1 files changed, 109 insertions, 0 deletions
diff --git a/test/xcomposite-projection.c b/test/xcomposite-projection.c
new file mode 100644
index 000000000..39686cf99
--- /dev/null
+++ b/test/xcomposite-projection.c
@@ -0,0 +1,109 @@
+/*
+ * Copyright 2009 Benjamin Otte
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Author: Benjamin Otte <otte@gnome.org>
+ */
+
+#include "cairo-test.h"
+
+/*
+ * Exercise a bug in the projection of a rotated trapezoid mask.
+ * I used CAIRO_ANTIALIAS_NONE and a single-color source in the test to get
+ * rid of aliasing issues in the output images. This makes some issues
+ * slightly less visible, but still fails for all of them. If you want to
+ * get a clearer view:
+ * #define ANTIALIAS CAIRO_ANTIALIAS_DEFAULT
+ */
+
+#define ANTIALIAS CAIRO_ANTIALIAS_NONE
+
+static const char png_filename[] = "romedalen.png";
+
+static cairo_pattern_t *
+get_source (const cairo_test_context_t *ctx,
+	    int *width, int *height)
+{
+    cairo_surface_t *surface;
+    cairo_pattern_t *pattern;
+
+    if (ANTIALIAS == CAIRO_ANTIALIAS_NONE) {
+	cairo_t *cr;
+
+	surface = cairo_image_surface_create (CAIRO_FORMAT_RGB24, 256, 192);
+	cr = cairo_create (surface);
+
+	cairo_set_source_rgb (cr, 0.75, 0.25, 0.25);
+	cairo_paint (cr);
+
+	pattern = cairo_pattern_create_for_surface (cairo_get_target (cr));
+	cairo_destroy (cr);
+    } else {
+	surface = cairo_test_create_surface_from_png (ctx, png_filename);
+	pattern = cairo_pattern_create_for_surface (surface);
+    }
+
+    *width = cairo_image_surface_get_width (surface);
+    *height = cairo_image_surface_get_height (surface);
+    cairo_surface_destroy (surface);
+
+    return pattern;
+}
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_pattern_t *image;
+    int img_width, img_height;
+
+    image = get_source (cairo_test_get_context (cr),
+			&img_width, &img_height);
+
+    /* we don't want to debug antialiasing artifacts */
+    cairo_set_antialias (cr, ANTIALIAS);
+
+    /* dark grey background */
+    cairo_set_source_rgb (cr, 0.25, 0.25, 0.25);
+    cairo_paint (cr);
+
+    /* magic transform */
+    cairo_translate (cr, 10, -40);
+    cairo_rotate (cr, -0.05);
+
+    /* place the image on our surface */
+    cairo_set_source (cr, image);
+
+    /* paint the image */
+    cairo_rectangle (cr, 0, 0, img_width, img_height);
+    cairo_fill (cr);
+
+    cairo_pattern_destroy (image);
+
+    return CAIRO_TEST_SUCCESS;
+}
+
+CAIRO_TEST (xcomposite_projection,
+	    "Test a bug with XRenderComposite reference computation when projecting the first trapezoid onto 16.16 space",
+	    "xlib", /* keywords */
+	    "target=raster", /* requirements */
+	    300, 150,
+	    NULL, draw)