Re: [PATCH v3 01/12] wined3d: Alpha test emulation for core profile contexts.

[Henri Verbeet]

On 20 May 2016 at 19:55, Matteo Bruni  wrote:
> +static void shader_glsl_generate_alpha_test(struct wined3d_string_buffer *buffer,
> -
>    const struct wined3d_gl_info *gl_info, enum wined3d_cmp_func alpha_func)
>
> +{
> - /* alpha_func is the PASS condition, not the DISCARD condition. Instead of
> -
> * flipping all the operators here, just negate the comparison below. */
> - static const char * const 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 */
> - };
> -
> - if (alpha_func == WINED3D_CMP_ALWAYS)
> -
>    return;
> -
> - if (alpha_func != WINED3D_CMP_NEVER)
> -
>    shader_addline(buffer, "if (!(%s[0].a %s alpha_test_ref))\n",
> -
>            get_fragment_output(gl_info), comparison_operator[alpha_func - WINED3D_CMP_NEVER]);
> - shader_addline(buffer, "    discard;\n");
>
> +}

I'm calling this good enough for a start. In case of WINED3D_CMP_EQUAL
and WINED3D_CMP_NOTEQUAL in particular there may come a point where
we'll have to do a range check like for color keys though.