I have some issues with this app http://sund.de/schott/depth_buffer.zip using GL_ARB_depth_texture extension on Radeon 9700 drivers (Cataclyst 3.1)
This demo is made for playing a little bit with the z-buffer. It allows manipulation
of various parameters. To show the z-buffer glRead/glDrawpixels is used.
To display the z buffer select the “display” listbox in the “depth buffer” rollout.
To improve rendering speed of the z buffer display the depth buffer is copied into a texture
rectangle and then a fullscreen quad is drawn. (“fast” modes in the listbox)
If a “fast” mode is selected, you can choose the format of the depth texture that gets copied
The problem I encounter is that on a Radeon 9700 the “fast” modes don’t work, the quad
The app needs NV_texture_rectangle or EXT_texture_rectangle (for both I use the same NV enumerants according to a forum posting sometime ago)
The app runs fine on a GeForce 4 Ti with 42.xx drivers.
I would like if somebody can reproduce the problem.