Re: [PATCH 4/7] wined3d: Initialize unwritten texcoord varyings in the VS.

[Henri Verbeet]

On 2 October 2015 at 14:54, Matteo Bruni <mbruni(a)codeweavers.com> wrote:
> @@ -4998,7 +4996,22 @@ static GLuint generate_param_reorder_function(struct shader_glsl_priv *priv,
>                          output->register_idx, reg_mask[1]);
>              }
>          }
> -        shader_addline(buffer, "}\n");
> +
> +        for (i = 0; i < MAX_TEXTURES; ++i)
> +        {
> +            if (ps && !(ps->reg_maps.texcoord & (1u << i)))
> +                continue;
> +
> +            if (texcoords_written_mask[i] != WINED3DSP_WRITEMASK_ALL)
> +            {
> +                if (gl_info->limits.glsl_varyings < wined3d_max_compat_varyings(gl_info)
> +                        && !texcoords_written_mask[i])
> +                    continue;
> +
> +                shader_glsl_write_mask_to_str(~texcoords_written_mask[i] & WINED3DSP_WRITEMASK_ALL, reg_mask);
> +                shader_addline(buffer, "gl_TexCoord[%u]%s = vec4(0.0)%s;\n", i, reg_mask, reg_mask);
> +            }
> +        }
>      }
>      else
>      {
> Doesn't this end up writing 0.0 to .w instead of 1.0? IIRC unwritten
> texture coordinates are assumed to be (0, 0, 0, 1) in D3D. May apply
> to the previous patch in the series as well.

[PATCH 4/7] wined3d: Initialize unwritten texcoord varyings in the VS.

[Matteo Bruni]

2015-10-05 11:49 GMT+02:00 Henri Verbeet <hverbeet(a)gmail.com>:
> On 2 October 2015 at 14:54, Matteo Bruni <mbruni(a)codeweavers.com> wrote:
> > @@ -4998,7 +4996,22 @@ static GLuint generate_param_reorder_function(struct shader_glsl_priv *priv,
> >                          output->register_idx, reg_mask[1]);
> >              }
> >          }
> > -        shader_addline(buffer, "}\n");
> > +
> > +        for (i = 0; i < MAX_TEXTURES; ++i)
> > +        {
> > +            if (ps && !(ps->reg_maps.texcoord & (1u << i)))
> > +                continue;
> > +
> > +            if (texcoords_written_mask[i] != WINED3DSP_WRITEMASK_ALL)
> > +            {
> > +                if (gl_info->limits.glsl_varyings < wined3d_max_compat_varyings(gl_info)
> > +                        && !texcoords_written_mask[i])
> > +                    continue;
> > +
> > +                shader_glsl_write_mask_to_str(~texcoords_written_mask[i] & WINED3DSP_WRITEMASK_ALL, reg_mask);
> > +                shader_addline(buffer, "gl_TexCoord[%u]%s = vec4(0.0)%s;\n", i, reg_mask, reg_mask);
> > +            }
> > +        }
> >      }
> >      else
> >      {
> > Doesn't this end up writing 0.0 to .w instead of 1.0? IIRC unwritten
> > texture coordinates are assumed to be (0, 0, 0, 1) in D3D. May apply
> > to the previous patch in the series as well.

My test (which is still a few patches ahead in the series but I can
send you somewhere) shows that on Nvidia the texture coordinate
defaults to (0, 0, 0, 0), while on AMD it defaults to (0, 0, 0, 1), so
the value of the .w component probably doesn't matter much. Assuming
the test is correct, of course...

[PATCH 4/7] wined3d: Initialize unwritten texcoord varyings in the VS.

[Henri Verbeet]

On 5 October 2015 at 12:39, Matteo Bruni <matteo.mystral(a)gmail.com> wrote:
> My test (which is still a few patches ahead in the series but I can
> send you somewhere) shows that on Nvidia the texture coordinate
> defaults to (0, 0, 0, 0), while on AMD it defaults to (0, 0, 0, 1), so
> the value of the .w component probably doesn't matter much. Assuming
> the test is correct, of course...

Does that include partially written coordinates? I'm fairly sure there
were applications that cared about this. It may have been Half-Life 2
(which is probably totally different today) or some other Source
Engine game. Maybe Stefan remembers. I suppose we could also just try
if anything breaks if we change it, although in that case we could get
rid of WINED3D_QUIRK_SET_TEXCOORD_W as well.

[PATCH 4/7] wined3d: Initialize unwritten texcoord varyings in the VS.

[Matteo Bruni]

2015-10-05 13:01 GMT+02:00 Henri Verbeet <hverbeet(a)gmail.com>:
> On 5 October 2015 at 12:39, Matteo Bruni <matteo.mystral(a)gmail.com> wrote:
> > My test (which is still a few patches ahead in the series but I can
> > send you somewhere) shows that on Nvidia the texture coordinate
> > defaults to (0, 0, 0, 0), while on AMD it defaults to (0, 0, 0, 1), so
> > the value of the .w component probably doesn't matter much. Assuming
> > the test is correct, of course...
>
> Does that include partially written coordinates? I'm fairly sure there
> were applications that cared about this. It may have been Half-Life 2
> (which is probably totally different today) or some other Source
> Engine game. Maybe Stefan remembers. I suppose we could also just try
> if anything breaks if we change it, although in that case we could get
> rid of WINED3D_QUIRK_SET_TEXCOORD_W as well.

Yes, same with partially written coordinates. I've kept the quirk
around for the time being because it's still used in the ARB backend,
although I guess I could update that.

[PATCH 4/7] wined3d: Initialize unwritten texcoord varyings in the VS.

[Stefan Dösinger]

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Am 2015-10-05 um 13:01 schrieb Henri Verbeet:
> Does that include partially written coordinates? I'm fairly sure
> there were applications that cared about this. It may have been
> Half-Life 2 (which is probably totally different today) or some
> other Source Engine game. Maybe Stefan remembers. I suppose we
> could also just try if anything breaks if we change it, although in
> that case we could get rid of WINED3D_QUIRK_SET_TEXCOORD_W as
> well.
> That problem was about the fixed function pipeline. A vertex shader
> wrote a partial texcoord, and fixed fucntion fragment processing was
> used. Normally GL always divides by .w, so it caused problems. ARBfp,
> GLSL and ATIfs can disable the .w divide, so the undefined content in
> .w doesn't matter.

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