[Piglit] [PATCH] Add a test for instanced GS inputs.

[andrii.simiklit]

Hello,

It would be great If somebody could take a look this test)
This test against following bug:
https://bugs.freedesktop.org/show_bug.cgi?id=96354

Regards,
Andrii.

On 05.06.18 16:33, Andrii Simiklit wrote:

>     All of our other tests for instanced geometry shaders don't actually
>     transfer the vertices to the geometry shader
>     from the vertex shader using gl_Position.
>     This used to be broken with the i965 driver's in Mesa 12.1.0
>     on revision d10ae20b9678f1a5b8a81716c68e612662665277.
>     This test should give us ability to detect
>     such kind of bugs like 96354 bug in future.
>
> Signed-off-by: Andrii Simiklit <andrii.simiklit at globallogic.com>
> ---
>   .../instanced-inputs-built-in-variable.shader_test | 68 ++++++++++++++++++++++
>   1 file changed, 68 insertions(+)
>   create mode 100644 tests/spec/arb_gpu_shader5/execution/instanced-inputs-built-in-variable.shader_test
>
> diff --git a/tests/spec/arb_gpu_shader5/execution/instanced-inputs-built-in-variable.shader_test b/tests/spec/arb_gpu_shader5/execution/instanced-inputs-built-in-variable.shader_test
> new file mode 100644
> index 0000000..86b2bbd
> --- /dev/null
> +++ b/tests/spec/arb_gpu_shader5/execution/instanced-inputs-built-in-variable.shader_test
> @@ -0,0 +1,68 @@
> +#It seems as duplicate of the "instanced-inputs.shader_test" test but it could not detect the bug 96354.
> +#It could detect the 96354 bug if and only if vertices are transferred
> +#from vertex shader into geometry shader through built-in variable gl_Position.
> +#
> +#Specification permits us to do it "11.3.4.4 Geometry Shader Inputs:
> +#    Structure member gl_Position holds the per-vertex position, as written
> +#    by the vertex shader to its built-in output variable gl_Position.
> +#    Note that writing to gl_Position from either the vertex or geometry shader is
> +#    optional (also see section 7.1(“Built-In Variables”) of the OpenGL Shading Language Specification)"
> +
> +[require]
> +GL >= 2.0
> +GLSL >= 1.50
> +GL_ARB_gpu_shader5
> +
> +[vertex shader]
> +in vec4 vertex;
> +
> +void main()
> +{
> +   gl_Position = vertex;
> +}
> +
> +[geometry shader]
> +#extension GL_ARB_gpu_shader5 : require
> +layout(triangles) in;
> +layout(triangle_strip, max_vertices = 3) out;
> +layout(invocations = 4) in;
> +
> +void main()
> +{
> +   vec2 offset;
> +   if (gl_InvocationID == 0)
> +      offset.xy = vec2(-0.5, -0.5);
> +   else if (gl_InvocationID == 1)
> +      offset.xy = vec2( 0.5, -0.5);
> +   else if (gl_InvocationID == 2)
> +      offset.xy = vec2(-0.5,  0.5);
> +   else if (gl_InvocationID == 3)
> +      offset.xy = vec2( 0.5,  0.5);
> +
> +   for (int i = 0; i < 3; i++) {
> +       gl_Position = gl_in[i].gl_Position;
> +       gl_Position.xy += offset;
> +       EmitVertex();
> +   }
> +}
> +
> +[fragment shader]
> +void main()
> +{
> +   gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
> +}
> +
> +[vertex data]
> +vertex/float/2
> +-0.5 -0.5
> + 0.5 -0.5
> +-0.5  0.0
> + 0.5  0.0
> +-0.5  0.5
> + 0.5  0.5
> +
> +[test]
> +clear color 0.0 0.0 0.0 0.0
> +clear
> +draw arrays GL_TRIANGLE_STRIP 0 6
> +probe all rgba 0.0 1.0 0.0 1.0
> \ No newline at end of file