[cogl/wip/neil/snippets: 26/27] test-snippets: Add a test to verify the order of the snippets

[Neil Roberts <nroberts src gnome org>]

commit 216f88978edec234689ba1c27f6d4c5909006c1e
Author: Neil Roberts <neil linux intel com>
Date:   Tue Dec 6 12:14:07 2011 +0000

    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.

 tests/conform/test-snippets.c |   32 ++++++++++++++++++++++++++++++++
 1 files changed, 32 insertions(+), 0 deletions(-)
---
diff --git a/tests/conform/test-snippets.c b/tests/conform/test-snippets.c
index 35e7d07..8a03391 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