Old 7900 Support

[ViolentHamster]

Unfortunately, I need to modify my application so it will run on an old GeForce 7900. My application sets up a 32 bit floating point FBO by calling glRenderbufferStorageMultisample with GL_R32F.

On the 7900, the call throws an "incomplete attachment" error. The driver is supposed to support GL_NV_float_buffer, so I tried GL_FLOAT_R32_NV, but that throws an "unsupported" error. Do the 7900s support any floating point renderbuffer formats?

Thanks.

[skynet]

GL_R32F is introduced by ARB_texture_rg. Does your card expose this extension? Also, 1- and 2-component attachments are not allowed by EXT_framebuffer_object. ARB_framebuffer_object started to allow them.

[ViolentHamster]

No, my card doesn't support ARB_texture_rg, so it's not surprising that GL_R32F didn't work. I'm looking for any floating point format that will work. I haven't had any success.

The card supports ARB_framebuffer_object.

[skynet]

have a look here:

http://developer.nvidia.com/object/nv_ogl_texture_formats.html

GL_ALPHA_FLOAT32
GL_INTENSITY_FLOAT32
GL_LUMINANCE_FLOAT32

_may_ be good candidates for you to try... I have never tried to render into these formats before, though.