arb_framebuffer_object: add missing MSAA alpha-to-coverage and alpha-to-one tests

The missing test is the one that enables both alpha-to-coverage and
alpha-to-one. It currently fails on AMD drivers, but passes on llvmpipe.

Reviewed-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <!978>

tests/shaders/shader_runner.c

@@ -3591,6 +3591,8 @@ static const struct string_to_enum enable_table[] = {
 	{ "GL_PROGRAM_POINT_SIZE", GL_PROGRAM_POINT_SIZE },
 	{ "GL_DEPTH_TEST", GL_DEPTH_TEST },
 	{ "GL_DEPTH_CLAMP", GL_DEPTH_CLAMP },
+	{ "GL_SAMPLE_ALPHA_TO_ONE", GL_SAMPLE_ALPHA_TO_ONE },
+	{ "GL_SAMPLE_ALPHA_TO_COVERAGE", GL_SAMPLE_ALPHA_TO_COVERAGE },
 	{ NULL, 0 }
 };
 

tests/spec/arb_framebuffer_object/execution/msaa-alpha-to-coverage.shader_test

+[require]
+GL >= 3.0
+GLSL >= 1.30
+INT GL_MAX_SAMPLES >= 4
+
+[vertex shader]
+#version 130
+
+in vec4 vertex;
+
+void main()
+{
+    gl_Position = vertex;
+}
+
+[fragment shader]
+#version 130
+
+out vec4 fcolor;
+
+void main()
+{
+    float g = gl_FragCoord.x / 250.0;
+    fcolor = vec4(0, g, 0, g);
+}
+
+[test]
+fb ms GL_RGBA8 250 250 4
+
+clear color 0.5 0.5 0.5 0.5
+clear
+
+enable GL_SAMPLE_ALPHA_TO_COVERAGE
+draw rect -1 -1 2 2
+
+fb draw winsys
+blit color linear
+
+fb read winsys
+relative probe rgba (0,    0)   (0.5,   0.5,    0.5,   0.5)
+relative probe rgba (0.25, 0)   (0.375, 0.4375, 0.375, 0.4375)
+relative probe rgba (0.5,  0)   (0.25,  0.5,    0.25,  0.5)
+relative probe rgba (0.75, 0)   (0.125, 0.6875, 0.125, 0.6875)
+relative probe rgba (1,    0)   (0,     1,      0,     1)

tests/spec/arb_framebuffer_object/execution/msaa-alpha-to-coverage_alpha-to-one.shader_test

+# GL_SAMPLE_ALPHA_TO_ONE is applied after GL_SAMPLE_ALPHA_TO_COVERAGE
+# determines the coverage.
+
+[require]
+GL >= 3.0
+GLSL >= 1.30
+INT GL_MAX_SAMPLES >= 4
+
+[vertex shader]
+#version 130
+
+in vec4 vertex;
+
+void main()
+{
+    gl_Position = vertex;
+}
+
+[fragment shader]
+#version 130
+
+out vec4 fcolor;
+
+void main()
+{
+    float g = gl_FragCoord.x / 250.0;
+    fcolor = vec4(0, g, 0, g);
+}
+
+[test]
+fb ms GL_RGBA8 250 250 4
+
+clear color 0.5 0.5 0.5 0.5
+clear
+
+enable GL_SAMPLE_ALPHA_TO_COVERAGE
+enable GL_SAMPLE_ALPHA_TO_ONE
+draw rect -1 -1 2 2
+
+fb draw winsys
+blit color linear
+
+fb read winsys
+relative probe rgba (0,    0)   (0.5,   0.5,    0.5,   0.5)
+relative probe rgba (0.25, 0)   (0.375, 0.4375, 0.375, 0.625)
+relative probe rgba (0.5,  0)   (0.25,  0.5,    0.25,  0.75)
+relative probe rgba (0.75, 0)   (0.125, 0.6875, 0.125, 0.875)
+relative probe rgba (1,    0)   (0,     1,      0,     1)

tests/spec/arb_framebuffer_object/execution/msaa-alpha-to-coverage_alpha-to-one_write-z.shader_test

+# GL_SAMPLE_ALPHA_TO_ONE is applied after GL_SAMPLE_ALPHA_TO_COVERAGE
+# determines the coverage while gl_FragDepth is also written.
+
+[require]
+GL >= 3.0
+GLSL >= 1.30
+INT GL_MAX_SAMPLES >= 4
+
+[vertex shader]
+#version 130
+
+in vec4 vertex;
+
+void main()
+{
+    gl_Position = vertex;
+}
+
+[fragment shader]
+#version 130
+
+out vec4 fcolor;
+
+void main()
+{
+    float g = gl_FragCoord.x / 250.0;
+    fcolor = vec4(0, g, 0, g);
+    gl_FragDepth = gl_FragCoord.z > -1000 ? gl_FragCoord.z : 0;
+}
+
+[test]
+fb ms GL_RGBA8 250 250 4
+
+clear color 0.5 0.5 0.5 0.5
+clear
+
+enable GL_SAMPLE_ALPHA_TO_COVERAGE
+enable GL_SAMPLE_ALPHA_TO_ONE
+draw rect -1 -1 2 2
+
+fb draw winsys
+blit color linear
+
+fb read winsys
+relative probe rgba (0,    0)   (0.5,   0.5,    0.5,   0.5)
+relative probe rgba (0.25, 0)   (0.375, 0.4375, 0.375, 0.625)
+relative probe rgba (0.5,  0)   (0.25,  0.5,    0.25,  0.75)
+relative probe rgba (0.75, 0)   (0.125, 0.6875, 0.125, 0.875)
+relative probe rgba (1,    0)   (0,     1,      0,     1)

tests/spec/arb_framebuffer_object/execution/msaa-alpha-to-one.shader_test

+[require]
+GL >= 3.0
+GLSL >= 1.30
+INT GL_MAX_SAMPLES >= 4
+
+[vertex shader]
+#version 130
+
+in vec4 vertex;
+
+void main()
+{
+    gl_Position = vertex;
+}
+
+[fragment shader]
+#version 130
+
+out vec4 fcolor;
+
+void main()
+{
+    float g = gl_FragCoord.x / 250.0;
+    fcolor = vec4(0, g, 0, g);
+}
+
+[test]
+fb ms GL_RGBA8 250 250 4
+
+clear color 0.1 0.1 0.1 0.1
+clear
+
+enable GL_SAMPLE_ALPHA_TO_ONE
+draw rect -1 -1 2 2
+
+fb draw winsys
+blit color linear
+
+fb read winsys
+relative probe rgba (0,    0)   (0, 0,    0, 1)
+relative probe rgba (0.25, 0)   (0, 0.25, 0, 1)
+relative probe rgba (0.5,  0)   (0, 0.5,  0, 1)
+relative probe rgba (0.75, 0)   (0, 0.75, 0, 1)
+relative probe rgba (1,    0)   (0, 1,    0, 1)

tests/spec/arb_framebuffer_object/execution/msaa-trivial.shader_test

+[require]
+GL >= 3.0
+GLSL >= 1.30
+INT GL_MAX_SAMPLES >= 4
+
+[vertex shader]
+#version 130
+
+in vec4 vertex;
+
+void main()
+{
+    gl_Position = vertex;
+}
+
+[fragment shader]
+#version 130
+
+out vec4 fcolor;
+
+void main()
+{
+    float g = gl_FragCoord.x / 250.0;
+    fcolor = vec4(0, g, 0, g);
+}
+
+[test]
+fb ms GL_RGBA8 250 250 4
+
+clear color 0.1 0.1 0.1 0.1
+clear
+
+draw rect -1 -1 2 2
+
+fb draw winsys
+blit color linear
+
+fb read winsys
+relative probe rgba (0,    0)   (0, 0,    0, 0)
+relative probe rgba (0.25, 0)   (0, 0.25, 0, 0.25)
+relative probe rgba (0.5,  0)   (0, 0.5,  0, 0.5)
+relative probe rgba (0.75, 0)   (0, 0.75, 0, 0.75)
+relative probe rgba (1,    0)   (0, 1,    0, 1)