Re: [Mesa3d-dev] r300g: hack around issue with doom3 and 0 stride

[Luca B. <lu...@lu...>]

> r300g: hack around issue with doom3 and 0 stride

> This is most likely a bug in the mesa state tracker, but do the quick hack
> for now to avoid the divide by 0.

This is not a bug: stride 0 means that the vertex attribute is
constant for all vertices.

It is not a special value either: advancing the vertex attribute
pointer by 0 will naturally result in always fetching the same value.

Thus, the patch is not likely to be correct: you should instead either
program stride 0 to the hardware if supported, or fetch the vertex
attribute with the CPU (I think it is always in a user buffer, but not
sure, maybe OpenGL allows explicitly specifying a VBO with stride 0)
and use whatever means Radeon provides to set a constant vertex
attribute (e.g. nVidia GPUs have a FIFO method exactly for that).