[test] add XFAIL test surface-pattern-big-scale down

Add test for image downscaling with large images severely limiting
the destination coordinate space.  See the test for more information.

1 files changed, 121 insertions, 0 deletions

diff --git a/test/surface-pattern-big-scale-down.c b/test/surface-pattern-big-scale-down.c
new file mode 100644
index 000000000..d1f818cf7
--- /dev/null
+++ b/test/surface-pattern-big-scale-down.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright © 2006 Mozilla Corporation
+ *
+ * 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
+ * Mozilla Corporation not be used in advertising or publicity pertaining to
+ * distribution of the software without specific, written prior
+ * permission. Mozilla Corporation makes no representations about the
+ * suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * MOZILLA CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL MOZILLA CORPORATION 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: Vladimir Vukicevic <vladimir@pobox.com>
+ */
+
+#include "cairo-test.h"
+
+static cairo_test_draw_function_t draw;
+
+#define SRC_WIDTH 2048
+#define SRC_HEIGHT 32
+
+cairo_test_t test = {
+    "surface-pattern-big-scale-down",
+    "Test scaled-down transformed not-repeated surface patterns with large images and offsets",
+    512, 16,
+    draw
+};
+
+static void
+setup_source_surface (cairo_surface_t *surface, int w, int h)
+{
+  cairo_t *cr = cairo_create (surface);
+
+  cairo_set_source_rgb (cr, 1.0, 0.0, 0.0);
+  cairo_rectangle (cr, 0, 0, w/2, h/2);
+  cairo_fill (cr);
+
+  cairo_set_source_rgb (cr, 0.0, 1.0, 0.0);
+  cairo_rectangle (cr, w/2, 0, w/2, h/2);
+  cairo_fill (cr);
+
+  cairo_set_source_rgb (cr, 0.0, 0.0, 1.0);
+  cairo_rectangle (cr, 0, h/2, w/2, h/2);
+  cairo_fill (cr);
+
+  cairo_set_source_rgb (cr, 1.0, 1.0, 0.0);
+  cairo_rectangle (cr, w/2, h/2, w/2, h/2);
+  cairo_fill (cr);
+
+  cairo_destroy (cr);
+}
+
+static void
+draw_n (cairo_t *cr, cairo_pattern_t *pat, double dest_size, int n)
+{
+  cairo_matrix_t mat;
+
+  cairo_matrix_init_scale (&mat, SRC_WIDTH / dest_size, SRC_HEIGHT / dest_size);
+  cairo_matrix_translate (&mat, n * -dest_size, 0.0);
+  cairo_pattern_set_matrix (pat, &mat);
+
+  cairo_set_source (cr, pat);
+  cairo_new_path (cr);
+  cairo_rectangle (cr, n * dest_size, 0.0, dest_size, dest_size);
+  cairo_fill (cr);
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_surface_t *surface;
+    cairo_pattern_t *pat;
+    int n;
+
+    cairo_set_source_rgb (cr, 0, 0, 0);
+    cairo_paint (cr);
+
+    surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, SRC_WIDTH, SRC_HEIGHT);
+    setup_source_surface (surface, SRC_WIDTH, SRC_HEIGHT);
+
+    pat = cairo_pattern_create_for_surface (surface);
+
+    /* We want to draw at a position such that n * SRC_WIDTH * (SRC_WIDTH/16.0) > 32768.
+     * x = n * 16.
+     *
+     * To show the bug, we want to draw on either side of the boundary;
+     * in our case here, n = 16 results in 32768, and n = 17 results in > 32768.
+     *
+     * Drawing at 16 and 17 is sufficient to show the problem.
+     */
+
+#if 1
+    /* n = 16 */
+    draw_n (cr, pat, 16.0, 16);
+
+    /* n = 17 */
+    draw_n (cr, pat, 16.0, 17);
+#else
+    for (n = 0; n < 32; n++)
+      draw_n (cr, pat, 16.0, n);
+#endif
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test);
+}