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View Full Version : WGL_ARB_pbuffer vs. PFD_DRAW_TO_BITMAP



gator
05-16-2005, 08:00 PM
Why is it that wglShareLists() fails when I create an offscreen buffer using PFD_DRAW_TO_BITMAP,
but it works when I create an offscreen buffer using the WGL_ARB_pbuffer method? :confused:

N64Marin
05-16-2005, 08:50 PM
Are you sure the pixel format you chose have hardware acceleration? That means, you may have choosen an generic pixel format that is not supported by your ICD. To call wglShareList successfully, the two contexts must be accelerated by the same ICD, or both of generic format.

Overmind
05-16-2005, 11:54 PM
With PFD_DRAW_TO_BITMAP, you will get a software renderer for sure, so you should propably use a pbuffer instead...

wglShareLists not working is not the only problem you will have with PFD_DRAW_TO_BITMAP. It will also be very slow, and you only have unextended OpenGL 1.1.

gator
05-17-2005, 10:51 AM
I thin you're right. I see it always comes back as software accelerated.

I also noticed that I can't get alpha blending to work with PFD_DRAW_TO_BITMAP. I made sure I created a 32-bit DIB section and a 32-bit RC, but I get no alpha blending.

gator
05-17-2005, 12:15 PM
Yep, I enumerated all 100 pixel formats for my graphics card, and not one format
is hardware accelerated for PFD_DRAW_TO_BITMAP. I don't even think I can do
alpha-blending on it either. Oh well.