src/cairo-path-bounds.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 © 2003 University of Southern California
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it either under the terms of the GNU Lesser General Public
   8  * License version 2.1 as published by the Free Software Foundation
   9  * (the "LGPL") or, at your option, under the terms of the Mozilla
  10  * Public License Version 1.1 (the "MPL"). If you do not alter this
  11  * notice, a recipient may use your version of this file under either
  12  * the MPL or the LGPL.
  13  *
  14  * You should have received a copy of the LGPL along with this library
  15  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  17  * You should have received a copy of the MPL along with this library
  18  * in the file COPYING-MPL-1.1
  19  *
  20  * The contents of this file are subject to the Mozilla Public License
  21  * Version 1.1 (the "License"); you may not use this file except in
  22  * compliance with the License. You may obtain a copy of the License at
  23  * http://www.mozilla.org/MPL/
  24  *
  25  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  26  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  27  * the specific language governing rights and limitations.
  28  *
  29  * The Original Code is the cairo graphics library.
  30  *
  31  * The Initial Developer of the Original Code is University of Southern
  32  * California.
  33  *
  34  * Contributor(s):
  35  *      Carl D. Worth <cworth@cworth.org>
  36  */
  37
  38 #include "cairoint.h"
  39 #include "cairo-box-inline.h"
  40 #include "cairo-error-private.h"
  41 #include "cairo-path-fixed-private.h"
  42
  43 typedef struct _cairo_path_bounder {
  44     cairo_point_t current_point;
  45     cairo_bool_t has_extents;
  46     cairo_box_t extents;
  47 } cairo_path_bounder_t;
  48
  49 static cairo_status_t
  50 _cairo_path_bounder_move_to (void *closure,
  51                              const cairo_point_t *point)
  52 {
  53     cairo_path_bounder_t *bounder = closure;
  54
  55     bounder->current_point = *point;
  56
  57     if (likely (bounder->has_extents)) {
  58         _cairo_box_add_point (&bounder->extents, point);
  59     } else {
  60         bounder->has_extents = TRUE;
  61         _cairo_box_set (&bounder->extents, point, point);
  62     }
  63
  64     return CAIRO_STATUS_SUCCESS;
  65 }
  66
  67 static cairo_status_t
  68 _cairo_path_bounder_line_to (void *closure,
  69                              const cairo_point_t *point)
  70 {
  71     cairo_path_bounder_t *bounder = closure;
  72
  73     bounder->current_point = *point;
  74     _cairo_box_add_point (&bounder->extents, point);
  75
  76     return CAIRO_STATUS_SUCCESS;
  77 }
  78
  79 static cairo_status_t
  80 _cairo_path_bounder_curve_to (void *closure,
  81                               const cairo_point_t *b,
  82                               const cairo_point_t *c,
  83                               const cairo_point_t *d)
  84 {
  85     cairo_path_bounder_t *bounder = closure;
  86
  87     _cairo_box_add_curve_to (&bounder->extents,
  88                              &bounder->current_point,
  89                              b, c, d);
  90     bounder->current_point = *d;
  91
  92     return CAIRO_STATUS_SUCCESS;
  93 }
  94
  95 static cairo_status_t
  96 _cairo_path_bounder_close_path (void *closure)
  97 {
  98     return CAIRO_STATUS_SUCCESS;
  99 }
 100
 101 cairo_bool_t
 102 _cairo_path_bounder_extents (const cairo_path_fixed_t *path,
 103                              cairo_box_t *extents)
 104 {
 105     cairo_path_bounder_t bounder;
 106     cairo_status_t status;
 107
 108     bounder.has_extents = FALSE;
 109     status = _cairo_path_fixed_interpret (path,
 110                                           _cairo_path_bounder_move_to,
 111                                           _cairo_path_bounder_line_to,
 112                                           _cairo_path_bounder_curve_to,
 113                                           _cairo_path_bounder_close_path,
 114                                           &bounder);
 115     assert (!status);
 116
 117     if (bounder.has_extents)
 118         *extents = bounder.extents;
 119
 120     return bounder.has_extents;
 121 }
 122
 123 void
 124 _cairo_path_fixed_approximate_clip_extents (const cairo_path_fixed_t *path,
 125                                             cairo_rectangle_int_t *extents)
 126 {
 127     _cairo_path_fixed_approximate_fill_extents (path, extents);
 128 }
 129
 130 void
 131 _cairo_path_fixed_approximate_fill_extents (const cairo_path_fixed_t *path,
 132                                             cairo_rectangle_int_t *extents)
 133 {
 134     _cairo_path_fixed_fill_extents (path, CAIRO_FILL_RULE_WINDING, 0, extents);
 135 }
 136
 137 void
 138 _cairo_path_fixed_fill_extents (const cairo_path_fixed_t        *path,
 139                                 cairo_fill_rule_t        fill_rule,
 140                                 double                   tolerance,
 141                                 cairo_rectangle_int_t   *extents)
 142 {
 143     if (path->extents.p1.x < path->extents.p2.x &&
 144         path->extents.p1.y < path->extents.p2.y) {
 145         _cairo_box_round_to_rectangle (&path->extents, extents);
 146     } else {
 147         extents->x = extents->y = 0;
 148         extents->width = extents->height = 0;
 149     }
 150 }
 151
 152 /* Adjusts the fill extents (above) by the device-space pen.  */
 153 void
 154 _cairo_path_fixed_approximate_stroke_extents (const cairo_path_fixed_t *path,
 155                                               const cairo_stroke_style_t *style,
 156                                               const cairo_matrix_t *ctm,
 157                                               cairo_rectangle_int_t *extents)
 158 {
 159     if (path->has_extents) {
 160         cairo_box_t box_extents;
 161         double dx, dy;
 162
 163         _cairo_stroke_style_max_distance_from_path (style, path, ctm, &dx, &dy);
 164
 165         box_extents = path->extents;
 166         box_extents.p1.x -= _cairo_fixed_from_double (dx);
 167         box_extents.p1.y -= _cairo_fixed_from_double (dy);
 168         box_extents.p2.x += _cairo_fixed_from_double (dx);
 169         box_extents.p2.y += _cairo_fixed_from_double (dy);
 170
 171         _cairo_box_round_to_rectangle (&box_extents, extents);
 172     } else {
 173         extents->x = extents->y = 0;
 174         extents->width = extents->height = 0;
 175     }
 176 }
 177
 178 cairo_status_t
 179 _cairo_path_fixed_stroke_extents (const cairo_path_fixed_t      *path,
 180                                   const cairo_stroke_style_t    *stroke_style,
 181                                   const cairo_matrix_t          *ctm,
 182                                   const cairo_matrix_t          *ctm_inverse,
 183                                   double                         tolerance,
 184                                   cairo_rectangle_int_t         *extents)
 185 {
 186     cairo_polygon_t polygon;
 187     cairo_status_t status;
 188
 189     _cairo_polygon_init (&polygon, NULL, 0);
 190     status = _cairo_path_fixed_stroke_to_polygon (path,
 191                                                   stroke_style,
 192                                                   ctm, ctm_inverse,
 193                                                   tolerance,
 194                                                   &polygon);
 195     _cairo_box_round_to_rectangle (&polygon.extents, extents);
 196     _cairo_polygon_fini (&polygon);
 197
 198     return status;
 199 }
 200
 201 cairo_bool_t
 202 _cairo_path_fixed_extents (const cairo_path_fixed_t *path,
 203                            cairo_box_t *box)
 204 {
 205     *box = path->extents;
 206     return path->has_extents;
 207 }