upscale demo

2 files changed, 167 insertions, 1 deletions

diff --git a/demos/Makefile.am b/demos/Makefile.am
index 9aac1f5e..a87bc34f 100644
--- a/demos/Makefile.am
+++ b/demos/Makefile.am
@@ -20,7 +20,8 @@ DEMOS =				\
 	trap-test		\
 	tri-test		\
 	quad2quad		\
-	checkerboard
+	checkerboard		\
+	upscale
 
 EXTRA_DIST = parrot.c parrot.jpg
 
@@ -35,6 +36,7 @@ convolution_test_SOURCES = convolution-test.c $(GTK_UTILS)
 radial_test_SOURCES = radial-test.c $(GTK_UTILS)
 tri_test_SOURCES = tri-test.c $(GTK_UTILS)
 checkerboard_SOURCES = checkerboard.c $(GTK_UTILS)
+upscale_SOURCES = upscale.c $(GTK_UTILS)
 
 noinst_PROGRAMS = $(DEMOS)
 
diff --git a/demos/upscale.c b/demos/upscale.c
new file mode 100644
index 00000000..02d4ec32
--- /dev/null
+++ b/demos/upscale.c
@@ -0,0 +1,164 @@
+/* Copyright (C) 2005, 2008 Red Hat, Inc.
+ * Copyright © 2002 University of Southern California
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include <math.h>
+#include <gtk/gtk.h>
+#include <pixman.h>
+#include <stdlib.h>
+#include "gtk-utils.h"
+
+static pixman_image_t *
+pixman_image_from_file (const char *filename)
+{
+    GdkPixbuf *pixbuf;
+    pixman_image_t *image;
+    int width, height;
+    uint32_t *data, *d;
+    uint8_t *gdk_data;
+    int n_channels;
+    int j, i;
+    int stride;
+
+    if (!(pixbuf = gdk_pixbuf_new_from_file (filename, NULL)))
+	return NULL;
+
+    image = NULL;
+
+    width = gdk_pixbuf_get_width (pixbuf);
+    height = gdk_pixbuf_get_height (pixbuf);
+    n_channels = gdk_pixbuf_get_n_channels (pixbuf);
+    gdk_data = gdk_pixbuf_get_pixels (pixbuf);
+    stride = gdk_pixbuf_get_rowstride (pixbuf);
+
+    if (!(data = malloc (width * height * sizeof (uint32_t))))
+	goto out;
+
+    d = data;
+    for (j = 0; j < height; ++j)
+    {
+	uint8_t *gdk_line = gdk_data;
+
+	for (i = 0; i < width; ++i)
+	{
+	    int r, g, b, a;
+	    uint32_t pixel;
+
+	    r = gdk_line[0];
+	    g = gdk_line[1];
+	    b = gdk_line[2];
+
+	    if (n_channels == 4)
+		a = gdk_line[3];
+	    else
+		a = 0xff;
+
+	    r = (r * a + 127) / 255;
+	    g = (g * a + 127) / 255;
+	    b = (b * a + 127) / 255;
+
+	    pixel = (a << 24) | (r << 16) | (g << 8) | b;
+
+	    *d++ = pixel;
+	    gdk_line += n_channels;
+	}
+
+	gdk_data += stride;
+    }
+
+    image = pixman_image_create_bits (
+	PIXMAN_a8r8g8b8, width, height, data, width * 4);
+
+out:
+    g_object_unref (pixbuf);
+    return image;
+}
+
+typedef struct pixman_f_transform pixman_f_transform_t;
+
+static pixman_image_t *
+scale_image (pixman_image_t *image, double scale_factor)
+{
+    pixman_image_t *result;
+    int old_width = pixman_image_get_width (image);
+    int old_height = pixman_image_get_height (image);
+    int new_width = sqrt (0.5 * old_width * scale_factor * 0.5 * old_width * scale_factor +
+			  0.5 * old_height * scale_factor * 0.5 * old_height * scale_factor) * 2;
+    int new_height = new_width;
+    pixman_f_transform_t ftransform;
+    pixman_transform_t transform;
+
+    result = pixman_image_create_bits (
+	PIXMAN_a8r8g8b8, new_width, new_height, NULL, -1);
+
+    pixman_f_transform_init_translate (
+	&ftransform, - old_width / 2.0, - old_height / 2.0);
+
+    pixman_f_transform_scale (
+	&ftransform, NULL, scale_factor, scale_factor);
+
+    pixman_f_transform_rotate (
+	&ftransform, NULL, sin (30.0), cos (30.0));
+
+    pixman_f_transform_translate (
+	&ftransform, NULL, 0.5 * new_width, 0.5 * new_height);
+
+    if (!pixman_f_transform_invert (&ftransform, &ftransform))
+	printf ("no invert\n");
+
+    pixman_transform_from_pixman_f_transform (&transform, &ftransform);
+
+    pixman_image_set_transform (image, &transform);
+#if 0
+    pixman_image_set_sampling (image, PIXMAN_SAMPLE_BOX);
+#endif
+
+    pixman_image_composite32 (PIXMAN_OP_SRC, image, NULL, result,
+			      0, 0, 0, 0, 0, 0, new_width, new_height);
+
+    return result;
+}
+
+int
+main (int argc, char **argv)
+{
+    pixman_image_t *image, *result;
+    char *filename;
+
+    gtk_init (&argc, &argv);
+
+    if (argc < 2)
+    {
+	printf ("%s <image file>\n", argv[0]);
+	return -1;
+    }
+
+    filename = argv[1];
+
+    if (!(image = pixman_image_from_file (filename)))
+    {
+	printf ("Could not read %s\n", filename);
+	return -1;
+    }
+
+    result = scale_image (image, 1/4.0);
+
+    show_image (result);
+
+    return 0;
+}