--- /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.
+ */
+
+
+#include "config.h"
+#include "art_svp_vpath_stroke.h"
+
+#include <stdlib.h>
+#include <math.h>
+
+#include "art_misc.h"
+
+#include "art_vpath.h"
+#include "art_svp.h"
+#ifdef ART_USE_NEW_INTERSECTOR
+#include "art_svp_intersect.h"
+#else
+#include "art_svp_wind.h"
+#endif
+#include "art_svp_vpath.h"
+
+#define EPSILON 1e-6
+#define EPSILON_2 1e-12
+
+#define yes_OPTIMIZE_INNER
+
+/* Render an arc segment starting at (xc + x0, yc + y0) to (xc + x1,
+ yc + y1), centered at (xc, yc), and with given radius. Both x0^2 +
+ y0^2 and x1^2 + y1^2 should be equal to radius^2.
+
+ A positive value of radius means curve to the left, negative means
+ curve to the right.
+*/
+static void
+art_svp_vpath_stroke_arc (ArtVpath **p_vpath, int *pn, int *pn_max,
+ double xc, double yc,
+ double x0, double y0,
+ double x1, double y1,
+ double radius,
+ double flatness)
+{
+ double theta;
+ double th_0, th_1;
+ int n_pts;
+ int i;
+ double aradius;
+
+ aradius = fabs (radius);
+ theta = 2 * M_SQRT2 * sqrt (flatness / aradius);
+ th_0 = atan2 (y0, x0);
+ th_1 = atan2 (y1, x1);
+ if (radius > 0)
+ {
+ /* curve to the left */
+ if (th_0 < th_1) th_0 += M_PI * 2;
+ n_pts = ceil ((th_0 - th_1) / theta);
+ }
+ else
+ {
+ /* curve to the right */
+ if (th_1 < th_0) th_1 += M_PI * 2;
+ n_pts = ceil ((th_1 - th_0) / theta);
+ }
+#ifdef VERBOSE
+ printf ("start %f %f; th_0 = %f, th_1 = %f, r = %f, theta = %f\n", x0, y0, th_0, th_1, radius, theta);
+#endif
+ art_vpath_add_point (p_vpath, pn, pn_max,
+ ART_LINETO, xc + x0, yc + y0);
+ for (i = 1; i < n_pts; i++)
+ {
+ theta = th_0 + (th_1 - th_0) * i / n_pts;
+ art_vpath_add_point (p_vpath, pn, pn_max,
+ ART_LINETO, xc + cos (theta) * aradius,
+ yc + sin (theta) * aradius);
+#ifdef VERBOSE
+ printf ("mid %f %f\n", cos (theta) * radius, sin (theta) * radius);
+#endif
+ }
+ art_vpath_add_point (p_vpath, pn, pn_max,
+ ART_LINETO, xc + x1, yc + y1);
+#ifdef VERBOSE
+ printf ("end %f %f\n", x1, y1);
+#endif
+}
+
+/* Assume that forw and rev are at point i0. Bring them to i1,
+ joining with the vector i1 - i2.
+
+ This used to be true, but isn't now that the stroke_raw code is
+ filtering out (near)zero length vectors: {It so happens that all
+ invocations of this function maintain the precondition i1 = i0 + 1,
+ so we could decrease the number of arguments by one. We haven't
+ done that here, though.}
+
+ forw is to the line's right and rev is to its left.
+
+ Precondition: no zero-length vectors, otherwise a divide by
+ zero will happen. */
+static void
+render_seg (ArtVpath **p_forw, int *pn_forw, int *pn_forw_max,
+ ArtVpath **p_rev, int *pn_rev, int *pn_rev_max,
+ ArtVpath *vpath, int i0, int i1, int i2,
+ ArtPathStrokeJoinType join,
+ double line_width, double miter_limit, double flatness)
+{
+ double dx0, dy0;
+ double dx1, dy1;
+ double dlx0, dly0;
+ double dlx1, dly1;
+ double dmx, dmy;
+ double dmr2;
+ double scale;
+ double cross;
+
+#ifdef VERBOSE
+ printf ("join style = %d\n", join);
+#endif
+
+ /* The vectors of the lines from i0 to i1 and i1 to i2. */
+ dx0 = vpath[i1].x - vpath[i0].x;
+ dy0 = vpath[i1].y - vpath[i0].y;
+
+ dx1 = vpath[i2].x - vpath[i1].x;
+ dy1 = vpath[i2].y - vpath[i1].y;
+
+ /* Set dl[xy]0 to the vector from i0 to i1, rotated counterclockwise
+ 90 degrees, and scaled to the length of line_width. */
+ scale = line_width / sqrt (dx0 * dx0 + dy0 * dy0);
+ dlx0 = dy0 * scale;
+ dly0 = -dx0 * scale;
+
+ /* Set dl[xy]1 to the vector from i1 to i2, rotated counterclockwise
+ 90 degrees, and scaled to the length of line_width. */
+ scale = line_width / sqrt (dx1 * dx1 + dy1 * dy1);
+ dlx1 = dy1 * scale;
+ dly1 = -dx1 * scale;
+
+#ifdef VERBOSE
+ printf ("%% render_seg: (%g, %g) - (%g, %g) - (%g, %g)\n",
+ vpath[i0].x, vpath[i0].y,
+ vpath[i1].x, vpath[i1].y,
+ vpath[i2].x, vpath[i2].y);
+
+ printf ("%% render_seg: d[xy]0 = (%g, %g), dl[xy]0 = (%g, %g)\n",
+ dx0, dy0, dlx0, dly0);
+
+ printf ("%% render_seg: d[xy]1 = (%g, %g), dl[xy]1 = (%g, %g)\n",
+ dx1, dy1, dlx1, dly1);
+#endif
+
+ /* now, forw's last point is expected to be colinear along d[xy]0
+ to point i0 - dl[xy]0, and rev with i0 + dl[xy]0. */
+
+ /* positive for positive area (i.e. left turn) */
+ cross = dx1 * dy0 - dx0 * dy1;
+
+ dmx = (dlx0 + dlx1) * 0.5;
+ dmy = (dly0 + dly1) * 0.5;
+ dmr2 = dmx * dmx + dmy * dmy;
+
+ if (join == ART_PATH_STROKE_JOIN_MITER &&
+ dmr2 * miter_limit * miter_limit < line_width * line_width)
+ join = ART_PATH_STROKE_JOIN_BEVEL;
+
+ /* the case when dmr2 is zero or very small bothers me
+ (i.e. near a 180 degree angle)
+ ALEX: So, we avoid the optimization when dmr2 is very small. This should
+ be safe since dmx/y is only used in optimization and in MITER case, and MITER
+ should be converted to BEVEL when dmr2 is very small. */
+ if (dmr2 > EPSILON_2)
+ {
+ scale = line_width * line_width / dmr2;
+ dmx *= scale;
+ dmy *= scale;
+ }
+
+ if (cross * cross < EPSILON_2 && dx0 * dx1 + dy0 * dy1 >= 0)
+ {
+ /* going straight */
+#ifdef VERBOSE
+ printf ("%% render_seg: straight\n");
+#endif
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
+ }
+ else if (cross > 0)
+ {
+ /* left turn, forw is outside and rev is inside */
+
+#ifdef VERBOSE
+ printf ("%% render_seg: left\n");
+#endif
+ if (
+#ifdef NO_OPTIMIZE_INNER
+ 0 &&
+#endif
+ (dmr2 > EPSILON_2) &&
+ /* check that i1 + dm[xy] is inside i0-i1 rectangle */
+ (dx0 + dmx) * dx0 + (dy0 + dmy) * dy0 > 0 &&
+ /* and that i1 + dm[xy] is inside i1-i2 rectangle */
+ ((dx1 - dmx) * dx1 + (dy1 - dmy) * dy1 > 0)
+#ifdef PEDANTIC_INNER
+ &&
+ /* check that i1 + dl[xy]1 is inside i0-i1 rectangle */
+ (dx0 + dlx1) * dx0 + (dy0 + dly1) * dy0 > 0 &&
+ /* and that i1 + dl[xy]0 is inside i1-i2 rectangle */
+ ((dx1 - dlx0) * dx1 + (dy1 - dly0) * dy1 > 0)
+#endif
+ )
+ {
+ /* can safely add single intersection point */
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dmx, vpath[i1].y + dmy);
+ }
+ else
+ {
+ /* need to loop-de-loop the inside */
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x, vpath[i1].y);
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dlx1, vpath[i1].y + dly1);
+ }
+
+ if (join == ART_PATH_STROKE_JOIN_BEVEL)
+ {
+ /* bevel */
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dlx1, vpath[i1].y - dly1);
+ }
+ else if (join == ART_PATH_STROKE_JOIN_MITER)
+ {
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dmx, vpath[i1].y - dmy);
+ }
+ else if (join == ART_PATH_STROKE_JOIN_ROUND) {
+ art_svp_vpath_stroke_arc (p_forw, pn_forw, pn_forw_max,
+ vpath[i1].x, vpath[i1].y,
+ -dlx0, -dly0,
+ -dlx1, -dly1,
+ line_width,
+ flatness);
+ }
+ }
+ else
+ {
+ /* right turn, rev is outside and forw is inside */
+#ifdef VERBOSE
+ printf ("%% render_seg: right\n");
+#endif
+
+ if (
+#ifdef NO_OPTIMIZE_INNER
+ 0 &&
+#endif
+ (dmr2 > EPSILON_2) &&
+ /* check that i1 - dm[xy] is inside i0-i1 rectangle */
+ (dx0 - dmx) * dx0 + (dy0 - dmy) * dy0 > 0 &&
+ /* and that i1 - dm[xy] is inside i1-i2 rectangle */
+ ((dx1 + dmx) * dx1 + (dy1 + dmy) * dy1 > 0)
+#ifdef PEDANTIC_INNER
+ &&
+ /* check that i1 - dl[xy]1 is inside i0-i1 rectangle */
+ (dx0 - dlx1) * dx0 + (dy0 - dly1) * dy0 > 0 &&
+ /* and that i1 - dl[xy]0 is inside i1-i2 rectangle */
+ ((dx1 + dlx0) * dx1 + (dy1 + dly0) * dy1 > 0)
+#endif
+ )
+ {
+ /* can safely add single intersection point */
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dmx, vpath[i1].y - dmy);
+ }
+ else
+ {
+ /* need to loop-de-loop the inside */
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x, vpath[i1].y);
+ art_vpath_add_point (p_forw, pn_forw, pn_forw_max,
+ ART_LINETO, vpath[i1].x - dlx1, vpath[i1].y - dly1);
+ }
+
+ if (join == ART_PATH_STROKE_JOIN_BEVEL)
+ {
+ /* bevel */
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dlx1, vpath[i1].y + dly1);
+ }
+ else if (join == ART_PATH_STROKE_JOIN_MITER)
+ {
+ art_vpath_add_point (p_rev, pn_rev, pn_rev_max,
+ ART_LINETO, vpath[i1].x + dmx, vpath[i1].y + dmy);
+ }
+ else if (join == ART_PATH_STROKE_JOIN_ROUND) {
+ art_svp_vpath_stroke_arc (p_rev, pn_rev, pn_rev_max,
+ vpath[i1].x, vpath[i1].y,
+ dlx0, dly0,
+ dlx1, dly1,
+ -line_width,
+ flatness);
+ }
+
+ }
+}
+
+/* caps i1, under the assumption of a vector from i0 */
+static void
+render_cap (ArtVpath **p_result, int *pn_result, int *pn_result_max,
+ ArtVpath *vpath, int i0, int i1,
+ ArtPathStrokeCapType cap, double line_width, double flatness)
+{
+ double dx0, dy0;
+ double dlx0, dly0;
+ double scale;
+ int n_pts;
+ int i;
+
+ dx0 = vpath[i1].x - vpath[i0].x;
+ dy0 = vpath[i1].y - vpath[i0].y;
+
+ /* Set dl[xy]0 to the vector from i0 to i1, rotated counterclockwise
+ 90 degrees, and scaled to the length of line_width. */
+ scale = line_width / sqrt (dx0 * dx0 + dy0 * dy0);
+ dlx0 = dy0 * scale;
+ dly0 = -dx0 * scale;
+
+#ifdef VERBOSE
+ printf ("cap style = %d\n", cap);
+#endif
+
+ switch (cap)
+ {
+ case ART_PATH_STROKE_CAP_BUTT:
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
+ break;
+ case ART_PATH_STROKE_CAP_ROUND:
+ n_pts = ceil (M_PI / (2.0 * M_SQRT2 * sqrt (flatness / line_width)));
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO, vpath[i1].x - dlx0, vpath[i1].y - dly0);
+ for (i = 1; i < n_pts; i++)
+ {
+ double theta, c_th, s_th;
+
+ theta = M_PI * i / n_pts;
+ c_th = cos (theta);
+ s_th = sin (theta);
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO,
+ vpath[i1].x - dlx0 * c_th - dly0 * s_th,
+ vpath[i1].y - dly0 * c_th + dlx0 * s_th);
+ }
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO, vpath[i1].x + dlx0, vpath[i1].y + dly0);
+ break;
+ case ART_PATH_STROKE_CAP_SQUARE:
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO,
+ vpath[i1].x - dlx0 - dly0,
+ vpath[i1].y - dly0 + dlx0);
+ art_vpath_add_point (p_result, pn_result, pn_result_max,
+ ART_LINETO,
+ vpath[i1].x + dlx0 - dly0,
+ vpath[i1].y + dly0 + dlx0);
+ break;
+ }
+}
+
+/**
+ * art_svp_from_vpath_raw: Stroke a vector path, raw version
+ * @vpath: #ArtVPath to stroke.
+ * @join: Join style.
+ * @cap: Cap style.
+ * @line_width: Width of stroke.
+ * @miter_limit: Miter limit.
+ * @flatness: Flatness.
+ *
+ * Exactly the same as art_svp_vpath_stroke(), except that the resulting
+ * stroke outline may self-intersect and have regions of winding number
+ * greater than 1.
+ *
+ * Return value: Resulting raw stroked outline in svp format.
+ **/
+ArtVpath *
+art_svp_vpath_stroke_raw (ArtVpath *vpath,
+ ArtPathStrokeJoinType join,
+ ArtPathStrokeCapType cap,
+ double line_width,
+ double miter_limit,
+ double flatness)
+{
+ int begin_idx, end_idx;
+ int i;
+ ArtVpath *forw, *rev;
+ int n_forw, n_rev;
+ int n_forw_max, n_rev_max;
+ ArtVpath *result;
+ int n_result, n_result_max;
+ double half_lw = 0.5 * line_width;
+ int closed;
+ int last, this, next, second;
+ double dx, dy;
+
+ n_forw_max = 16;
+ forw = art_new (ArtVpath, n_forw_max);
+
+ n_rev_max = 16;
+ rev = art_new (ArtVpath, n_rev_max);
+
+ n_result = 0;
+ n_result_max = 16;
+ result = art_new (ArtVpath, n_result_max);
+
+ for (begin_idx = 0; vpath[begin_idx].code != ART_END; begin_idx = end_idx)
+ {
+ n_forw = 0;
+ n_rev = 0;
+
+ closed = (vpath[begin_idx].code == ART_MOVETO);
+
+ /* we don't know what the first point joins with until we get to the
+ last point and see if it's closed. So we start with the second
+ line in the path.
+
+ Note: this is not strictly true (we now know it's closed from
+ the opening pathcode), but why fix code that isn't broken?
+ */
+
+ this = begin_idx;
+ /* skip over identical points at the beginning of the subpath */
+ for (i = this + 1; vpath[i].code == ART_LINETO; i++)
+ {
+ dx = vpath[i].x - vpath[this].x;
+ dy = vpath[i].y - vpath[this].y;
+ if (dx * dx + dy * dy > EPSILON_2)
+ break;
+ }
+ next = i;
+ second = next;
+
+ /* invariant: this doesn't coincide with next */
+ while (vpath[next].code == ART_LINETO)
+ {
+ last = this;
+ this = next;
+ /* skip over identical points after the beginning of the subpath */
+ for (i = this + 1; vpath[i].code == ART_LINETO; i++)
+ {
+ dx = vpath[i].x - vpath[this].x;
+ dy = vpath[i].y - vpath[this].y;
+ if (dx * dx + dy * dy > EPSILON_2)
+ break;
+ }
+ next = i;
+ if (vpath[next].code != ART_LINETO)
+ {
+ /* reached end of path */
+ /* make "closed" detection conform to PostScript
+ semantics (i.e. explicit closepath code rather than
+ just the fact that end of the path is the beginning) */
+ if (closed &&
+ vpath[this].x == vpath[begin_idx].x &&
+ vpath[this].y == vpath[begin_idx].y)
+ {
+ int j;
+
+ /* path is closed, render join to beginning */
+ render_seg (&forw, &n_forw, &n_forw_max,
+ &rev, &n_rev, &n_rev_max,
+ vpath, last, this, second,
+ join, half_lw, miter_limit, flatness);
+
+#ifdef VERBOSE
+ printf ("%% forw %d, rev %d\n", n_forw, n_rev);
+#endif
+ /* do forward path */
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_MOVETO, forw[n_forw - 1].x,
+ forw[n_forw - 1].y);
+ for (j = 0; j < n_forw; j++)
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_LINETO, forw[j].x,
+ forw[j].y);
+
+ /* do reverse path, reversed */
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_MOVETO, rev[0].x,
+ rev[0].y);
+ for (j = n_rev - 1; j >= 0; j--)
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_LINETO, rev[j].x,
+ rev[j].y);
+ }
+ else
+ {
+ /* path is open */
+ int j;
+
+ /* add to forw rather than result to ensure that
+ forw has at least one point. */
+ render_cap (&forw, &n_forw, &n_forw_max,
+ vpath, last, this,
+ cap, half_lw, flatness);
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_MOVETO, forw[0].x,
+ forw[0].y);
+ for (j = 1; j < n_forw; j++)
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_LINETO, forw[j].x,
+ forw[j].y);
+ for (j = n_rev - 1; j >= 0; j--)
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_LINETO, rev[j].x,
+ rev[j].y);
+ render_cap (&result, &n_result, &n_result_max,
+ vpath, second, begin_idx,
+ cap, half_lw, flatness);
+ art_vpath_add_point (&result, &n_result, &n_result_max,
+ ART_LINETO, forw[0].x,
+ forw[0].y);
+ }
+ }
+ else
+ render_seg (&forw, &n_forw, &n_forw_max,
+ &rev, &n_rev, &n_rev_max,
+ vpath, last, this, next,
+ join, half_lw, miter_limit, flatness);
+ }
+ end_idx = next;
+ }
+
+ art_free (forw);
+ art_free (rev);
+#ifdef VERBOSE
+ printf ("%% n_result = %d\n", n_result);
+#endif
+ art_vpath_add_point (&result, &n_result, &n_result_max, ART_END, 0, 0);
+ return result;
+}
+
+#define noVERBOSE
+
+#ifdef VERBOSE
+
+#define XOFF 50
+#define YOFF 700
+
+static void
+print_ps_vpath (ArtVpath *vpath)
+{
+ int i;
+
+ for (i = 0; vpath[i].code != ART_END; i++)
+ {
+ switch (vpath[i].code)
+ {
+ case ART_MOVETO:
+ printf ("%g %g moveto\n", XOFF + vpath[i].x, YOFF - vpath[i].y);
+ break;
+ case ART_LINETO:
+ printf ("%g %g lineto\n", XOFF + vpath[i].x, YOFF - vpath[i].y);
+ break;
+ default:
+ break;
+ }
+ }
+ printf ("stroke showpage\n");
+}
+
+static void
+print_ps_svp (ArtSVP *vpath)
+{
+ int i, j;
+
+ printf ("%% begin\n");
+ for (i = 0; i < vpath->n_segs; i++)
+ {
+ printf ("%g setgray\n", vpath->segs[i].dir ? 0.7 : 0);
+ for (j = 0; j < vpath->segs[i].n_points; j++)
+ {
+ printf ("%g %g %s\n",
+ XOFF + vpath->segs[i].points[j].x,
+ YOFF - vpath->segs[i].points[j].y,
+ j ? "lineto" : "moveto");
+ }
+ printf ("stroke\n");
+ }
+
+ printf ("showpage\n");
+}
+#endif
+
+/* Render a vector path into a stroked outline.
+
+ Status of this routine:
+
+ Basic correctness: Only miter and bevel line joins are implemented,
+ and only butt line caps. Otherwise, seems to be fine.
+
+ Numerical stability: We cheat (adding random perturbation). Thus,
+ it seems very likely that no numerical stability problems will be
+ seen in practice.
+
+ Speed: Should be pretty good.
+
+ Precision: The perturbation fuzzes the coordinates slightly,
+ but not enough to be visible. */
+/**
+ * art_svp_vpath_stroke: Stroke a vector path.
+ * @vpath: #ArtVPath to stroke.
+ * @join: Join style.
+ * @cap: Cap style.
+ * @line_width: Width of stroke.
+ * @miter_limit: Miter limit.
+ * @flatness: Flatness.
+ *
+ * Computes an svp representing the stroked outline of @vpath. The
+ * width of the stroked line is @line_width.
+ *
+ * Lines are joined according to the @join rule. Possible values are
+ * ART_PATH_STROKE_JOIN_MITER (for mitered joins),
+ * ART_PATH_STROKE_JOIN_ROUND (for round joins), and
+ * ART_PATH_STROKE_JOIN_BEVEL (for bevelled joins). The mitered join
+ * is converted to a bevelled join if the miter would extend to a
+ * distance of more than @miter_limit * @line_width from the actual
+ * join point.
+ *
+ * If there are open subpaths, the ends of these subpaths are capped
+ * according to the @cap rule. Possible values are
+ * ART_PATH_STROKE_CAP_BUTT (squared cap, extends exactly to end
+ * point), ART_PATH_STROKE_CAP_ROUND (rounded half-circle centered at
+ * the end point), and ART_PATH_STROKE_CAP_SQUARE (squared cap,
+ * extending half @line_width past the end point).
+ *
+ * The @flatness parameter controls the accuracy of the rendering. It
+ * is most important for determining the number of points to use to
+ * approximate circular arcs for round lines and joins. In general, the
+ * resulting vector path will be within @flatness pixels of the "ideal"
+ * path containing actual circular arcs. I reserve the right to use
+ * the @flatness parameter to convert bevelled joins to miters for very
+ * small turn angles, as this would reduce the number of points in the
+ * resulting outline path.
+ *
+ * The resulting path is "clean" with respect to self-intersections, i.e.
+ * the winding number is 0 or 1 at each point.
+ *
+ * Return value: Resulting stroked outline in svp format.
+ **/
+ArtSVP *
+art_svp_vpath_stroke (ArtVpath *vpath,
+ ArtPathStrokeJoinType join,
+ ArtPathStrokeCapType cap,
+ double line_width,
+ double miter_limit,
+ double flatness)
+{
+#ifdef ART_USE_NEW_INTERSECTOR
+ ArtVpath *vpath_stroke;
+ ArtSVP *svp, *svp2;
+ ArtSvpWriter *swr;
+
+ vpath_stroke = art_svp_vpath_stroke_raw (vpath, join, cap,
+ line_width, miter_limit, flatness);
+#ifdef VERBOSE
+ //print_ps_vpath (vpath_stroke);
+#endif
+ svp = art_svp_from_vpath (vpath_stroke);
+#ifdef VERBOSE
+ //print_ps_svp (svp);
+#endif
+ art_free (vpath_stroke);
+
+ swr = art_svp_writer_rewind_new (ART_WIND_RULE_NONZERO);
+ art_svp_intersector (svp, swr);
+
+ svp2 = art_svp_writer_rewind_reap (swr);
+#ifdef VERBOSE
+ //print_ps_svp (svp2);
+#endif
+ art_svp_free (svp);
+ return svp2;
+#else
+ ArtVpath *vpath_stroke, *vpath2;
+ ArtSVP *svp, *svp2, *svp3;
+
+ vpath_stroke = art_svp_vpath_stroke_raw (vpath, join, cap,
+ line_width, miter_limit, flatness);
+#ifdef VERBOSE
+ //print_ps_vpath (vpath_stroke);
+#endif
+ vpath2 = art_vpath_perturb (vpath_stroke);
+#ifdef VERBOSE
+ //print_ps_vpath (vpath2);
+#endif
+ art_free (vpath_stroke);
+ svp = art_svp_from_vpath (vpath2);
+#ifdef VERBOSE
+ //print_ps_svp (svp);
+#endif
+ art_free (vpath2);
+ svp2 = art_svp_uncross (svp);
+#ifdef VERBOSE
+ //print_ps_svp (svp2);
+#endif
+ art_svp_free (svp);
+ svp3 = art_svp_rewind_uncrossed (svp2, ART_WIND_RULE_NONZERO);
+#ifdef VERBOSE
+ //print_ps_svp (svp3);
+#endif
+ art_svp_free (svp2);
+
+ return svp3;
+#endif
+}
git.asbjorn.biz / swftools.git / blobdiff