+++ /dev/null
-/* Libart_LGPL - library of basic graphic primitives
- * Copyright (C) 1998-2000 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"
-#include "art_svp_vpath.h"
-
-
-/* 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;
- }
-}
-
-/**
- * art_svp_from_vpath: Convert a vpath to a sorted vector path.
- * @vpath: #ArtVPath to convert.
- *
- * Converts a vector path into sorted vector path form. The svp form is
- * more efficient for rendering and other vector operations.
- *
- * Basically, the implementation is to traverse the vector path,
- * generating a new segment for each "run" of points in the vector
- * path with monotonically increasing Y values. All the resulting
- * values are then sorted.
- *
- * Note: I'm not sure that the sorting rule is correct with respect
- * to numerical stability issues.
- *
- * Return value: Resulting sorted vector path.
- **/
-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;
- 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++;
- points = NULL;
- }
-
- if (points == NULL)
- {
- 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;
-}
-
projects / rrdtool.git / blobdiff