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-rw-r--r--src/cairo-surface-clipper.c196
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diff --git a/src/cairo-surface-clipper.c b/src/cairo-surface-clipper.c
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+/* cairo - a vector graphics library with display and print output
+ *
+ * Copyright © 2009 Chris Wilson
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it either under the terms of the GNU Lesser General Public
+ * License version 2.1 as published by the Free Software Foundation
+ * (the "LGPL") or, at your option, under the terms of the Mozilla
+ * Public License Version 1.1 (the "MPL"). If you do not alter this
+ * notice, a recipient may use your version of this file under either
+ * the MPL or the LGPL.
+ *
+ * You should have received a copy of the LGPL along with this library
+ * in the file COPYING-LGPL-2.1; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
+ * You should have received a copy of the MPL along with this library
+ * in the file COPYING-MPL-1.1
+ *
+ * The contents of this file are subject to the Mozilla Public License
+ * Version 1.1 (the "License"); you may not use this file except in
+ * compliance with the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
+ * OF ANY KIND, either express or implied. See the LGPL or the MPL for
+ * the specific language governing rights and limitations.
+ *
+ * The Original Code is the cairo graphics library.
+ *
+ * The Initial Developer of the Original Code is Red Hat, Inc.
+ *
+ * Contributor(s):
+ * Chris Wilson <chris@chris-wilson.co.uk>
+ */
+
+#include "cairoint.h"
+
+#include "cairo-clip-inline.h"
+#include "cairo-surface-clipper-private.h"
+
+/* A collection of routines to facilitate vector surface clipping */
+
+/* XXX Eliminate repeated paths and nested clips */
+
+static cairo_status_t
+_cairo_path_fixed_add_box (cairo_path_fixed_t *path,
+ const cairo_box_t *box)
+{
+ cairo_status_t status;
+
+ status = _cairo_path_fixed_move_to (path, box->p1.x, box->p1.y);
+ if (unlikely (status))
+ return status;
+
+ status = _cairo_path_fixed_line_to (path, box->p2.x, box->p1.y);
+ if (unlikely (status))
+ return status;
+
+ status = _cairo_path_fixed_line_to (path, box->p2.x, box->p2.y);
+ if (unlikely (status))
+ return status;
+
+ status = _cairo_path_fixed_line_to (path, box->p1.x, box->p2.y);
+ if (unlikely (status))
+ return status;
+
+ return _cairo_path_fixed_close_path (path);
+}
+
+static cairo_status_t
+_cairo_surface_clipper_intersect_clip_boxes (cairo_surface_clipper_t *clipper,
+ const cairo_clip_t *clip)
+{
+ cairo_path_fixed_t path;
+ cairo_status_t status;
+ int i;
+
+ if (clip->num_boxes == 0)
+ return CAIRO_STATUS_SUCCESS;
+
+ /* Reconstruct the path for the clip boxes.
+ * XXX maybe a new clipper callback?
+ */
+
+ _cairo_path_fixed_init (&path);
+ for (i = 0; i < clip->num_boxes; i++) {
+ status = _cairo_path_fixed_add_box (&path, &clip->boxes[i]);
+ if (unlikely (status)) {
+ _cairo_path_fixed_fini (&path);
+ return status;
+ }
+ }
+
+ status = clipper->intersect_clip_path (clipper, &path,
+ CAIRO_FILL_RULE_WINDING,
+ 0.,
+ CAIRO_ANTIALIAS_DEFAULT);
+ _cairo_path_fixed_fini (&path);
+
+ return status;
+}
+
+static cairo_status_t
+_cairo_surface_clipper_intersect_clip_path_recursive (cairo_surface_clipper_t *clipper,
+ cairo_clip_path_t *clip_path,
+ cairo_clip_path_t *end)
+{
+ cairo_status_t status;
+
+ if (clip_path->prev != end) {
+ status =
+ _cairo_surface_clipper_intersect_clip_path_recursive (clipper,
+ clip_path->prev,
+ end);
+ if (unlikely (status))
+ return status;
+ }
+
+ return clipper->intersect_clip_path (clipper,
+ &clip_path->path,
+ clip_path->fill_rule,
+ clip_path->tolerance,
+ clip_path->antialias);
+}
+
+cairo_status_t
+_cairo_surface_clipper_set_clip (cairo_surface_clipper_t *clipper,
+ const cairo_clip_t *clip)
+{
+ cairo_status_t status;
+ cairo_bool_t incremental = FALSE;
+
+ if (_cairo_clip_equal (clip, clipper->clip))
+ return CAIRO_STATUS_SUCCESS;
+
+ /* all clipped out state should never propagate this far */
+ assert (!_cairo_clip_is_all_clipped (clip));
+
+ /* XXX Is this an incremental clip? */
+ if (clipper->clip && clip &&
+ clip->num_boxes == clipper->clip->num_boxes &&
+ memcmp (clip->boxes, clipper->clip->boxes,
+ sizeof (cairo_box_t) * clip->num_boxes) == 0)
+ {
+ cairo_clip_path_t *clip_path = clip->path;
+ while (clip_path != NULL && clip_path != clipper->clip->path)
+ clip_path = clip_path->prev;
+
+ if (clip_path) {
+ incremental = TRUE;
+ status = _cairo_surface_clipper_intersect_clip_path_recursive (clipper,
+ clip->path,
+ clipper->clip->path);
+ }
+ }
+
+ _cairo_clip_destroy (clipper->clip);
+ clipper->clip = _cairo_clip_copy (clip);
+
+ if (incremental)
+ return status;
+
+ status = clipper->intersect_clip_path (clipper, NULL, 0, 0, 0);
+ if (unlikely (status))
+ return status;
+
+ if (clip == NULL)
+ return CAIRO_STATUS_SUCCESS;
+
+ status = _cairo_surface_clipper_intersect_clip_boxes (clipper, clip);
+ if (unlikely (status))
+ return status;
+
+ if (clip->path != NULL) {
+ status = _cairo_surface_clipper_intersect_clip_path_recursive (clipper,
+ clip->path,
+ NULL);
+ }
+
+ return status;
+}
+
+void
+_cairo_surface_clipper_init (cairo_surface_clipper_t *clipper,
+ cairo_surface_clipper_intersect_clip_path_func_t func)
+{
+ clipper->clip = NULL;
+ clipper->intersect_clip_path = func;
+}
+
+void
+_cairo_surface_clipper_reset (cairo_surface_clipper_t *clipper)
+{
+ _cairo_clip_destroy (clipper->clip);
+ clipper->clip = NULL;
+}