src/cairo-surface.c src/cairoint.h: Add _cairo_surface_begin/end to save and restore the clip state of a surface. Copy and store clip regions set on a surface so that we can save and restore them.

Add a CAIRO_STATUS_BAD_NESTING error for interleaved use of two cairo_t's on the same surface. Also, add a skeleton doc comment for cairo_status_t.
src/cairo.c src/cairo-gstate.c src/cairoint.h: Use _cairo_surface_begin/end to replace _cairo_gstate_restore_external_state.
Use _cairo_surface_begin/end to save the state of a surface when we start drawing at it and restore it at the end. Check that the save level of the surface is what we expect on drawing operations and fail with CAIRO_STATUS_BAD_NESTING otherwise.
src/cairo-pattern.c src/cairoint.h (_cairo_pattern_acquire_surface_for_surface) (_cairo_pattern_release_surface): Surround use of pattern->surface with _cairo_surface->begin/end so we don't clip surfaces used as sources.
test/clip-nesting.c test/Makefile.am: Test of destinatin clipping with the nested creation of cairo_t's for the same context.
test/source-clip.c test/Makefile.am: Test that clipping on a source as a destination doesn't affect use of it as a source.
XFAIL test for copying from a surface as a source to itself as a destination with a clip.

1 files changed, 101 insertions, 0 deletions

diff --git a/test/clip-nesting.c b/test/clip-nesting.c
new file mode 100644
index 000000000..03760b017
--- /dev/null
+++ b/test/clip-nesting.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright © 2005 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: Owen Taylor <otaylor@redhat.com>
+ */
+
+#include <math.h>
+#include "cairo-test.h"
+#include <stdio.h>
+
+#define SIZE 100
+#define BORDER 10
+#define LINE_WIDTH 20
+
+cairo_test_t test = {
+    "clip-nesting",
+    "Test clipping with multiple contexts for the same surface",
+    SIZE, SIZE
+};
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    cairo_surface_t *target_surface;
+    cairo_t *cr2, *cr3;
+
+    target_surface = cairo_get_target_surface (cr);
+
+    cr2 = cairo_create ();
+    cairo_set_target_surface (cr2, target_surface);
+
+    /* Draw a diagonal line and clip to it */
+    
+    cairo_move_to (cr2, BORDER,                     BORDER);
+    cairo_line_to (cr2, BORDER + LINE_WIDTH,        BORDER);
+    cairo_line_to (cr2, SIZE - BORDER,              SIZE - BORDER);
+    cairo_line_to (cr2, SIZE - BORDER - LINE_WIDTH, SIZE - BORDER);
+
+    cairo_clip (cr2);
+    cairo_set_source_rgb (cr2, 0, 0, 1); /* Blue */
+    cairo_paint (cr2);
+
+    /* Clipping affects this cairo_t */
+
+    cairo_set_source_rgb (cr2, 1, 1, 1); /* White */
+    cairo_rectangle (cr2,
+		     SIZE / 2 - LINE_WIDTH / 2, BORDER,
+		     LINE_WIDTH,                SIZE - 2 * BORDER);
+    cairo_fill (cr2);
+
+    /* But doesn't affect another cairo_t that we create temporarily for
+     * the same surface
+     */
+    cr3 = cairo_create ();
+    
+    cairo_set_target_surface (cr3, target_surface);
+    cairo_set_source_rgb (cr3, 1, 1, 1); /* White */
+    cairo_rectangle (cr3,
+		     SIZE - BORDER - LINE_WIDTH, BORDER,
+		     LINE_WIDTH,                 SIZE - 2 * BORDER);
+    cairo_fill (cr3);
+
+    cairo_destroy (cr3);
+    cairo_destroy (cr2);
+
+    /* And doesn't affect anything after this cairo_t is destroyed */
+
+    cairo_set_source_rgb (cr, 1, 1, 1); /* White */
+    cairo_rectangle (cr,
+		     BORDER,     BORDER,
+		     LINE_WIDTH, SIZE - 2 * BORDER);
+    cairo_fill (cr);
+    
+    return CAIRO_TEST_SUCCESS;
+
+}
+
+int
+main (void)
+{
+    return cairo_test (&test, draw);
+}