X-Git-Url: http://git.asbjorn.biz/?a=blobdiff_plain;f=lib%2Fart%2Fart_svp_vpath_stroke.c;fp=lib%2Fart%2Fart_svp_vpath_stroke.c;h=bf3111b538e90f6e8c7922da27b5cab7ba4fabca;hb=418ef05b5d0b74e6f19200ffa40bcc3afccb5029;hp=0000000000000000000000000000000000000000;hpb=c1f4a906117e98e2f4ba59abc1ce153e8129bc19;p=swftools.git diff --git a/lib/art/art_svp_vpath_stroke.c b/lib/art/art_svp_vpath_stroke.c new file mode 100644 index 0000000..bf3111b --- /dev/null +++ b/lib/art/art_svp_vpath_stroke.c @@ -0,0 +1,741 @@ +/* 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 +#include + +#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 +}