art_svp_vpath.c 4.85 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
/* Libart_LGPL - library of basic graphic primitives
 * Copyright (C) 1998 Raph Levien
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/* Sort vector paths into sorted vector paths */

#include <stdlib.h>
#include <math.h>

#include "art_misc.h"

#include "art_vpath.h"
#include "art_svp.h"
29
#include "art_svp_vpath.h"
30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92


/* reverse a list of points in place */
static void
reverse_points (ArtPoint *points, int n_points)
{
  int i;
  ArtPoint tmp_p;

  for (i = 0; i < (n_points >> 1); i++)
    {
      tmp_p = points[i];
      points[i] = points[n_points - (i + 1)];
      points[n_points - (i + 1)] = tmp_p;
    }
}

/* convert a vec_path to sorted form */
ArtSVP *
art_svp_from_vpath (ArtVpath *vpath)
{
  int n_segs, n_segs_max;
  ArtSVP *svp;
  int dir;
  int new_dir;
  int i;
  ArtPoint *points;
  int n_points, n_points_max;
  double x, y;
  double x_min, x_max;

  n_segs = 0;
  n_segs_max = 16;
  svp = (ArtSVP *)art_alloc (sizeof(ArtSVP) +
			     (n_segs_max - 1) * sizeof(ArtSVPSeg));

  dir = 0;
  n_points = 0;
  n_points_max = 0;
  points = NULL;
  i = 0;

  x = y = 0; /* unnecessary, given "first code must not be LINETO" invariant,
		but it makes gcc -Wall -ansi -pedantic happier */
  x_min = x_max = 0; /* same */

  while (vpath[i].code != ART_END) {
    if (vpath[i].code == ART_MOVETO || vpath[i].code == ART_MOVETO_OPEN)
      {
	if (points != NULL && n_points >= 2)
	  {
	    if (n_segs == n_segs_max)
	      {
		n_segs_max <<= 1;
		svp = (ArtSVP *)art_realloc (svp, sizeof(ArtSVP) +
					     (n_segs_max - 1) *
					     sizeof(ArtSVPSeg));
	      }
	    svp->segs[n_segs].n_points = n_points;
	    svp->segs[n_segs].dir = (dir > 0);
	    if (dir < 0)
	      reverse_points (points, n_points);
	    svp->segs[n_segs].points = points;
93 94 95 96
	    svp->segs[n_segs].bbox.x0 = x_min;
	    svp->segs[n_segs].bbox.x1 = x_max;
	    svp->segs[n_segs].bbox.y0 = points[0].y;
	    svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
97
	    n_segs++;
98
	    points = NULL;
99
	  }
100 101

	if (points == NULL)
102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197
	  {
	    n_points_max = 4;
	    points = art_new (ArtPoint, n_points_max);
	  }

	n_points = 1;
	points[0].x = x = vpath[i].x;
	points[0].y = y = vpath[i].y;
	x_min = x;
	x_max = x;
	dir = 0;
      }
    else /* must be LINETO */
      {
	new_dir = (vpath[i].y > y ||
		   (vpath[i].y == y && vpath[i].x > x)) ? 1 : -1;
	if (dir && dir != new_dir)
	  {
	    /* new segment */
	    x = points[n_points - 1].x;
	    y = points[n_points - 1].y;
	    if (n_segs == n_segs_max)
	      {
		n_segs_max <<= 1;
		svp = (ArtSVP *)art_realloc (svp, sizeof(ArtSVP) +
					     (n_segs_max - 1) *
					     sizeof(ArtSVPSeg));
	      }
	    svp->segs[n_segs].n_points = n_points;
	    svp->segs[n_segs].dir = (dir > 0);
	    if (dir < 0)
	      reverse_points (points, n_points);
	    svp->segs[n_segs].points = points;
	    svp->segs[n_segs].bbox.x0 = x_min;
	    svp->segs[n_segs].bbox.x1 = x_max;
	    svp->segs[n_segs].bbox.y0 = points[0].y;
	    svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
	    n_segs++;

	    n_points = 1;
	    n_points_max = 4;
	    points = art_new (ArtPoint, n_points_max);
	    points[0].x = x;
	    points[0].y = y;
	    x_min = x;
	    x_max = x;
	  }

	if (points != NULL)
	  {
	    if (n_points == n_points_max)
	      art_expand (points, ArtPoint, n_points_max);
	    points[n_points].x = x = vpath[i].x;
	    points[n_points].y = y = vpath[i].y;
	    if (x < x_min) x_min = x;
	    else if (x > x_max) x_max = x;
	    n_points++;
	  }
	dir = new_dir;
      }
    i++;
  }

  if (points != NULL)
    {
      if (n_points >= 2)
	{
	  if (n_segs == n_segs_max)
	    {
	      n_segs_max <<= 1;
	      svp = (ArtSVP *)art_realloc (svp, sizeof(ArtSVP) +
					   (n_segs_max - 1) *
					   sizeof(ArtSVPSeg));
	    }
	  svp->segs[n_segs].n_points = n_points;
	  svp->segs[n_segs].dir = (dir > 0);
	  if (dir < 0)
	    reverse_points (points, n_points);
	  svp->segs[n_segs].points = points;
	  svp->segs[n_segs].bbox.x0 = x_min;
	  svp->segs[n_segs].bbox.x1 = x_max;
	  svp->segs[n_segs].bbox.y0 = points[0].y;
	  svp->segs[n_segs].bbox.y1 = points[n_points - 1].y;
	  n_segs++;
	}
      else
	art_free (points);
    }

  svp->n_segs = n_segs;

  qsort (&svp->segs, n_segs, sizeof (ArtSVPSeg), art_svp_seg_compare);

  return svp;
}