bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)
{
QGLTemporaryContext tempContext;
PFNWGLCREATEPBUFFERARBPROC wglCreatePbufferARB =
(PFNWGLCREATEPBUFFERARBPROC) wglGetProcAddress("wglCreatePbufferARB");
PFNWGLGETPBUFFERDCARBPROC wglGetPbufferDCARB =
(PFNWGLGETPBUFFERDCARBPROC) wglGetProcAddress("wglGetPbufferDCARB");
PFNWGLQUERYPBUFFERARBPROC wglQueryPbufferARB =
(PFNWGLQUERYPBUFFERARBPROC) wglGetProcAddress("wglQueryPbufferARB");
PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormatARB =
(PFNWGLCHOOSEPIXELFORMATARBPROC) wglGetProcAddress("wglChoosePixelFormatARB");
if (!wglCreatePbufferARB) // assumes that if one can be resolved, all of them can
return false;
dc = wglGetCurrentDC();
Q_ASSERT(dc);
has_render_texture = false;
// sample buffers doesn't work in conjunction with the render_texture extension
if (!f.sampleBuffers()) {
PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB =
(PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");
if (wglGetExtensionsStringARB) {
QString extensions(QLatin1String(wglGetExtensionsStringARB(dc)));
has_render_texture = extensions.contains(QLatin1String("WGL_ARB_render_texture"));
}
}
int attribs[40];
qt_format_to_attrib_list(has_render_texture, f, attribs);
// Find pbuffer capable pixel format.
unsigned int num_formats = 0;
int pixel_format;
wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);
// some GL implementations don't support pbuffers with accum
// buffers, so try that before we give up
if (num_formats == 0 && f.accum()) {
QGLFormat tmp = f;
tmp.setAccum(false);
qt_format_to_attrib_list(has_render_texture, tmp, attribs);
wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);
}
if (num_formats == 0) {
qWarning("QGLPixelBuffer: Unable to find a pixel format with pbuffer - giving up.");
return false;
}
format = pfiToQGLFormat(dc, pixel_format);
// NB! The below ONLY works if the width/height are powers of 2.
// Set some pBuffer attributes so that we can use this pBuffer as
// a 2D RGBA texture target.
int pb_attribs[] = {WGL_TEXTURE_FORMAT_ARB, WGL_TEXTURE_RGBA_ARB,
WGL_TEXTURE_TARGET_ARB, WGL_TEXTURE_2D_ARB, 0};
int pb_attribs_null[] = {0};
pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(),
has_render_texture ? pb_attribs : pb_attribs_null);
if (!pbuf) {
// try again without the render_texture extension
pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(), pb_attribs_null);
has_render_texture = false;
if (!pbuf) {
qWarning("QGLPixelBuffer: Unable to create pbuffer [w=%d, h=%d] - giving up.", size.width(), size.height());
return false;
}
}
dc = wglGetPbufferDCARB(pbuf);
ctx = wglCreateContext(dc);
if (!dc || !ctx) {
qWarning("QGLPixelBuffer: Unable to create pbuffer context - giving up.");
return false;
}
// Explicitly disable the render_texture extension if we have a
// multi-sampled pbuffer context. This seems to be a problem only with
// ATI cards if multi-sampling is forced globally in the driver.
wglMakeCurrent(dc, ctx);
GLint samples = 0;
glGetIntegerv(GL_SAMPLES_ARB, &samples);
if (has_render_texture && samples != 0)
has_render_texture = false;
HGLRC share_ctx = shareWidget ? shareWidget->d_func()->glcx->d_func()->rc : 0;
if (share_ctx && !wglShareLists(share_ctx, ctx))
qWarning("QGLPixelBuffer: Unable to share display lists - with share widget.");
int width, height;
wglQueryPbufferARB(pbuf, WGL_PBUFFER_WIDTH_ARB, &width);
wglQueryPbufferARB(pbuf, WGL_PBUFFER_HEIGHT_ARB, &height);
return true;
}
bool QGLPixelBufferPrivate::init(const QSize &size, const QGLFormat &f, QGLWidget *shareWidget)
{
QGLWidget dmy;
dmy.makeCurrent(); // needed for wglGetProcAddress() to succeed
PFNWGLCREATEPBUFFERARBPROC wglCreatePbufferARB =
(PFNWGLCREATEPBUFFERARBPROC) wglGetProcAddress("wglCreatePbufferARB");
PFNWGLGETPBUFFERDCARBPROC wglGetPbufferDCARB =
(PFNWGLGETPBUFFERDCARBPROC) wglGetProcAddress("wglGetPbufferDCARB");
PFNWGLQUERYPBUFFERARBPROC wglQueryPbufferARB =
(PFNWGLQUERYPBUFFERARBPROC) wglGetProcAddress("wglQueryPbufferARB");
PFNWGLCHOOSEPIXELFORMATARBPROC wglChoosePixelFormatARB =
(PFNWGLCHOOSEPIXELFORMATARBPROC) wglGetProcAddress("wglChoosePixelFormatARB");
if (!wglCreatePbufferARB) // assumes that if one can be resolved, all of them can
return false;
dc = GetDC(dmy.winId());
Q_ASSERT(dc);
PFNWGLGETEXTENSIONSSTRINGARBPROC wglGetExtensionsStringARB =
(PFNWGLGETEXTENSIONSSTRINGARBPROC) wglGetProcAddress("wglGetExtensionsStringARB");
if (wglGetExtensionsStringARB) {
QString extensions(QLatin1String(wglGetExtensionsStringARB(dc)));
has_render_texture = extensions.contains(QLatin1String("WGL_ARB_render_texture"));
}
int attribs[40];
qt_format_to_attrib_list(has_render_texture, f, attribs);
// Find pbuffer capable pixel format.
unsigned int num_formats = 0;
int pixel_format;
wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);
// some GL implementations don't support pbuffers with accum
// buffers, so try that before we give up
if (num_formats == 0 && f.accum()) {
QGLFormat tmp = f;
tmp.setAccum(false);
qt_format_to_attrib_list(has_render_texture, tmp, attribs);
wglChoosePixelFormatARB(dc, attribs, 0, 1, &pixel_format, &num_formats);
}
if (num_formats == 0) {
qWarning("QGLPixelBuffer: Unable to find a pixel format with pbuffer - giving up.");
ReleaseDC(dmy.winId(), dc);
return false;
}
format = pfiToQGLFormat(dc, pixel_format);
// NB! The below ONLY works if the width/height are powers of 2.
// Set some pBuffer attributes so that we can use this pBuffer as
// a 2D RGBA texture target.
int pb_attribs[] = {WGL_TEXTURE_FORMAT_ARB, WGL_TEXTURE_RGBA_ARB,
WGL_TEXTURE_TARGET_ARB, WGL_TEXTURE_2D_ARB, 0};
pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(),
has_render_texture ? pb_attribs : 0);
if(!pbuf) {
// try again without the render_texture extension
pbuf = wglCreatePbufferARB(dc, pixel_format, size.width(), size.height(), 0);
has_render_texture = false;
if (!pbuf) {
qWarning("QGLPixelBuffer: Unable to create pbuffer [w=%d, h=%d] - giving up.", size.width(), size.height());
ReleaseDC(dmy.winId(), dc);
return false;
}
}
ReleaseDC(dmy.winId(), dc);
dc = wglGetPbufferDCARB(pbuf);
ctx = wglCreateContext(dc);
if (!dc || !ctx) {
qWarning("QGLPixelBuffer: Unable to create pbuffer context - giving up.");
return false;
}
HGLRC share_ctx = shareWidget ? shareWidget->d_func()->glcx->d_func()->rc : 0;
if (share_ctx && !wglShareLists(share_ctx, ctx))
qWarning("QGLPixelBuffer: Unable to share display lists - with share widget.");
int width, height;
wglQueryPbufferARB(pbuf, WGL_PBUFFER_WIDTH_ARB, &width);
wglQueryPbufferARB(pbuf, WGL_PBUFFER_HEIGHT_ARB, &height);
return true;
}