//draw a frame
void RenderFrame()
{
//Draw to pbuffer
pbuffer.MakeCurrent();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity(); //reset modelview matrix
gluLookAt( 0.0f, 0.0f, 4.0f,
0.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f);
//Draw scene
if(drawTextured)
{
glBindTexture(GL_TEXTURE_2D, decalTexture);
glEnable(GL_TEXTURE_2D);
glPushMatrix();
glRotatef(timer.GetTime()/20, 0.0f, 1.0f, 0.0f);
glutSolidTeapot(0.8f);
glPopMatrix();
glDisable(GL_TEXTURE_2D);
}
else
{
glPushMatrix();
glRotatef(timer.GetTime()/20, 0.0f, 1.0f, 0.0f);
glRotatef(55.0f, 1.0f, 0.0f, 0.0f);
glutWireTorus(0.3f, 1.0f, 12, 24);
glPopMatrix();
glPushMatrix();
glRotatef(timer.GetTime()/20, 0.0f, 1.0f, 0.0f);
glRotatef(-55.0f, 1.0f, 0.0f, 0.0f);
glutWireTorus(0.3f, 1.0f, 12, 24);
glPopMatrix();
}
//Draw to window
window.MakeCurrent();
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
camera.SetupViewMatrix();
glLoadMatrixf(camera.viewMatrix);
glBindTexture(GL_TEXTURE_2D, pbufferTexture);
//use the pbuffer as the texture
wglBindTexImageARB(pbuffer.hBuffer, WGL_FRONT_LEFT_ARB);
//Draw simple rectangle
glBegin(GL_TRIANGLE_STRIP);
{
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, 0.0f);
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-1.0f, 1.0f, 0.0f);
glTexCoord2f(1.0f, 0.0f);
glVertex3f( 1.0f, -1.0f, 0.0f);
glTexCoord2f(1.0f, 1.0f);
glVertex3f( 1.0f, 1.0f, 0.0f);
}
glEnd();
//release the pbuffer for further rendering
wglReleaseTexImageARB(pbuffer.hBuffer, WGL_FRONT_LEFT_ARB);
fpsCounter.Update(); //update frames per second counter
glColor4f(1.0f, 1.0f, 0.0f, 1.0f);
window.StartTextMode();
window.Print(0, 28, "FPS: %.2f", fpsCounter.GetFps()); //print the fps
glColor4f(1.0f, 0.0f, 0.0f, 1.0f);
window.Print(0, 48, "%dx Anisotropy", currentAnisotropy);
glColor4f(0.0f, 1.0f, 0.0f, 1.0f);
window.Print(0, 68, "%s", useMipmapFilter ? "LINEAR_MIPMAP_LINEAR filtering" :
"LINEAR filtering");
window.EndTextMode();
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
if(window.isKeyPressed(VK_F1))
{
window.SaveScreenshot();
window.SetKeyReleased(VK_F1);
}
window.SwapBuffers(); //swap buffers
//check for any opengl errors
window.CheckGLError();
//quit if necessary
if(window.isKeyPressed(VK_ESCAPE))
PostQuitMessage(0);
}
//Set up variables
bool DemoInit()
{
if(!window.Init("Render To Texture", 640, 480, 32, 24, 8, WINDOWED_SCREEN))
return 0; //quit if not created
camera.Init(VECTOR3D(0.0f, 0.0f, -2.5f), 2.0f, 100.0f);
//Set up extensions
if( !SetUpWGL_ARB_extensions_string())
return false;
SetUpEXT_texture_filter_anisotropic();
SetUpSGIS_generate_mipmap();
//Get the WGL extensions string
const char * wglExtensions;
wglExtensions=wglGetExtensionsStringARB(window.hDC);
//Set up wgl extensions
if( !SetUpWGL_ARB_pbuffer(wglExtensions) || !SetUpWGL_ARB_pixel_format(wglExtensions) ||
!SetUpWGL_ARB_render_texture(wglExtensions))
return false;
//Init the pbuffer
int pbufferExtraIAttribs[]={WGL_BIND_TO_TEXTURE_RGBA_ARB, true,
0};
int pbufferFlags[]={WGL_TEXTURE_FORMAT_ARB, WGL_TEXTURE_RGBA_ARB,
WGL_TEXTURE_TARGET_ARB, WGL_TEXTURE_2D_ARB,
//request mipmap space if mipmaps are to be used
SGIS_generate_mipmap_supported ? WGL_MIPMAP_TEXTURE_ARB : 0,
SGIS_generate_mipmap_supported ? true : 0,
0};
if(!pbuffer.Init(pbufferSize, pbufferSize, 32, 24, 8, 1, pbufferExtraIAttribs, pbufferFlags))
return false;
//Create the texture object to relate to the pbuffer
glGenTextures(1, &pbufferTexture);
glBindTexture(GL_TEXTURE_2D, pbufferTexture);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//Use generated mipmaps if supported
if(SGIS_generate_mipmap_supported)
{
glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP_SGIS, true);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glHint(GL_GENERATE_MIPMAP_HINT_SGIS, GL_NICEST);
useMipmapFilter=true;
}
//Use maximum anisotropy if supported
if(EXT_texture_filter_anisotropic_supported)
{
glGetIntegerv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maxAnisotropy);
currentAnisotropy=maxAnisotropy;
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, currentAnisotropy);
}
//Load the decal texture
//Note: This MUST be done when the pbuffer is the current context
pbuffer.MakeCurrent();
IMAGE decalImage;
decalImage.Load("decal.bmp");
glGenTextures(1, &decalTexture);
glBindTexture(GL_TEXTURE_2D, decalTexture);
glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA8, decalImage.width, decalImage.height,
0, decalImage.format, GL_UNSIGNED_BYTE, decalImage.data);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
//reset timer for start
timer.Reset();
return true;
}
//Set up openGL
bool GLInit()
{
//Set up for pbuffer
pbuffer.MakeCurrent();
//set viewport
glViewport(0, 0, pbufferSize, pbufferSize);
//set up projection matrix
glMatrixMode(GL_PROJECTION); //select projection matrix
glLoadIdentity(); //reset
gluPerspective(45.0f, 1.0f, 1.0f, 100.0f);
//load identity modelview
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//other states
//shading
glShadeModel(GL_SMOOTH);
glClearColor( pbufferBackgroundColor.r,
pbufferBackgroundColor.g,
pbufferBackgroundColor.b,
pbufferBackgroundColor.a);
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
//depth
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
//hints
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
//Set up for window
window.MakeCurrent();
//set viewport
int height;
if (window.height==0)
height=1;
else
height=window.height;
glViewport(0, 0, window.width, height); //reset viewport
//set up projection matrix
glMatrixMode(GL_PROJECTION); //select projection matrix
glLoadIdentity(); //reset
gluPerspective(45.0f, (GLfloat)window.width/(GLfloat)height, 1.0f, 100.0f);
//load identity modelview
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
//other states
//shading
glShadeModel(GL_SMOOTH);
glClearColor( windowBackgroundColor.r,
windowBackgroundColor.g,
windowBackgroundColor.b,
windowBackgroundColor.a);
glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
//depth
glClearDepth(1.0f);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
//hints
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
glEnable(GL_TEXTURE_2D);
return true;
}
