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author | Chris Wilson <chris@chris-wilson.co.uk> | 2011-07-14 21:19:54 +0100 |
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committer | Chris Wilson <chris@chris-wilson.co.uk> | 2011-07-19 21:14:34 +0100 |
commit | b132fae5e843c329d1414d1a65b2e8d66b99852f (patch) | |
tree | 7df5e21300eefe3abcc30616b22d7f5d3248b4d4 /src/cairo-clip-polygon.c | |
parent | f58ade7bace8c82d0ea6740f56d227696181d616 (diff) | |
download | cairo-b132fae5e843c329d1414d1a65b2e8d66b99852f.tar.gz |
clip: Rudimentary support for clip-polygon extraction
Step 1, fix the failings sighted recently by tracking clip-boxes as an
explicit property of the clipping and of composition.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'src/cairo-clip-polygon.c')
-rw-r--r-- | src/cairo-clip-polygon.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/cairo-clip-polygon.c b/src/cairo-clip-polygon.c new file mode 100644 index 000000000..19da15dc5 --- /dev/null +++ b/src/cairo-clip-polygon.c @@ -0,0 +1,127 @@ +/* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */ +/* cairo - a vector graphics library with display and print output + * + * Copyright © 2011 Intel Corporation + * + * 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 University of Southern + * California. + * + * Contributor(s): + * Chris Wilson <chris@chris-wilson.co.uk> + */ + +#include "cairoint.h" +#include "cairo-clip-private.h" +#include "cairo-error-private.h" +#include "cairo-freed-pool-private.h" +#include "cairo-gstate-private.h" +#include "cairo-path-fixed-private.h" +#include "cairo-pattern-private.h" +#include "cairo-composite-rectangles-private.h" +#include "cairo-region-private.h" + +static cairo_bool_t +can_convert_to_polygon (const cairo_clip_t *clip) +{ + cairo_clip_path_t *clip_path = clip->path; + cairo_antialias_t antialias = clip_path->antialias; + + while ((clip_path = clip_path->prev) != NULL) { + if (clip_path->antialias != antialias) + return FALSE; + } + + return TRUE; +} + +cairo_int_status_t +_cairo_clip_get_polygon (const cairo_clip_t *clip, + cairo_polygon_t *polygon, + cairo_fill_rule_t *fill_rule, + cairo_antialias_t *antialias) +{ + cairo_status_t status; + cairo_clip_path_t *clip_path; + + if (_cairo_clip_is_all_clipped (clip)) { + _cairo_polygon_init (polygon, NULL, 0); + return CAIRO_INT_STATUS_SUCCESS; + } + + /* If there is no clip, we need an infinite polygon */ + assert (clip && (clip->path || clip->num_boxes)); + + if (clip->path == NULL) { + *fill_rule = CAIRO_FILL_RULE_WINDING; + *antialias = CAIRO_ANTIALIAS_DEFAULT; + return _cairo_polygon_init_box_array (polygon, + clip->boxes, + clip->num_boxes); + } + + /* check that residual is all of the same type/tolerance */ + if (! can_convert_to_polygon (clip)) + return CAIRO_INT_STATUS_UNSUPPORTED; + + _cairo_polygon_init_with_clip (polygon, clip); + + clip_path = clip->path; + status = _cairo_path_fixed_fill_to_polygon (&clip_path->path, + clip_path->tolerance, + polygon); + if (unlikely (status)) { + _cairo_polygon_fini (polygon); + return status; + } + + polygon->limits = NULL; + polygon->num_limits = 0; + + *fill_rule = clip_path->fill_rule; + *antialias = clip_path->antialias; + while ((clip_path = clip_path->prev) != NULL) { + cairo_polygon_t next; + + _cairo_polygon_init (&next, NULL, 0); + status = _cairo_path_fixed_fill_to_polygon (&clip_path->path, + clip_path->tolerance, + &next); + if (likely (status == CAIRO_STATUS_SUCCESS)) + status = _cairo_polygon_intersect (polygon, *fill_rule, + &next, clip_path->fill_rule); + _cairo_polygon_fini (&next); + if (unlikely (status)) { + _cairo_polygon_fini (polygon); + return status; + } + + *fill_rule = CAIRO_FILL_RULE_WINDING; + } + + return CAIRO_STATUS_SUCCESS; +} |