/* static */
bool wxGLCanvasBase::IsExtensionSupported(const char *extension)
{
static const char *s_extensionsList = (char *)wxUIntPtr(-1);
if ( s_extensionsList == (char *)wxUIntPtr(-1) )
{
typedef const char * (WINAPI *wglGetExtensionsStringARB_t)(HDC hdc);
wxDEFINE_WGL_FUNC(wglGetExtensionsStringARB);
if ( wglGetExtensionsStringARB )
{
s_extensionsList = wglGetExtensionsStringARB(wglGetCurrentDC());
}
else
{
typedef const char * (WINAPI * wglGetExtensionsStringEXT_t)();
wxDEFINE_WGL_FUNC(wglGetExtensionsStringEXT);
if ( wglGetExtensionsStringEXT )
{
s_extensionsList = wglGetExtensionsStringEXT();
}
else
{
s_extensionsList = NULL;
}
}
}
return s_extensionsList && IsExtensionInList(s_extensionsList, extension);
}
// this is a wrapper around wglChoosePixelFormatARB(): returns the pixel format
// index matching the given attributes on success or 0 on failure
static int ChoosePixelFormatARB(HDC hdc, const int *attribList)
{
if ( !wxGLCanvas::IsExtensionSupported("WGL_ARB_multisample") )
return 0;
typedef BOOL (WINAPI * wglChoosePixelFormatARB_t)
(HDC hdc,
const int *piAttribIList,
const FLOAT *pfAttribFList,
UINT nMaxFormats,
int *piFormats,
UINT *nNumFormats
);
wxDEFINE_WGL_FUNC(wglChoosePixelFormatARB);
if ( !wglChoosePixelFormatARB )
return 0; // should not occur if extension is supported
int iAttributes[128];
int dst = 0; // index in iAttributes array
#define ADD_ATTR(attr, value) \
iAttributes[dst++] = attr; iAttributes[dst++] = value
ADD_ATTR( WGL_DRAW_TO_WINDOW_ARB, GL_TRUE );
ADD_ATTR( WGL_SUPPORT_OPENGL_ARB, GL_TRUE );
ADD_ATTR( WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB );
if ( !attribList )
{
ADD_ATTR( WGL_COLOR_BITS_ARB, 24 );
ADD_ATTR( WGL_ALPHA_BITS_ARB, 8 );
ADD_ATTR( WGL_DEPTH_BITS_ARB, 16 );
ADD_ATTR( WGL_STENCIL_BITS_ARB, 0 );
ADD_ATTR( WGL_DOUBLE_BUFFER_ARB, GL_TRUE );
ADD_ATTR( WGL_SAMPLE_BUFFERS_ARB, GL_TRUE );
ADD_ATTR( WGL_SAMPLES_ARB, 4 );
}
else // have custom attributes
{
#define ADD_ATTR_VALUE(attr) ADD_ATTR(attr, attribList[src++])
int src = 0;
while ( attribList[src] )
{
switch ( attribList[src++] )
{
case WX_GL_RGBA:
ADD_ATTR( WGL_COLOR_BITS_ARB, 24 );
ADD_ATTR( WGL_ALPHA_BITS_ARB, 8 );
break;
case WX_GL_BUFFER_SIZE:
ADD_ATTR_VALUE( WGL_COLOR_BITS_ARB);
break;
case WX_GL_LEVEL:
if ( attribList[src] > 0 )
{
ADD_ATTR( WGL_NUMBER_OVERLAYS_ARB, 1 );
}
else if ( attribList[src] <0 )
{
ADD_ATTR( WGL_NUMBER_UNDERLAYS_ARB, 1 );
}
//else: ignore it
src++; // skip the value in any case
break;
case WX_GL_DOUBLEBUFFER:
ADD_ATTR( WGL_DOUBLE_BUFFER_ARB, GL_TRUE );
break;
case WX_GL_STEREO:
ADD_ATTR( WGL_STEREO_ARB, GL_TRUE );
break;
case WX_GL_AUX_BUFFERS:
ADD_ATTR_VALUE( WGL_AUX_BUFFERS_ARB );
break;
case WX_GL_MIN_RED:
ADD_ATTR_VALUE( WGL_RED_BITS_ARB );
break;
case WX_GL_MIN_GREEN:
ADD_ATTR_VALUE( WGL_GREEN_BITS_ARB );
break;
case WX_GL_MIN_BLUE:
ADD_ATTR_VALUE( WGL_BLUE_BITS_ARB );
break;
case WX_GL_MIN_ALPHA:
ADD_ATTR_VALUE( WGL_ALPHA_BITS_ARB );
break;
case WX_GL_DEPTH_SIZE:
ADD_ATTR_VALUE( WGL_DEPTH_BITS_ARB );
break;
case WX_GL_STENCIL_SIZE:
ADD_ATTR_VALUE( WGL_STENCIL_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_RED:
ADD_ATTR_VALUE( WGL_ACCUM_RED_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_GREEN:
ADD_ATTR_VALUE( WGL_ACCUM_GREEN_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_BLUE:
ADD_ATTR_VALUE( WGL_ACCUM_BLUE_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_ALPHA:
ADD_ATTR_VALUE( WGL_ACCUM_ALPHA_BITS_ARB );
break;
case WX_GL_SAMPLE_BUFFERS:
ADD_ATTR_VALUE( WGL_SAMPLE_BUFFERS_ARB );
break;
case WX_GL_SAMPLES:
ADD_ATTR_VALUE( WGL_SAMPLES_ARB );
break;
}
}
#undef ADD_ATTR_VALUE
}
#undef ADD_ATTR
iAttributes[dst++] = 0;
int pf;
UINT numFormats = 0;
if ( !wglChoosePixelFormatARB(hdc, iAttributes, NULL, 1, &pf, &numFormats) )
{
wxLogLastError(_T("wglChoosePixelFormatARB"));
return 0;
}
return pf;
}
// this is a wrapper around wglChoosePixelFormatARB(): returns the pixel format
// index matching the given attributes on success or 0 on failure
static int ChoosePixelFormatARB(HDC hdc, const int *attribList)
{
if ( !wxGLCanvas::IsExtensionSupported("WGL_ARB_multisample") )
return 0;
typedef BOOL (WINAPI * wglChoosePixelFormatARB_t)
(HDC hdc,
const int *piAttribIList,
const FLOAT *pfAttribFList,
UINT nMaxFormats,
int *piFormats,
UINT *nNumFormats
);
wxDEFINE_WGL_FUNC(wglChoosePixelFormatARB);
if ( !wglChoosePixelFormatARB )
return 0; // should not occur if extension is supported
int iAttributes[128];
int dst = 0; // index in iAttributes array
#define ADD_ATTR(attr, value) \
iAttributes[dst++] = attr; iAttributes[dst++] = value
ADD_ATTR( WGL_DRAW_TO_WINDOW_ARB, GL_TRUE );
ADD_ATTR( WGL_SUPPORT_OPENGL_ARB, GL_TRUE );
ADD_ATTR( WGL_ACCELERATION_ARB, WGL_FULL_ACCELERATION_ARB );
if ( !attribList )
{
ADD_ATTR( WGL_COLOR_BITS_ARB, 24 );
ADD_ATTR( WGL_ALPHA_BITS_ARB, 8 );
ADD_ATTR( WGL_DEPTH_BITS_ARB, 16 );
ADD_ATTR( WGL_STENCIL_BITS_ARB, 0 );
ADD_ATTR( WGL_DOUBLE_BUFFER_ARB, GL_TRUE );
ADD_ATTR( WGL_SAMPLE_BUFFERS_ARB, GL_TRUE );
ADD_ATTR( WGL_SAMPLES_ARB, 4 );
}
else // have custom attributes
{
#define ADD_ATTR_VALUE(attr) ADD_ATTR(attr, attribList[src++])
int src = 0;
while ( attribList[src] )
{
switch ( attribList[src++] )
{
case WX_GL_RGBA:
ADD_ATTR( WGL_COLOR_BITS_ARB, 24 );
ADD_ATTR( WGL_ALPHA_BITS_ARB, 8 );
break;
case WX_GL_BUFFER_SIZE:
ADD_ATTR_VALUE( WGL_COLOR_BITS_ARB);
break;
case WX_GL_LEVEL:
if ( attribList[src] > 0 )
{
ADD_ATTR( WGL_NUMBER_OVERLAYS_ARB, 1 );
}
else if ( attribList[src] <0 )
{
ADD_ATTR( WGL_NUMBER_UNDERLAYS_ARB, 1 );
}
//else: ignore it
src++; // skip the value in any case
break;
case WX_GL_DOUBLEBUFFER:
ADD_ATTR( WGL_DOUBLE_BUFFER_ARB, GL_TRUE );
break;
case WX_GL_STEREO:
ADD_ATTR( WGL_STEREO_ARB, GL_TRUE );
break;
case WX_GL_AUX_BUFFERS:
ADD_ATTR_VALUE( WGL_AUX_BUFFERS_ARB );
break;
case WX_GL_MIN_RED:
ADD_ATTR_VALUE( WGL_RED_BITS_ARB );
break;
case WX_GL_MIN_GREEN:
ADD_ATTR_VALUE( WGL_GREEN_BITS_ARB );
break;
case WX_GL_MIN_BLUE:
ADD_ATTR_VALUE( WGL_BLUE_BITS_ARB );
break;
case WX_GL_MIN_ALPHA:
ADD_ATTR_VALUE( WGL_ALPHA_BITS_ARB );
break;
case WX_GL_DEPTH_SIZE:
ADD_ATTR_VALUE( WGL_DEPTH_BITS_ARB );
break;
case WX_GL_STENCIL_SIZE:
ADD_ATTR_VALUE( WGL_STENCIL_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_RED:
ADD_ATTR_VALUE( WGL_ACCUM_RED_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_GREEN:
ADD_ATTR_VALUE( WGL_ACCUM_GREEN_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_BLUE:
ADD_ATTR_VALUE( WGL_ACCUM_BLUE_BITS_ARB );
break;
case WX_GL_MIN_ACCUM_ALPHA:
ADD_ATTR_VALUE( WGL_ACCUM_ALPHA_BITS_ARB );
break;
case WX_GL_SAMPLE_BUFFERS:
ADD_ATTR_VALUE( WGL_SAMPLE_BUFFERS_ARB );
break;
case WX_GL_SAMPLES:
ADD_ATTR_VALUE( WGL_SAMPLES_ARB );
break;
}
}
#undef ADD_ATTR_VALUE
}
#undef ADD_ATTR
iAttributes[dst++] = 0;
int pf;
UINT numFormats = 0;
if ( !wglChoosePixelFormatARB(hdc, iAttributes, NULL, 1, &pf, &numFormats) )
{
wxLogLastError(wxT("wglChoosePixelFormatARB"));
return 0;
}
// Although TRUE is returned if no matching formats are found (see
// http://www.opengl.org/registry/specs/ARB/wgl_pixel_format.txt), pf is
// not initialized in this case so we need to check for numFormats being
// not 0 explicitly (however this is not an error so don't call
// wxLogLastError() here).
if ( !numFormats )
pf = 0;
return pf;
}
