Re: [WINED3D 3/3] Fix fog in the case of vertex shaders

[Ivan Gyurdiev]

On 6/19/06, Jason Green <jave27(a)gmail.com> wrote:
> - Fixes both ARB and GLSL shaders that use fog.

Is it really necessary to keep track of whether the shader uses fog or not?
What happens if you disable this post-processing for a shader that doesn't
write to the fog register?
Also, how come the ARB version forces the fog value to be > 0, but the GLSL
one has both lower and upper limit (clamp to 0,1) ? Shouldn't you use
saturate (_SAT) to achieve the same effect?

[WINED3D 3/3] Fix fog in the case of vertex shaders

[H. Verbeet]

On 20/06/06, Ivan Gyurdiev <ivg231(a)gmail.com> wrote:
> Is it really necessary to keep track of whether the shader uses fog or not?
> What happens if you disable this post-processing for a shader that doesn't
> write to the fog register?
> Not "really necessary", but it does save a couple of GL state changes
> if fog isn't used in the shader, and it's pretty easy to keep track
> of.