source/libs/cairo/cairo-src/src/cairo-clip-region.c

   1 /* -*- Mode: c; tab-width: 8; c-basic-offset: 4; indent-tabs-mode: t; -*- */
   2 /* cairo - a vector graphics library with display and print output
   3  *
   4  * Copyright © 2002 University of Southern California
   5  * Copyright © 2005 Red Hat, Inc.
   6  * Copyright © 2009 Chris Wilson
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it either under the terms of the GNU Lesser General Public
  10  * License version 2.1 as published by the Free Software Foundation
  11  * (the "LGPL") or, at your option, under the terms of the Mozilla
  12  * Public License Version 1.1 (the "MPL"). If you do not alter this
  13  * notice, a recipient may use your version of this file under either
  14  * the MPL or the LGPL.
  15  *
  16  * You should have received a copy of the LGPL along with this library
  17  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  19  * You should have received a copy of the MPL along with this library
  20  * in the file COPYING-MPL-1.1
  21  *
  22  * The contents of this file are subject to the Mozilla Public License
  23  * Version 1.1 (the "License"); you may not use this file except in
  24  * compliance with the License. You may obtain a copy of the License at
  25  * http://www.mozilla.org/MPL/
  26  *
  27  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  28  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  29  * the specific language governing rights and limitations.
  30  *
  31  * The Original Code is the cairo graphics library.
  32  *
  33  * The Initial Developer of the Original Code is University of Southern
  34  * California.
  35  *
  36  * Contributor(s):
  37  *      Carl D. Worth <cworth@cworth.org>
  38  *      Kristian Høgsberg <krh@redhat.com>
  39  *      Chris Wilson <chris@chris-wilson.co.uk>
  40  */
  41
  42 #include "cairoint.h"
  43 #include "cairo-clip-private.h"
  44 #include "cairo-error-private.h"
  45 #include "cairo-freed-pool-private.h"
  46 #include "cairo-gstate-private.h"
  47 #include "cairo-path-fixed-private.h"
  48 #include "cairo-pattern-private.h"
  49 #include "cairo-composite-rectangles-private.h"
  50 #include "cairo-region-private.h"
  51
  52 static void
  53 _cairo_clip_extract_region (cairo_clip_t *clip)
  54 {
  55     cairo_rectangle_int_t stack_rects[CAIRO_STACK_ARRAY_LENGTH (cairo_rectangle_int_t)];
  56     cairo_rectangle_int_t *r = stack_rects;
  57     cairo_bool_t is_region;
  58     int i;
  59
  60     if (clip->num_boxes == 0)
  61         return;
  62
  63     if (clip->num_boxes > ARRAY_LENGTH (stack_rects)) {
  64         r = _cairo_malloc_ab (clip->num_boxes, sizeof (cairo_rectangle_int_t));
  65         if (r == NULL){
  66             _cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
  67             return;
  68         }
  69     }
  70
  71     is_region = clip->path == NULL;
  72     for (i = 0; i < clip->num_boxes; i++) {
  73         cairo_box_t *b = &clip->boxes[i];
  74         if (is_region)
  75             is_region =
  76                 _cairo_fixed_is_integer (b->p1.x | b->p1.y |  b->p2.x | b->p2.y);
  77         r[i].x = _cairo_fixed_integer_floor (b->p1.x);
  78         r[i].y = _cairo_fixed_integer_floor (b->p1.y);
  79         r[i].width  = _cairo_fixed_integer_ceil (b->p2.x) - r[i].x;
  80         r[i].height = _cairo_fixed_integer_ceil (b->p2.y) - r[i].y;
  81     }
  82     clip->is_region = is_region;
  83
  84     clip->region = cairo_region_create_rectangles (r, i);
  85
  86     if (r != stack_rects)
  87         free (r);
  88 }
  89
  90 cairo_region_t *
  91 _cairo_clip_get_region (const cairo_clip_t *clip)
  92 {
  93     if (clip == NULL)
  94         return NULL;
  95
  96     if (clip->region == NULL)
  97         _cairo_clip_extract_region ((cairo_clip_t *) clip);
  98
  99     return clip->region;
 100 }
 101
 102 cairo_bool_t
 103 _cairo_clip_is_region (const cairo_clip_t *clip)
 104 {
 105     if (clip == NULL)
 106         return TRUE;
 107
 108     if (clip->is_region)
 109         return TRUE;
 110
 111     /* XXX Geometric reduction? */
 112
 113     if (clip->path)
 114         return FALSE;
 115
 116     if (clip->num_boxes == 0)
 117         return TRUE;
 118
 119     if (clip->region == NULL)
 120         _cairo_clip_extract_region ((cairo_clip_t *) clip);
 121
 122     return clip->is_region;
 123 }