GLXContext
CreateContext(Display *dpy, int screen, FBCONFIG config)
{
int pbSupport = QueryPbuffers(dpy, screen);
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
/* GLX 1.3 */
GLXContext c;
c = glXCreateNewContext(dpy, config, GLX_RGBA_TYPE, NULL, True);
if (!c) {
/* try indirect */
c = glXCreateNewContext(dpy, config, GLX_RGBA_TYPE, NULL, False);
}
return c;
}
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
GLXContext c;
c = glXCreateContextWithConfigSGIX(dpy, config, GLX_RGBA_TYPE_SGIX, NULL, True);
if (!c) {
c = glXCreateContextWithConfigSGIX(dpy, config, GLX_RGBA_TYPE_SGIX, NULL, False);
}
return c;
}
#endif
return 0;
}
/**
* Either use glXGetFBConfigAttrib() or glXGetFBConfigAttribSGIX()
* to query an fbconfig attribute.
*/
static int
GetFBConfigAttrib(Display *dpy, int screen,
#if defined(GLX_VERSION_1_3)
const GLXFBConfig config,
#elif defined(GLX_SGIX_fbconfig)
const GLXFBConfigSGIX config,
#endif
int attrib
)
{
int pbSupport = QueryPbuffers(dpy, screen);
int value = 0;
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
/* ok */
if (glXGetFBConfigAttrib(dpy, config, attrib, &value) != 0) {
value = 0;
}
return value;
}
/* fall-through */
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
if (glXGetFBConfigAttribSGIX(dpy, config, attrib, &value) != 0) {
value = 0;
}
return value;
}
#endif
return value;
}
/**
* Create a Pbuffer. Use an X error handler to deal with potential
* BadAlloc errors.
*
* Input: dpy - the X display
* fbConfig - an FBConfig as returned by glXChooseFBConfigSGIX().
* width, height - size of pixel buffer to request, in pixels.
* pbAttribs - list of optional pixel buffer attributes
* Return: a Pbuffer or None.
*/
PBUFFER
CreatePbuffer(Display *dpy, int screen, FBCONFIG config,
int width, int height, Bool largest, Bool preserve)
{
int (*oldHandler)(Display *, XErrorEvent *);
PBUFFER pBuffer = None;
int pbSupport = QueryPbuffers(dpy, screen);
/* Catch X protocol errors with our own error handler */
oldHandler = XSetErrorHandler(HandleXError);
XErrorFlag = 0;
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
/* GLX 1.3 */
int attribs[100], i = 0;
attribs[i++] = GLX_PBUFFER_WIDTH;
attribs[i++] = width;
attribs[i++] = GLX_PBUFFER_HEIGHT;
attribs[i++] = height;
attribs[i++] = GLX_PRESERVED_CONTENTS;
attribs[i++] = preserve;
attribs[i++] = GLX_LARGEST_PBUFFER;
attribs[i++] = largest;
attribs[i++] = 0;
pBuffer = glXCreatePbuffer(dpy, config, attribs);
}
else
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
int attribs[100], i = 0;
attribs[i++] = GLX_PRESERVED_CONTENTS;
attribs[i++] = preserve;
attribs[i++] = GLX_LARGEST_PBUFFER;
attribs[i++] = largest;
attribs[i++] = 0;
pBuffer = glXCreateGLXPbufferSGIX(dpy, config, width, height, attribs);
}
else
#endif
{
pBuffer = None;
}
/* Restore original X error handler */
(void) XSetErrorHandler(oldHandler);
/* Return pbuffer (may be None) */
if (!XErrorFlag && pBuffer != None) {
/*printf("config %d worked!\n", i);*/
return pBuffer;
}
else {
return None;
}
}
FBCONFIG *
ChooseFBConfig(Display *dpy, int screen, const int attribs[], int *nConfigs)
{
int pbSupport = QueryPbuffers(dpy, screen);
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
return glXChooseFBConfig(dpy, screen, attribs, nConfigs);
}
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
return glXChooseFBConfigSGIX(dpy, screen, (int *) attribs, nConfigs);
}
#endif
return NULL;
}
XVisualInfo *
GetVisualFromFBConfig(Display *dpy, int screen, FBCONFIG config)
{
int pbSupport = QueryPbuffers(dpy, screen);
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
return glXGetVisualFromFBConfig(dpy, config);
}
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
return glXGetVisualFromFBConfigSGIX(dpy, config);
}
#endif
return NULL;
}
void
DestroyPbuffer(Display *dpy, int screen, PBUFFER pbuffer)
{
int pbSupport = QueryPbuffers(dpy, screen);
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
glXDestroyPbuffer(dpy, pbuffer);
return;
}
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
glXDestroyGLXPbufferSGIX(dpy, pbuffer);
return;
}
#endif
}
FBCONFIG *
GetAllFBConfigs(Display *dpy, int screen, int *nConfigs)
{
int pbSupport = QueryPbuffers(dpy, screen);
#if defined(GLX_VERSION_1_3)
if (pbSupport == 1) {
return glXGetFBConfigs(dpy, screen, nConfigs);
}
#endif
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
if (pbSupport == 2) {
/* The GLX_SGIX_fbconfig extensions says to pass NULL to get list
* of all available configurations.
*/
return glXChooseFBConfigSGIX(dpy, screen, NULL, nConfigs);
}
#endif
return NULL;
}
/*
* Do all the X / GLX setup stuff.
*/
static int
Setup(int width, int height)
{
#if defined(GLX_SGIX_fbconfig) && defined(GLX_SGIX_pbuffer)
XVisualInfo *visInfo;
GLXContext glCtx;
/* Open the X display */
gDpy = XOpenDisplay(NULL);
if (!gDpy) {
printf("Error: couldn't open default X display.\n");
return 0;
}
/* Get default screen */
gScreen = DefaultScreen(gDpy);
/* Test that pbuffers are available */
if (!QueryPbuffers(gDpy, gScreen)) {
printf("Error: pbuffers not available on this screen\n");
XCloseDisplay(gDpy);
return 0;
}
/* Create Pbuffer */
gPBuffer = MakePbuffer( gDpy, gScreen, width, height );
if (gPBuffer==None) {
printf("Error: couldn't create pbuffer\n");
XCloseDisplay(gDpy);
return 0;
}
/* Get corresponding XVisualInfo */
visInfo = glXGetVisualFromFBConfigSGIX(gDpy, gFBconfig);
if (!visInfo) {
printf("Error: can't get XVisualInfo from FBconfig\n");
XCloseDisplay(gDpy);
return 0;
}
/* Create GLX context */
glCtx = glXCreateContext(gDpy, visInfo, NULL, True);
if (!glCtx) {
/* try indirect */
glCtx = glXCreateContext(gDpy, visInfo, NULL, False);
if (!glCtx) {
printf("Error: Couldn't create GLXContext\n");
XFree(visInfo);
XCloseDisplay(gDpy);
return 0;
}
else {
printf("Warning: using indirect GLXContext\n");
}
}
/* Bind context to pbuffer */
if (!glXMakeCurrent(gDpy, gPBuffer, glCtx)) {
printf("Error: glXMakeCurrent failed\n");
XFree(visInfo);
XCloseDisplay(gDpy);
return 0;
}
return 1; /* Success!! */
#else
printf("Error: GLX_SGIX_fbconfig and/or GLX_SGIX_pbuffer extensions not"
" available at compile-time.\n");
return 0;
#endif
}
