xserver pixman mesa git update 19 jan 2011

3 files changed, 458 insertions, 259 deletions

diff --git a/pixman/test/Makefile.am b/pixman/test/Makefile.am
index 71e535374..8d8471d1c 100644
--- a/pixman/test/Makefile.am
+++ b/pixman/test/Makefile.am
@@ -92,6 +92,7 @@ TESTPROGRAMS_GTK =		\
 	clip-in			\
 	composite-test		\
 	gradient-test		\
+	radial-test		\
 	alpha-test		\
 	screen-test		\
 	convolution-test	\
@@ -102,6 +103,9 @@ INCLUDES += $(GTK_CFLAGS)
 gradient_test_LDADD = $(GTK_LDADD)
 gradient_test_SOURCES = gradient-test.c $(GTK_UTILS)
 
+radial_test_LDADD = $(GTK_LDADD)
+radial_test_SOURCES = radial-test.c utils.c utils.h $(GTK_UTILS)
+
 alpha_test_LDADD = $(GTK_LDADD)
 alpha_test_SOURCES = alpha-test.c $(GTK_UTILS)
 
diff --git a/pixman/test/alphamap.c b/pixman/test/alphamap.c
index ba3130e5d..554b309fb 100644
--- a/pixman/test/alphamap.c
+++ b/pixman/test/alphamap.c
@@ -1,259 +1,256 @@
-#include <stdio.h>

-#include <stdlib.h>

-#include "utils.h"

-

-#define WIDTH 100

-#define HEIGHT 100

-

-static const pixman_format_code_t formats[] =

-{

-    PIXMAN_a8r8g8b8,

-    PIXMAN_a2r10g10b10,

-    PIXMAN_a4r4g4b4,

-    PIXMAN_a8

-};

-

-static const pixman_format_code_t alpha_formats[] =

-{

-    PIXMAN_null,

-    PIXMAN_a8,

-    PIXMAN_a2r10g10b10,

-    PIXMAN_a4r4g4b4

-};

-

-static const int origins[] =

-{

-    0, 10, -100

-};

-

-static const char *

-format_name (pixman_format_code_t format)

-{

-    if (format == PIXMAN_a8)

-	return "a8";

-    else if (format == PIXMAN_a2r10g10b10)

-	return "a2r10g10b10";

-    else if (format == PIXMAN_a8r8g8b8)

-	return "a8r8g8b8";

-    else if (format == PIXMAN_a4r4g4b4)

-	return "a4r4g4b4";

-    else if (format == PIXMAN_null)

-	return "none";

-    else

-	assert (0);

-

-    return "<unknown - bug in alphamap.c>";

-}

-

-static void

-on_destroy (pixman_image_t *image, void *data)

-{

-    uint32_t *bits = pixman_image_get_data (image);

-

-    fence_free (bits);

-}

-

-static pixman_image_t *

-make_image (pixman_format_code_t format)

-{

-    uint32_t *bits;

-    uint8_t bpp = PIXMAN_FORMAT_BPP (format) / 8;

-    pixman_image_t *image;

-

-    bits = (uint32_t *)make_random_bytes (WIDTH * HEIGHT * bpp);

-

-    image = pixman_image_create_bits (format, WIDTH, HEIGHT, bits, WIDTH * bpp);

-

-    if (image && bits)

-	pixman_image_set_destroy_function (image, on_destroy, NULL);

-

-    return image;

-}

-

-static pixman_image_t *

-create_image (pixman_format_code_t format, pixman_format_code_t alpha_format,

-	      int alpha_origin_x, int alpha_origin_y)

-{

-    pixman_image_t *image = make_image (format);

-

-    if (alpha_format != PIXMAN_null)

-    {

-	pixman_image_t *alpha = make_image (alpha_format);

-

-	pixman_image_set_alpha_map (image, alpha,

-				    alpha_origin_x, alpha_origin_y);

-	pixman_image_unref (alpha);

-    }

-

-    return image;

-}

-

-static uint8_t

-get_alpha (pixman_image_t *image, int x, int y, int orig_x, int orig_y)

-{

-    uint8_t *bits;

-    uint8_t r;

-

-    if (image->common.alpha_map)

-    {

-	if (x - orig_x >= 0 && x - orig_x < WIDTH &&

-	    y - orig_y >= 0 && y - orig_y < HEIGHT)

-	{

-	    image = (pixman_image_t *)image->common.alpha_map;

-

-	    x -= orig_x;

-	    y -= orig_y;

-	}

-	else

-	{

-	    return 0;

-	}

-    }

-

-    bits = (uint8_t *)image->bits.bits;

-

-    if (image->bits.format == PIXMAN_a8)

-    {

-	r = bits[y * WIDTH + x];

-    }

-    else if (image->bits.format == PIXMAN_a2r10g10b10)

-    {

-	r = ((uint32_t *)bits)[y * WIDTH + x] >> 30;

-	r |= r << 2;

-	r |= r << 4;

-    }

-    else if (image->bits.format == PIXMAN_a8r8g8b8)

-    {

-	r = ((uint32_t *)bits)[y * WIDTH + x] >> 24;

-    }

-    else if (image->bits.format == PIXMAN_a4r4g4b4)

-    {

-	r = ((uint16_t *)bits)[y * WIDTH + x] >> 12;

-	r |= r << 4;

-    }

-    else

-    {

-	assert (0);

-    }

-

-    return r;

-}

-

-#define ARRAY_LENGTH(A) ((int) (sizeof (A) / sizeof ((A) [0])))

-

-static int

-run_test (int s, int d, int sa, int da, int soff, int doff)

-{

-    pixman_format_code_t sf = formats[s];

-    pixman_format_code_t df = formats[d];

-    pixman_format_code_t saf = alpha_formats[sa];

-    pixman_format_code_t daf = alpha_formats[da];

-    pixman_image_t *src, *dst, *orig_dst;

-    pixman_transform_t t1;

-    int j, k;

-    int n_alpha_bits;

-

-    soff = origins[soff];

-    doff = origins[doff];

-

-    n_alpha_bits = PIXMAN_FORMAT_A (df);

-    if (daf != PIXMAN_null)

-	n_alpha_bits = PIXMAN_FORMAT_A (daf);

-

-

-    src = create_image (sf, saf, soff, soff);

-    orig_dst = create_image (df, daf, doff, doff);

-    dst = create_image (df, daf, doff, doff);

-

-    /* Transformations on destinations should be ignored, so just set some

-     * random one.

-     */

-    pixman_transform_init_identity (&t1);

-    pixman_transform_scale (&t1, NULL, pixman_int_to_fixed (100), pixman_int_to_fixed (11));

-    pixman_transform_rotate (&t1, NULL, pixman_double_to_fixed (0.5), pixman_double_to_fixed (0.11));

-    pixman_transform_translate (&t1, NULL, pixman_int_to_fixed (11), pixman_int_to_fixed (17));

-

-#if 0

-    /* Unfortunately, this is actually broken at the moment, so we can't

-     * actually turn it on

-     */

-    pixman_image_set_transform (dst, &t1);

-#endif

-

-    pixman_image_composite (PIXMAN_OP_SRC, orig_dst, NULL, dst,

-			    0, 0, 0, 0, 0, 0, WIDTH, HEIGHT);

-

-    pixman_image_composite (PIXMAN_OP_ADD, src, NULL, dst,

-			    0, 0, 0, 0, 0, 0, WIDTH, HEIGHT);

-

-    for (j = MAX (doff, 0); j < MIN (HEIGHT, HEIGHT + doff); ++j)

-    {

-	for (k = MAX (doff, 0); k < MIN (WIDTH, WIDTH + doff); ++k)

-	{

-	    uint8_t sa, da, oda, ref;

-

-	    sa = get_alpha (src, k, j, soff, soff);

-	    da = get_alpha (dst, k, j, doff, doff);

-	    oda = get_alpha (orig_dst, k, j, doff, doff);

-

-	    if (sa + oda > 255)

-		ref = 255;

-	    else

-		ref = sa + oda;

-

-	    if (da >> (8 - n_alpha_bits) != ref >> (8 - n_alpha_bits))

-	    {

-		printf ("\nWrong alpha value at (%d, %d). Should be 0x%x; got 0x%x. Source was 0x%x, original dest was 0x%x\n",

-			k, j, ref, da, sa, oda);

-

-		printf ("src: %s, alpha: %s, origin %d %d\ndst: %s, alpha: %s, origin: %d %d\n\n",

-			format_name (sf),

-			format_name (saf),

-			soff, soff,

-			format_name (df),

-			format_name (daf),

-			doff, doff);

-		return 1;

-	    }

-	}

-    }

-

-    pixman_image_set_alpha_map (src, NULL, 0, 0);

-    pixman_image_set_alpha_map (dst, NULL, 0, 0);

-    pixman_image_set_alpha_map (orig_dst, NULL, 0, 0);

-

-    pixman_image_unref (src);

-    pixman_image_unref (dst);

-    pixman_image_unref (orig_dst);

-

-    return 0;

-}

-

-int

-main (int argc, char **argv)

-{

-    int i, j, a, b, x, y;

-

-    for (i = 0; i < ARRAY_LENGTH (formats); ++i)

-    {

-	for (j = 0; j < ARRAY_LENGTH (formats); ++j)

-	{

-	    for (a = 0; a < ARRAY_LENGTH (alpha_formats); ++a)

-	    {

-		for (b = 0; b < ARRAY_LENGTH (alpha_formats); ++b)

-		{

-		    for (x = 0; x < ARRAY_LENGTH (origins); ++x)

-		    {

-			for (y = 0; y < ARRAY_LENGTH (origins); ++y)

-			{

-			    if (run_test (i, j, a, b, x, y) != 0)

-				return 1;

-			}

-		    }

-		}

-	    }

-	}

-    }

-

-    return 0;

-}

+#include <stdio.h>
+#include <stdlib.h>
+#include "utils.h"
+
+#define WIDTH 100
+#define HEIGHT 100
+
+static const pixman_format_code_t formats[] =
+{
+    PIXMAN_a8r8g8b8,
+    PIXMAN_a2r10g10b10,
+    PIXMAN_a4r4g4b4,
+    PIXMAN_a8
+};
+
+static const pixman_format_code_t alpha_formats[] =
+{
+    PIXMAN_null,
+    PIXMAN_a8,
+    PIXMAN_a2r10g10b10,
+    PIXMAN_a4r4g4b4
+};
+
+static const int origins[] =
+{
+    0, 10, -100
+};
+
+static const char *
+format_name (pixman_format_code_t format)
+{
+    if (format == PIXMAN_a8)
+	return "a8";
+    else if (format == PIXMAN_a2r10g10b10)
+	return "a2r10g10b10";
+    else if (format == PIXMAN_a8r8g8b8)
+	return "a8r8g8b8";
+    else if (format == PIXMAN_a4r4g4b4)
+	return "a4r4g4b4";
+    else if (format == PIXMAN_null)
+	return "none";
+    else
+	assert (0);
+
+    return "<unknown - bug in alphamap.c>";
+}
+
+static void
+on_destroy (pixman_image_t *image, void *data)
+{
+    uint32_t *bits = pixman_image_get_data (image);
+
+    fence_free (bits);
+}
+
+static pixman_image_t *
+make_image (pixman_format_code_t format)
+{
+    uint32_t *bits;
+    uint8_t bpp = PIXMAN_FORMAT_BPP (format) / 8;
+    pixman_image_t *image;
+
+    bits = (uint32_t *)make_random_bytes (WIDTH * HEIGHT * bpp);
+
+    image = pixman_image_create_bits (format, WIDTH, HEIGHT, bits, WIDTH * bpp);
+
+    if (image && bits)
+	pixman_image_set_destroy_function (image, on_destroy, NULL);
+
+    return image;
+}
+
+static pixman_image_t *
+create_image (pixman_format_code_t format, pixman_format_code_t alpha_format,
+	      int alpha_origin_x, int alpha_origin_y)
+{
+    pixman_image_t *image = make_image (format);
+
+    if (alpha_format != PIXMAN_null)
+    {
+	pixman_image_t *alpha = make_image (alpha_format);
+
+	pixman_image_set_alpha_map (image, alpha,
+				    alpha_origin_x, alpha_origin_y);
+	pixman_image_unref (alpha);
+    }
+
+    return image;
+}
+
+static uint8_t
+get_alpha (pixman_image_t *image, int x, int y, int orig_x, int orig_y)
+{
+    uint8_t *bits;
+    uint8_t r;
+
+    if (image->common.alpha_map)
+    {
+	if (x - orig_x >= 0 && x - orig_x < WIDTH &&
+	    y - orig_y >= 0 && y - orig_y < HEIGHT)
+	{
+	    image = (pixman_image_t *)image->common.alpha_map;
+
+	    x -= orig_x;
+	    y -= orig_y;
+	}
+	else
+	{
+	    return 0;
+	}
+    }
+
+    bits = (uint8_t *)image->bits.bits;
+
+    if (image->bits.format == PIXMAN_a8)
+    {
+	r = bits[y * WIDTH + x];
+    }
+    else if (image->bits.format == PIXMAN_a2r10g10b10)
+    {
+	r = ((uint32_t *)bits)[y * WIDTH + x] >> 30;
+	r |= r << 2;
+	r |= r << 4;
+    }
+    else if (image->bits.format == PIXMAN_a8r8g8b8)
+    {
+	r = ((uint32_t *)bits)[y * WIDTH + x] >> 24;
+    }
+    else if (image->bits.format == PIXMAN_a4r4g4b4)
+    {
+	r = ((uint16_t *)bits)[y * WIDTH + x] >> 12;
+	r |= r << 4;
+    }
+    else
+    {
+	assert (0);
+    }
+
+    return r;
+}
+
+#define ARRAY_LENGTH(A) ((int) (sizeof (A) / sizeof ((A) [0])))
+
+static int
+run_test (int s, int d, int sa, int da, int soff, int doff)
+{
+    pixman_format_code_t sf = formats[s];
+    pixman_format_code_t df = formats[d];
+    pixman_format_code_t saf = alpha_formats[sa];
+    pixman_format_code_t daf = alpha_formats[da];
+    pixman_image_t *src, *dst, *orig_dst;
+    pixman_transform_t t1;
+    int j, k;
+    int n_alpha_bits;
+
+    soff = origins[soff];
+    doff = origins[doff];
+
+    n_alpha_bits = PIXMAN_FORMAT_A (df);
+    if (daf != PIXMAN_null)
+	n_alpha_bits = PIXMAN_FORMAT_A (daf);
+
+
+    src = create_image (sf, saf, soff, soff);
+    orig_dst = create_image (df, daf, doff, doff);
+    dst = create_image (df, daf, doff, doff);
+
+    /* Transformations, repeats and filters on destinations should be ignored,
+     * so just set some random ones.
+     */
+    pixman_transform_init_identity (&t1);
+    pixman_transform_scale (&t1, NULL, pixman_int_to_fixed (100), pixman_int_to_fixed (11));
+    pixman_transform_rotate (&t1, NULL, pixman_double_to_fixed (0.5), pixman_double_to_fixed (0.11));
+    pixman_transform_translate (&t1, NULL, pixman_int_to_fixed (11), pixman_int_to_fixed (17));
+
+    pixman_image_set_transform (dst, &t1);
+    pixman_image_set_filter (dst, PIXMAN_FILTER_BILINEAR, NULL, 0);
+    pixman_image_set_repeat (dst, PIXMAN_REPEAT_REFLECT);
+
+    pixman_image_composite (PIXMAN_OP_SRC, orig_dst, NULL, dst,
+			    0, 0, 0, 0, 0, 0, WIDTH, HEIGHT);
+
+    pixman_image_composite (PIXMAN_OP_ADD, src, NULL, dst,
+			    0, 0, 0, 0, 0, 0, WIDTH, HEIGHT);
+
+    for (j = MAX (doff, 0); j < MIN (HEIGHT, HEIGHT + doff); ++j)
+    {
+	for (k = MAX (doff, 0); k < MIN (WIDTH, WIDTH + doff); ++k)
+	{
+	    uint8_t sa, da, oda, ref;
+
+	    sa = get_alpha (src, k, j, soff, soff);
+	    da = get_alpha (dst, k, j, doff, doff);
+	    oda = get_alpha (orig_dst, k, j, doff, doff);
+
+	    if (sa + oda > 255)
+		ref = 255;
+	    else
+		ref = sa + oda;
+
+	    if (da >> (8 - n_alpha_bits) != ref >> (8 - n_alpha_bits))
+	    {
+		printf ("\nWrong alpha value at (%d, %d). Should be 0x%x; got 0x%x. Source was 0x%x, original dest was 0x%x\n",
+			k, j, ref, da, sa, oda);
+
+		printf ("src: %s, alpha: %s, origin %d %d\ndst: %s, alpha: %s, origin: %d %d\n\n",
+			format_name (sf),
+			format_name (saf),
+			soff, soff,
+			format_name (df),
+			format_name (daf),
+			doff, doff);
+		return 1;
+	    }
+	}
+    }
+
+    pixman_image_set_alpha_map (src, NULL, 0, 0);
+    pixman_image_set_alpha_map (dst, NULL, 0, 0);
+    pixman_image_set_alpha_map (orig_dst, NULL, 0, 0);
+
+    pixman_image_unref (src);
+    pixman_image_unref (dst);
+    pixman_image_unref (orig_dst);
+
+    return 0;
+}
+
+int
+main (int argc, char **argv)
+{
+    int i, j, a, b, x, y;
+
+    for (i = 0; i < ARRAY_LENGTH (formats); ++i)
+    {
+	for (j = 0; j < ARRAY_LENGTH (formats); ++j)
+	{
+	    for (a = 0; a < ARRAY_LENGTH (alpha_formats); ++a)
+	    {
+		for (b = 0; b < ARRAY_LENGTH (alpha_formats); ++b)
+		{
+		    for (x = 0; x < ARRAY_LENGTH (origins); ++x)
+		    {
+			for (y = 0; y < ARRAY_LENGTH (origins); ++y)
+			{
+			    if (run_test (i, j, a, b, x, y) != 0)
+				return 1;
+			}
+		    }
+		}
+	    }
+	}
+    }
+
+    return 0;
+}
diff --git a/pixman/test/radial-test.c b/pixman/test/radial-test.c
new file mode 100644
index 000000000..5d716c339
--- /dev/null
+++ b/pixman/test/radial-test.c
@@ -0,0 +1,198 @@
+#include "utils.h"
+#include "gtk-utils.h"
+
+#define NUM_GRADIENTS 7
+#define NUM_STOPS 3
+#define NUM_REPEAT 4
+#define SIZE 128
+#define WIDTH (SIZE * NUM_GRADIENTS)
+#define HEIGHT (SIZE * NUM_REPEAT)
+
+/*
+ * We want to test all the possible relative positions of the start
+ * and end circle:
+ *
+ *  - The start circle can be smaller/equal/bigger than the end
+ *    circle. A radial gradient can be classified in one of these
+ *    three cases depending on the sign of dr.
+ *
+ *  - The smaller circle can be completely inside/internally
+ *    tangent/outside (at least in part) of the bigger circle. This
+ *    classification is the same as the one which can be computed by
+ *    examining the sign of a = (dx^2 + dy^2 - dr^2).
+ *
+ *  - If the two circles have the same size, neither can be inside or
+ *    internally tangent
+ *
+ * This test draws radial gradients whose circles always have the same
+ * centers (0, 0) and (1, 0), but with different radiuses. From left
+ * to right:
+ *
+ * - Small start circle completely inside the end circle
+ *     0.25 -> 1.75; dr =  1.5 > 0; a = 1 - 1.50^2 < 0
+ *
+ * - Small start circle internally tangent to the end circle
+ *     0.50 -> 1.50; dr =  1.0 > 0; a = 1 - 1.00^2 = 0
+ *
+ * - Small start circle outside of the end circle
+ *     0.50 -> 1.00; dr =  0.5 > 0; a = 1 - 0.50^2 > 0
+ *
+ * - Start circle with the same size as the end circle
+ *     1.00 -> 1.00; dr =  0.0 = 0; a = 1 - 0.00^2 > 0
+ *
+ * - Small end circle outside of the start circle
+ *     1.00 -> 0.50; dr = -0.5 > 0; a = 1 - 0.50^2 > 0
+ *
+ * - Small end circle internally tangent to the start circle
+ *     1.50 -> 0.50; dr = -1.0 > 0; a = 1 - 1.00^2 = 0
+ *
+ * - Small end circle completely inside the start circle
+ *     1.75 -> 0.25; dr = -1.5 > 0; a = 1 - 1.50^2 < 0
+ *
+ */
+
+const static double radiuses[NUM_GRADIENTS] = {
+    0.25,
+    0.50,
+    0.50,
+    1.00,
+    1.00,
+    1.50,
+    1.75
+};
+
+#define double_to_color(x)					\
+    (((uint32_t) ((x)*65536)) - (((uint32_t) ((x)*65536)) >> 16))
+
+#define PIXMAN_STOP(offset,r,g,b,a)		\
+    { pixman_double_to_fixed (offset),		\
+	{					\
+	double_to_color (r),			\
+	double_to_color (g),			\
+	double_to_color (b),			\
+	double_to_color (a)			\
+	}					\
+    }
+
+static const pixman_gradient_stop_t stops[NUM_STOPS] = {
+    PIXMAN_STOP (0.0,        1, 0, 0, 0.75),
+    PIXMAN_STOP (0.70710678, 0, 1, 0, 0),
+    PIXMAN_STOP (1.0,        0, 0, 1, 1)
+};
+
+static pixman_image_t *
+create_radial (int index)
+{
+    pixman_point_fixed_t p0, p1;
+    pixman_fixed_t r0, r1;
+    double x0, x1, radius0, radius1, left, right, center;
+
+    x0 = 0;
+    x1 = 1;
+    radius0 = radiuses[index];
+    radius1 = radiuses[NUM_GRADIENTS - index - 1];
+
+    /* center the gradient */
+    left = MIN (x0 - radius0, x1 - radius1);
+    right = MAX (x0 + radius0, x1 + radius1);
+    center = (left + right) * 0.5;
+    x0 -= center;
+    x1 -= center;
+
+    /* scale to make it fit within a 1x1 rect centered in (0,0) */
+    x0 *= 0.25;
+    x1 *= 0.25;
+    radius0 *= 0.25;
+    radius1 *= 0.25;
+
+    p0.x = pixman_double_to_fixed (x0);
+    p0.y = pixman_double_to_fixed (0);
+
+    p1.x = pixman_double_to_fixed (x1);
+    p1.y = pixman_double_to_fixed (0);
+
+    r0 = pixman_double_to_fixed (radius0);
+    r1 = pixman_double_to_fixed (radius1);
+
+    return pixman_image_create_radial_gradient (&p0, &p1,
+						r0, r1,
+						stops, NUM_STOPS);
+}
+
+static const pixman_repeat_t repeat[NUM_REPEAT] = {
+    PIXMAN_REPEAT_NONE,
+    PIXMAN_REPEAT_NORMAL,
+    PIXMAN_REPEAT_REFLECT,
+    PIXMAN_REPEAT_PAD
+};
+
+int
+main (int argc, char **argv)
+{
+    pixman_transform_t transform;
+    pixman_image_t *src_img, *dest_img;
+    int i, j;
+
+    enable_fp_exceptions ();
+
+    dest_img = pixman_image_create_bits (PIXMAN_a8r8g8b8,
+					 WIDTH, HEIGHT,
+					 NULL, 0);
+
+    pixman_transform_init_identity (&transform);
+
+    /*
+     * The create_radial() function returns gradients centered in the
+     * origin and whose interesting part fits a 1x1 square. We want to
+     * paint these gradients on a SIZExSIZE square and to make things
+     * easier we want the origin in the top-left corner of the square
+     * we want to see.
+     */
+    pixman_transform_translate (NULL, &transform,
+				pixman_double_to_fixed (0.5),
+				pixman_double_to_fixed (0.5));
+
+    pixman_transform_scale (NULL, &transform,
+			    pixman_double_to_fixed (SIZE),
+			    pixman_double_to_fixed (SIZE));
+
+    /*
+     * Gradients are evaluated at the center of each pixel, so we need
+     * to translate by half a pixel to trigger some interesting
+     * cornercases. In particular, the original implementation of PDF
+     * radial gradients tried to divide by 0 when using this transform
+     * on the "tangent circles" cases.
+     */
+    pixman_transform_translate (NULL, &transform,
+				pixman_double_to_fixed (0.5),
+				pixman_double_to_fixed (0.5));
+
+    for (i = 0; i < NUM_GRADIENTS; i++)
+    {
+	src_img = create_radial (i);
+	pixman_image_set_transform (src_img, &transform);
+
+	for (j = 0; j < NUM_REPEAT; j++)
+	{
+	    pixman_image_set_repeat (src_img, repeat[j]);
+
+	    pixman_image_composite32 (PIXMAN_OP_OVER,
+				      src_img,
+				      NULL,
+				      dest_img,
+				      0, 0,
+				      0, 0,
+				      i * SIZE, j * SIZE,
+				      SIZE, SIZE);
+
+	}
+
+	pixman_image_unref (src_img);
+    }
+
+    show_image (dest_img);
+
+    pixman_image_unref (dest_img);
+
+    return 0;
+}