[Piglit] [PATCH] draw-vertices-2101010: Accept either SNORM conversion formula.

[Roland Scheidegger]

I'm pretty sure that helps llvmpipe too.

Reviewed-by: Roland Scheidegger <sroland at vmware.com>


Am 26.12.2017 um 07:55 schrieb Kenneth Graunke:
> OpenGL defines two equations for converting from signed-normalized
> to floating point data.  These are:
> 
>     f = (2c + 1)/(2^b - 1)                (equation 2.2)
>     f = max{c/2^(b-1) - 1), -1.0}         (equation 2.3)
> 
> ARB_vertex_type_2_10_10_10_rev specifies equation 2.2 is to be used.
> 
> However, OpenGL 4.2 switched to use equation 2.3 in all scenarios.
> This matched an earlier OpenGL ES 3.0 decision to only have one formula,
> as well as a DirectX decision to change to equation 2.3.  Some hardware
> also only supports equation 2.3.  So, basically no one can rely on
> equation 2.2 happening, and some people do rely on 2.3.
> 
> This patch continues to require equation 2.3 for GL 4.2+, but relaxes
> the test to allow either behavior for earlier GL versions.
> 
> See the following discussion for more details:
> https://lists.freedesktop.org/archives/mesa-dev/2013-August/042680.html
> 
> This makes this test pass on i965 with Haswell and later.
> ---
>  .../draw-vertices-2101010.c                        | 48 ++++++++++++++--------
>  1 file changed, 32 insertions(+), 16 deletions(-)
> 
> diff --git a/tests/spec/arb_vertex_type_2_10_10_10_rev/draw-vertices-2101010.c b/tests/spec/arb_vertex_type_2_10_10_10_rev/draw-vertices-2101010.c
> index 661fa9ca2..5ce4c0655 100644
> --- a/tests/spec/arb_vertex_type_2_10_10_10_rev/draw-vertices-2101010.c
> +++ b/tests/spec/arb_vertex_type_2_10_10_10_rev/draw-vertices-2101010.c
> @@ -187,20 +187,28 @@ static void test_int_vertices_abi(float x1, float y1, float x2, float y2, int in
>  struct test {
>      void (*test)(float x1, float y1, float x2, float y2, int index);
>      int index;
> -    float expected_color[4];
> +    float expected_color_equation_22[4];
> +    float expected_color_equation_23[4];
>      const char *name;
>  };
>  
>  struct test tests[] = {
> -    {test_packed_int_vertices, 0, {1, 1, 1, 1}, "Int vertices - 2/10/10/10"},
> -    {test_packed_int_vertices, 1, {1, 1, 1, 1}, "Unsigned Int vertices - 2/10/10/10"},
> -    {test_packed_int_color_vertices, 0, {1, 0, 0, 0.333}, "Int Color - 2/10/10/10"},
> -    {test_packed_int_color_vertices, 1, {1, 0, 0, 0}, "Unsigned Int Color - 2/10/10/10"},
> -    {test_packed_int_color_vertices, 2, {0, 0, 1, 0.333}, "Int BGRA Color - 2/10/10/10"},
> -    {test_packed_int_color_vertices, 3, {0, 0, 1, 0}, "Unsigned Int BGRA Color - 2/10/10/10"},
> -
> -    {test_int_vertices_abi, 0, {1, 0, 0, 1}, "Int 2/10/10/10 - test ABI" },
> -    {test_int_vertices_abi, 1, {1, 0, 0, 1}, "Unsigned 2/10/10/10 - test ABI" },
> +    {test_packed_int_vertices, 0, {1, 1, 1, 1}, {1, 1, 1, 1},
> +     "Int vertices - 2/10/10/10"},
> +    {test_packed_int_vertices, 1, {1, 1, 1, 1}, {1, 1, 1, 1},
> +     "Unsigned Int vertices - 2/10/10/10"},
> +    {test_packed_int_color_vertices, 0, {1, 0, 0, 0.333}, {1, 0, 0, 0},
> +     "Int Color - 2/10/10/10"},
> +    {test_packed_int_color_vertices, 1, {1, 0, 0, 0}, {1, 0, 0, 0},
> +     "Unsigned Int Color - 2/10/10/10"},
> +    {test_packed_int_color_vertices, 2, {0, 0, 1, 0.333}, {0, 0, 1, 0},
> +     "Int BGRA Color - 2/10/10/10"},
> +    {test_packed_int_color_vertices, 3, {0, 0, 1, 0}, {0, 0, 1, 0},
> +     "Unsigned Int BGRA Color - 2/10/10/10"},
> +    {test_int_vertices_abi, 0, {1, 0, 0, 1}, {1, 0, 0, 1},
> +     "Int 2/10/10/10 - test ABI" },
> +    {test_int_vertices_abi, 1, {1, 0, 0, 1}, {1, 0, 0, 1},
> +     "Unsigned 2/10/10/10 - test ABI" },
>      {0}
>  };
>  
> @@ -213,7 +221,7 @@ piglit_display(void)
>      /* To know what this is all about, see:
>       * http://lists.freedesktop.org/archives/mesa-dev/2013-August/042680.html
>       */
> -    GLboolean snorm_equation_23 = piglit_get_gl_version() >= 42;
> +    bool require_snorm_equation_23 = piglit_get_gl_version() >= 42;
>  
>      glClear(GL_COLOR_BUFFER_BIT);
>      glEnableClientState(GL_VERTEX_ARRAY);
> @@ -222,14 +230,22 @@ piglit_display(void)
>      for (i = 0; tests[i].test; i++) {
>          glBindBuffer(GL_ARRAY_BUFFER, 0);
>  
> -	if (snorm_equation_23 && fabs(tests[i].expected_color[3] - 0.333) < 0.0001)
> -	    tests[i].expected_color[3] = 0;
> -
> -        printf("%s\n", tests[i].name);
>          tests[i].test(x, y, x+20, y+20, tests[i].index);
>          if (!piglit_check_gl_error(GL_NO_ERROR))
>  		piglit_report_result(PIGLIT_FAIL);
> -        pass = piglit_probe_pixel_rgba(x+5, y+5, tests[i].expected_color) && pass;
> +
> +        printf("%s\n", tests[i].name);
> +
> +        if (require_snorm_equation_23) {
> +            pass = piglit_probe_pixel_rgba(x+5, y+5, tests[i].expected_color_equation_23) && pass;
> +        } else {
> +            bool equation_22_pass = piglit_probe_pixel_rgba(x+5, y+5, tests[i].expected_color_equation_22);
> +            bool equation_23_pass = piglit_probe_pixel_rgba(x+5, y+5, tests[i].expected_color_equation_23);
> +            if (!equation_22_pass && equation_23_pass) {
> +                printf("warning: driver uses GL 4.2+ rules for signed normalized to float conversions\n");
> +            }
> +            pass = (equation_22_pass || equation_23_pass) && pass;
> +        }
>  
>          x += 20;
>          if (x > 300) {
>