LCOV - code coverage report
Current view: directory - gfx/cairo/cairo/src - cairo-path-in-fill.c (source / functions) Found Hit Coverage
Test: app.info Lines: 115 0 0.0 %
Date: 2012-06-02 Functions: 9 0 0.0 %

       1                 : /* cairo - a vector graphics library with display and print output
       2                 :  *
       3                 :  * Copyright © 2008 Chris Wilson
       4                 :  *
       5                 :  * This library is free software; you can redistribute it and/or
       6                 :  * modify it either under the terms of the GNU Lesser General Public
       7                 :  * License version 2.1 as published by the Free Software Foundation
       8                 :  * (the "LGPL") or, at your option, under the terms of the Mozilla
       9                 :  * Public License Version 1.1 (the "MPL"). If you do not alter this
      10                 :  * notice, a recipient may use your version of this file under either
      11                 :  * the MPL or the LGPL.
      12                 :  *
      13                 :  * You should have received a copy of the LGPL along with this library
      14                 :  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
      15                 :  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
      16                 :  * You should have received a copy of the MPL along with this library
      17                 :  * in the file COPYING-MPL-1.1
      18                 :  *
      19                 :  * The contents of this file are subject to the Mozilla Public License
      20                 :  * Version 1.1 (the "License"); you may not use this file except in
      21                 :  * compliance with the License. You may obtain a copy of the License at
      22                 :  * http://www.mozilla.org/MPL/
      23                 :  *
      24                 :  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
      25                 :  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
      26                 :  * the specific language governing rights and limitations.
      27                 :  *
      28                 :  * The Original Code is the cairo graphics library.
      29                 :  *
      30                 :  * The Initial Developer of the Original Code is Chris Wilson.
      31                 :  *
      32                 :  * Contributor(s):
      33                 :  *      Chris Wilson <chris@chris-wilson.co.uk>
      34                 :  */
      35                 : 
      36                 : #include "cairoint.h"
      37                 : #include "cairo-path-fixed-private.h"
      38                 : 
      39                 : typedef struct cairo_in_fill {
      40                 :     double tolerance;
      41                 :     cairo_bool_t on_edge;
      42                 :     int winding;
      43                 : 
      44                 :     cairo_fixed_t x, y;
      45                 : 
      46                 :     cairo_bool_t has_current_point;
      47                 :     cairo_point_t current_point;
      48                 :     cairo_point_t first_point;
      49                 : } cairo_in_fill_t;
      50                 : 
      51                 : static void
      52               0 : _cairo_in_fill_init (cairo_in_fill_t    *in_fill,
      53                 :                      double              tolerance,
      54                 :                      double              x,
      55                 :                      double              y)
      56                 : {
      57               0 :     in_fill->on_edge = FALSE;
      58               0 :     in_fill->winding = 0;
      59               0 :     in_fill->tolerance = tolerance;
      60                 : 
      61               0 :     in_fill->x = _cairo_fixed_from_double (x);
      62               0 :     in_fill->y = _cairo_fixed_from_double (y);
      63                 : 
      64               0 :     in_fill->has_current_point = FALSE;
      65               0 :     in_fill->current_point.x = 0;
      66               0 :     in_fill->current_point.y = 0;
      67               0 : }
      68                 : 
      69                 : static void
      70               0 : _cairo_in_fill_fini (cairo_in_fill_t *in_fill)
      71                 : {
      72               0 : }
      73                 : 
      74                 : static int
      75               0 : edge_compare_for_y_against_x (const cairo_point_t *p1,
      76                 :                               const cairo_point_t *p2,
      77                 :                               cairo_fixed_t y,
      78                 :                               cairo_fixed_t x)
      79                 : {
      80                 :     cairo_fixed_t adx, ady;
      81                 :     cairo_fixed_t dx, dy;
      82                 :     cairo_int64_t L, R;
      83                 : 
      84               0 :     adx = p2->x - p1->x;
      85               0 :     dx = x - p1->x;
      86                 : 
      87               0 :     if (adx == 0)
      88               0 :         return -dx;
      89               0 :     if ((adx ^ dx) < 0)
      90               0 :         return adx;
      91                 : 
      92               0 :     dy = y - p1->y;
      93               0 :     ady = p2->y - p1->y;
      94                 : 
      95               0 :     L = _cairo_int32x32_64_mul (dy, adx);
      96               0 :     R = _cairo_int32x32_64_mul (dx, ady);
      97                 : 
      98               0 :     return _cairo_int64_cmp (L, R);
      99                 : }
     100                 : 
     101                 : static void
     102               0 : _cairo_in_fill_add_edge (cairo_in_fill_t *in_fill,
     103                 :                          const cairo_point_t *p1,
     104                 :                          const cairo_point_t *p2)
     105                 : {
     106                 :     int dir;
     107                 : 
     108               0 :     if (in_fill->on_edge)
     109               0 :         return;
     110                 : 
     111                 :     /* count the number of edge crossing to -∞ */
     112                 : 
     113               0 :     dir = 1;
     114               0 :     if (p2->y < p1->y) {
     115                 :         const cairo_point_t *tmp;
     116                 : 
     117               0 :         tmp = p1;
     118               0 :         p1 = p2;
     119               0 :         p2 = tmp;
     120                 : 
     121               0 :         dir = -1;
     122                 :     }
     123                 : 
     124                 :     /* First check whether the query is on an edge */
     125               0 :     if ((p1->x == in_fill->x && p1->y == in_fill->y) ||
     126               0 :         (p2->x == in_fill->x && p2->y == in_fill->y) ||
     127               0 :         (! (p2->y < in_fill->y || p1->y > in_fill->y ||
     128               0 :            (p1->x > in_fill->x && p2->x > in_fill->x) ||
     129               0 :            (p1->x < in_fill->x && p2->x < in_fill->x)) &&
     130               0 :          edge_compare_for_y_against_x (p1, p2, in_fill->y, in_fill->x) == 0))
     131                 :     {
     132               0 :         in_fill->on_edge = TRUE;
     133               0 :         return;
     134                 :     }
     135                 : 
     136                 :     /* edge is entirely above or below, note the shortening rule */
     137               0 :     if (p2->y <= in_fill->y || p1->y > in_fill->y)
     138               0 :         return;
     139                 : 
     140                 :     /* edge lies wholly to the right */
     141               0 :     if (p1->x >= in_fill->x && p2->x >= in_fill->x)
     142               0 :         return;
     143                 : 
     144               0 :     if ((p1->x <= in_fill->x && p2->x <= in_fill->x) ||
     145               0 :         edge_compare_for_y_against_x (p1, p2, in_fill->y, in_fill->x) < 0)
     146                 :     {
     147               0 :         in_fill->winding += dir;
     148                 :     }
     149                 : }
     150                 : 
     151                 : static cairo_status_t
     152               0 : _cairo_in_fill_move_to (void *closure,
     153                 :                         const cairo_point_t *point)
     154                 : {
     155               0 :     cairo_in_fill_t *in_fill = closure;
     156                 : 
     157                 :     /* implicit close path */
     158               0 :     if (in_fill->has_current_point) {
     159               0 :         _cairo_in_fill_add_edge (in_fill,
     160               0 :                                  &in_fill->current_point,
     161               0 :                                  &in_fill->first_point);
     162                 :     }
     163                 : 
     164               0 :     in_fill->first_point = *point;
     165               0 :     in_fill->current_point = *point;
     166               0 :     in_fill->has_current_point = TRUE;
     167                 : 
     168               0 :     return CAIRO_STATUS_SUCCESS;
     169                 : }
     170                 : 
     171                 : static cairo_status_t
     172               0 : _cairo_in_fill_line_to (void *closure,
     173                 :                         const cairo_point_t *point)
     174                 : {
     175               0 :     cairo_in_fill_t *in_fill = closure;
     176                 : 
     177               0 :     if (in_fill->has_current_point)
     178               0 :         _cairo_in_fill_add_edge (in_fill, &in_fill->current_point, point);
     179                 : 
     180               0 :     in_fill->current_point = *point;
     181               0 :     in_fill->has_current_point = TRUE;
     182                 : 
     183               0 :     return CAIRO_STATUS_SUCCESS;
     184                 : }
     185                 : 
     186                 : static cairo_status_t
     187               0 : _cairo_in_fill_curve_to (void *closure,
     188                 :                          const cairo_point_t *b,
     189                 :                          const cairo_point_t *c,
     190                 :                          const cairo_point_t *d)
     191                 : {
     192               0 :     cairo_in_fill_t *in_fill = closure;
     193                 :     cairo_spline_t spline;
     194                 :     cairo_fixed_t top, bot, left;
     195                 : 
     196                 :     /* first reject based on bbox */
     197               0 :     bot = top = in_fill->current_point.y;
     198               0 :     if (b->y < top) top = b->y;
     199               0 :     if (b->y > bot) bot = b->y;
     200               0 :     if (c->y < top) top = c->y;
     201               0 :     if (c->y > bot) bot = c->y;
     202               0 :     if (d->y < top) top = d->y;
     203               0 :     if (d->y > bot) bot = d->y;
     204               0 :     if (bot < in_fill->y || top > in_fill->y) {
     205               0 :         in_fill->current_point = *d;
     206               0 :         return CAIRO_STATUS_SUCCESS;
     207                 :     }
     208                 : 
     209               0 :     left = in_fill->current_point.x;
     210               0 :     if (b->x < left) left = b->x;
     211               0 :     if (c->x < left) left = c->x;
     212               0 :     if (d->x < left) left = d->x;
     213               0 :     if (left > in_fill->x) {
     214               0 :         in_fill->current_point = *d;
     215               0 :         return CAIRO_STATUS_SUCCESS;
     216                 :     }
     217                 : 
     218                 :     /* XXX Investigate direct inspection of the inflections? */
     219               0 :     if (! _cairo_spline_init (&spline,
     220                 :                               _cairo_in_fill_line_to,
     221                 :                               in_fill,
     222               0 :                               &in_fill->current_point, b, c, d))
     223                 :     {
     224               0 :         return CAIRO_STATUS_SUCCESS;
     225                 :     }
     226                 : 
     227               0 :     return _cairo_spline_decompose (&spline, in_fill->tolerance);
     228                 : }
     229                 : 
     230                 : static cairo_status_t
     231               0 : _cairo_in_fill_close_path (void *closure)
     232                 : {
     233               0 :     cairo_in_fill_t *in_fill = closure;
     234                 : 
     235               0 :     if (in_fill->has_current_point) {
     236               0 :         _cairo_in_fill_add_edge (in_fill,
     237               0 :                                  &in_fill->current_point,
     238               0 :                                  &in_fill->first_point);
     239                 : 
     240               0 :         in_fill->has_current_point = FALSE;
     241                 :     }
     242                 : 
     243               0 :     return CAIRO_STATUS_SUCCESS;
     244                 : }
     245                 : 
     246                 : cairo_bool_t
     247               0 : _cairo_path_fixed_in_fill (const cairo_path_fixed_t     *path,
     248                 :                            cairo_fill_rule_t     fill_rule,
     249                 :                            double                tolerance,
     250                 :                            double                x,
     251                 :                            double                y)
     252                 : {
     253                 :     cairo_in_fill_t in_fill;
     254                 :     cairo_status_t status;
     255                 :     cairo_bool_t is_inside;
     256                 : 
     257               0 :     if (path->is_empty_fill)
     258               0 :         return FALSE;
     259                 : 
     260               0 :     _cairo_in_fill_init (&in_fill, tolerance, x, y);
     261                 : 
     262               0 :     status = _cairo_path_fixed_interpret (path,
     263                 :                                           CAIRO_DIRECTION_FORWARD,
     264                 :                                           _cairo_in_fill_move_to,
     265                 :                                           _cairo_in_fill_line_to,
     266                 :                                           _cairo_in_fill_curve_to,
     267                 :                                           _cairo_in_fill_close_path,
     268                 :                                           &in_fill);
     269               0 :     assert (status == CAIRO_STATUS_SUCCESS);
     270                 : 
     271               0 :     _cairo_in_fill_close_path (&in_fill);
     272                 : 
     273               0 :     if (in_fill.on_edge) {
     274               0 :         is_inside = TRUE;
     275               0 :     } else switch (fill_rule) {
     276                 :     case CAIRO_FILL_RULE_EVEN_ODD:
     277               0 :         is_inside = in_fill.winding & 1;
     278               0 :         break;
     279                 :     case CAIRO_FILL_RULE_WINDING:
     280               0 :         is_inside = in_fill.winding != 0;
     281               0 :         break;
     282                 :     default:
     283               0 :         ASSERT_NOT_REACHED;
     284               0 :         is_inside = FALSE;
     285               0 :         break;
     286                 :     }
     287                 : 
     288               0 :     _cairo_in_fill_fini (&in_fill);
     289                 : 
     290               0 :     return is_inside;
     291                 : }

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