[cairo-png] Support generating CAIRO_FORMAT_RGB24 from PNGs.

If the PNG does not have an alpha channel, then create an opaque image.

1 files changed, 149 insertions, 0 deletions

diff --git a/test/png.c b/test/png.c
new file mode 100644
index 000000000..65e465dfd
--- /dev/null
+++ b/test/png.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright © 2008 Chris Wilson
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of
+ * Chris Wilson not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Chris Wilson makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * CHRIS WILSON DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL CHRIS WILSON BE LIABLE FOR ANY SPECIAL,
+ * INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
+ * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Author: Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "cairo-test.h"
+
+#include <cairo.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <assert.h>
+
+/* Test the idempotency of write_png->read_png */
+
+#define RGB_MASK 0x00ffffff
+
+static cairo_bool_t
+image_surface_equals (cairo_surface_t *A, cairo_surface_t *B)
+{
+    if (cairo_image_surface_get_format (A) !=
+	cairo_image_surface_get_format (B))
+	return 0;
+
+    if (cairo_image_surface_get_width (A) !=
+	cairo_image_surface_get_width (B))
+	return 0;
+
+    if (cairo_image_surface_get_height (A) !=
+	cairo_image_surface_get_height (B))
+	return 0;
+
+    return 1;
+}
+
+static const char *
+format_to_string (cairo_format_t format)
+{
+    switch (format) {
+    case CAIRO_FORMAT_A1:     return "a1";
+    case CAIRO_FORMAT_A8:     return "a8";
+    case CAIRO_FORMAT_RGB24:  return "rgb24";
+    case CAIRO_FORMAT_ARGB32: return "argb32";
+    default: return "???";
+    }
+}
+
+static void
+print_surface (cairo_surface_t *surface)
+{
+    printf ("%s (%dx%d)\n",
+	    format_to_string (cairo_image_surface_get_format (surface)),
+	    cairo_image_surface_get_width (surface),
+	    cairo_image_surface_get_height (surface));
+}
+
+int
+main (void)
+{
+    cairo_surface_t *surface0, *surface1;
+    cairo_status_t status;
+    uint32_t argb32 = 0xdeadbede;
+
+    surface0 = cairo_image_surface_create_for_data ((unsigned char *) &argb32,
+						    CAIRO_FORMAT_ARGB32,
+						    1, 1, 4);
+    assert (cairo_surface_status (surface0) == CAIRO_STATUS_SUCCESS);
+    status = cairo_surface_write_to_png (surface0, "png-test.png");
+    if (status) {
+	printf ("Error writing 'png-test.png': %s\n",
+		cairo_status_to_string (status));
+	return CAIRO_TEST_FAILURE;
+    }
+    surface1 = cairo_image_surface_create_from_png ("png-test.png");
+    status = cairo_surface_status (surface1);
+    if (status) {
+	printf ("Error reading 'png-test.png': %s\n",
+		cairo_status_to_string (status));
+	return CAIRO_TEST_FAILURE;
+    }
+
+    if (! image_surface_equals (surface0, surface1)) {
+	printf ("Error surface mismatch.\n");
+	printf ("to png: "); print_surface (surface0);
+	printf ("from png: "); print_surface (surface1);
+	return CAIRO_TEST_FAILURE;
+    }
+    assert (*(uint32_t *) cairo_image_surface_get_data (surface1) == argb32);
+
+    cairo_surface_destroy (surface0);
+    cairo_surface_destroy (surface1);
+
+
+    surface0 = cairo_image_surface_create_for_data ((unsigned char *) &argb32,
+						    CAIRO_FORMAT_RGB24,
+						    1, 1, 4);
+    assert (cairo_surface_status (surface0) == CAIRO_STATUS_SUCCESS);
+    status = cairo_surface_write_to_png (surface0, "png-test.png");
+    if (status) {
+	printf ("Error writing 'png-test.png': %s\n",
+		cairo_status_to_string (status));
+	return CAIRO_TEST_FAILURE;
+    }
+    surface1 = cairo_image_surface_create_from_png ("png-test.png");
+    status = cairo_surface_status (surface1);
+    if (status) {
+	printf ("Error reading 'png-test.png': %s\n",
+		cairo_status_to_string (status));
+	return CAIRO_TEST_FAILURE;
+    }
+
+    if (! image_surface_equals (surface0, surface1)) {
+	printf ("Error surface mismatch.\n");
+	printf ("to png: "); print_surface (surface0);
+	printf ("from png: "); print_surface (surface1);
+	return CAIRO_TEST_FAILURE;
+    }
+    assert ((*(uint32_t *) cairo_image_surface_get_data (surface1) & RGB_MASK)
+	    == (argb32 & RGB_MASK));
+
+    cairo_surface_destroy (surface0);
+    cairo_surface_destroy (surface1);
+
+
+    return CAIRO_TEST_SUCCESS;
+}