I have a RadeonHD 3850 card working fine with fglrx driver (Catalyst 8.6) in Linux.
I have an application using texture lookup in vertex shader. The shaders fails with texture2d() function. It works fine without, however.
As I know, vertex texture fetch is supported by all ATI hardware since r600, so I though at first it may be a driver issue.
I queryed GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS and it returned 16. As I understand this means the vertex fetch should be supported by the hardware and the driver.
Perhaps I am missing the texture format. I tried GL_LUMINANCE_FLOAT32_ATI, GL_LUMINANCE32F_ARB and GL_RGBA32F_ARB, none of them working.
Is this a driver issue or am I missing something? Has anyone managed to run VTF in linux? If so what driver version?