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]

1 files changed, 70 insertions, 28 deletions

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");