static bool GLimp_SetPixelFormat()
{
static const PIXELFORMATDESCRIPTOR pfdBase =
{
sizeof(PIXELFORMATDESCRIPTOR),
1, // version number
PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA, // RGBA type
24, // 24-bit color depth
0, 0, 0, 0, 0, 0, // color bits ignored
0, // no alpha buffer
0, // shift bit ignored
0, // no accumulation buffer
0, 0, 0, 0, // accum bits ignored
32, // 32-bit z-buffer
0, // no stencil buffer
0, // no auxiliary buffer
PFD_MAIN_PLANE, // main layer
0, // reserved
0, 0, 0 // layer masks ignored
};
int pixelformat;
if ((pixelformat = wglChoosePixelFormat(gl_hDC, &pfdBase)) == 0)
{
ErrFail("(wgl)ChoosePixelFormat()");
return false;
}
if (wglSetPixelFormat(gl_hDC, pixelformat, &pfdBase) == FALSE)
{
ErrFail("(wgl)SetPixelFormat()");
return false;
}
PIXELFORMATDESCRIPTOR pfd;
wglDescribePixelFormat(gl_hDC, pixelformat, sizeof(pfd), &pfd);
// startup the OpenGL subsystem by creating a context and making it current
if (!CreateGLcontext()) return false;
if (!ActivateGLcontext()) return false;
if (!(pfd.dwFlags & PFD_GENERIC_ACCELERATED) && (pfd.dwFlags & PFD_GENERIC_FORMAT))
{
appWPrintf("...no hardware acceleration detected\n");
return false;
}
// print PFD info
appPrintf("Pixelformat %d: color:%d depth:%d\n", pixelformat, pfd.cColorBits, pfd.cDepthBits);
return true;
}
WINGDIAPI int WINAPI DrvDescribePixelFormat(HDC hdc, int pixelFormat, UINT numBytes, LPPIXELFORMATDESCRIPTOR ppFD)
{
return wglDescribePixelFormat(hdc, pixelFormat, numBytes, ppFD);
}
INT WINAPI wglChoosePixelFormat(HDC hdc, const PIXELFORMATDESCRIPTOR* ppfd)
{
PIXELFORMATDESCRIPTOR format, best;
int i, count, best_format;
int bestDBuffer = -1, bestStereo = -1;
TRACE_(wgl)( "%p %p: size %u version %u flags %u type %u color %u %u,%u,%u,%u "
"accum %u depth %u stencil %u aux %u\n",
hdc, ppfd, ppfd->nSize, ppfd->nVersion, ppfd->dwFlags, ppfd->iPixelType,
ppfd->cColorBits, ppfd->cRedBits, ppfd->cGreenBits, ppfd->cBlueBits, ppfd->cAlphaBits,
ppfd->cAccumBits, ppfd->cDepthBits, ppfd->cStencilBits, ppfd->cAuxBuffers );
count = wglDescribePixelFormat( hdc, 0, 0, NULL );
if (!count) return 0;
best_format = 0;
best.dwFlags = PFD_GENERIC_FORMAT;
best.cAlphaBits = -1;
best.cColorBits = -1;
best.cDepthBits = -1;
best.cStencilBits = -1;
best.cAuxBuffers = -1;
for (i = 1; i <= count; i++)
{
if (!wglDescribePixelFormat( hdc, i, sizeof(format), &format )) continue;
if (ppfd->iPixelType != format.iPixelType)
{
TRACE( "pixel type mismatch for iPixelFormat=%d\n", i );
continue;
}
/* only use bitmap capable formats for bitmap rendering */
if ((ppfd->dwFlags & PFD_DRAW_TO_BITMAP) != (format.dwFlags & PFD_DRAW_TO_BITMAP))
{
TRACE( "PFD_DRAW_TO_BITMAP mismatch for iPixelFormat=%d\n", i );
continue;
}
/* only use window capable formats for window rendering */
if ((ppfd->dwFlags & PFD_DRAW_TO_WINDOW) != (format.dwFlags & PFD_DRAW_TO_WINDOW))
{
TRACE( "PFD_DRAW_TO_WINDOW mismatch for iPixelFormat=%d\n", i );
continue;
}
/* only use opengl capable formats for opengl rendering */
if ((ppfd->dwFlags & PFD_SUPPORT_OPENGL) != (format.dwFlags & PFD_SUPPORT_OPENGL))
{
TRACE( "PFD_SUPPORT_OPENGL mismatch for iPixelFormat=%d\n", i );
continue;
}
/* only use GDI capable formats for GDI rendering */
if ((ppfd->dwFlags & PFD_SUPPORT_GDI) != (format.dwFlags & PFD_SUPPORT_GDI))
{
TRACE( "PFD_SUPPORT_GDI mismatch for iPixelFormat=%d\n", i );
continue;
}
/* The behavior of PDF_STEREO/PFD_STEREO_DONTCARE and PFD_DOUBLEBUFFER / PFD_DOUBLEBUFFER_DONTCARE
* is not very clear on MSDN. They specify that ChoosePixelFormat tries to match pixel formats
* with the flag (PFD_STEREO / PFD_DOUBLEBUFFERING) set. Otherwise it says that it tries to match
* formats without the given flag set.
* A test on Windows using a Radeon 9500pro on WinXP (the driver doesn't support Stereo)
* has indicated that a format without stereo is returned when stereo is unavailable.
* So in case PFD_STEREO is set, formats that support it should have priority above formats
* without. In case PFD_STEREO_DONTCARE is set, stereo is ignored.
*
* To summarize the following is most likely the correct behavior:
* stereo not set -> prefer non-stereo formats, but also accept stereo formats
* stereo set -> prefer stereo formats, but also accept non-stereo formats
* stereo don't care -> it doesn't matter whether we get stereo or not
*
* In Wine we will treat non-stereo the same way as don't care because it makes
* format selection even more complicated and second drivers with Stereo advertise
* each format twice anyway.
*/
/* Doublebuffer, see the comments above */
if (!(ppfd->dwFlags & PFD_DOUBLEBUFFER_DONTCARE))
{
if (((ppfd->dwFlags & PFD_DOUBLEBUFFER) != bestDBuffer) &&
((format.dwFlags & PFD_DOUBLEBUFFER) == (ppfd->dwFlags & PFD_DOUBLEBUFFER)))
goto found;
if (bestDBuffer != -1 && (format.dwFlags & PFD_DOUBLEBUFFER) != bestDBuffer) continue;
}
/* Stereo, see the comments above. */
if (!(ppfd->dwFlags & PFD_STEREO_DONTCARE))
{
if (((ppfd->dwFlags & PFD_STEREO) != bestStereo) &&
((format.dwFlags & PFD_STEREO) == (ppfd->dwFlags & PFD_STEREO)))
goto found;
if (bestStereo != -1 && (format.dwFlags & PFD_STEREO) != bestStereo) continue;
}
/* Below we will do a number of checks to select the 'best' pixelformat.
* We assume the precedence cColorBits > cAlphaBits > cDepthBits > cStencilBits -> cAuxBuffers.
* The code works by trying to match the most important options as close as possible.
* When a reasonable format is found, we will try to match more options.
* It appears (see the opengl32 test) that Windows opengl drivers ignore options
* like cColorBits, cAlphaBits and friends if they are set to 0, so they are considered
* as DONTCARE. At least Serious Sam TSE relies on this behavior. */
if (ppfd->cColorBits)
{
if (((ppfd->cColorBits > best.cColorBits) && (format.cColorBits > best.cColorBits)) ||
((format.cColorBits >= ppfd->cColorBits) && (format.cColorBits < best.cColorBits)))
goto found;
if (best.cColorBits != format.cColorBits) /* Do further checks if the format is compatible */
{
TRACE( "color mismatch for iPixelFormat=%d\n", i );
continue;
}
}
if (ppfd->cAlphaBits)
{
if (((ppfd->cAlphaBits > best.cAlphaBits) && (format.cAlphaBits > best.cAlphaBits)) ||
((format.cAlphaBits >= ppfd->cAlphaBits) && (format.cAlphaBits < best.cAlphaBits)))
goto found;
if (best.cAlphaBits != format.cAlphaBits)
{
TRACE( "alpha mismatch for iPixelFormat=%d\n", i );
continue;
}
}
if (ppfd->cDepthBits)
{
if (((ppfd->cDepthBits > best.cDepthBits) && (format.cDepthBits > best.cDepthBits)) ||
((format.cDepthBits >= ppfd->cDepthBits) && (format.cDepthBits < best.cDepthBits)))
goto found;
if (best.cDepthBits != format.cDepthBits)
{
TRACE( "depth mismatch for iPixelFormat=%d\n", i );
continue;
}
}
if (ppfd->cStencilBits)
{
if (((ppfd->cStencilBits > best.cStencilBits) && (format.cStencilBits > best.cStencilBits)) ||
((format.cStencilBits >= ppfd->cStencilBits) && (format.cStencilBits < best.cStencilBits)))
goto found;
if (best.cStencilBits != format.cStencilBits)
{
TRACE( "stencil mismatch for iPixelFormat=%d\n", i );
continue;
}
}
if (ppfd->cAuxBuffers)
{
if (((ppfd->cAuxBuffers > best.cAuxBuffers) && (format.cAuxBuffers > best.cAuxBuffers)) ||
((format.cAuxBuffers >= ppfd->cAuxBuffers) && (format.cAuxBuffers < best.cAuxBuffers)))
goto found;
if (best.cAuxBuffers != format.cAuxBuffers)
{
TRACE( "aux mismatch for iPixelFormat=%d\n", i );
continue;
}
}
continue;
found:
/* Prefer HW accelerated formats */
if ((format.dwFlags & PFD_GENERIC_FORMAT) && !(best.dwFlags & PFD_GENERIC_FORMAT))
continue;
best_format = i;
best = format;
bestDBuffer = format.dwFlags & PFD_DOUBLEBUFFER;
bestStereo = format.dwFlags & PFD_STEREO;
}
TRACE( "returning %u\n", best_format );
return best_format;
}