test-snippets: Add a test to verify the order of the snippets

This verifies that the post strings are executed in the order they
were added to the pipeline and the post strings are executed in the
reverse order.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/conform/test-snippets.c b/tests/conform/test-snippets.c
index 35e7d070..8a033919 100644
--- a/tests/conform/test-snippets.c
+++ b/tests/conform/test-snippets.c
@@ -388,6 +388,37 @@ paint (TestState *state)
   /* Restore the projection matrix */
   cogl_set_projection_matrix (&matrix);
 
+  /* Verify that the snippets are executed in the right order. We'll
+     replace the r component of the color in the pre sections of the
+     snippets and the g component in the post. The pre sections should
+     be executed in the reverse order they were added and the post
+     sections in the same order as they were added. Therefore the r
+     component should be taken from the the second snippet and the g
+     component from the first */
+  pipeline = cogl_pipeline_new ();
+
+  cogl_pipeline_set_color4ub (pipeline, 0, 0, 0, 255);
+
+  snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT,
+                              NULL,
+                              "cogl_color_out.g = 0.5;\n");
+  cogl_snippet_set_pre (snippet, "cogl_color_out.r = 0.5;\n");
+  cogl_snippet_set_replace (snippet, "cogl_color_out.ba = vec2 (0.0, 1.0);");
+  cogl_pipeline_add_snippet (pipeline, snippet);
+  cogl_object_unref (snippet);
+
+  snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT,
+                              NULL,
+                              "cogl_color_out.g = 1.0;\n");
+  cogl_snippet_set_pre (snippet, "cogl_color_out.r = 1.0;\n");
+  cogl_pipeline_add_snippet (pipeline, snippet);
+  cogl_object_unref (snippet);
+
+  cogl_push_source (pipeline);
+  cogl_rectangle (160, 0, 170, 10);
+  cogl_pop_source ();
+  cogl_object_unref (pipeline);
+
   /* Sanity check modifying the snippet */
   snippet = cogl_snippet_new (COGL_SNIPPET_HOOK_FRAGMENT, "foo", "bar");
   g_assert_cmpstr (cogl_snippet_get_declarations (snippet), ==, "foo");
@@ -443,6 +474,7 @@ validate_result (void)
   test_utils_check_pixel (135, 5, 0xffff00ff);
   test_utils_check_pixel (145, 5, 0x00ff00ff);
   test_utils_check_pixel (155, 5, 0xff00ffff);
+  test_utils_check_pixel (165, 5, 0x80ff00ff);
 }
 
 void