[cogl] test-utils: Expose the compare_pixel function

[Neil Roberts <nroberts src gnome org>]

commit cd9e1be6ae40720ba54aff496d4a3ff928e57741
Author: Neil Roberts <neil linux intel com>
Date:   Sat Jan 28 13:40:22 2012 +0000

    test-utils: Expose the compare_pixel function
    
    The compare pixel function was a static function used internally by
    the test_utils_check_* functions. It takes a pointer to a pixel in a
    buffer read back from Cogl and compares it with an expected value.
    This function could also be useful in tests wanting to check the data
    returned from a call to cogl_texture_get_data so we should share it
    with the rest of the tests.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=668913
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 tests/conform/test-utils.c |    8 ++++----
 tests/conform/test-utils.h |   13 +++++++++++++
 2 files changed, 17 insertions(+), 4 deletions(-)
---
diff --git a/tests/conform/test-utils.c b/tests/conform/test-utils.c
index 9d4d7e9..a5ba891 100644
--- a/tests/conform/test-utils.c
+++ b/tests/conform/test-utils.c
@@ -85,8 +85,8 @@ compare_component (int a, int b)
   return ABS (a - b) <= 1;
 }
 
-static void
-compare_pixel (const guint8 *screen_pixel, guint32 expected_pixel)
+void
+test_utils_compare_pixel (const guint8 *screen_pixel, guint32 expected_pixel)
 {
   /* Compare each component with a small fuzz factor */
   if (!compare_component (screen_pixel[0], expected_pixel >> 24) ||
@@ -115,7 +115,7 @@ test_utils_check_pixel (int x, int y, guint32 expected_pixel)
                     COGL_PIXEL_FORMAT_RGBA_8888_PRE,
                     pixel);
 
-  compare_pixel (pixel, expected_pixel);
+  test_utils_compare_pixel (pixel, expected_pixel);
 }
 
 void
@@ -144,7 +144,7 @@ test_utils_check_region (int x, int y,
   for (y = 0; y < height; y++)
     for (x = 0; x < width; x++)
       {
-        compare_pixel (p, expected_rgba);
+        test_utils_compare_pixel (p, expected_rgba);
         p += 4;
       }
 
diff --git a/tests/conform/test-utils.h b/tests/conform/test-utils.h
index a82766c..c530374 100644
--- a/tests/conform/test-utils.h
+++ b/tests/conform/test-utils.h
@@ -88,4 +88,17 @@ test_utils_check_region (int x, int y,
                          int width, int height,
                          guint32 expected_rgba);
 
+/*
+ * test_utils_compare_pixel:
+ * @screen_pixel: A pixel stored in memory
+ * @expected_pixel: The expected RGBA value
+ *
+ * Compares a pixel from a buffer to an expected value. The pixels are
+ * converted to a string and compared with g_assert_cmpstr so that if
+ * the comparison fails then the assert will display a meaningful
+ * message.
+ */
+void
+test_utils_compare_pixel (const guint8 *screen_pixel, guint32 expected_pixel);
+
 #endif /* _TEST_UTILS_H_ */