https://bugs.freedesktop.org/show_bug.cgi?id=44499 --- Comment #10 from Roland Scheidegger <sroland@xxxxxxxxxx> 2012-01-17 08:50:18 PST --- Not sure what fog test that is, but this and blender show some unaccelerated meta ops. For blender, it's caused by glDrawPixels to z buffer (which will always result in fallback for r200), for fog it's glBitmap (which could be accelerated in theory, presumably some gl state causes the fallback). The problem might be that in earlier drivers not the whole buffer was mapped (that is, copied/untiled etc. back from video memory), only the spans affected by such swrast operations. But nowadays the whole buffers are mapped. So the cost of something like glDrawPixels of a single pixel to the depth buffer is very high (most likely approximately the same as a glDrawPixels affecting every pixel in the buffer). I don't know how this could be solved. Generally apps should avoid these operations. For glDrawPixels to the depth buffer, the chip can't handle outputting depth values from a pixel shader(*). One idea to accelerate this might be to output one vertex per pixel set up appropriately, for only a few pixels that sure would be way faster (might even be faster for all pixels), at least I think it should work. But meta ops can't do that. For the glBitmap case, it's possible the state preventing acceleration to happen could be incorporated into the code, but it might not be worth the trouble. I can't tell though if xbmc really hits any of these fallbacks. Its slowness could be due to some entirely different reason. (*)Actually it can as this is a d3d8 feature. The driver definitely can't, and even if it could the precision would be insufficient for this feature to be really useful. Not to mention you'd need a custom r200 shader. -- Configure bugmail: https://bugs.freedesktop.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
