Hook up pdiff to the test suite now that its written in C

1 files changed, 30 insertions, 0 deletions

diff --git a/test/buffer-diff.c b/test/buffer-diff.c
index 99501bce8..e4324ff2a 100644
--- a/test/buffer-diff.c
+++ b/test/buffer-diff.c
@@ -38,6 +38,7 @@
 
 #include "cairo-test.h"
 
+#include "pdiff.h"
 #include "buffer-diff.h"
 #include "xmalloc.h"
 
@@ -122,6 +123,18 @@ compare_surfaces (cairo_surface_t	*surface_a,
 		  cairo_surface_t	*surface_diff,
 		  buffer_diff_result_t	*result)
 {
+    /* These default values were taken straight from the
+     * perceptualdiff program. We'll probably want to tune these as
+     * necessary. */
+    double gamma = 2.2;
+    double luminance = 100.0;
+    double field_of_view = 45.0;
+    int discernible_pixels_changed;
+
+    /* First, we run cairo's old buffer_diff algorithm which looks for
+     * pixel-perfect images, (we do this first since the test suite
+     * runs about 3x slower if we run pdiff_compare first).
+     */
     buffer_diff_core (cairo_image_surface_get_data (surface_a),
 		      cairo_image_surface_get_data (surface_b),
 		      cairo_image_surface_get_data (surface_diff),
@@ -130,6 +143,23 @@ compare_surfaces (cairo_surface_t	*surface_a,
 		      cairo_image_surface_get_stride (surface_a),
 		      0xffffffff,
 		      result);
+    if (result->pixels_changed == 0)
+	return;
+
+    cairo_test_log ("%d pixels differ (with maximum difference of %d) from reference image\n",
+		    result->pixels_changed, result->max_diff);
+
+    /* Then, if there are any different pixels, we give the pdiff code
+     * a crack at the images. If it decides that there are no visually
+     * discernible differences in any pixels, then we accept this
+     * result as good enough. */
+    discernible_pixels_changed = pdiff_compare (surface_a, surface_b,
+						gamma, luminance, field_of_view);
+    if (discernible_pixels_changed == 0) {
+	result->pixels_changed = 0;
+	cairo_test_log ("But perceptual diff finds no visually discernible difference.\n"
+			"Accepting result.\n");
+    }
 }
 
 void