nPTB-ERROR[ChoosePixelFormat failed: %s]: Reason unknown. There could be insufficient video memory or a driver malfunction. Giving up.\n\n", CGLErrorString(error));
        return(FALSE);
    }

    // Create an OpenGL rendering context with the selected pixelformat: Share its ressources with 'slaveWindow's context, if slaveWindow is non-NULL.
    // If slaveWindow is non-NULL here, then slaveWindow is typically another onscreen window. Therefore this establishes OpenGL resource sharing across
    // different onscreen windows in a session, e.g., for multi-display operation:
    error=CGLCreateContext(windowRecord->targetSpecific.pixelFormatObject, ((windowRecord->slaveWindow) ? windowRecord->slaveWindow->targetSpecific.contextObject : NULL),
                           &(windowRecord->targetSpecific.contextObject));
    if (error) {
        printf("\nPTB-ERROR[ContextCreation failed: %s]: Could not create master OpenGL context for new onscreen window. Insufficient video memory?\n\n", CGLErrorString(error));
        return(FALSE);
    }

    // Enable the OpenGL rendering context associated with our window:
    error=CGLSetCurrentContext(windowRecord->targetSpecific.contextObject);
    if (error) {
        printf("\nPTB-ERROR[SetCurrentContext failed: %s]: Insufficient video memory\n\n", CGLErrorString(error));
        return(FALSE);
    }

    // NULL-out the AGL context field, just for safety...
    windowRecord->targetSpecific.deviceContext = NULL;

    // Ok, the master OpenGL rendering context for this new onscreen window is up and running.
    // Auto-detect and bind all available OpenGL extensions via GLEW:
    glerr = glewInit();
    if (GLEW_OK != glerr)
    {
        /* Problem: glewInit failed, something is seriously wrong. */
        printf("\nPTB-ERROR[GLEW init failed: %s]: Please report this to the forum. Will try to continue, but may crash soon!\n\n", glewGetErrorString(glerr));
        fflush(NULL);
    }
    else {
        if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Using GLEW version %s for automatic detection of OpenGL extensions...\n", glewGetString(GLEW_VERSION));
    }

    // Enable multisampling if it was requested:
    if (windowRecord->multiSample > 0) glEnable(GL_MULTISAMPLE);

    // External 3D graphics support enabled?
    if (PsychPrefStateGet_3DGfx()) {
        // Yes. We need to create an extra OpenGL rendering context for the external
        // OpenGL code to provide optimal state-isolation. The context shares all
        // heavyweight ressources likes textures, FBOs, VBOs, PBOs, shader, display lists and
        // starts off as an identical copy of PTB's context as of here.
        error=CGLCreateContext(windowRecord->targetSpecific.pixelFormatObject, windowRecord->targetSpecific.contextObject, &(windowRecord->targetSpecific.glusercontextObject));
        if (error) {
            printf("\nPTB-ERROR[UserContextCreation failed: %s]: Creating a private OpenGL context for userspace OpenGL failed.\n\n", CGLErrorString(error));
            return(FALSE);
        }
    }

    // Create glswapcontextObject - An OpenGL context for exclusive use by parallel background threads,
    // e.g., our thread for async flip operations and self-made frame-sequential stereo:
    error=CGLCreateContext(windowRecord->targetSpecific.pixelFormatObject, windowRecord->targetSpecific.contextObject, &(windowRecord->targetSpecific.glswapcontextObject));
    if (error) {
        printf("\nPTB-ERROR[SwapContextCreation failed: %s]: Creating a private OpenGL context for async-bufferswaps failed.\n\n", CGLErrorString(error));
        CGLSetCurrentContext(NULL);
        return(FALSE);
    }

    // Store Cocoa onscreen window handle:
    windowRecord->targetSpecific.windowHandle = cocoaWindow;

    // Objective-C setup path, using Cocoa + NSOpenGLContext wrapped around already
    // existing and setup CGLContext:
    if (PsychCocoaSetupAndAssignOpenGLContextsFromCGLContexts(cocoaWindow, windowRecord)) {
        printf("\nPTB-ERROR[Cocoa OpenGL setup failed]: Setup failed for unknown reasons.\n\n");
        PsychCocoaDisposeWindow(windowRecord);
        return(FALSE);
    }

    // Check for output display rotation enabled. Will impair timing/timestamping because
    // it uses the desktop compositor for a rotated copy blit, instead of via rotated crtc
    // scanout, as most crtc's don't support this in hardware:
    if ((((int) CGDisplayRotation(cgDisplayID)) != 0) && (PsychPrefStateGet_Verbosity() > 1)) {
        printf("PTB-WARNING: Your onscreen windows output display has rotation enabled. It is not displaying in upright orientation.\n");
        printf("PTB-WARNING: On most graphics cards this will cause unreliable stimulus presentation timing and timestamping.\n");
        printf("PTB-WARNING: If you want non-upright stimulus presentation, look at 'help PsychImaging' on how to achieve this in\n");
        printf("PTB-WARNING: a way that doesn't impair timing. The subfunctions 'FlipHorizontal' and 'FlipVertical' are what you probably need.\n");
    }

    // First reference to this screen by a window?
    if (screenRefCount[screenSettings->screenNumber] == 0) {
        // High precision timestamping enabled? If so, we need to setup the fallback
        // timestamping methods in case beamposition timestamping doesn't work:
        if (PsychPrefStateGet_VBLTimestampingMode() > 0) {
            // Use of CoreVideo is needed on 10.7 and later due to brokeness of the old method (thanks Apple!):
            if (PsychPrefStateGet_Verbosity() > 2) {
                printf("PTB-INFO: Will use fragile CoreVideo timestamping as fallback if beamposition timestamping doesn't work.\n");
                // Recommend use of kernel driver if it isn't installed already for all but Intel GPU's:
                if (!PsychOSIsKernelDriverAvailable(screenSettings->screenNumber) && !strstr((char*) glGetString(GL_VENDOR), "Intel")) {
                    printf("PTB-INFO: Installation of the PsychtoolboxKernelDriver is strongly recommended if you care about precise visual\n");
                    printf("PTB-INFO: onset timestamping or timing. See 'help PsychtoolboxKernelDriver' for installation instructions.\n");
                }
            }

            if (NULL == cvDisplayLink[screenSettings->screenNumber]) {
                // CoreVideo timestamping:
                //
                // Create and start a CVDisplayLink for this screen.
                if (kCVReturnSuccess != CVDisplayLinkCreateWithCGDisplay(cgDisplayID, &cvDisplayLink[screenSettings->screenNumber])) {
                    if (PsychPrefStateGet_Verbosity()>1) printf("PTB-WARNING: Failed to create CVDisplayLink for screenId %i. This may impair VBL timestamping.\n", screenSettings->screenNumber);
                } else {
                    // Assign dummy output callback, as this is mandatory to get the link up and running:
                    CVDisplayLinkSetOutputCallback(cvDisplayLink[screenSettings->screenNumber], &PsychCVDisplayLinkOutputCallback, (void*) (long int) screenSettings->screenNumber);

                    // Setup shared data structure and mutex:
                    memset(&cvDisplayLinkData[screenSettings->screenNumber], 0, sizeof(cvDisplayLinkData[screenSettings->screenNumber]));
                    PsychInitMutex(&(cvDisplayLinkData[screenSettings->screenNumber].mutex));

                    // Start the link:
                    if (kCVReturnSuccess != CVDisplayLinkStart(cvDisplayLink[screenSettings->screenNumber])) {
                        // Failed to start: Release it again and report error:
                        CVDisplayLinkRelease(cvDisplayLink[screenSettings->screenNumber]);
                        cvDisplayLink[screenSettings->screenNumber] = NULL;

                        // Teardown shared data structure and mutex:
                        PsychDestroyMutex(&(cvDisplayLinkData[screenSettings->screenNumber].mutex));
                        if (PsychPrefStateGet_Verbosity()>1) printf("PTB-WARNING: Failed to start CVDisplayLink for screenId %i. This may impair VBL timestamping.\n", screenSettings->screenNumber);
                    }
                    else {
                        // Display link started: Report some stuff for the fun of it...
                        if (PsychPrefStateGet_Verbosity() > 3) {
                            // Wait for 50 msecs before query of video refresh from display link to give it a chance to start up:
                            PsychWaitIntervalSeconds(0.050);

                            printf("PTB-INFO: CVDisplayLink for screen %i created to work around the brokenness of Apple Mac OS/X 10.7 and later:\n", screenSettings->screenNumber);
                            printf("PTB-INFO: Video refresh interval as measured by CoreVideo display link: %f msecs.\n", (float) CVDisplayLinkGetActualOutputVideoRefreshPeriod(cvDisplayLink[screenSettings->screenNumber]) * 1000.0);
                            CVTime outLatency = CVDisplayLinkGetOutputVideoLatency(cvDisplayLink[screenSettings->screenNumber]);
                            printf("PTB-INFO: Video display output delay as reported by CoreVideo display link: %f msecs.\n", screenSettings->screenNumber, (float) (((double) outLatency.timeValue / (double) outLatency.timeScale) * 1000.0));
                        }
                    }
                }
            }
        }
        else {
            // VBLtimestampingmode 0 or -1 -- No CoreVideo fallback for timestamping if beamposition timestamping is unavailable:
            // This is the new default as of Psychtoolbox 3.0.12 to avoid the buggy, crashy, unreliably CoreVideo fallback.

            // Recommend use of kernel driver if it isn't installed already for all but Intel GPU's:
            if (!PsychOSIsKernelDriverAvailable(screenSettings->screenNumber) && !strstr((char*) glGetString(GL_VENDOR), "Intel")) {
                printf("PTB-INFO: Installation of the PsychtoolboxKernelDriver is strongly recommended if you care about precise visual\n");
                printf("PTB-INFO: onset timestamping or timing. See 'help PsychtoolboxKernelDriver' for installation instructions.\n");
            }
        }
    }

    // Retain reference of this window to its screen:
    screenRefCount[screenSettings->screenNumber]++;

    // Done.
    return(TRUE);
}
Ejemplo n.º 12
0
PsychError SCREENCopyWindow(void) 
{
	PsychRectType			sourceRect, targetRect, targetRectInverted;
	PsychWindowRecordType	*sourceWin, *targetWin;
	GLdouble				sourceVertex[2], targetVertex[2]; 
	double					t1;
	double					sourceRectWidth, sourceRectHeight;
	GLuint					srcFBO, dstFBO;
	GLenum					glerr;
	
	//all sub functions should have these two lines
	PsychPushHelp(useString, synopsisString, seeAlsoString);
	if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};

	//cap the number of inputs
	PsychErrorExit(PsychCapNumInputArgs(5));   //The maximum number of inputs
	PsychErrorExit(PsychCapNumOutputArgs(0));  //The maximum number of outputs
        
	//get parameters for the source window:
	PsychAllocInWindowRecordArg(1, TRUE, &sourceWin);
	PsychCopyRect(sourceRect, sourceWin->rect);

	// Special case for stereo: Only half the real window width:
	PsychMakeRect(&sourceRect, sourceWin->rect[kPsychLeft], sourceWin->rect[kPsychTop],
				  sourceWin->rect[kPsychLeft] + PsychGetWidthFromRect(sourceWin->rect)/((sourceWin->specialflags & kPsychHalfWidthWindow) ? 2 : 1),
				  sourceWin->rect[kPsychTop] + PsychGetHeightFromRect(sourceWin->rect)/((sourceWin->specialflags & kPsychHalfHeightWindow) ? 2 : 1));
	
	PsychCopyInRectArg(3, FALSE, sourceRect);
	if (IsPsychRectEmpty(sourceRect)) return(PsychError_none);

	//get paramters for the target window:
	PsychAllocInWindowRecordArg(2, TRUE, &targetWin);

	// By default, the targetRect is equal to the sourceRect, but centered in
	// the target window.
	PsychCopyRect(targetRect, targetWin->rect);

	// Special case for stereo: Only half the real window width:
	PsychMakeRect(&targetRect, targetWin->rect[kPsychLeft], targetWin->rect[kPsychTop],
				  targetWin->rect[kPsychLeft] + PsychGetWidthFromRect(targetWin->rect)/((targetWin->specialflags & kPsychHalfWidthWindow) ? 2 : 1),
				  targetWin->rect[kPsychTop] + PsychGetHeightFromRect(targetWin->rect)/((targetWin->specialflags & kPsychHalfHeightWindow) ? 2 : 1));

	PsychCopyInRectArg(4, FALSE, targetRect);
	if (IsPsychRectEmpty(targetRect)) return(PsychError_none);

	if (0) {
		printf("SourceRect: %f %f %f %f  ---> TargetRect: %f %f %f %f\n", sourceRect[0], sourceRect[1],
             sourceRect[2], sourceRect[3], targetRect[0], targetRect[1],targetRect[2],targetRect[3]);
	}

	// Validate rectangles:
	if (!ValidatePsychRect(sourceRect) || sourceRect[kPsychLeft]<sourceWin->rect[kPsychLeft] ||
		sourceRect[kPsychTop]<sourceWin->rect[kPsychTop] || sourceRect[kPsychRight]>sourceWin->rect[kPsychRight] ||
		sourceRect[kPsychBottom]>sourceWin->rect[kPsychBottom]) {
		PsychErrorExitMsg(PsychError_user, "Invalid source rectangle specified - (Partially) outside of source window.");
	}
	
	if (!ValidatePsychRect(targetRect) || targetRect[kPsychLeft]<targetWin->rect[kPsychLeft] ||
		targetRect[kPsychTop]<targetWin->rect[kPsychTop] || targetRect[kPsychRight]>targetWin->rect[kPsychRight] ||
		targetRect[kPsychBottom]>targetWin->rect[kPsychBottom]) {
		PsychErrorExitMsg(PsychError_user, "Invalid target rectangle specified - (Partially) outside of target window.");
	}
	
	if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) PsychTestForGLErrors();

	// Does this GL implementation support the EXT_framebuffer_blit extension for fast blitting between
	// framebuffers? And is the imaging pipeline active? And is the kPsychAvoidFramebufferBlitIfPossible not set?
	if ((sourceWin->gfxcaps & kPsychGfxCapFBOBlit) && (targetWin->gfxcaps & kPsychGfxCapFBOBlit) &&
		(sourceWin->imagingMode > 0) && (targetWin->imagingMode > 0) && !(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidFramebufferBlitIfPossible)) {
		// Yes :-) -- This simplifies the CopyWindow implementation to a simple framebuffer blit op,
		// regardless what the source- or destination is:
		
		// Set each windows framebuffer as a drawingtarget once: This is just to make sure all of them
		// have proper FBO's attached:
		PsychSetDrawingTarget(sourceWin);
		PsychSetDrawingTarget(targetWin);
		
		// Soft-Reset drawing target - Detach anything bound or setup:
		PsychSetDrawingTarget(0x1);
		
		// Find source framebuffer:
		if (sourceWin->fboCount == 0) {
			// No FBO's attached to sourceWin: Must be a system framebuffer, e.g., if imagingMode == kPsychNeedFastOffscreenWindows and
			// this is the onscreen window system framebuffer. Assign system framebuffer handle:
			srcFBO = 0;
		}
		else {
			// FBO's attached: Want drawBufferFBO 0 or 1 - 1 for right eye view in stereomode, 0 for
			// everything else: left eye view, monoscopic buffer, offscreen windows / textures:
			if ((sourceWin->stereomode > 0) && (sourceWin->stereodrawbuffer == 1)) {
				// We are in stereo mode and want to access the right-eye channel. Bind FBO-1
				srcFBO = sourceWin->fboTable[sourceWin->drawBufferFBO[1]]->fboid;
			}
			else {
				srcFBO = sourceWin->fboTable[sourceWin->drawBufferFBO[0]]->fboid;
			}
		}

		// Find target framebuffer:
		if (targetWin->fboCount == 0) {
			// No FBO's attached to targetWin: Must be a system framebuffer, e.g., if imagingMode == kPsychNeedFastOffscreenWindows and
			// this is the onscreen window system framebuffer. Assign system framebuffer handle:
			dstFBO = 0;
		}
		else {
			// FBO's attached: Want drawBufferFBO 0 or 1 - 1 for right eye view in stereomode, 0 for
			// everything else: left eye view, monoscopic buffer, offscreen windows / textures:
			if ((targetWin->stereomode > 0) && (targetWin->stereodrawbuffer == 1)) {
				// We are in stereo mode and want to access the right-eye channel. Bind FBO-1
				dstFBO = targetWin->fboTable[targetWin->drawBufferFBO[1]]->fboid;
			}
			else {
				dstFBO = targetWin->fboTable[targetWin->drawBufferFBO[0]]->fboid;
			}
		}

		// Bind read- / write- framebuffers:
		glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, srcFBO);
		glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, dstFBO);

		// Perform blit-operation: If blitting from a multisampled FBO into a non-multisampled one, this will also perform the
		// multisample resolve operation:
		glBlitFramebufferEXT(sourceRect[kPsychLeft], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychBottom], sourceRect[kPsychRight], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychTop],
							 targetRect[kPsychLeft], PsychGetHeightFromRect(targetWin->rect) - targetRect[kPsychBottom], targetRect[kPsychRight], PsychGetHeightFromRect(targetWin->rect) - targetRect[kPsychTop],
							 GL_COLOR_BUFFER_BIT, GL_NEAREST);

		if (PsychPrefStateGet_Verbosity() > 5) {
			printf("FBB-SRC: X0 = %f Y0 = %f X1 = %f Y1 = %f \n", sourceRect[kPsychLeft], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychBottom], sourceRect[kPsychRight], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychTop]);
			printf("FBB-DST: X0 = %f Y0 = %f X1 = %f Y1 = %f \n", targetRect[kPsychLeft], PsychGetHeightFromRect(targetWin->rect) - targetRect[kPsychBottom], targetRect[kPsychRight], PsychGetHeightFromRect(targetWin->rect) - targetRect[kPsychTop]);
		}
		
		if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) {
			if ((glerr = glGetError())!=GL_NO_ERROR) {			

				// Reset framebuffer binding to something safe - The system framebuffer:
				glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
			
				if((glerr == GL_INVALID_OPERATION) && (PsychGetWidthFromRect(sourceRect) != PsychGetWidthFromRect(targetRect) ||
													   PsychGetHeightFromRect(sourceRect) != PsychGetHeightFromRect(targetRect))) {
					// Non-matching sizes. Make sure we do not operate on multisampled stuff
					PsychErrorExitMsg(PsychError_user, "CopyWindow failed: Most likely cause: You tried to copy a multi-sampled window into a non-multisampled window, but there is a size mismatch of sourceRect and targetRect. Matching size is required for such copies.");
				}
				else {
					if (glerr == GL_INVALID_OPERATION) {
						PsychErrorExitMsg(PsychError_user, "CopyWindow failed: Most likely cause: You tried to copy from a multi-sampled window into another multisampled window, but there is a mismatch between the multiSample levels of both. Identical multiSample values are required for such copies.");
					}
					else {
						printf("CopyWindow failed for unresolved reason: OpenGL says after call to glBlitFramebufferEXT(): %s\n", gluErrorString(glerr));
						PsychErrorExitMsg(PsychError_user, "CopyWindow failed for unresolved reason.");
					}
				}
			}
		}
		
		// Reset framebuffer binding to something safe - The system framebuffer:
		glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
		
		// Just to make sure we catch invalid values:
		if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) PsychTestForGLErrors();
		
		// Done.
		return(PsychError_none);
	}

	// We have four possible combinations for copy ops:
	// Onscreen -> Onscreen
	// Onscreen -> Texture
	// Texture  -> Texture
	// Texture  -> Onscreen
        
	// Texture -> something copy? (Offscreen to Offscreen or Offscreen to Onscreen)
	// This should work for both, copies from a texture/offscreen window to a different texture/offscreen window/onscreen window,
	// and for copies of a subregion of a texture/offscreen window into a non-overlapping subregion of the texture/offscreen window
	// itself:
	if (sourceWin->windowType == kPsychTexture) {
		// Bind targetWin (texture or onscreen windows framebuffer) as
		// drawing target and just blit texture into it. Binding is done implicitely
		
		if ((sourceWin == targetWin) && (targetWin->imagingMode > 0)) {
			// Copy of a subregion of an offscreen window into itself while imaging pipe active, ie. FBO storage: This is actually the same
			// as on onscreen -> onscreen copy, just with the targetWin FBO bound.
			
			// Set target windows framebuffer as drawing target:
			PsychSetDrawingTarget(targetWin);

			// Disable alpha-blending:
			glDisable(GL_BLEND);
			
			// Disable any shading during copy-op:
			PsychSetShader(targetWin, 0);

			// Start position for pixel write is:
			glRasterPos2f(targetRect[kPsychLeft], targetRect[kPsychBottom]);
			
			// Zoom factor if rectangle sizes don't match:
			glPixelZoom(PsychGetWidthFromRect(targetRect) / PsychGetWidthFromRect(sourceRect), PsychGetHeightFromRect(targetRect) / PsychGetHeightFromRect(sourceRect));
			
			// Perform pixel copy operation:
			glCopyPixels(sourceRect[kPsychLeft], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychBottom], (int) PsychGetWidthFromRect(sourceRect), (int) PsychGetHeightFromRect(sourceRect), GL_COLOR);
			
			// That's it.
			glPixelZoom(1,1);
			
			// Flush drawing commands and wait for render-completion in single-buffer mode:
			PsychFlushGL(targetWin);				
		}
		else {
				// Sourcewin != Targetwin and/or imaging pipe (FBO storage) not used. We blit the
				// backing texture into itself, aka into its representation inside the system
				// backbuffer. The blit routine will setup proper bindings:

				// Disable alpha-blending:
				glDisable(GL_BLEND);

				// We use filterMode == 1 aka Bilinear filtering, so we get nice texture copies
				// if size of sourceRect and targetRect don't match and some scaling is needed.
				// We maybe could map the copyMode argument into some filterMode settings, but
				// i don't know the spec of copyMode, so ...
				PsychBlitTextureToDisplay(sourceWin, targetWin, sourceRect, targetRect, 0, 1, 1);
				
				// That's it.
				
				// Flush drawing commands and wait for render-completion in single-buffer mode:
				PsychFlushGL(targetWin);
		}
	}

	// Onscreen to texture copy?
	if (PsychIsOnscreenWindow(sourceWin) && PsychIsOffscreenWindow(targetWin)) {
		// With the current implemenation we can't zoom if sizes of sourceRect and targetRect don't
		// match: Only one-to-one copy possible...
		if(PsychGetWidthFromRect(sourceRect) != PsychGetWidthFromRect(targetRect) ||
		   PsychGetHeightFromRect(sourceRect) != PsychGetHeightFromRect(targetRect)) {
				// Non-matching sizes. We can't perform requested scaled copy :(
				PsychErrorExitMsg(PsychError_user, "Size mismatch of sourceRect and targetRect. Matching size is required for Onscreen to Offscreen copies. Sorry.");
		}
		
		// Update selected textures content:
		// Looks weird but we need the framebuffer of sourceWin:
		PsychSetDrawingTarget(sourceWin);

		// Disable alpha-blending:
		glDisable(GL_BLEND);
		
		// Disable any shading during copy-op:
		PsychSetShader(sourceWin, 0);

		// Texture objects are shared across contexts, so doesn't matter if targetWin's texture actually
		// belongs to the bound context of sourceWin:
		glBindTexture(PsychGetTextureTarget(targetWin), targetWin->textureNumber);
		
		// Copy into texture:
		glCopyTexSubImage2D(PsychGetTextureTarget(targetWin), 0, targetRect[kPsychLeft], PsychGetHeightFromRect(targetWin->rect) - targetRect[kPsychBottom], sourceRect[kPsychLeft], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychBottom],
							(int) PsychGetWidthFromRect(sourceRect), (int) PsychGetHeightFromRect(sourceRect));
		
		// Unbind texture object:
		glBindTexture(PsychGetTextureTarget(targetWin), 0);
		
		// That's it.
		glPixelZoom(1,1);
	}

	// Onscreen to Onscreen copy?
	if (PsychIsOnscreenWindow(sourceWin) && PsychIsOnscreenWindow(targetWin)) {
		// Currently only works for copies of subregion -> subregion inside same onscreen window,
		// not across different onscreen windows! TODO: Only possible with EXT_framebuffer_blit
		if (sourceWin != targetWin) PsychErrorExitMsg(PsychError_user, "Sorry, the current implementation only supports copies within the same onscreen window, not accross onscreen windows.");

		// Set target windows framebuffer as drawing target:
		PsychSetDrawingTarget(targetWin);
		
		// Disable alpha-blending:
		glDisable(GL_BLEND);
		
		// Disable any shading during copy-op:
		PsychSetShader(targetWin, 0);

		// Start position for pixel write is:
		glRasterPos2f(targetRect[kPsychLeft], targetRect[kPsychBottom]);
		
		// Zoom factor if rectangle sizes don't match:
		glPixelZoom(PsychGetWidthFromRect(targetRect) / PsychGetWidthFromRect(sourceRect), PsychGetHeightFromRect(targetRect) / PsychGetHeightFromRect(sourceRect));
		
		// Perform pixel copy operation:
		glCopyPixels(sourceRect[kPsychLeft], PsychGetHeightFromRect(sourceWin->rect) - sourceRect[kPsychBottom], (int) PsychGetWidthFromRect(sourceRect), (int) PsychGetHeightFromRect(sourceRect), GL_COLOR);
		
		// That's it.
		glPixelZoom(1,1);
		
		// Flush drawing commands and wait for render-completion in single-buffer mode:
		PsychFlushGL(targetWin);
	}

	// Just to make sure we catch invalid values:
	if (!(PsychPrefStateGet_ConserveVRAM() & kPsychAvoidCPUGPUSync)) PsychTestForGLErrors();

	// Done.
	return(PsychError_none);
}
PsychError SCREENOpenWindow(void) 

{
    int						screenNumber, numWindowBuffers, stereomode, multiSample, imagingmode, specialflags;
    PsychRectType 			rect, screenrect;
    PsychColorType			color;
    psych_bool				isArgThere, didWindowOpen, useAGL;
    PsychScreenSettingsType	screenSettings;
    PsychWindowRecordType	*windowRecord;
    PsychDepthType			specifiedDepth, possibleDepths, currentDepth, useDepth;
	int                     dummy1;
	double                  dummy2, dummy3, dummy4;

	psych_bool EmulateOldPTB = PsychPrefStateGet_EmulateOldPTB();

    //all sub functions should have these two lines
    PsychPushHelp(useString, synopsisString, seeAlsoString);
    if(PsychIsGiveHelp()){PsychGiveHelp();return(PsychError_none);};

    //cap the number of inputs
    PsychErrorExit(PsychCapNumInputArgs(9));   //The maximum number of inputs
    PsychErrorExit(PsychCapNumOutputArgs(2));  //The maximum number of outputs

    //get the screen number from the windowPtrOrScreenNumber.  This also checks to make sure that the specified screen exists.  
    PsychCopyInScreenNumberArg(kPsychUseDefaultArgPosition, TRUE, &screenNumber);
    if(screenNumber==-1)
        PsychErrorExitMsg(PsychError_user, "The specified onscreen window has no ancestral screen."); 

    /*
      The depth checking is ugly because of this stupid depth structure stuff.  
      Instead get a descriptor of the current video settings, change the depth field,
      and pass it to a validate function wich searches a list of valid video modes for the display.
      There seems to be no point in checking the depths alone because the legality of a particular
      depth depends on the other settings specified below.  Its probably best to wait until we have
      digested all settings and then test the full mode, declarin an invalid
      mode and not an invalid pixel size.  We could notice when the depth alone is specified 
      and in that case issue an invalid depth value.
     */  

    //find the PixelSize first because the color specifier depends on the screen depth.  
    PsychInitDepthStruct(&currentDepth);  //get the current depth
    PsychGetScreenDepth(screenNumber, &currentDepth);
    PsychInitDepthStruct(&possibleDepths); //get the possible depths
    PsychGetScreenDepths(screenNumber, &possibleDepths);

    #if PSYCH_SYSTEM == PSYCH_OSX || PSYCH_SYSTEM == PSYCH_WINDOWS
       // MK Experimental Hack: Add the special depth values 64 and 128 to the depth struct. This should 
       // allows for 16 bpc, 32 bpc floating point color buffers on the latest ATI and NVidia hardware.
	   // "Should" means: It doesn't really work with any current driver, but we leave the testcode in
	   // in the hope for future OS and driver releases ;-)
       // Unfortunately at this point of the init sequence, we are not able
       // to check if these formats are supported by the hardware. Ugly ugly ugly...
       PsychAddValueToDepthStruct(64, &possibleDepths);
       PsychAddValueToDepthStruct(128, &possibleDepths);
    #endif

//    #if PSYCH_SYSTEM == PSYCH_OSX || PSYCH_SYSTEM == PSYCH_LINUX
		// On MacOS/X and Linux with ATI Radeon X1000/HD2000/HD3000 hardware and the special
		// kernel support driver installed, we should be able to configure the hardwares
		// framebuffers into ABGR2101010 mode, ie. 2 bits alpha, 10 bpc for red, green, blue.
		// This needs support from the imaging pipeline, or manually converted stimuli, as
		// the GPU doesn't format pixel data properly, only the CRTC scans out in that format.
		// Anyway, allow this setting on OS/X and Linux:
		
		// Update: Some FireGL cards (2008 and later) claim to support this on MS-Windows. Enable
		// this option on Windows as well, so it is at least testable:
		PsychAddValueToDepthStruct(30, &possibleDepths);
//    #endif


    PsychInitDepthStruct(&specifiedDepth); //get the requested depth and validate it.  
    isArgThere = PsychCopyInSingleDepthArg(4, FALSE, &specifiedDepth);

    PsychInitDepthStruct(&useDepth);
    if(isArgThere){ //if the argument is there check that the screen supports it...
        if(!PsychIsMemberDepthStruct(&specifiedDepth, &possibleDepths))
            PsychErrorExit(PsychError_invalidDepthArg);
        else
            PsychCopyDepthStruct(&useDepth, &specifiedDepth);
    }else //otherwise use the default
        PsychCopyDepthStruct(&useDepth, &currentDepth);

    // Initialize the rect argument to the screen rectangle:
    PsychGetGlobalScreenRect(screenNumber, rect); 	//get the rect describing the screen bounds.  This is the default Rect.  

    // Override it with a user supplied rect, if one was supplied:
    isArgThere=PsychCopyInRectArg(kPsychUseDefaultArgPosition, FALSE, rect );
    if (IsPsychRectEmpty(rect)) PsychErrorExitMsg(PsychError_user, "OpenWindow called with invalid (empty) rect argument.");

	if (PSYCH_SYSTEM == PSYCH_OSX) {
		// OS/X system: Need to decide if we use a Carbon window + AGL
		// or a fullscreen context with CGL:
		
		// Default to AGL, switch to CGL if below constraints are met:
		useAGL = TRUE;
	
		// Window rect provided which has a different size than screen?

		// We do not use windowed mode if the provided window rectangle either
		// matches the target screens rectangle (and therefore its exact size)
		// or its screens global rectangle.
		PsychGetScreenRect(screenNumber, screenrect);
		if (PsychMatchRect(screenrect, rect)) useAGL=FALSE;
		PsychGetGlobalScreenRect(screenNumber, screenrect);
		if (PsychMatchRect(screenrect, rect)) useAGL=FALSE;

		// Override for use on f$%#$Fd OS/X 10.5.3 - 10.5.6 with NVidia GF 8800 GPU's:
		if (PsychPrefStateGet_ConserveVRAM() & kPsychUseAGLCompositorForFullscreenWindows) useAGL = TRUE;
	}
	else {
		// Non OS/X system: Do not use AGL ;-)
		useAGL = FALSE;
	}
	
    //find the number of specified buffers. 

    //OS X:	The number of backbuffers is not a property of the display mode but an attribute of the pixel format.
    //		Therefore the value is held by a window record and not a screen record.    

    numWindowBuffers=2;	
    PsychCopyInIntegerArg(5,FALSE,&numWindowBuffers);
    if(numWindowBuffers < 1 || numWindowBuffers > kPsychMaxNumberWindowBuffers) PsychErrorExit(PsychError_invalidNumberBuffersArg);

    stereomode=0;
    PsychCopyInIntegerArg(6,FALSE,&stereomode);
    if(stereomode < 0 || stereomode > 11) PsychErrorExitMsg(PsychError_user, "Invalid stereomode provided (Valid between 0 and 11).");
	if (stereomode!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, stereo display functions are not supported in OS-9 PTB emulation mode.");

    multiSample=0;
    PsychCopyInIntegerArg(7,FALSE,&multiSample);
    if(multiSample < 0) PsychErrorExitMsg(PsychError_user, "Invalid multisample value provided (Valid are positive numbers >= 0).");
	if (multiSample!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, anti-aliasing functions are not supported in OS-9 PTB emulation mode.");

	imagingmode=0;
    PsychCopyInIntegerArg(8,FALSE,&imagingmode);
    if(imagingmode < 0) PsychErrorExitMsg(PsychError_user, "Invalid imaging mode provided (See 'help PsychImagingMode' for usage info).");
	if (imagingmode!=0 && EmulateOldPTB) PsychErrorExitMsg(PsychError_user, "Sorry, imaging pipeline functions are not supported in OS-9 PTB emulation mode.");
	
	specialflags=0;
    PsychCopyInIntegerArg(9,FALSE,&specialflags);
    if (specialflags < 0 || (specialflags > 0 && specialflags!=kPsychGUIWindow)) PsychErrorExitMsg(PsychError_user, "Invalid 'specialflags' provided.");

	// We require use of the imaging pipeline if stereomode for dualwindow display is requested.
	// This makes heavy use of FBO's and blit operations, so imaging pipeline is needed.
	if ((stereomode==kPsychDualWindowStereo) || (imagingmode & kPsychNeedDualWindowOutput)) {
		// Dual window stereo requested, but imaging pipeline not enabled. Enable it:
		imagingmode|= kPsychNeedFastBackingStore;
		if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Trying to enable imaging pipeline for dual-window stereo display mode or dual-window output mode...\n");
	}
	
    //set the video mode to change the pixel size.  TO DO: Set the rect and the default color  
    PsychGetScreenSettings(screenNumber, &screenSettings);    
    PsychInitDepthStruct(&(screenSettings.depth));
    PsychCopyDepthStruct(&(screenSettings.depth), &useDepth);

    // Here is where all the work goes on:

    // If the screen is not already captured then to that:
    if(!PsychIsScreenCaptured(screenNumber) && !useAGL) {
        PsychCaptureScreen(screenNumber);
    }

#if PSYCH_SYSTEM == PSYCH_WINDOWS
    // On M$-Windows we currently only support - and therefore require >= 30 bpp color depth.
    if (PsychGetScreenDepthValue(screenNumber) < 30) {
		// Display running at less than 30 bpp. OpenWindow will fail on M$-Windows anyway, so let's abort
		// now.

		// Output warning text:
        printf("PTB-ERROR: Your display screen %i is not running at the required color depth of at least 30 bit.\n", screenNumber);
        printf("PTB-ERROR: The current setting is %i bit color depth..\n", PsychGetScreenDepthValue(screenNumber));
        printf("PTB-ERROR: This will not work on Microsoft Windows operating systems.\n");
        printf("PTB-ERROR: Please use the 'Display settings' control panel of Windows to change the color depth to\n");
        printf("PTB-ERROR: 32 bits per pixel ('True color' or 'Highest' setting) and then retry. It may be neccessary\n");
        printf("PTB-ERROR: to restart Matlab after applying the change...\n");
        fflush(NULL);

		// Release the captured screen:
		PsychRestoreScreenSettings(screenNumber);
		PsychReleaseScreen(screenNumber);

        // Reset master assignment to prepare possible further dual-window config operations:
		sharedContextWindow = NULL;

		// Abort with Matlab error:
		PsychErrorExitMsg(PsychError_user, "Insufficient color depth setting for display device (smaller than 30 bpp).");
    }

#endif

    //if (PSYCH_DEBUG == PSYCH_ON) printf("Entering PsychOpenOnscreenWindow\n");
    PsychCopyDepthStruct(&(screenSettings.depth), &useDepth);
	
	// Create the onscreen window and perform initialization of everything except
	// imaging pipeline and a few other special quirks. If sharedContextWindow is non-NULL,
	// the new window will share its OpenGL context ressources with sharedContextWindow.
	// This is typically used for dual-window stereo mode. Btw. If imaging pipeline is really
	// active, we force multiSample to zero: This way the system backbuffer / pixelformat
	// is enabled without multisampling support, as we do all the multisampling stuff ourselves
	// within the imaging pipeline with multisampled drawbuffer FBO's...
    didWindowOpen=PsychOpenOnscreenWindow(&screenSettings, &windowRecord, numWindowBuffers, stereomode, rect, ((imagingmode==0 || imagingmode==kPsychNeedFastOffscreenWindows) ? multiSample : 0), sharedContextWindow, specialflags);
    if (!didWindowOpen) {
        if (!useAGL) {
			PsychRestoreScreenSettings(screenNumber);
			PsychReleaseScreen(screenNumber);
		}

		// Reset master assignment to prepare possible further dual-window config operations:
		sharedContextWindow = NULL;

        // We use this dirty hack to exit with an error, but without printing
        // an error message. The specific error message has been printed in
        // PsychOpenOnscreenWindow() already..
        PsychErrMsgTxt("");
    }

    // Sufficient display depth for full alpha-blending and such?
    if (PsychGetScreenDepthValue(screenNumber) < 24) {
        // Nope. Output a little warning.
        printf("PTB-WARNING: Your display screen %i is not running at 24 bit color depth or higher.\n", screenNumber);
        printf("PTB-WARNING: The current setting is %i bit color depth..\n", PsychGetScreenDepthValue(screenNumber));
        printf("PTB-WARNING: This could cause failure to work correctly or visual artifacts in stimuli\n");
        printf("PTB-WARNING: that involve Alpha-Blending. It can also cause drastically reduced color resolution\n");
        printf("PTB-WARNING: for your stimuli! Please try to switch your display to 'True Color' (Windows)\n");
        printf("PTB-WARNING: our 'Millions of Colors' (MacOS-X) to get rid of this warning and the visual artifacts.\n");
        fflush(NULL);
    }
    
	// Define clear color: This depends on the color range of our onscreen window...
    isArgThere=PsychCopyInColorArg(kPsychUseDefaultArgPosition, FALSE, &color); //get from user
    if(!isArgThere) PsychLoadColorStruct(&color, kPsychIndexColor, PsychGetWhiteValueFromWindow(windowRecord)); //or use the default
    PsychCoerceColorMode(&color);

    // The imaging pipeline and graphics drivers had over 5 years of time to mature. As of 2012, imaging pipeline based
    // support for fast offscreen windows and for stereoscopic display modes is far superior in performance,
    // robustness, flexibility and convenience to the legacy method which was used in ptb by default so far.
    // Now it is 2012+ and we switch the defaults: If the GPU+driver combo supports it, and usercode doesn't
    // actively opt-out of it, we auto-enable use of FBO backed fast offscreen windows. We don't auto-enable
    // the full pipeline for stereoscopic display modes, but we print some recommendations to the user to
    // consider enabling the full pipeline for stereo display:
    if ((windowRecord->gfxcaps & kPsychGfxCapFBO) && !(PsychPrefStateGet_ConserveVRAM() & kPsychDontAutoEnableImagingPipeline)) {
        // Support for basic use of the PTB imaging pipeline and/or for fast offscreen windows
        // is available - a GPU + driver combo with support for OpenGL framebuffer objects with
        // at least RGBA8 format and rectangle rendertargets.
        // Usercode doesn't disallow automatic use of imaging pipeline or fast offscreen windows,
        // ie. it didn't set the kPsychDontAutoEnableImagingPipeline conserveVRAM flag.
        // Good!
        
        // We will therefore auto-enable use of fast offscreen windows:
        imagingmode |= kPsychNeedFastOffscreenWindows;
        
        // Is a stereomode requested which would benefit from enabling the full imaging pipeline?
        if (stereomode > 0) {
	    if (((stereomode == kPsychOpenGLStereo) && !(windowRecord->gfxcaps & kPsychGfxCapNativeStereo)) || (stereomode == kPsychFrameSequentialStereo)) {
		// Native OpenGL quad-buffered frame-sequential stereo requested, but unsupported by gpu & driver.
		// Or use of our own method requested. We have FBO and framebuffer blit support, so we can roll our
		// own framesequential stereo by use of the imaging pipeline. Enable basic imaging pipeline:
		imagingmode |= kPsychNeedFastBackingStore;

		// Override stereomode to our own homegrown implementation:
		stereomode = kPsychFrameSequentialStereo;
		windowRecord->stereomode = stereomode;

		if (PsychPrefStateGet_Verbosity() > 2) {
		    printf("\n");
		    printf("PTB-INFO: Your script requests use of frame-sequential stereo, but your graphics card\n");
		    printf("PTB-INFO: and driver doesn't support this. I will now fully enable the imaging pipeline\n");
		    printf("PTB-INFO: and use my own home-grown frame-sequential stereo implementation. Note that this\n");
		    printf("PTB-INFO: may not be as robust and high-performance as using a graphics card with native\n");
		    printf("PTB-INFO: frame-sequential stereo support. But let's see what i can do for you...\n\n");
		}
	    }
	    else {
		// Yes: Provide the user with recommendations to enable the pipeline.
		if (!(imagingmode & kPsychNeedFastBackingStore) && (PsychPrefStateGet_Verbosity() > 2)) {
		    printf("\n");
		    printf("PTB-INFO: Your script requests use of a stereoscopic display mode (stereomode = %i).\n", stereomode);
		    printf("PTB-INFO: Stereoscopic stimulus display is usually more flexible, convenient and robust if\n");
		    printf("PTB-INFO: the Psychtoolbox imaging pipeline is enabled. Your graphics card is capable\n");
		    printf("PTB-INFO: of using the pipeline but your script doesn't enable use of the pipeline.\n");
		    printf("PTB-INFO: I recommend you enable use of the pipeline for enhanced stereo stimulus display.\n");
		    printf("PTB-INFO: Have a look at the demoscript ImagingStereoDemo.m on how to do this.\n\n");
		}
	    }
        }
    }

	// Query if OpenGL stereo is natively supported or if our own emulation mode will work:
	if ((((stereomode == kPsychOpenGLStereo) && !(windowRecord->gfxcaps & kPsychGfxCapNativeStereo)) || (stereomode == kPsychFrameSequentialStereo)) &&
	    (!(imagingmode & kPsychNeedFastBackingStore) || (windowRecord->stereomode != kPsychFrameSequentialStereo) || !(windowRecord->gfxcaps & kPsychGfxCapFBO))) {
		// OpenGL native stereo was requested, but is obviously not supported and we can't roll our own implementation either :-(
		printf("\nPTB-ERROR: Asked for OpenGL native stereo (frame-sequential mode) but this doesn't seem to be supported by your graphics hardware or driver.\n");
		printf("PTB-ERROR: Unfortunately using my own implementation via imaging pipeline did not work either, due to lack of hardware support, or because\n");
		printf("PTB-ERROR: did not allow me to auto-enable the pipeline and use this method. This means game over!\n");
		if (PSYCH_SYSTEM == PSYCH_OSX) {
			printf("PTB-ERROR: Frame-sequential stereo should be supported on all recent ATI/AMD and NVidia cards on OS/X, except for the Intel onboard chips,\n");
			printf("PTB-ERROR: at least in fullscreen mode with OS/X 10.5, and also mostly on OS/X 10.4. If it doesn't work, check for OS updates etc.\n\n");
		}
		else {
			printf("PTB-ERROR: Frame-sequential native stereo on Windows or Linux is usually only supported with the professional line of graphics cards\n");
			printf("PTB-ERROR: from NVidia and ATI/AMD, e.g., NVidia Quadro series or ATI Fire series. If you happen to have such a card, check\n");
			printf("PTB-ERROR: your driver settings and/or update your graphics driver.\n\n");
		}
		PsychErrMsgTxt("Frame-Sequential stereo display mode requested, but unsupported. Emulation unsupported as well. Game over!");
	}

	// Special setup code for dual window stereomode or output mode:
	if (stereomode == kPsychDualWindowStereo || (imagingmode & kPsychNeedDualWindowOutput)) {
		if (sharedContextWindow) {
			// This is creation & setup of the slave onscreen window, ie. the one
			// representing the right-eye or channel 1 view. This window doesn't do much. It
			// is not used or referenced in the users experiment script. It receives
			// its final image content during Screen('Flip') operation of the master
			// onscreen window, then gets flipped in sync with the master window.
			
			// Ok, we already have the slave window open and it shares its OpenGL context
			// with the master window. Reset its internal reference to the master:
			windowRecord->slaveWindow = NULL;
			
			// Reset imagingmode for this window prior to imaging pipeline setup. This
			// window is totally passive so it doesn't need the imaging pipeline.
			imagingmode = 0;

			// Assign this window to the master window as a slave:
			sharedContextWindow->slaveWindow = windowRecord;
			
			// Try to optionally enable framelock / swaplock extensions for the window-pair
			// if this is supported by the given system configuration. If supported, this
			// should guarantee perfect synchronization of bufferswaps across the window-pair:
			PsychOSSetupFrameLock(sharedContextWindow, windowRecord);

			// Reset master assignment to prepare possible further dual-window config operations:
			sharedContextWindow = NULL;

			// Activate the IdentitiyBlitChain for the slave window and add a single identity blit
			// operation to it: This is needed in PsychPreFlipOperations() for final copy of stimulus
			// image into this slave window:
			PsychPipelineAddBuiltinFunctionToHook(windowRecord, "IdentityBlitChain", "Builtin:IdentityBlit", INT_MAX, "");
			PsychPipelineEnableHook(windowRecord, "IdentityBlitChain");

			if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Created master-slave window relationship for dual-window stereo/output display mode...\n");

			// Special config finished. The master-slave combo should work from now on...			
		}
		else {
			// This is initial setup & creation of the master onscreen window, ie. the one
			// representing the left-eye or channel 0 view and doing all the heavy work, acting as a
			// proxy for both windows.
			
			// Not much to do here. Just store its windowRecord as a reference for creation
			// of the slave window. We'll need it for that purpose...
			sharedContextWindow = windowRecord;
		}
	}

	// Set special half-width flag for window if we are either in a dual-display/dual-view stereo mode or if
	// if is requested as part of the imagingMode flag. This will cause PTB 2D drawing routines and window size
	// query routines etc. to return an effective window width or window rect only half the real width.
	if (windowRecord->stereomode==kPsychFreeFusionStereo || windowRecord->stereomode==kPsychFreeCrossFusionStereo || (imagingmode & kPsychHalfWidthWindow)) {
		windowRecord->specialflags = windowRecord->specialflags | kPsychHalfWidthWindow;
		imagingmode = imagingmode & (~kPsychHalfWidthWindow);
	}

    // Similar handling for twice-width windows: Used for certain packed-pixels (2 stimulus pixels in one fb pixel) formats:
	if (imagingmode & kPsychTwiceWidthWindow) {
		windowRecord->specialflags = windowRecord->specialflags | kPsychTwiceWidthWindow;
		imagingmode = imagingmode & (~kPsychTwiceWidthWindow);
	}

	// Similar handling for windows of half the real height, except that none of our built-in stereo modes requires these,
	// so this is only done on request from external code via the imagingmode flag kPsychHalfHeightWindow.
	// One use of this is when using interleaved line stereo mode (PsychImaging(...'InterleavedLineStereo')) where windows
	// only have a useable net height of half their physical height:
	if (imagingmode & kPsychHalfHeightWindow) {
		windowRecord->specialflags = windowRecord->specialflags | kPsychHalfHeightWindow;
		imagingmode = imagingmode & (~kPsychHalfHeightWindow);
	}

	// Define windows clientrect. It is a copy of windows rect, but stretched or compressed
    // to twice or half the width or height of the windows rect, depending on the special size
    // flags. clientrect is used as reference for all size query functions Screen('Rect'), Screen('WindowSize')
    // and for all Screen 2D drawing functions:
    PsychSetupClientRect(windowRecord);

	// Initialize internal image processing pipeline if requested:
	if (numWindowBuffers > 0) PsychInitializeImagingPipeline(windowRecord, imagingmode, multiSample);
	
	// On OS-X, if we are in quad-buffered frame sequential stereo mode, we automatically generate
	// blue-line-sync style sync lines for use with stereo shutter glasses. We don't do this
	// by default on Windows or Linux: These systems either don't have stereo capable hardware,
	// or they have some and its drivers already take care of sync signal generation.
	if (((PSYCH_SYSTEM == PSYCH_OSX) && (windowRecord->stereomode == kPsychOpenGLStereo)) || (windowRecord->stereomode == kPsychFrameSequentialStereo)) {
		if (PsychPrefStateGet_Verbosity()>3) printf("PTB-INFO: Enabling internal blue line sync renderer for quad-buffered stereo...\n");
		PsychPipelineAddBuiltinFunctionToHook(windowRecord, "LeftFinalizerBlitChain", "Builtin:RenderStereoSyncLine", INT_MAX, "");
		PsychPipelineEnableHook(windowRecord, "LeftFinalizerBlitChain");		
		PsychPipelineAddBuiltinFunctionToHook(windowRecord, "RightFinalizerBlitChain", "Builtin:RenderStereoSyncLine", INT_MAX, "");
		PsychPipelineEnableHook(windowRecord, "RightFinalizerBlitChain");		
	}

	// Activate new onscreen window for userspace drawing: If imaging pipeline is active, this
	// will bind the correct rendertargets for the first time. We soft-reset first to get
	// into a defined state:
	PsychSetDrawingTarget((PsychWindowRecordType*) 0x1);
	PsychSetDrawingTarget(windowRecord);

    // Set the clear color and perform a backbuffer-clear:
    PsychConvertColorToDoubleVector(&color, windowRecord, windowRecord->clearColor);
    PsychGLClear(windowRecord);

    // Mark end of drawing op. This is needed for single buffered drawing:
    PsychFlushGL(windowRecord);

    // Make sure no OpenGL errors happened up to this point:
    PsychTestForGLErrors();

    // If we are in logo-startup mode (former blue-screen mode) and double-buffering
    // is enabled, then do an initial bufferswap & clear, so the display starts in
    // the user selected background color instead of staying at the blue screen or
    // logo display until the Matlab script first calls 'Flip'.
    if (((PsychPrefStateGet_VisualDebugLevel()>=4) || (windowRecord->stereomode > 0)) && numWindowBuffers>=2) {
      // Do three immediate bufferswaps by an internal call to Screen('Flip'). This will also
      // take care of clearing the backbuffer in preparation of first userspace drawing
      // commands and such. We need up-to 3 calls to clear triple-buffered setups from framebuffer junk.
      PsychFlipWindowBuffers(windowRecord, 0, 0, 0, 0, &dummy1, &dummy2, &dummy3, &dummy4);
      PsychFlipWindowBuffers(windowRecord, 0, 0, 0, 0, &dummy1, &dummy2, &dummy3, &dummy4);
      PsychFlipWindowBuffers(windowRecord, 0, 0, 0, 0, &dummy1, &dummy2, &dummy3, &dummy4);
      // Display now shows background color, so user knows that PTB's 'OpenWindow'
      // procedure is successfully finished.
    }

    PsychTestForGLErrors();

    // Reset flipcounter to zero:
    windowRecord->flipCount = 0;
	
    //Return the window index and the rect argument.
    PsychCopyOutDoubleArg(1, FALSE, windowRecord->windowIndex);

    // Optionally return the windows clientrect:
    PsychCopyOutRectArg(2, FALSE, windowRecord->clientrect);

    return(PsychError_none);   
}