Augment test framework to test everything under device offsets as well.

[With this change, two tests with gradients exhibit subtle differences
under device offsets. I don't think we actually care about them
though. -cworth]

7 files changed, 244 insertions, 195 deletions

diff --git a/test/.gitignore b/test/.gitignore
index 3f3c5821c..d4472f2b0 100644
--- a/test/.gitignore
+++ b/test/.gitignore
@@ -91,38 +91,10 @@ unantialiased-shapes
 unbounded-operator
 user-data
 xlib-surface
-*-image-out.png
-*-image-argb32-out.png
-*-image-rgb24-out.png
-*-pdf-argb32-out.png
-*-pdf-argb32-out.pdf
-*-pdf-rgb24-out.png
-*-pdf-rgb24-out.pdf
-*-ps-argb32-out.png
-*-ps-argb32-out.ps
-*-ps-rgb24-out.png
-*-ps-rgb24-out.ps
-*-svg-argb32-out.png
-*-svg-argb32-out.svg
-*-svg-rgb24-out.png
-*-svg-rgb24-out.svg
-*-test-fallback-argb32-out.png
-*-test-fallback-rgb24-out.png
-*-test-meta-argb32-out.png
-*-test-meta-rgb24-out.png
-*-test-paginated-argb32-out.png
-*-test-paginated-rgb24-out.png
-*-xcb-out.png
-*-xcb-argb32-out.png
-*-xcb-rgb24-out.png
-*-xlib-out.png
-*-xlib-argb32-out.png
-*-xlib-rgb24-out.png
-*-beos-rgb24-out.png
-*-beos_bitmap-rgb24-out.png
-*-beos_bitmap-argb32-out.png
-*-glitz-glx-rgb24-out.png
-*-glitz-glx-argb32-out.png
+*-out.pdf
+*-out.png
+*-out.ps
+*-out.svg
 *-diff.png
 *.gcno
 *.la
diff --git a/test/buffer-diff.c b/test/buffer-diff.c
index dd1b7c664..c62c44ef4 100644
--- a/test/buffer-diff.c
+++ b/test/buffer-diff.c
@@ -62,7 +62,9 @@ buffer_diff_core (unsigned char *_buf_a,
 		  unsigned char *_buf_diff,
 		  int		width,
 		  int		height,
-		  int		stride,
+		  int		stride_a,
+		  int		stride_b,
+		  int		stride_diff,
 		  pixman_bits_t mask)
 {
     int x, y;
@@ -72,12 +74,14 @@ buffer_diff_core (unsigned char *_buf_a,
     pixman_bits_t *buf_b = (pixman_bits_t*)_buf_b;
     pixman_bits_t *buf_diff = (pixman_bits_t*)_buf_diff;
 
-    stride /= sizeof(pixman_bits_t);
+    stride_a /= sizeof(pixman_bits_t);
+    stride_b /= sizeof(pixman_bits_t);
+    stride_diff /= sizeof(pixman_bits_t);
     for (y = 0; y < height; y++)
     {
-	row_a = buf_a + y * stride;
-	row_b = buf_b + y * stride;
-	row = buf_diff + y * stride;
+	row_a = buf_a + y * stride_a;
+	row_b = buf_b + y * stride_b;
+	row = buf_diff + y * stride_diff;
 	for (x = 0; x < width; x++)
 	{
 	    /* check if the pixels are the same */
@@ -112,9 +116,12 @@ buffer_diff (unsigned char *buf_a,
 	     unsigned char *buf_diff,
 	     int	   width,
 	     int	   height,
-	     int	   stride)
+	     int	   stride_a,
+	     int	   stride_b,
+	     int	   stride_diff)
 {
-    return buffer_diff_core(buf_a, buf_b, buf_diff, width, height, stride, 0xffffffff);
+    return buffer_diff_core(buf_a, buf_b, buf_diff,
+			    width, height, stride_a, stride_b, stride_diff, 0xffffffff);
 }
 
 int
@@ -123,9 +130,12 @@ buffer_diff_noalpha (unsigned char *buf_a,
 		     unsigned char *buf_diff,
 		     int	   width,
 		     int	   height,
-		     int	   stride)
+		     int	   stride_a,
+		     int	   stride_b,
+		     int	   stride_diff)
 {
-    return buffer_diff_core(buf_a, buf_b, buf_diff, width, height, stride, 0x00ffffff);
+    return buffer_diff_core(buf_a, buf_b, buf_diff,
+			    width, height, stride_a, stride_b, stride_diff, 0x00ffffff);
 }
 
 /* Image comparison code courtesy of Richard Worth <richard@theworths.org>
@@ -136,11 +146,16 @@ buffer_diff_noalpha (unsigned char *buf_a,
 int
 image_diff (const char *filename_a,
 	    const char *filename_b,
-	    const char *filename_diff)
+	    const char *filename_diff,
+	    int		ax,
+	    int		ay,
+	    int		bx,
+	    int		by)
 {
     int pixels_changed;
     unsigned int width_a, height_a, stride_a;
     unsigned int width_b, height_b, stride_b;
+    unsigned int stride_diff;
     unsigned char *buf_a, *buf_b, *buf_diff;
     read_png_status_t status;
 
@@ -154,9 +169,13 @@ image_diff (const char *filename_a,
 	return -1;
     }
 
+    width_a -= ax;
+    height_a -= ay;
+    width_b -= bx;
+    height_b -= by;
+
     if (width_a  != width_b  ||
-	height_a != height_b ||
-	stride_a != stride_b)
+	height_a != height_b)
     {
 	cairo_test_log ("Error: Image size mismatch: (%dx%d@%d) vs. (%dx%d@%d)\n"
 			"       for %s vs. %s\n",
@@ -168,17 +187,27 @@ image_diff (const char *filename_a,
 	return -1;
     }
 
-    buf_diff = xcalloc (stride_a * height_a, 1);
+    stride_diff = 4 * width_a;
+    buf_diff = xcalloc (stride_diff * height_a, 1);
 
-    pixels_changed = buffer_diff (buf_a, buf_b, buf_diff,
-				  width_a, height_a, stride_a);
+    pixels_changed = buffer_diff (buf_a + (ay * stride_a) + ax * 4,
+                                  buf_b + (by * stride_b) + by * 4,
+                                  buf_diff,
+                                  width_a, height_a,
+				  stride_a, stride_b, stride_diff);
 
     if (pixels_changed) {
-	FILE *png_file = fopen (filename_diff, "wb");
-	write_png_argb32 (buf_diff, png_file, width_a, height_a, stride_a);
-	fclose (png_file);
+	FILE *png_file;
+	if (filename_diff)
+	    png_file = fopen (filename_diff, "wb");
+	else
+	    png_file = stdout;
+	write_png_argb32 (buf_diff, png_file, width_a, height_a, stride_diff);
+	if (png_file != stdout)
+	    fclose (png_file);
     } else {
-	xunlink (filename_diff);
+	if (filename_diff)
+	    xunlink (filename_diff);
     }
 
     free (buf_a);
@@ -204,7 +233,11 @@ image_diff (const char *filename_a,
 int
 image_diff_flattened (const char *filename_a,
 		      const char *filename_b,
-		      const char *filename_diff)
+		      const char *filename_diff,
+		      int	  ax,
+		      int	  ay,
+		      int	  bx,
+		      int	  by)
 {
     int pixels_changed;
     unsigned int width_a, height_a, stride_a;
@@ -225,9 +258,13 @@ image_diff_flattened (const char *filename_a,
 	return -1;
     }
 
+    width_a -= ax;
+    height_a -= ay;
+    width_b -= bx;
+    height_b -= by;
+
     if (width_a  != width_b  ||
-	height_a != height_b ||
-	stride_a != stride_b)
+	height_a != height_b)
     {
 	cairo_test_log ("Error: Image size mismatch: (%dx%d@%d) vs. (%dx%d@%d)\n"
 			"       for %s vs. %s\n",
@@ -241,17 +278,19 @@ image_diff_flattened (const char *filename_a,
 
     buf_b_surface =  cairo_image_surface_create_for_data (buf_b,
 							  CAIRO_FORMAT_ARGB32,
-							  width_b, height_b,
+							  width_b + bx, height_b + bx,
 							  stride_b);
 
     buf_diff = xcalloc (stride_a * height_a, 1);
 
-    b_flat = xcalloc (stride_b * height_b, 1);
+    b_flat = xcalloc (stride_a * height_a, 1);
 
     b_flat_surface = cairo_image_surface_create_for_data (b_flat,
 							  CAIRO_FORMAT_ARGB32,
-							  width_b, height_b,
-							  stride_b);
+							  width_a, height_a,
+							  stride_a);
+    /*cairo_surface_set_device_offset (b_flat_surface, -bx, -by);*/
+
     cr = cairo_create (b_flat_surface);
 
     cairo_set_source_rgb (cr, 1, 1, 1);
@@ -263,8 +302,11 @@ image_diff_flattened (const char *filename_a,
     cairo_surface_destroy (b_flat_surface);
     cairo_surface_destroy (buf_b_surface);
 
-    pixels_changed = buffer_diff (buf_a, b_flat, buf_diff,
-				  width_a, height_a, stride_a);
+    pixels_changed = buffer_diff (buf_a + (ay * stride_a) + ax * 4,
+                                  b_flat,
+                                  buf_diff,
+				  width_a, height_a,
+				  stride_a, stride_a, stride_a);
 
     if (pixels_changed) {
 	FILE *png_file = fopen (filename_diff, "wb");
diff --git a/test/buffer-diff.h b/test/buffer-diff.h
index b9c48ed3b..fd9662eac 100644
--- a/test/buffer-diff.h
+++ b/test/buffer-diff.h
@@ -36,7 +36,9 @@ buffer_diff (unsigned char *buf_a,
 	     unsigned char *buf_diff,
 	     int	    width,
 	     int	    height,
-	     int	    stride);
+	     int	    stride_a,
+	     int	    stride_b,
+	     int	    stride_diff);
 
 /* Returns number of pixels changed ignoring the alpha channel.
  * Also fills in a "diff" buffer intended to visually show where the
@@ -48,7 +50,10 @@ buffer_diff_noalpha (unsigned char *buf_a,
 		     unsigned char *buf_diff,
 		     int	    width,
 		     int	    height,
-		     int	    stride);
+		     int	    stride_a,
+		     int	    stride_b,
+		     int	    stride_diff);
+
 
 /* Returns number of pixels changed, (or -1 on error).
  * Also saves a "diff" image intended to visually show where the
@@ -57,13 +62,21 @@ buffer_diff_noalpha (unsigned char *buf_a,
 int
 image_diff (const char *filename_a,
 	    const char *filename_b,
-	    const char *filename_diff);
+	    const char *filename_diff,
+	    int		ax,
+	    int		ay,
+	    int		bx,
+	    int		by);
 
 /* Like image_diff, but blending the contents of b over white first. */
 int
 image_diff_flattened (const char *filename_a,
 		      const char *filename_b,
-		      const char *filename_diff);
+		      const char *filename_diff,
+                      int         ax,
+                      int         ay,
+                      int         bx,
+                      int         by);
 
 
 #endif
diff --git a/test/cairo-test.c b/test/cairo-test.c
index 6615b87e3..6a3d52a5a 100644
--- a/test/cairo-test.c
+++ b/test/cairo-test.c
@@ -78,6 +78,8 @@ static const char *fail_face = "", *normal_face = "";
 #define CAIRO_TEST_REF_SUFFIX "-ref.png"
 #define CAIRO_TEST_DIFF_SUFFIX "-diff.png"
 
+#define NUM_DEVICE_OFFSETS 2
+
 /* A fake format we use for the flattened ARGB output of the PS and
  * PDF surfaces. */
 #define CAIRO_TEST_CONTENT_COLOR_ALPHA_FLATTENED -1
@@ -1403,12 +1405,13 @@ cleanup_svg (void *closure)
 static cairo_test_status_t
 cairo_test_for_target (cairo_test_t *test,
 		       cairo_test_draw_function_t draw,
-		       cairo_test_target_t	 *target)
+		       cairo_test_target_t	 *target,
+		       int			  dev_offset)
 {
     cairo_test_status_t status;
     cairo_surface_t *surface;
     cairo_t *cr;
-    char *png_name, *ref_name, *diff_name;
+    char *png_name, *ref_name, *diff_name, *offset_str;
     char *srcdir;
     char *format;
     cairo_test_status_t ret;
@@ -1418,10 +1421,16 @@ cairo_test_for_target (cairo_test_t *test,
     if (!srcdir)
 	srcdir = ".";
     format = _cairo_test_content_name (target->content);
+
+    if (dev_offset)
+	xasprintf (&offset_str, "-%d", dev_offset);
+    else
+	offset_str = strdup("");
     
+    xasprintf (&png_name, "%s-%s-%s%s%s", test->name,
+	       target->name, format, offset_str, CAIRO_TEST_PNG_SUFFIX);
+
     /* First look for a target/format-specific reference image. */
-    xasprintf (&png_name, "%s-%s-%s%s", test->name,
-	       target->name, format, CAIRO_TEST_PNG_SUFFIX);
     xasprintf (&ref_name, "%s/%s-%s-%s%s", srcdir, test->name,
 	       target->name, format, CAIRO_TEST_REF_SUFFIX);
     if (access (ref_name, F_OK) != 0) {
@@ -1439,11 +1448,22 @@ cairo_test_for_target (cairo_test_t *test,
 		       CAIRO_TEST_REF_SUFFIX);
 	}
     }
-    xasprintf (&diff_name, "%s-%s-%s%s", test->name,
-	       target->name, format, CAIRO_TEST_DIFF_SUFFIX);
+    xasprintf (&diff_name, "%s-%s-%s%s%s", test->name,
+	       target->name, format, offset_str, CAIRO_TEST_DIFF_SUFFIX);
 
     /* Run the actual drawing code. */
+    if (test->width && test->height) {
+	test->width += dev_offset;
+	test->height += dev_offset;
+    }
+
     surface = (target->create_target_surface) (test, target->content, &target->closure);
+
+    if (test->width && test->height) {
+	test->width -= dev_offset;
+	test->height -= dev_offset;;
+    }
+
     if (surface == NULL) {
 	cairo_test_log ("Error: Failed to set %s target\n", target->name);
 	ret = CAIRO_TEST_UNTESTED;
@@ -1457,6 +1477,8 @@ cairo_test_for_target (cairo_test_t *test,
 	goto UNWIND_SURFACE;
     }
 
+    cairo_surface_set_device_offset (surface, dev_offset, dev_offset);
+
     cr = cairo_create (surface);
 
     /* Clear to transparent (or black) depending on whether the target
@@ -1490,9 +1512,9 @@ cairo_test_for_target (cairo_test_t *test,
 	xunlink (png_name);
 	(target->write_to_png) (surface, png_name);
 	if (target->content == CAIRO_TEST_CONTENT_COLOR_ALPHA_FLATTENED)
-	    pixels_changed = image_diff_flattened (png_name, ref_name, diff_name);
+	    pixels_changed = image_diff_flattened (png_name, ref_name, diff_name, dev_offset, dev_offset, 0, 0);
 	else
-	    pixels_changed = image_diff (png_name, ref_name, diff_name);
+	    pixels_changed = image_diff (png_name, ref_name, diff_name, dev_offset, dev_offset, 0, 0);
 	if (pixels_changed) {
 	    if (pixels_changed > 0)
 		cairo_test_log ("Error: %d pixels differ from reference image %s\n",
@@ -1518,6 +1540,7 @@ UNWIND_STRINGS:
     free (png_name);
     free (ref_name);
     free (diff_name);
+    free (offset_str);
 
     return ret;
 }
@@ -1526,7 +1549,7 @@ static cairo_test_status_t
 cairo_test_expecting (cairo_test_t *test, cairo_test_draw_function_t draw,
 		      cairo_test_status_t expectation)
 {
-    int i, num_targets;
+    int i, j, num_targets;
     const char *tname;
     cairo_test_status_t status, ret;
     cairo_test_target_t **targets_to_test;
@@ -1698,39 +1721,45 @@ cairo_test_expecting (cairo_test_t *test, cairo_test_draw_function_t draw,
      */
     ret = CAIRO_TEST_UNTESTED;
     for (i = 0; i < num_targets; i++) {
-    	cairo_test_target_t *target = targets_to_test[i];
-	cairo_test_log ("Testing %s with %s target\n", test->name, target->name);
-	printf ("%s-%s-%s:\t", test->name, target->name,
-		_cairo_test_content_name (target->content));
-
-	status = cairo_test_for_target (test, draw, target);
-
-	cairo_test_log ("TEST: %s TARGET: %s FORMAT: %s RESULT: ",
-			test->name, target->name,
-			_cairo_test_content_name (target->content));
-
-	switch (status) {
-	case CAIRO_TEST_SUCCESS:
-	    printf ("PASS\n");
-	    cairo_test_log ("PASS\n");
-	    if (ret == CAIRO_TEST_UNTESTED)
-		ret = CAIRO_TEST_SUCCESS;
-	    break;
-	case CAIRO_TEST_UNTESTED:
-	    printf ("UNTESTED\n");
-	    cairo_test_log ("UNTESTED\n");
-	    break;
-	default:
-	case CAIRO_TEST_FAILURE:
-	    if (expectation == CAIRO_TEST_FAILURE) {
-		printf ("XFAIL\n");
-		cairo_test_log ("XFAIL\n");
-	    } else {
-		printf ("%sFAIL%s\n", fail_face, normal_face);
-		cairo_test_log ("FAIL\n");
+	for (j = 0; j < NUM_DEVICE_OFFSETS; j++) {
+	    cairo_test_target_t *target = targets_to_test[i];
+	    int dev_offset = j * 25;
+
+	    cairo_test_log ("Testing %s with %s target (dev offset %d)\n", test->name, target->name, dev_offset);
+	    printf ("%s-%s-%s [%d]:\t", test->name, target->name,
+		    _cairo_test_content_name (target->content),
+		    dev_offset);
+
+	    status = cairo_test_for_target (test, draw, target, dev_offset);
+
+	    cairo_test_log ("TEST: %s TARGET: %s FORMAT: %s OFFSET: %d RESULT: ",
+			    test->name, target->name,
+			    _cairo_test_content_name (target->content),
+			    dev_offset);
+
+	    switch (status) {
+	    case CAIRO_TEST_SUCCESS:
+		printf ("PASS\n");
+		cairo_test_log ("PASS\n");
+		if (ret == CAIRO_TEST_UNTESTED)
+		    ret = CAIRO_TEST_SUCCESS;
+		break;
+	    case CAIRO_TEST_UNTESTED:
+		printf ("UNTESTED\n");
+		cairo_test_log ("UNTESTED\n");
+		break;
+	    default:
+	    case CAIRO_TEST_FAILURE:
+		if (expectation == CAIRO_TEST_FAILURE) {
+		    printf ("XFAIL\n");
+		    cairo_test_log ("XFAIL\n");
+		} else {
+		    printf ("%sFAIL%s\n", fail_face, normal_face);
+		    cairo_test_log ("FAIL\n");
+		}
+		ret = status;
+		break;
 	    }
-	    ret = status;
-	    break;
 	}
     }
     if (ret == CAIRO_TEST_UNTESTED)
diff --git a/test/imagediff.c b/test/imagediff.c
index de66b68d2..41d065cce 100644
--- a/test/imagediff.c
+++ b/test/imagediff.c
@@ -34,54 +34,31 @@
 int 
 main (int argc, char *argv[])
 {
-    read_png_status_t status;
-    unsigned char *buffer_a;
-    unsigned int width_a, height_a, stride_a;
-    unsigned char *buffer_b;
-    unsigned int width_b, height_b, stride_b;
+    int total_pixels_changed;
 
-    unsigned char *buffer;
-    unsigned int width, height, stride;
-    int buffer_size, total_pixels_changed;
+    unsigned int ax, ay, bx, by;
 
-    if (argc < 2) {
-	fprintf (stderr, "Usage: %s image1.png image2.png\n", argv[0]);
+    if (argc != 3 && argc != 7) {
+	fprintf (stderr, "Usage: %s image1.png image2.png [ax ay bx by]\n", argv[0]);
 	fprintf (stderr, "Computes an output image designed to present a \"visual diff\" such that even\n");
 	fprintf (stderr, "small errors in single pixels are readily apparent in the output.\n");
 	fprintf (stderr, "The output image is written on stdout.\n");
 	exit (1);
     }
 
-    status = read_png_argb32 (argv[1], &buffer_a, &width_a, &height_a, &stride_a);
-    if (status)
-	return 1;
-
-    status = read_png_argb32 (argv[2], &buffer_b, &width_b, &height_b, &stride_b);
-    if (status)
-	return 1;
-
-    if ((width_a == width_b) && (height_a == height_b) && (stride_a == stride_b))
-    {
-	width = width_a;
-	height = height_a;
-	stride = stride_a;
+    if (argc == 7) {
+	ax = strtoul (argv[3], NULL, 0);
+	ay = strtoul (argv[4], NULL, 0);
+	bx = strtoul (argv[5], NULL, 0);
+	by = strtoul (argv[6], NULL, 0);
     } else {
-	fprintf (stderr, "Error. Both images must be the same size\n");
-	return 1;
+	ax = ay = bx = by = 0;
     }
 
-    buffer_size = stride * height;
-    buffer = xmalloc (buffer_size);
-    
-    total_pixels_changed = buffer_diff (buffer_a, buffer_b, buffer,
-					width_a, height_a, stride_a);
-
+    total_pixels_changed = image_diff (argv[1], argv[2], NULL, ax, ay, bx, by);
 
     if (total_pixels_changed)
 	fprintf (stderr, "Total pixels changed: %d\n", total_pixels_changed);
-    write_png_argb32 (buffer, stdout, width, height, stride);
-
-    free (buffer);
 
     return (total_pixels_changed != 0);
 }
diff --git a/test/make-html.pl b/test/make-html.pl
index f4bbb8c88..8b34e1254 100755
--- a/test/make-html.pl
+++ b/test/make-html.pl
@@ -29,8 +29,6 @@
 ## html to stdout that can be used to view all the test results at once.
 ##
 
-# some config options:
-
 # show reference images
 my $config_show_ref = 0;
 
@@ -49,20 +47,22 @@ my $teststats = {};
 foreach (<*.log>) {
   (open LOG, "$_") || next;
   while (<LOG>) {
-    next unless /^TEST: (.*) TARGET: (.*) FORMAT: (.*) RESULT: (.*)$/;
+    next unless /^TEST: (.*) TARGET: (.*) FORMAT: (.*) OFFSET: (.*) RESULT: (.*)$/;
     $tests->{$1} = {} unless $tests->{$1};
     $tests->{$1}->{$2} = {} unless $tests->{$1}->{$2};
-    $tests->{$1}->{$2}->{$3} = $4;
+    $tests->{$1}->{$2}->{$3} = {} unless $tests->{$1}->{$2}->{$3};
+    $tests->{$1}->{$2}->{$3}->{$4} = $5;
 
     $teststats->{$2} = {"PASS" => 0, "FAIL" => 0, "XFAIL" => 0, "UNTESTED" => 0}
       unless $teststats->{$2};
-    ($teststats->{$2}->{$4})++;
+    ($teststats->{$2}->{$5})++;
   }
   close LOG;
 }
 
 my $targeth = {};
 my $formath = {};
+my $offseth = {};
 
 foreach my $testname (sort(keys %$tests)) {
   my $v0 = $tests->{$testname};
@@ -71,13 +71,19 @@ foreach my $testname (sort(keys %$tests)) {
 
     $targeth->{$targetname} = 1;
     foreach my $formatname (sort(keys %$v1)) {
+      my $v2 = $v1->{$formatname};
+
       $formath->{$formatname} = 1;
+      foreach my $offsetval (sort(keys %$v2)) {
+        $offseth->{$offsetval} = 1;
+      }
     }
   }
 }
 
 my @targets = sort(keys %$targeth);
 my @formats = sort(keys %$formath);
+my @offsets = sort(keys %$offseth);
 
 sub printl {
   print @_, "\n";
@@ -133,72 +139,78 @@ sub testref {
 }
 
 sub testfiles {
-  my ($test, $target, $format, $rest) = @_;
+  my ($test, $target, $format, $offset, $rest) = @_;
   my $fmtstr = "";
+  my $offstr = "";
   if ($format eq "rgb24") {
     $fmtstr = "-rgb24";
   } elsif ($format eq "argb32") {
     $fmtstr = "-argb32";
   }
+  if ($offset ne "0") {
+    $offstr = "-" . $offset;
+  }
 
-  return ("out" => "$test-$target$fmtstr-out.png",
-	  "diff" => "$test-$target$fmtstr-diff.png");
+  return ("out" => "$test-$target$fmtstr$offstr-out.png",
+	  "diff" => "$test-$target$fmtstr$offstr-diff.png");
 }
 
 foreach my $test (sort(keys %$tests)) {
-  foreach my $format (@formats) {
-    my $testline = "";
-
-    my $num_failed = 0;
-
-    foreach my $target (@targets) {
-      my $tgtdata = $tests->{$test}->{$target};
-      if ($tgtdata) {
-	my $testres = $tgtdata->{$format};
-	if ($testres) {
-	  my %testfiles = testfiles($test, $target, $format);
-	  $testline .= "<td class=\"$testres\">";
-	  $stats{$target}{$testres}++;
-	  if ($testres eq "PASS") {
-	    if ($config_show_all) {
-	      $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
-	    }
-	  } elsif ($testres eq "FAIL") {
-	    $num_failed++;
-
-	    if ($config_show_fail || $config_show_all) {
-	      $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
-	      $testline .= "<hr size=\"1\">";
-	      $testline .= "<a href=\"" . $testfiles{"diff"} . "\"><img src=\"" . $testfiles{"diff"} . "\"></a>";
-	    }
-	  } elsif ($testres eq "XFAIL") {
-	    #nothing
-	    if ($config_show_all) {
-	      $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
-	      $testline .= "<hr size=\"1\">";
-	      $testline .= "<a href=\"" . $testfiles{"diff"} . "\"><img src=\"" . $testfiles{"diff"} . "\"></a>";
-	    }
-	  }
-
-	  $testline .= "</td>";
-	} else {
-	  $testline .= '<td></td>';
-	}
-      } else {
-	$testline .= '<td></td>';
+  foreach my $offset (@offsets) {
+    foreach my $format (@formats) {
+      my $testline = "";
+
+      my $num_failed = 0;
+
+      foreach my $target (@targets) {
+        my $tgtdata = $tests->{$test}->{$target};
+        if ($tgtdata) {
+          my $testres = $tgtdata->{$format}->{$offset};
+          if ($testres) {
+            my %testfiles = testfiles($test, $target, $format, $offset);
+            $testline .= "<td class=\"$testres\">";
+            $stats{$target}{$testres}++;
+            if ($testres eq "PASS") {
+              if ($config_show_all) {
+                $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
+              }
+            } elsif ($testres eq "FAIL") {
+              $num_failed++;
+
+              if ($config_show_fail || $config_show_all) {
+                $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
+                $testline .= "<hr size=\"1\">";
+                $testline .= "<a href=\"" . $testfiles{"diff"} . "\"><img src=\"" . $testfiles{"diff"} . "\"></a>";
+              }
+            } elsif ($testres eq "XFAIL") {
+              #nothing
+              if ($config_show_all) {
+                $testline .= "<a href=\"" . $testfiles{"out"} . "\"><img src=\"" . $testfiles{"out"} . "\"></a>";
+                $testline .= "<hr size=\"1\">";
+                $testline .= "<a href=\"" . $testfiles{"diff"} . "\"><img src=\"" . $testfiles{"diff"} . "\"></a>";
+              }
+            }
+
+            $testline .= "</td>";
+          } else {
+            $testline .= '<td></td>';
+          }
+        } else {
+          $testline .= '<td></td>';
+        }
       }
-    }
 
-    my $testref = testref($test, $format);
-    print '<tr><td>', "<a href=\"$testref\">", $test, ' (', $format, ')</a></td>';
+      my $testref = testref($test, $format);
+      print '<tr><td>', "<a href=\"$testref\">", $test, ' (', $format, '/', $offset, ')</a></td>';
 
-    if ($config_show_ref) {
-      print "<td><a href=\"$testref\"><img src=\"$testref\"></img></a></td>";
-    }
+      if ($config_show_ref) {
+        print "<td><a href=\"$testref\"><img src=\"$testref\"></img></a></td>";
+      }
 
-    print $testline;
+      print $testline;
 
-    print "</tr>\n";
+      print "</tr>\n";
+    }
   }
 }
 
diff --git a/test/xlib-surface.c b/test/xlib-surface.c
index 0df5514fa..1aea8734d 100644
--- a/test/xlib-surface.c
+++ b/test/xlib-surface.c
@@ -160,6 +160,8 @@ do_test (Display        *dpy,
 				       diff_data + offset,
 				       SIZE - OFFSCREEN_OFFSET,
 				       SIZE - OFFSCREEN_OFFSET,
+				       4 * SIZE,
+				       4 * SIZE,
 				       4 * SIZE);
     } else {
 	result = !buffer_diff_noalpha (reference_data,
@@ -167,6 +169,8 @@ do_test (Display        *dpy,
 				       diff_data,
 				       SIZE,
 				       SIZE,
+				       4 * SIZE,
+				       4 * SIZE,
 				       4 * SIZE);
     }