The only complete cascaded shadowmap sample I can find on internet is the one present in NVIDIA OpenGL SDK10 , but unfortunately It failed to correctly render on my ATI HD4670 but give corrent result on my GF9800/GTS250
Running the program on HD4670 will give a lot of shader compilation error and the result look like application only render the first slice of shadowmap.
The code itself is very complex (for me) and involed using FBO with texture Array.
They also use glFramebufferTextureLayerEXT(GL_FRAMEBUFFER_EXT,
GL_DEPTH_ATTACHMENT_EXT, depth_tex_ar, 0, i) which is the part where I dont understand.
Is the above function (non EXT version) even exist in GL 3.2 core spec ?.
Can somebody give me an example (OpenGL 3.2 way) of how to set up FBO with texture array of depth component. and selecting which layer of depth to render to ?
If the texture array / layer rendering method is not possible on ATIHD4670 please give me some alternative approach.
Thank in advance.