Fragment shader - GL_BLEND

Graphics and GPU Programming Programming

Started by uto314 August 11, 2005 07:03 PM

1 comment, last by uto314 18 years, 9 months ago

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August 11, 2005 07:03 PM

Hi, I draw in a floating point pbuffer (128 bits/pixel) with stencil and depth buffer. Everything works fine. Once I enable GL_BLEND, it goes insanely slow. I'd like to know if someone ever had a trouble such this one. The graphics I use is a NVidia Quadro FX 4400 with the driver 77.18 Any comment would help a lot, Thanks, -uto-

- a human beyond the bug -

Lutz

462

August 12, 2005 09:38 AM

AFAIK, floating point buffers and blending together is not supported in hardware.
That's probably why it's so slow since it's emulated in software.

I found this page with Google saying that it's possible to filter and blend 64-bit floating point stuff, so it's probably not possible to blend 128-bit textures.

Lutz