Re: [PATCH v2 1/8] wined3d: Alpha test emulation for core profile contexts.

[Henri Verbeet]

On 19 April 2016 at 18:56, Matteo Bruni  wrote:
> - /* alpha_func is the PASS condition, not the DISCARD condition. Instead of
> -
> * flipping all the operators here, just negate the comparison below. */

As an aside, note that in general inverting operators isn't safe if
there are potential NaNs involved.
> - static const char *comparison_operator[] =
> - {
> -
>    "",   /* WINED3D_CMP_NEVER */
> -
>    "<",  /* WINED3D_CMP_LESS */
> -
>    "==", /* WINED3D_CMP_EQUAL */
> -
>    "<=", /* WINED3D_CMP_LESSEQUAL */
> -
>    ">",  /* WINED3D_CMP_GREATER */
> -
>    "!=", /* WINED3D_CMP_NOTEQUAL */
> -
>    ">=", /* WINED3D_CMP_GREATEREQUAL */
> -
>    ""    /* WINED3D_CMP_ALWAYS */
> - };

I should have noticed the first time, but I think you'll want to make
the string pointers const as well.
> @@ -3091,6 +3091,13 @@ void find_ps_compile_args(const struct wined3d_state *state, const struct wined3
>      args->pointsprite = state->render_states[WINED3D_RS_POINTSPRITEENABLE]
>              && state->gl_primitive_type == GL_POINTS;
> - if (gl_info->supported[WINED3D_GL_LEGACY_CONTEXT])
> -
>    args->alpha_test_func = WINED3D_CMP_ALWAYS - 1;
> - else
> -
>    args->alpha_test_func = (state->render_states[WINED3D_RS_ALPHATESTENABLE]
> -
>            ? wined3d_sanitize_cmp_func(state->render_states[WINED3D_RS_ALPHAFUNC])
> -
>            : WINED3D_CMP_ALWAYS) - 1;

For what it's worth, what I originally had in mind was mapping
WINED3D_CMP_ALWAYS to 0. I.e., masking with 7. This works as well.