test: Test negative strides

Pixman supports negative strides, but up until now they haven't been
tested outside of stress-test. This commit adds testing of negative
strides to blitters-test, scaling-test, affine-test, rotate-test, and
composite-traps-test.

6 files changed, 98 insertions, 13 deletions

diff --git a/test/affine-test.c b/test/affine-test.c
index 03d296f..8e19023 100644
--- a/test/affine-test.c
+++ b/test/affine-test.c
@@ -80,6 +80,18 @@ test_composite (int      testnum,
     prng_randmemset (srcbuf, src_stride * src_height, 0);
     prng_randmemset (dstbuf, dst_stride * dst_height, 0);
 
+    if (prng_rand_n (2) == 0)
+    {
+	srcbuf += (src_stride / 4) * (src_height - 1);
+	src_stride = - src_stride;
+    }
+
+    if (prng_rand_n (2) == 0)
+    {
+	dstbuf += (dst_stride / 4) * (dst_height - 1);
+	dst_stride = - dst_stride;
+    }
+    
     src_fmt = src_bpp == 4 ? (prng_rand_n (2) == 0 ?
                               PIXMAN_a8r8g8b8 : PIXMAN_x8r8g8b8) : PIXMAN_r5g6b5;
 
@@ -281,6 +293,12 @@ test_composite (int      testnum,
     pixman_image_unref (src_img);
     pixman_image_unref (dst_img);
 
+    if (src_stride < 0)
+	srcbuf += (src_stride / 4) * (src_height - 1);
+
+    if (dst_stride < 0)
+	dstbuf += (dst_stride / 4) * (dst_height - 1);
+    
     free (srcbuf);
     free (dstbuf);
 
@@ -289,9 +307,9 @@ test_composite (int      testnum,
 }
 
 #if BILINEAR_INTERPOLATION_BITS == 7
-#define CHECKSUM 0xBC00B1DF
+#define CHECKSUM 0xBE724CFE
 #elif BILINEAR_INTERPOLATION_BITS == 4
-#define CHECKSUM 0xA227306B
+#define CHECKSUM 0x79BBE501
 #else
 #define CHECKSUM 0x00000000
 #endif
diff --git a/test/blitters-test.c b/test/blitters-test.c
index 2120daf..af94835 100644
--- a/test/blitters-test.c
+++ b/test/blitters-test.c
@@ -57,6 +57,13 @@ create_random_image (pixman_format_code_t *allowed_formats,
 	prng_randmemset (buf, stride * height, RANDMEMSET_MORE_00_AND_FF);
     }
 
+    /* test negative stride */
+    if (prng_rand_n (4) == 0)
+    {
+	buf += (stride / 4) * (height - 1);
+	stride = - stride;
+    }
+    
     img = pixman_image_create_bits (fmt, width, height, buf, stride);
 
     if (PIXMAN_FORMAT_TYPE (fmt) == PIXMAN_TYPE_COLOR)
@@ -89,6 +96,9 @@ free_random_image (uint32_t initcrc,
     if (fmt != PIXMAN_null)
 	crc32 = compute_crc32_for_image (initcrc, img);
 
+    if (img->bits.rowstride < 0)
+	data += img->bits.rowstride * (img->bits.height - 1);
+
     pixman_image_unref (img);
     free (data);
 
@@ -385,6 +395,6 @@ main (int argc, const char *argv[])
     }
 
     return fuzzer_test_main("blitters", 2000000,
-			    0x0CF3283B,
+			    0xAC8FDA98,
 			    test_composite, argc, argv);
 }
diff --git a/test/composite-traps-test.c b/test/composite-traps-test.c
index 44d5012..86a0355 100644
--- a/test/composite-traps-test.c
+++ b/test/composite-traps-test.c
@@ -97,19 +97,25 @@ test_composite (int      testnum,
 	int src_width = prng_rand_n (MAX_SRC_WIDTH) + 1;
 	int src_height = prng_rand_n (MAX_SRC_HEIGHT) + 1;
 	int src_stride = src_width * src_bpp + prng_rand_n (MAX_STRIDE) * src_bpp;
-	uint32_t *bits;
+	uint32_t *bits, *orig;
 
 	src_x = -(src_width / 4) + prng_rand_n (src_width * 3 / 2);
 	src_y = -(src_height / 4) + prng_rand_n (src_height * 3 / 2);
 
 	src_stride = (src_stride + 3) & ~3;
 	
-	bits = (uint32_t *)make_random_bytes (src_stride * src_height);
+	orig = bits = (uint32_t *)make_random_bytes (src_stride * src_height);
 
+	if (prng_rand_n (2) == 0)
+	{
+	    bits += (src_stride / 4) * (src_height - 1);
+	    src_stride = - src_stride;
+	}
+	
 	src_img = pixman_image_create_bits (
 	    src_format, src_width, src_height, bits, src_stride);
 
-	pixman_image_set_destroy_function (src_img, destroy_bits, bits);
+	pixman_image_set_destroy_function (src_img, destroy_bits, orig);
 
 	if (prng_rand_n (8) == 0)
 	{
@@ -153,6 +159,12 @@ test_composite (int      testnum,
 	
 	dst_bits = (uint32_t *)make_random_bytes (dst_stride * dst_height);
 
+	if (prng_rand_n (2) == 0)
+	{
+	    dst_bits += (dst_stride / 4) * (dst_height - 1);
+	    dst_stride = - dst_stride;
+	}
+	
 	dst_x = -(dst_width / 4) + prng_rand_n (dst_width * 3 / 2);
 	dst_y = -(dst_height / 4) + prng_rand_n (dst_height * 3 / 2);
 	
@@ -219,6 +231,9 @@ test_composite (int      testnum,
     if (verbose)
 	print_image (dst_img);
 
+    if (dst_stride < 0)
+	dst_bits += (dst_stride / 4) * (dst_height - 1);
+    
     fence_free (dst_bits);
     
     pixman_image_unref (src_img);
@@ -232,6 +247,6 @@ test_composite (int      testnum,
 int
 main (int argc, const char *argv[])
 {
-    return fuzzer_test_main("composite traps", 40000, 0x749BCC57,
+    return fuzzer_test_main("composite traps", 40000, 0xAF41D210,
 			    test_composite, argc, argv);
 }
diff --git a/test/rotate-test.c b/test/rotate-test.c
index 9d2a620..18ca60d 100644
--- a/test/rotate-test.c
+++ b/test/rotate-test.c
@@ -61,16 +61,25 @@ static pixman_image_t *
 make_image (void)
 {
     pixman_format_code_t format = RANDOM_FORMAT();
-    uint32_t *bytes = malloc (WIDTH * HEIGHT * 4);
+    uint32_t *bytes, *orig;
     pixman_image_t *image;
+    int stride;
 
+    orig = bytes = malloc (WIDTH * HEIGHT * 4);
     prng_randmemset (bytes, WIDTH * HEIGHT * 4, 0);
 
+    stride = WIDTH * 4;
+    if (prng_rand_n (2) == 0)
+    {
+	bytes += (stride / 4) * (HEIGHT - 1);
+	stride = - stride;
+    }
+
     image = pixman_image_create_bits (
-	format, WIDTH, HEIGHT, bytes, WIDTH * 4);
+	format, WIDTH, HEIGHT, bytes, stride);
 
     pixman_image_set_transform (image, RANDOM_TRANSFORM());
-    pixman_image_set_destroy_function (image, on_destroy, bytes);
+    pixman_image_set_destroy_function (image, on_destroy, orig);
     pixman_image_set_repeat (image, PIXMAN_REPEAT_NORMAL);
 
     image_endian_swap (image);
@@ -106,6 +115,6 @@ int
 main (int argc, const char *argv[])
 {
     return fuzzer_test_main ("rotate", 15000,
-			     0xECF5E426,
+			     0x81E9EC2F,
 			     test_transform, argc, argv);
 }
diff --git a/test/scaling-test.c b/test/scaling-test.c
index 0778d2d..e2f7fa9 100644
--- a/test/scaling-test.c
+++ b/test/scaling-test.c
@@ -147,6 +147,24 @@ test_composite (int      testnum,
     src_fmt = get_format (src_bpp);
     dst_fmt = get_format (dst_bpp);
 
+    if (prng_rand_n (2))
+    {
+	srcbuf += (src_stride / 4) * (src_height - 1);
+	src_stride = - src_stride;
+    }
+
+    if (prng_rand_n (2))
+    {
+	maskbuf += (mask_stride / 4) * (mask_height - 1);
+	mask_stride = - mask_stride;
+    }
+
+    if (prng_rand_n (2))
+    {
+	dstbuf += (dst_stride / 4) * (dst_height - 1);
+	dst_stride = - dst_stride;
+    }
+
     src_img = pixman_image_create_bits (
         src_fmt, src_width, src_height, srcbuf, src_stride);
 
@@ -349,6 +367,15 @@ test_composite (int      testnum,
     pixman_image_unref (mask_img);
     pixman_image_unref (dst_img);
 
+    if (src_stride < 0)
+	srcbuf += (src_stride / 4) * (src_height - 1);
+
+    if (mask_stride < 0)
+	maskbuf += (mask_stride / 4) * (mask_height - 1);
+
+    if (dst_stride < 0)
+	dstbuf += (dst_stride / 4) * (dst_height - 1);
+
     free (srcbuf);
     free (maskbuf);
     free (dstbuf);
@@ -358,9 +385,9 @@ test_composite (int      testnum,
 }
 
 #if BILINEAR_INTERPOLATION_BITS == 7
-#define CHECKSUM 0xCE8EC6BA
+#define CHECKSUM 0x92E0F068
 #elif BILINEAR_INTERPOLATION_BITS == 4
-#define CHECKSUM 0xAB1D39BE
+#define CHECKSUM 0x8EFFA1E5
 #else
 #define CHECKSUM 0x00000000
 #endif
diff --git a/test/utils.c b/test/utils.c
index a693f30..3400747 100644
--- a/test/utils.c
+++ b/test/utils.c
@@ -150,6 +150,12 @@ compute_crc32_for_image_internal (uint32_t        crc32,
     uint32_t mask = 0xffffffff;
     int i;
 
+    if (stride < 0)
+    {
+	data += (stride / 4) * (height - 1);
+	stride = - stride;
+    }
+
     /* mask unused 'x' part */
     if (PIXMAN_FORMAT_BPP (fmt) - PIXMAN_FORMAT_DEPTH (fmt) &&
 	PIXMAN_FORMAT_DEPTH (fmt) != 0)