[Piglit] [PATCH 5/3] fbo-alphatest-formats: Skip testing for ALPHA-only formats

[Carl Worth]

The test uses an RGB probe to determine whether a pixel was rendered
or not. By definition, an RGB proble will always return values of 0
whether or not the pixel was rendered. So the results are meaningless
for an alpha-only format.
---
 tests/fbo/fbo-alphatest-formats.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/fbo/fbo-alphatest-formats.c b/tests/fbo/fbo-alphatest-formats.c
index 30a7164..759eea6 100644
--- a/tests/fbo/fbo-alphatest-formats.c
+++ b/tests/fbo/fbo-alphatest-formats.c
@@ -77,7 +77,8 @@ static enum piglit_result test_format(const struct format_desc *format)
 	float pos7[] = { 0.75, -1.0, 0.25, 2.0};
 
         if (format->base_internal_format == GL_DEPTH_COMPONENT ||
-            format->base_internal_format == GL_DEPTH_STENCIL)
+            format->base_internal_format == GL_DEPTH_STENCIL ||
+	    format->base_internal_format == GL_ALPHA)
 		return PIGLIT_SKIP;
 
 	/*
-- 
1.7.10.4