Add initial regression test suite.

Don't AC_SUBST a dozen different FOO_CFLAGS and FOO_LIBS. Instead, incrementally build up just CAIRO_CFLAGS and CAIRO_LIBS.
Don't list flags that should get picked up via dependency information through Requires.
Add description of move_to_show_surface.

1 files changed, 191 insertions, 0 deletions

diff --git a/test/cairo_test.c b/test/cairo_test.c
new file mode 100644
index 000000000..0c2d09f3a
--- /dev/null
+++ b/test/cairo_test.c
@@ -0,0 +1,191 @@
+/*
+ * Copyright © 2004 Red Hat, Inc.
+ *
+ * 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
+ * Red Hat, Inc. not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Red Hat, Inc. makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * RED HAT, INC. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL RED HAT, INC. 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: Carl D. Worth <cworth@cworth.org>
+ */
+
+#include <unistd.h>
+#include <errno.h>
+
+#include "cairo_test.h"
+
+#include "read_png.h"
+#include "write_png.h"
+#include "xmalloc.h"
+
+#define CAIRO_TEST_PNG_SUFFIX "-out.png"
+#define CAIRO_TEST_REF_SUFFIX "-ref.png"
+#define CAIRO_TEST_DIFF_SUFFIX "-diff.png"
+
+static char *
+xstrcat_alloc (const char *s1, const char *s2)
+{
+    char *ret;
+
+    ret = xmalloc (strlen (s1) + strlen (s2) + 1);
+    strcpy (ret, s1);
+    strcat (ret, s2);
+
+    return ret;
+}
+
+/* Image comparison code courttesy of Richard Worth.
+ * Returns number of pixels changed.
+ * Also fills out a "diff" image intended to visually show where the
+ * images differ.
+ */
+static int
+image_diff (char *buf_a, char *buf_b, char *buf_diff,
+	    int width, int height, int stride)
+{
+    int x, y;
+    int total_pixels_changed = 0;
+    unsigned char *row_a, *row_b, *row;
+
+    for (y = 0; y < height; y++)
+    {
+	row_a = buf_a + y * stride;
+	row_b = buf_b + y * stride;
+	row = buf_diff + y * stride;
+	for (x = 0; x < width; x++)
+	{
+	    int channel;
+	    unsigned char value_a, value_b;
+	    int pixel_changed = 0;
+	    for (channel = 0; channel < 4; channel++)
+	    {
+		double diff;
+		value_a = row_a[x * 4 + channel];
+		value_b = row_b[x * 4 + channel];
+		if (value_a != value_b)
+		    pixel_changed = 1;
+		diff = value_a - value_b;
+		row[x * 4 + channel] = 128 + diff / 3.0;
+	    }
+	    if (pixel_changed) {
+		total_pixels_changed++;
+	    } else {
+		row[x*4+0] = 0;
+		row[x*4+1] = 0;
+		row[x*4+2] = 0;
+	    }
+	    row[x * 4 + 3] = 0xff; /* Set ALPHA to 100% (opaque) */
+	}
+    }
+
+    return total_pixels_changed;
+}
+
+cairo_test_status_t
+cairo_test (cairo_test_t *test, cairo_test_draw_function_t draw)
+{
+    cairo_t *cr;
+    int stride;
+    unsigned char *png_buf, *ref_buf, *diff_buf;
+    char *png_name, *ref_name, *diff_name;
+    int pixels_changed;
+    int ref_width, ref_height, ref_stride;
+    read_png_status_t png_status;
+    cairo_test_status_t ret;
+
+    /* The cairo part of the test is the easiest part */
+    cr = cairo_create ();
+
+    stride = 4 * test->width;
+
+    png_buf = xcalloc (stride * test->height, 1);
+    diff_buf = xcalloc (stride * test->height, 1);
+
+    cairo_set_target_image (cr, png_buf, CAIRO_FORMAT_ARGB32,
+			    test->width, test->height, stride);
+
+    (draw) (cr, test->width, test->height);
+
+    cairo_destroy (cr);
+
+    /* Then we've got a bunch of string manipulation and file I/O for the check */
+
+    png_name = xstrcat_alloc (test->name, CAIRO_TEST_PNG_SUFFIX);
+    ref_name = xstrcat_alloc (test->name, CAIRO_TEST_REF_SUFFIX);
+    diff_name = xstrcat_alloc (test->name, CAIRO_TEST_DIFF_SUFFIX);
+
+    write_png_argb32 (png_buf, png_name, test->width, test->height, stride);
+
+    ref_buf = NULL;
+    png_status = (read_png_argb32 (ref_name, &ref_buf, &ref_width, &ref_height, &ref_stride));
+    if (png_status) {
+	switch (png_status)
+	{
+	case READ_PNG_FILE_NOT_FOUND:
+	    fprintf (stderr, "  Error: No reference image found: %s\n", ref_name);
+	    break;
+	case READ_PNG_FILE_NOT_PNG:
+	    fprintf (stderr, "  Error: %s is not a png image\n", ref_name);
+	    break;
+	default:
+	    fprintf (stderr, "  Error: Failed to read %s\n", ref_name);
+	}
+		
+	ret = CAIRO_TEST_FAILURE;
+	goto BAIL;
+    }
+
+    if (test->width != ref_width || test->height != ref_height) {
+	fprintf (stderr,
+		 "  Error: Image size mismatch: (%dx%d) vs. (%dx%d)\n"
+		 "         for %s vs %s\n",
+		 test->width, test->height,
+		 ref_width, ref_height,
+		 png_name, ref_name);
+	ret = CAIRO_TEST_FAILURE;
+	goto BAIL;
+    }
+
+    pixels_changed = image_diff (png_buf, ref_buf, diff_buf,
+				 test->width, test->height, stride);
+    if (pixels_changed) {
+	fprintf (stderr, "  Error: %d pixels differ from reference image %s\n",
+		 pixels_changed, ref_name);
+	write_png_argb32 (diff_buf, diff_name, test->width, test->height, stride);
+	ret = CAIRO_TEST_FAILURE;
+	goto BAIL;
+    } else {
+	if (unlink (diff_name) < 0 && errno != ENOENT) {
+	    fprintf (stderr, "  Error: Cannot remove %s: %s\n",
+		     diff_name, strerror (errno));
+	    ret = CAIRO_TEST_FAILURE;
+	    goto BAIL;
+	}
+    }
+
+    ret = CAIRO_TEST_SUCCESS;
+
+BAIL:
+    free (png_buf);
+    free (ref_buf);
+    free (diff_buf);
+    free (png_name);
+    free (ref_name);
+    free (diff_name);
+
+    return ret;
+}