[gtk/wip/matthiasc/lottie-stroke: 208/217] Add gsk_path_to_stroke
- From: Matthias Clasen <matthiasc src gnome org>
- To: commits-list gnome org
- Cc:
- Subject: [gtk/wip/matthiasc/lottie-stroke: 208/217] Add gsk_path_to_stroke
- Date: Sat, 5 Dec 2020 08:00:23 +0000 (UTC)
commit c9bcf6181dbe3ef2313be193311802ae549933af
Author: Matthias Clasen <mclasen redhat com>
Date: Fri Nov 27 14:05:25 2020 -0500
Add gsk_path_to_stroke
Implement gsk_path_to_stroke, which takes a path and stroke
parameters, and returns a new path for the outline the would
be produced by stroking the path with these parameters.
There are still some stability issues with sharp joins, and
subdividing is not done yet.
gsk/gskcontourprivate.h | 4 +
gsk/gskpath.c | 4 +
gsk/gskpath.h | 5 +
gsk/gskpathmeasure.c | 30 +-
gsk/gskpathmeasure.h | 4 +
gsk/gskpathstroke.c | 1375 ++++++++++++++++++++++++++++++++++++
gsk/meson.build | 1 +
testsuite/gsk/path-special-cases.c | 41 ++
8 files changed, 1463 insertions(+), 1 deletion(-)
---
diff --git a/gsk/gskcontourprivate.h b/gsk/gskcontourprivate.h
index 13e54a8e5d..4fef8189c1 100644
--- a/gsk/gskcontourprivate.h
+++ b/gsk/gskcontourprivate.h
@@ -96,6 +96,10 @@ void gsk_contour_add_segment (const GskContou
gpointer measure_data,
float start,
float end);
+void gsk_contour_stroke (const GskContour *contour,
+ GskStroke *stroke,
+ GskPathBuilder *builder);
+
G_END_DECLS
diff --git a/gsk/gskpath.c b/gsk/gskpath.c
index 9e9dac1023..c5f5101a6a 100644
--- a/gsk/gskpath.c
+++ b/gsk/gskpath.c
@@ -24,6 +24,10 @@
#include "gskpathbuilder.h"
#include "gsksplineprivate.h"
+#include "gskstrokeprivate.h"
+
+#include "gdk/gdk-private.h"
+
/**
* SECTION:gskpath
* @Title: Path
diff --git a/gsk/gskpath.h b/gsk/gskpath.h
index 31f4cd10e9..911aecaa07 100644
--- a/gsk/gskpath.h
+++ b/gsk/gskpath.h
@@ -106,6 +106,11 @@ gboolean gsk_path_foreach (GskPath
GskPathForeachFunc func,
gpointer user_data);
+GDK_AVAILABLE_IN_ALL
+gboolean gsk_path_in_fill (GskPath *path,
+ graphene_point_t *point,
+ GskFillRule fill_rule);
+
G_END_DECLS
#endif /* __GSK_PATH_H__ */
diff --git a/gsk/gskpathmeasure.c b/gsk/gskpathmeasure.c
index b834ea0642..d497304998 100644
--- a/gsk/gskpathmeasure.c
+++ b/gsk/gskpathmeasure.c
@@ -20,6 +20,7 @@
#include "config.h"
#include "gskpathmeasure.h"
+#include "gskpathbuilder.h"
#include "gskpathbuilder.h"
#include "gskpathprivate.h"
@@ -415,7 +416,6 @@ gsk_path_measure_in_fill (GskPathMeasure *self,
}
}
-
/**
* gsk_path_builder_add_segment:
* @self: a #GskPathBuilder
@@ -476,3 +476,31 @@ gsk_path_builder_add_segment (GskPathBuilder *self,
}
}
+/**
+ * gsk_path_measure_stroke:
+ * @self: a #GskPathMeasure
+ * @stroke: stroke parameters
+ *
+ * Create a new path that follows the outline of the area
+ * that would be affected by stroking along the path of
+ * @self with the given stroke parameters.
+ *
+ * Returns: a new #GskPath
+ */
+GskPath *
+gsk_path_measure_stroke (GskPathMeasure *self,
+ GskStroke *stroke)
+{
+ GskPathBuilder *builder;
+ int i;
+
+ builder = gsk_path_builder_new ();
+
+ for (i = 0; i < self->n_contours; i++)
+ {
+ gsk_contour_stroke (gsk_path_get_contour (self->path, i), stroke, builder);
+ }
+
+ return gsk_path_builder_free_to_path (builder);
+}
+
diff --git a/gsk/gskpathmeasure.h b/gsk/gskpathmeasure.h
index 5d93167be5..5d2bbe1d34 100644
--- a/gsk/gskpathmeasure.h
+++ b/gsk/gskpathmeasure.h
@@ -69,6 +69,10 @@ gboolean gsk_path_measure_in_fill (GskPathMeasure
graphene_point_t *point,
GskFillRule fill_rule);
+GDK_AVAILABLE_IN_ALL
+GskPath * gsk_path_measure_stroke (GskPathMeasure *self,
+ GskStroke *stroke);
+
G_END_DECLS
#endif /* __GSK_PATH_MEASURE_H__ */
diff --git a/gsk/gskpathstroke.c b/gsk/gskpathstroke.c
new file mode 100644
index 0000000000..6d2b22a015
--- /dev/null
+++ b/gsk/gskpathstroke.c
@@ -0,0 +1,1375 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen redhat com>
+ */
+
+#define STROKE_DEBUG 1
+
+#include "config.h"
+
+#include "gskpathprivate.h"
+
+#include "gskpathbuilder.h"
+#include "gsksplineprivate.h"
+
+#include "gskstrokeprivate.h"
+
+#include "gdk/gdk-private.h"
+
+#ifdef STROKE_DEBUG
+static const char * op_to_string (GskPathOperation op) G_GNUC_UNUSED;
+#endif
+
+#define DEG_TO_RAD(x) ((x) * (G_PI / 180.f))
+#define RAD_TO_DEG(x) ((x) / (G_PI / 180.f))
+
+/* Set n to the normal of the line through p0 and p1 */
+static void
+normal_vector (const graphene_point_t *p0,
+ const graphene_point_t *p1,
+ graphene_vec2_t *n)
+{
+ graphene_vec2_init (n, p0->y - p1->y, p1->x - p0->x);
+ graphene_vec2_normalize (n, n);
+}
+
+static void
+direction_vector (const graphene_point_t *p0,
+ const graphene_point_t *p1,
+ graphene_vec2_t *t)
+{
+ graphene_vec2_init (t, p1->x - p0->x, p1->y - p0->y);
+ graphene_vec2_normalize (t, t);
+}
+
+static void
+get_bezier (const graphene_point_t *points,
+ int length,
+ float t,
+ graphene_point_t *p)
+{
+ if (length == 1)
+ *p = points[0];
+ else
+ {
+ graphene_point_t *newpoints;
+ int i;
+
+ newpoints = g_alloca (sizeof (graphene_point_t) * (length - 1));
+ for (i = 0; i < length - 1; i++)
+ graphene_point_interpolate (&points[i], &points[i + 1], t, &newpoints[i]);
+ get_bezier (newpoints, length - 1, t, p);
+ }
+}
+
+static void
+get_cubic (const graphene_point_t points[4],
+ float t,
+ graphene_point_t *p)
+{
+ get_bezier (points, 4, t, p);
+}
+
+static void
+split_bezier_recurse (const graphene_point_t *points,
+ int length,
+ float t,
+ graphene_point_t *left,
+ graphene_point_t *right,
+ int *lpos,
+ int *rpos)
+{
+ if (length == 1)
+ {
+ left[*lpos] = points[0];
+ (*lpos)++;
+ right[*rpos] = points[length - 1];
+ (*rpos)--;
+ }
+ else
+ {
+ graphene_point_t *newpoints;
+ int i;
+
+ newpoints = g_alloca (sizeof (graphene_point_t) * (length - 1));
+ for (i = 0; i < length - 1; i++)
+ {
+ if (i == 0)
+ {
+ left[*lpos] = points[i];
+ (*lpos)++;
+ }
+ if (i + 1 == length - 1)
+ {
+ right[*rpos] = points[i + 1];
+ (*rpos)--;
+ }
+ graphene_point_interpolate (&points[i], &points[i + 1], t, &newpoints[i]);
+ }
+ split_bezier_recurse (newpoints, length - 1, t, left, right, lpos, rpos);
+ }
+}
+
+/* Given Bezier control points and a t value between 0 and 1,
+ * return new Bezier control points for two segments in left
+ * and right that are obtained by splitting the curve at the
+ * point for t.
+ */
+static void
+split_bezier (const graphene_point_t *points,
+ int length,
+ float t,
+ graphene_point_t *left,
+ graphene_point_t *right)
+{
+ int lpos = 0;
+ int rpos = length - 1;
+
+ split_bezier_recurse (points, length, t, left, right, &lpos, &rpos);
+}
+
+/* compute the angle between a, b and c in the range of [0, 360] */
+static float
+three_point_angle (const graphene_point_t *a,
+ const graphene_point_t *b,
+ const graphene_point_t *c)
+{
+ float angle = atan2 (c->y - b->y, c->x - b->x) - atan2 (a->y - b->y, a->x - b->x);
+
+ if (angle < 0)
+ angle += 2 * M_PI;
+
+ return RAD_TO_DEG (angle);
+}
+
+static gboolean
+cubic_is_simple (const graphene_point_t *pts)
+{
+ float a1, a2, s;
+ graphene_vec2_t n1, n2;
+
+ a1 = three_point_angle (&pts[0], &pts[1], &pts[2]);
+ a2 = three_point_angle (&pts[1], &pts[2], &pts[3]);
+
+ if ((a1 < 180.f && a2 > 180.f) || (a1 > 180.f && a2 < 180.f))
+ return FALSE;
+
+ normal_vector (&pts[0], &pts[1], &n1);
+ normal_vector (&pts[2], &pts[3], &n2);
+
+ s = graphene_vec2_dot (&n1, &n2);
+
+ if (fabs (acos (s)) >= M_PI / 3.f)
+ return FALSE;
+
+ return TRUE;
+}
+
+static gboolean
+acceptable (float t)
+{
+ return 0 <= t && t <= 1;
+}
+
+static float
+cuberoot (float v)
+{
+ if (v < 0)
+ return -pow (-v, 1.f / 3);
+ return pow (v, 1.f / 3);
+}
+
+static int
+get_cubic_roots (float pa,
+ float pb,
+ float pc,
+ float pd,
+ float roots[3])
+{
+ float a, b, c, d;
+ float q, q2;
+ float p, p3;
+ float discriminant;
+ float u1, v1, sd;
+ int n_roots = 0;
+
+ d = -pa + 3*pb - 3*pc + pd;
+ a = 3*pa - 6*pb + 3*pc;
+ b = -3*pa + 3*pb;
+ c = pa;
+
+ if (fabs (d) < 0.0001)
+ {
+ if (fabs (a) < 0.0001)
+ {
+ if (fabs (b) < 0.0001)
+ return 0;
+
+ if (acceptable (-c / b))
+ {
+ roots[0] = -c / b;
+ return 1;
+ }
+
+ return 0;
+ }
+ q = sqrt (b*b - 4*a*c);
+ roots[n_roots] = (-b + q) / (2 * a);
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ roots[n_roots] = (-b - q) / (2 * a);
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ return n_roots;
+ }
+
+ a /= d;
+ b /= d;
+ c /= d;
+
+ p = (3*b - a*a)/3;
+ p3 = p/3;
+ q = (2*a*a*a - 9*a*b + 27*c)/27;
+ q2 = q/2;
+ discriminant = q2*q2 + p3*p3*p3;
+
+ if (discriminant < 0)
+ {
+ float mp3 = -p/3;
+ float mp33 = mp3*mp3*mp3;
+ float r = sqrt (mp33);
+ float t = -q / (2*r);
+ float cosphi = t < -1 ? -1 : (t > 1 ? 1 : t);
+ float phi = acos (cosphi);
+ float crtr = cuberoot (r);
+ float t1 = 2*crtr;
+
+ roots[n_roots] = t1 * cos (phi/3) - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ roots[n_roots] = t1 * cos ((phi + 2*M_PI) / 3) - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ roots[n_roots] = t1 * cos ((phi + 4*M_PI) / 3) - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ return n_roots;
+ }
+
+ if (discriminant == 0)
+ {
+ u1 = q2 < 0 ? cuberoot (-q2) : -cuberoot (q2);
+ roots[n_roots] = 2*u1 - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ roots[n_roots] = -u1 - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ return n_roots;
+ }
+
+ sd = sqrt (discriminant);
+ u1 = cuberoot (sd - q2);
+ v1 = cuberoot (sd + q2);
+ roots[n_roots] = u1 - v1 - a/3;
+ if (acceptable (roots[n_roots]))
+ n_roots++;
+ return n_roots;
+}
+
+static int
+get_cubic_extrema (float pa,
+ float pb,
+ float pc,
+ float pd,
+ float roots[2])
+{
+ float a, b, c;
+ float d, t;
+ int n_roots = 0;
+
+ a = 3 * (pd - 3*pc + 3*pb - pa);
+ b = 6 * (pc - 2*pb + pa);
+ c = 3 * (pb - pa);
+
+ if (fabs (a) > 0.0001)
+ {
+ if (b*b > 4*a*c)
+ {
+ d = sqrt (b*b - 4*a*c);
+ t = (-b + d)/(2*a);
+ if (acceptable (t))
+ roots[n_roots++] = t;
+ t = (-b - d)/(2*a);
+ if (acceptable (t))
+ roots[n_roots++] = t;
+ }
+ else
+ {
+ t = -b / (2*a);
+ if (acceptable (t))
+ roots[n_roots++] = t;
+ }
+ }
+ else if (fabs (b) > 0.0001)
+ {
+ t = -c / b;
+ if (acceptable (t))
+ roots[n_roots++] = t;
+ }
+
+ return n_roots;
+}
+
+/* Compute q = p + d * n */
+static void
+scale_point (const graphene_point_t *p,
+ const graphene_vec2_t *n,
+ float d,
+ graphene_point_t *q)
+{
+ q->x = p->x + d * graphene_vec2_get_x (n);
+ q->y = p->y + d * graphene_vec2_get_y (n);
+}
+
+static void
+midpoint (const graphene_point_t *a,
+ const graphene_point_t *b,
+ graphene_point_t *q)
+{
+ q->x = (a->x + b->x) / 2;
+ q->y = (a->y + b->y) / 2;
+}
+
+/* Set p to the intersection of the lines through a, b and c, d.
+ * Return the number of intersections found (0 or 1) */
+static int
+line_intersection (const graphene_point_t *a,
+ const graphene_point_t *b,
+ const graphene_point_t *c,
+ const graphene_point_t *d,
+ graphene_point_t *p)
+{
+ float a1 = b->y - a->y;
+ float b1 = a->x - b->x;
+ float c1 = a1*a->x + b1*a->y;
+
+ float a2 = d->y - c->y;
+ float b2 = c->x - d->x;
+ float c2 = a2*c->x+ b2*c->y;
+
+ float det = a1*b2 - a2*b1;
+
+ if (det == 0)
+ {
+ p->x = NAN;
+ p->y = NAN;
+ return 0;
+ }
+ else
+ {
+ p->x = (b2*c1 - b1*c2) / det;
+ p->y = (a1*c2 - a2*c1) / det;
+ return 1;
+ }
+}
+
+static void
+align_point (const graphene_point_t *p0,
+ const graphene_point_t *a,
+ const graphene_point_t *b,
+ graphene_point_t *q)
+{
+ graphene_vec2_t n;
+ float angle;
+
+ direction_vector (a, b, &n);
+ angle = -atan2 (graphene_vec2_get_y (&n), graphene_vec2_get_x (&n));
+ q->x = (p0->x - a->x) * cos (angle) - (p0->y - a->y) * sin (angle);
+ q->y = (p0->x - a->x) * sin (angle) + (p0->y - a->y) * cos (angle);
+}
+
+static int
+cmpfloat (const void *p1, const void *p2)
+{
+ const float *f1 = p1;
+ const float *f2 = p2;
+ return f1 < f2 ? -1 : (f1 > f2 ? 1 : 0);
+}
+
+/* Place intersections between the line and the curve in q,
+ * and their Bezier positions in t.
+ * Return the number of intersections found (0 to 3).
+ */
+static int
+line_curve_intersection (const graphene_point_t *a,
+ const graphene_point_t *b,
+ const graphene_point_t pts[4],
+ float t[3],
+ graphene_point_t q[3])
+{
+ graphene_point_t p[4];
+ int n, i;
+
+ align_point (&pts[0], a, b, &p[0]);
+ align_point (&pts[1], a, b, &p[1]);
+ align_point (&pts[2], a, b, &p[2]);
+ align_point (&pts[3], a, b, &p[3]);
+
+ n = get_cubic_roots (p[0].y, p[1].y, p[2].y, p[3].y, t);
+ qsort (t, n, sizeof (float), cmpfloat);
+ for (i = 0; i < n; i++)
+ get_cubic (pts, t[i], &q[i]);
+
+ return n;
+}
+
+static void
+get_curve_bounds (const graphene_point_t pts[4],
+ graphene_rect_t *bounds)
+{
+ graphene_point_t p;
+ float t[2];
+ int n, i;
+
+ get_cubic (pts, 0, &p);
+ graphene_rect_init (bounds, p.x, p.y, 0, 0);
+
+ get_cubic (pts, 1, &p);
+ graphene_rect_expand (bounds, &p, bounds);
+
+ n = get_cubic_extrema (pts[0].x, pts[1].x, pts[2].x, pts[3].x, t);
+ for (i = 0; i < n; i++)
+ {
+ get_cubic (pts, t[i], &p);
+ graphene_rect_expand (bounds, &p, bounds);
+ }
+
+ n = get_cubic_extrema (pts[0].y, pts[1].y, pts[2].y, pts[3].y, t);
+ for (i = 0; i < n; i++)
+ {
+ get_cubic (pts, t[i], &p);
+ graphene_rect_expand (bounds, &p, bounds);
+ }
+}
+
+static void
+curve_intersection_recurse (const graphene_point_t pts1[4],
+ const graphene_point_t pts2[4],
+ float t1,
+ float t2,
+ float s1,
+ float s2,
+ float t[9],
+ float s[9],
+ graphene_point_t q[9],
+ int *pos)
+{
+ graphene_rect_t b1, b2;
+ float d;
+ float e;
+
+ graphene_point_t p11[4];
+ graphene_point_t p12[4];
+ graphene_point_t p21[4];
+ graphene_point_t p22[4];
+
+ if (*pos == 9)
+ return;
+
+ get_curve_bounds (pts1, &b1);
+ get_curve_bounds (pts2, &b2);
+
+ if (!graphene_rect_intersection (&b1, &b2, NULL))
+ return;
+
+ d = (t2 - t1) / 2;
+ e = (s2 - s1) / 2;
+
+ if (b1.size.width < 0.1 && b1.size.height < 0.1 &&
+ b2.size.width < 0.1 && b2.size.height < 0.1)
+ {
+ t[*pos] = t1 + d;
+ s[*pos] = s1 + e;
+ get_cubic (pts1, 0.5, &q[*pos]);
+ (*pos)++;
+ return;
+ }
+
+ split_bezier (pts1, 4, 0.5, p11, p12);
+ split_bezier (pts2, 4, 0.5, p21, p22);
+
+ curve_intersection_recurse (p11, p21, t1, t1 + d, s1, s1 + e, t, s, q, pos);
+ curve_intersection_recurse (p11, p22, t1, t1 + d, s1 + e, s2, t, s, q, pos);
+ curve_intersection_recurse (p12, p21, t1 + d, t2, s1, s1 + e, t, s, q, pos);
+ curve_intersection_recurse (p12, p22, t1 + d, t2, s1 + e, s2, t, s, q, pos);
+}
+
+/* Place intersections between the curves in q, and
+ * their Bezier positions in t and s.
+ * Return the number of intersections found (0 to 9).
+ */
+static int
+curve_intersection (const graphene_point_t pts1[4],
+ const graphene_point_t pts2[4],
+ float t[9],
+ float s[9],
+ graphene_point_t q[9])
+{
+ int pos = 0;
+
+ curve_intersection_recurse (pts1, pts2, 0, 1, 0, 1, t, s, q, &pos);
+ return pos;
+}
+
+
+typedef struct
+{
+ GskPathOperation op;
+ int n_pts;
+ graphene_point_t pts[4]; /* points of the curve */
+
+ graphene_point_t r[4]; /* offset to the right */
+ graphene_point_t l[4]; /* offset to the left */
+ graphene_point_t re[2]; /* intersection of adjacent r lines of this and next op */
+ graphene_point_t le[2]; /* intersection of adjacent l lines of this and next op */
+ float angle[2]; /* angles between tangents at the both ends */
+} PathOpData;
+
+static void
+compute_offsets (PathOpData *op,
+ float d)
+{
+ graphene_vec2_t n1, n2, n3;
+
+ normal_vector (&op->pts[0], &op->pts[1], &n1);
+ normal_vector (&op->pts[op->n_pts - 1], &op->pts[op->n_pts - 2], &n3);
+
+ scale_point (&op->pts[0], &n1, d, &op->r[0]);
+ scale_point (&op->pts[0], &n1, -d, &op->l[0]);
+
+ scale_point (&op->pts[op->n_pts - 1], &n3, -d, &op->r[op->n_pts - 1]);
+ scale_point (&op->pts[op->n_pts - 1], &n3, d, &op->l[op->n_pts - 1]);
+
+ if (op->op == GSK_PATH_CURVE)
+ {
+ graphene_point_t m1, m2, m3, m4;
+
+ /* Simply scale control points, a la Tiller and Hanson */
+
+ normal_vector (&op->pts[1], &op->pts[2], &n2);
+
+ scale_point (&op->pts[1], &n1, d, &m1);
+ scale_point (&op->pts[2], &n3, -d, &m4);
+
+ scale_point (&op->pts[1], &n2, d, &m2);
+ scale_point (&op->pts[2], &n2, d, &m3);
+
+ if (!line_intersection (&op->r[0], &m1, &m2, &m3, &op->r[1]))
+ op->r[1] = m1;
+
+ if (!line_intersection (&m2, &m3, &m4, &op->r[3], &op->r[2]))
+ op->r[2] = m4;
+
+ scale_point (&op->pts[1], &n1, -d, &m1);
+ scale_point (&op->pts[2], &n3, d, &m4);
+
+ scale_point (&op->pts[1], &n2, -d, &m2);
+ scale_point (&op->pts[2], &n2, -d, &m3);
+
+ if (!line_intersection (&op->l[0], &m1, &m2, &m3, &op->l[1]))
+ op->l[1] = m1;
+
+ if (!line_intersection (&m2, &m3, &m4, &op->l[3], &op->l[2]))
+ op->l[2] = m4;
+ }
+
+ op->re[0] = op->r[0];
+ op->le[0] = op->l[0];
+ op->re[1] = op->r[op->n_pts - 1];
+ op->le[1] = op->l[op->n_pts - 1];
+ op->angle[0] = op->angle[1] = 180.f;
+}
+
+static int
+find_smallest (float t[], int n)
+{
+ float d = t[0];
+ int i0 = 0;
+ int i;
+
+ for (i = 1; i < n; i++)
+ {
+ if (t[i] < d)
+ {
+ d = t[i];
+ i0 = i;
+ }
+ }
+
+ return i0;
+}
+
+static int
+find_largest (float t[], int n)
+{
+ float d = t[0];
+ int i0 = 0;
+ int i;
+
+ for (i = 1; i < n; i++)
+ {
+ if (t[i] > d)
+ {
+ d = t[i];
+ i0 = i;
+ }
+ }
+
+ return i0;
+}
+
+static void
+compute_intersections (PathOpData *op1,
+ PathOpData *op2)
+{
+ op1->angle[1] = three_point_angle (&op1->pts[op1->n_pts - 2],
+ &op1->pts[op1->n_pts - 1],
+ &op2->pts[1]);
+
+ op2->angle[0] = op1->angle[1];
+
+ if (fabs (op1->angle[1] - 180.f) >= 1)
+ {
+ graphene_point_t left[4];
+ graphene_point_t right[4];
+ graphene_point_t p[9];
+ float t[9];
+ float s[9];
+ int i, n;
+
+ if (!line_intersection (&op1->r[op1->n_pts - 2], &op1->r[op1->n_pts - 1],
+ &op2->r[0], &op2->r[1],
+ &op1->re[1]))
+ midpoint (&op1->r[op1->n_pts - 1], &op2->r[0], &op1->re[1]);
+
+ if (!line_intersection (&op1->l[op1->n_pts - 2], &op1->l[op1->n_pts - 1],
+ &op2->l[0], &op2->l[1],
+ &op1->le[1]))
+ midpoint (&op1->l[op1->n_pts - 1], &op2->l[0], &op1->le[1]);
+
+ if (op1->n_pts == 2 && op2->n_pts == 4)
+ {
+ if (op1->angle[1] > 180.f)
+ {
+ n = line_curve_intersection (&op1->r[0], &op1->r[1], op2->r, t, p);
+ if (n > 0)
+ {
+ i = find_smallest (t, n);
+ op1->re[1] = p[i];
+ split_bezier (op2->r, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op2->r[i] = right[i];
+ }
+ }
+ else
+ {
+ n = line_curve_intersection (&op1->l[0], &op1->l[1], op2->l, t, p);
+ if (n > 0)
+ {
+ i = find_smallest (t, n);
+ op1->le[1] = p[i];
+ split_bezier (op2->l, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op2->l[i] = right[i];
+ }
+ }
+ }
+ else if (op1->n_pts == 4 && op2->n_pts == 2)
+ {
+ if (op1->angle[1] > 180.f)
+ {
+ n = line_curve_intersection (&op2->r[0], &op2->r[1], op1->r, t, p);
+ if (n > 0)
+ {
+ i = find_largest (t, n);
+ op1->re[1] = p[i];
+ split_bezier (op1->r, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op1->r[i] = left[i];
+ }
+ }
+ else
+ {
+ n = line_curve_intersection (&op2->l[0], &op2->l[1], op1->l, t, p);
+ if (n > 0)
+ {
+ i = find_largest (t, n);
+ op1->le[1] = p[i];
+ split_bezier (op1->l, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op1->l[i] = left[i];
+ }
+ }
+ }
+ else if (op1->n_pts == 4 && op2->n_pts == 4)
+ {
+ if (op1->angle[1] > 180.f)
+ {
+ n = curve_intersection (op1->r, op2->r, t, s, p);
+ if (n > 0)
+ {
+ i = find_largest (t, n);
+ split_bezier (op1->r, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op1->r[i] = left[i];
+ op1->re[1] = op1->r[3];
+ i = find_smallest (s, n);
+ split_bezier (op2->r, 4, s[i], left, right);
+ for (i = 0; i < 4; i++)
+ op2->r[i] = right[i];
+ }
+ }
+ else
+ {
+ n = curve_intersection (op1->l, op2->l, t, s, p);
+ if (n > 0)
+ {
+ i = find_largest (t, n);
+ split_bezier (op1->l, 4, t[i], left, right);
+ for (i = 0; i < 4; i++)
+ op1->l[i] = left[i];
+ op1->le[1] = op1->l[3];
+ i = find_smallest (s, n);
+ split_bezier (op2->l, 4, s[i], left, right);
+ for (i = 0; i < 4; i++)
+ op2->l[i] = right[i];
+ }
+ }
+ }
+ }
+ else
+ {
+ midpoint (&op1->r[op1->n_pts - 1], &op2->r[0], &op1->re[1]);
+ midpoint (&op1->l[op1->n_pts - 1], &op2->l[0], &op1->le[1]);
+ }
+
+ op2->re[0] = op1->re[1];
+ op2->le[0] = op1->le[1];
+}
+
+static PathOpData *
+path_op_data_new (GskPathOperation op,
+ const graphene_point_t *pts,
+ gsize n_pts)
+{
+ PathOpData *d;
+ int i;
+
+ d = g_new0 (PathOpData, 1);
+ d->op = op;
+ for (i = 0; i < n_pts; i++)
+ d->pts[i] = pts[i];
+ d->n_pts = n_pts;
+
+#if STROKE_DEBUG
+ /* detect uninitialized values */
+ for (i = 0; i < n_pts; i++)
+ d->l[i].x = d->l[i].y = d->r[i].x = d->r[i].y = NAN;
+ for (i = 0; i < 2; i++)
+ {
+ d->le[i].x = d->le[i].y = d->re[i].x = d->re[i].y = NAN;
+ d->angle[i] = NAN;
+ }
+#endif
+
+ return d;
+}
+
+typedef struct
+{
+ GList *ops;
+ graphene_point_t *start;
+} AddOpData;
+
+static void
+subdivide_and_add (const graphene_point_t pts[4],
+ AddOpData *data,
+ int level)
+{
+ if (level == 0 || cubic_is_simple (pts))
+ data->ops = g_list_prepend (data->ops,
+ path_op_data_new (GSK_PATH_CURVE, pts, 4));
+ else
+ {
+ graphene_point_t left[4];
+ graphene_point_t right[4];
+
+ split_bezier (pts, 4, 0.5, left, right);
+
+ subdivide_and_add (left, data, level - 1);
+ subdivide_and_add (right, data, level - 1);
+ }
+}
+
+static gboolean
+add_op_to_list (GskPathOperation op,
+ const graphene_point_t *pts,
+ gsize n_pts,
+ float weight,
+ gpointer user_data)
+{
+ AddOpData *data = user_data;
+
+ switch (op)
+ {
+ case GSK_PATH_MOVE:
+ *data->start = pts[0];
+ break;
+
+ case GSK_PATH_CLOSE:
+ case GSK_PATH_LINE:
+ data->ops = g_list_prepend (data->ops, path_op_data_new (op, pts, n_pts));
+ break;
+
+ case GSK_PATH_CURVE:
+ subdivide_and_add (pts, data, 2);
+ break;
+
+ case GSK_PATH_CONIC:
+ g_warning ("FIXME: support conics in the stroker");
+ g_assert_not_reached ();
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+
+ return TRUE;
+}
+
+static GList *
+contour_to_ops (const GskContour *contour,
+ graphene_point_t *start)
+{
+ AddOpData data;
+
+ data.ops = NULL;
+ data.start = start;
+
+ gsk_contour_foreach (contour, GSK_PATH_TOLERANCE_DEFAULT, add_op_to_list, &data);
+
+ return g_list_reverse (data.ops);
+}
+
+#ifdef STROKE_DEBUG
+
+static const char *
+op_to_string (GskPathOperation op)
+{
+ const char *names[] = { "MOVE", "CLOSE", "LINE", "CURVE" };
+ return names[op];
+}
+
+enum {
+ STROKE_DEBUG_LEFT_CURVES = 1 << 0,
+ STROKE_DEBUG_RIGHT_CURVES = 1 << 1,
+ STROKE_DEBUG_LEFT_POINTS = 1 << 2,
+ STROKE_DEBUG_RIGHT_POINTS = 1 << 3,
+ STROKE_DEBUG_OFFSET_LINES = 1 << 4,
+ STROKE_DEBUG_LEFT_INTERSECTIONS = 1 << 5,
+ STROKE_DEBUG_RIGHT_INTERSECTIONS = 1 << 6,
+ STROKE_DEBUG_CURVE_POINTS = 1 << 7,
+ STROKE_DEBUG_CURVE_LINES = 1 << 8
+};
+
+static void
+emit_debug (GskPathBuilder *builder,
+ GList *ops)
+{
+ GList *l;
+ PathOpData *op;
+ int i;
+ const GdkDebugKey debug_keys[] = {
+ { "left-curves", STROKE_DEBUG_LEFT_CURVES, "Show left offset curve" },
+ { "right-curves", STROKE_DEBUG_RIGHT_CURVES, "Show right offset curve" },
+ { "offset-curves", STROKE_DEBUG_LEFT_CURVES|STROKE_DEBUG_RIGHT_CURVES, "Show offset curves" },
+ { "left-points", STROKE_DEBUG_LEFT_POINTS, "Show left offset points" },
+ { "right-points", STROKE_DEBUG_RIGHT_POINTS, "Show right offset points" },
+ { "offset-points", STROKE_DEBUG_LEFT_POINTS|STROKE_DEBUG_RIGHT_POINTS, "Show offset points" },
+ { "offset-lines", STROKE_DEBUG_OFFSET_LINES, "Show offset lines" },
+ { "left-intersections", STROKE_DEBUG_LEFT_INTERSECTIONS, "Show left intersection" },
+ { "right-intersections", STROKE_DEBUG_RIGHT_INTERSECTIONS, "Show right intersections" },
+ { "intersections", STROKE_DEBUG_LEFT_INTERSECTIONS|STROKE_DEBUG_RIGHT_INTERSECTIONS, "Show intersection"
},
+ { "curve-points", STROKE_DEBUG_CURVE_POINTS, "Show curve points" },
+ { "curve-lines", STROKE_DEBUG_CURVE_LINES, "Show curve lines" },
+ };
+ static guint debug;
+ static int initialized = 0;
+
+ if (!initialized)
+ {
+ debug = gdk_parse_debug_var ("STROKE_DEBUG", debug_keys, G_N_ELEMENTS (debug_keys));
+ initialized = 1;
+ }
+
+ for (l = ops; l; l = l->next)
+ {
+ op = l->data;
+
+ if (debug & STROKE_DEBUG_LEFT_CURVES)
+ {
+ gsk_path_builder_move_to (builder, op->l[0].x, op->l[0].y);
+ if (op->op == GSK_PATH_CURVE)
+ gsk_path_builder_curve_to (builder,
+ op->l[1].x, op->l[1].y,
+ op->l[2].x, op->l[2].y,
+ op->l[3].x, op->l[3].y);
+ else if (op->op == GSK_PATH_LINE)
+ gsk_path_builder_line_to (builder, op->l[1].x, op->l[1].y);
+ }
+ if (debug & STROKE_DEBUG_RIGHT_CURVES)
+ {
+ gsk_path_builder_move_to (builder, op->r[0].x, op->r[0].y);
+ if (op->op == GSK_PATH_CURVE)
+ gsk_path_builder_curve_to (builder,
+ op->r[1].x, op->r[1].y,
+ op->r[2].x, op->r[2].y,
+ op->r[3].x, op->r[3].y);
+ else if (op->op == GSK_PATH_LINE)
+ gsk_path_builder_line_to (builder, op->r[1].x, op->r[1].y);
+ }
+
+ for (i = 0; i < op->n_pts; i++)
+ {
+ if (debug & STROKE_DEBUG_LEFT_POINTS)
+ gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (op->l[i].x, op->l[i].y), 2);
+ if (debug & STROKE_DEBUG_RIGHT_POINTS)
+ gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (op->r[i].x, op->r[i].y), 2);
+ if (debug & STROKE_DEBUG_CURVE_POINTS)
+ gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (op->pts[i].x, op->pts[i].y), 2);
+ if (debug & STROKE_DEBUG_OFFSET_LINES)
+ {
+ gsk_path_builder_move_to (builder, op->r[i].x, op->r[i].y);
+ gsk_path_builder_line_to (builder, op->pts[i].x, op->pts[i].y);
+ gsk_path_builder_line_to (builder, op->l[i].x, op->l[i].y);
+ }
+ }
+ for (i = 0; i < 1; i++)
+ {
+ if (debug & STROKE_DEBUG_LEFT_INTERSECTIONS)
+ gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (op->le[i].x, op->le[i].y), 2);
+ if (debug & STROKE_DEBUG_RIGHT_INTERSECTIONS)
+ gsk_path_builder_add_circle (builder, &GRAPHENE_POINT_INIT (op->re[i].x, op->re[i].y), 2);
+ }
+
+ if (debug & STROKE_DEBUG_CURVE_LINES)
+ {
+ gsk_path_builder_move_to (builder, op->pts[0].x, op->pts[0].y);
+ for (i = 1; i < op->n_pts; i++)
+ gsk_path_builder_line_to (builder, op->pts[i].x, op->pts[i].y);
+ }
+ }
+}
+#endif
+
+static void
+add_cap (GskPathBuilder *builder,
+ const graphene_point_t *s,
+ const graphene_point_t *e,
+ GskStroke *stroke)
+{
+ switch (stroke->line_cap)
+ {
+ case GSK_LINE_CAP_BUTT:
+ gsk_path_builder_line_to (builder, e->x, e->y);
+ break;
+
+ case GSK_LINE_CAP_ROUND:
+ gsk_path_builder_svg_arc_to (builder,
+ stroke->line_width / 2, stroke->line_width / 2,
+ 0, 1, 0,
+ e->x, e->y);
+ break;
+
+ case GSK_LINE_CAP_SQUARE:
+ {
+ float cx = (s->x + e->x) / 2;
+ float cy = (s->y + e->y) / 2;
+ float dx = s->y - cy;
+ float dy = - s->x + cx;
+
+ gsk_path_builder_line_to (builder, s->x + dx, s->y + dy);
+ gsk_path_builder_line_to (builder, e->x + dx, e->y + dy);
+ gsk_path_builder_line_to (builder, e->x, e->y);
+ }
+ break;
+
+ default:
+ g_assert_not_reached ();
+ break;
+ }
+}
+
+void
+gsk_contour_stroke (const GskContour *contour,
+ GskStroke *stroke,
+ GskPathBuilder *builder)
+{
+ GList *ops, *l;
+ GList *last = NULL;
+ PathOpData *op;
+ PathOpData *op1;
+ gboolean draw_caps;
+ graphene_point_t start;
+
+ ops = contour_to_ops (contour, &start);
+
+ /* Compute offset start and end points */
+ for (l = ops; l; l = l->next)
+ {
+ op = l->data;
+ last = l;
+ compute_offsets (op, stroke->line_width / 2);
+ }
+
+ /* Compute intersections */
+ for (l = ops; l; l = l->next)
+ {
+ op = l->data;
+ last = l;
+ if (l->next != NULL)
+ {
+ op1 = l->next->data;
+ if (op1->op == GSK_PATH_CLOSE)
+ {
+ if (graphene_point_near (&op1->pts[0], &op1->pts[1], 0.0001))
+ {
+ compute_intersections (op, (PathOpData *)ops->data);
+ op1->re[0] = op1->r[0] = op->re[op1->n_pts - 1];
+ op1->le[0] = op1->l[0] = op->le[op1->n_pts - 1];
+
+ op1->re[1] = op1->r[1] = ((PathOpData *)ops->data)->re[0];
+ op1->le[1] = op1->l[1] = ((PathOpData *)ops->data)->le[0];
+ }
+ else
+ {
+ compute_intersections (op, op1);
+ compute_intersections (op1, (PathOpData *)ops->data);
+ }
+ }
+ else
+ {
+ compute_intersections (op, op1);
+ }
+ }
+ }
+
+#ifdef STROKE_DEBUG
+ for (l = ops; l; l = l->next)
+ {
+ int i;
+
+ op = l->data;
+
+ for (i = 0; i < op->n_pts; i++)
+ {
+ g_assert_true (!isnan (op->l[i].x) && !isnan (op->l[i].y));
+ g_assert_true (!isnan (op->r[i].x) && !isnan (op->r[i].y));
+ }
+ for (i = 0; i < 2; i++)
+ {
+ g_assert_true (!isnan (op->le[i].x) && !isnan (op->le[i].y));
+ g_assert_true (!isnan (op->re[i].x) && !isnan (op->re[i].y));
+ g_assert_true (!isnan (op->angle[i]));
+ }
+ }
+#endif
+
+ draw_caps = TRUE;
+
+ if (ops == NULL && stroke->line_cap == GSK_LINE_CAP_BUTT)
+ draw_caps = FALSE; /* isolated points have no butts */
+
+ /* Walk the ops for the right edge */
+ last = NULL;
+ for (l = ops; l; l = l->next)
+ {
+ op = l->data;
+ last = l;
+
+ if (l->prev == NULL)
+ gsk_path_builder_move_to (builder, op->re[0].x, op->re[0].y);
+ switch (op->op)
+ {
+ case GSK_PATH_MOVE:
+ g_assert_not_reached ();
+ break;
+
+ case GSK_PATH_CLOSE:
+ draw_caps = FALSE;
+ if (graphene_point_near (&op->pts[0], &op->pts[1], 0.0001))
+ break;
+ G_GNUC_FALLTHROUGH;
+
+ case GSK_PATH_LINE:
+ if (op->angle[1] >= 181)
+ gsk_path_builder_line_to (builder, op->re[1].x, op->re[1].y);
+ else
+ gsk_path_builder_line_to (builder, op->r[1].x, op->r[1].y);
+ break;
+
+ case GSK_PATH_CURVE:
+ if (op->angle[1] >= 181)
+ gsk_path_builder_curve_to (builder, op->r[1].x, op->r[1].y,
+ op->r[2].x, op->r[2].y,
+ op->re[1].x, op->re[1].y);
+ else
+ gsk_path_builder_curve_to (builder, op->r[1].x, op->r[1].y,
+ op->r[2].x, op->r[2].y,
+ op->r[3].x, op->r[3].y);
+ break;
+
+ case GSK_PATH_CONIC:
+ g_warning ("FIXME: support conics in the stroker");
+ g_assert_not_reached ();
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+
+ if (l->next || op->op == GSK_PATH_CLOSE)
+ {
+ op1 = l->next ? l->next->data : ops->data;
+
+ if (op->angle[1] <= 179) /* avoid rounding */
+ {
+ /* Deal with joins */
+ switch (stroke->line_join)
+ {
+ case GSK_LINE_JOIN_MITER:
+ case GSK_LINE_JOIN_MITER_CLIP:
+ if (op->angle[1] != 0 && fabs (1 / sin (DEG_TO_RAD (op->angle[1]) / 2) <=
stroke->miter_limit))
+ {
+ gsk_path_builder_line_to (builder, op->re[1].x, op->re[1].y);
+ gsk_path_builder_line_to (builder, op1->r[0].x, op1->r[0].y);
+ }
+ else if (stroke->line_join == GSK_LINE_JOIN_MITER_CLIP)
+ {
+ graphene_point_t p, q, p1, p2;
+ graphene_vec2_t t, n;
+
+ direction_vector (&op->pts[op->n_pts - 1], &op->re[1], &t);
+ scale_point (&op->pts[op->n_pts - 1], &t, stroke->line_width * stroke->miter_limit /
2, &p);
+
+ normal_vector (&op->pts[op->n_pts - 1], &op->re[1], &n);
+ scale_point (&p, &n, 1, &q);
+
+ line_intersection (&p, &q, &op->r[1], &op->re[1], &p1);
+ line_intersection (&p, &q, &op1->r[0], &op->re[1], &p2);
+
+ gsk_path_builder_line_to (builder, p1.x, p1.y);
+ gsk_path_builder_line_to (builder, p2.x, p2.y);
+ gsk_path_builder_line_to (builder, op1->r[0].x, op1->r[0].y);
+ }
+ else
+ {
+ gsk_path_builder_line_to (builder, op1->r[0].x, op1->r[0].y);
+ }
+ break;
+
+ case GSK_LINE_JOIN_BEVEL:
+ gsk_path_builder_line_to (builder, op1->r[0].x, op1->r[0].y);
+ break;
+
+ case GSK_LINE_JOIN_ROUND:
+ gsk_path_builder_svg_arc_to (builder,
+ stroke->line_width / 2, stroke->line_width / 2,
+ 0, 0, 0,
+ op1->r[0].x, op1->r[0].y);
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+ }
+ }
+ }
+
+ if (draw_caps)
+ {
+ /* Deal with the cap at the end */
+ if (ops)
+ {
+ add_cap (builder, &op->re[1], &op->le[1], stroke);
+ }
+ else
+ {
+ graphene_point_t s, e;
+
+ /* an isolated point, we have it in start */
+ e = s = start;
+ s.y += stroke->line_width / 2;
+ e.y -= stroke->line_width / 2;
+
+ gsk_path_builder_move_to (builder, s.x, s.y);
+ add_cap (builder, &s, &e, stroke);
+ }
+ }
+ else if (ops)
+ {
+ gsk_path_builder_close (builder);
+
+ /* Start the left contour */
+ op = last->data;
+ if (op->angle[0] <= 179)
+ gsk_path_builder_move_to (builder, op->le[1].x, op->le[1].y);
+ else
+ gsk_path_builder_move_to (builder, op->l[1].x, op->l[1].y);
+ }
+
+ /* Walk the ops backwards for the left edge */
+ for (l = last; l; l = l->prev)
+ {
+ op = l->data;
+
+ switch (op->op)
+ {
+ case GSK_PATH_MOVE:
+ g_assert_not_reached ();
+ break;
+
+ case GSK_PATH_CLOSE:
+ if (graphene_point_near (&op->pts[0], &op->pts[1], 0.0001))
+ break;
+ G_GNUC_FALLTHROUGH;
+
+ case GSK_PATH_LINE:
+ if (op->angle[0] <= 179)
+ gsk_path_builder_line_to (builder, op->le[0].x, op->le[0].y);
+ else
+ gsk_path_builder_line_to (builder, op->l[0].x, op->l[0].y);
+ break;
+
+ case GSK_PATH_CURVE:
+ if (op->angle[0] <= 179)
+ gsk_path_builder_curve_to (builder, op->l[2].x, op->l[2].y,
+ op->l[1].x, op->l[1].y,
+ op->le[0].x, op->le[0].y);
+ else
+ gsk_path_builder_curve_to (builder, op->l[2].x, op->l[2].y,
+ op->l[1].x, op->l[1].y,
+ op->l[0].x, op->l[0].y);
+ break;
+
+ case GSK_PATH_CONIC:
+ g_warning ("FIXME: support conics in the stroker");
+ g_assert_not_reached ();
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+
+ if (l->prev || ((PathOpData *)last->data)->op == GSK_PATH_CLOSE)
+ {
+ op1 = l->prev ? l->prev->data : last->data;
+
+ if (op->angle[0] >= 181)
+ {
+ /* Deal with joins */
+ switch (stroke->line_join)
+ {
+ case GSK_LINE_JOIN_MITER:
+ case GSK_LINE_JOIN_MITER_CLIP:
+ if (op->angle[0] != 0 && fabs (1 / sin (DEG_TO_RAD (op->angle[0]) / 2) <=
stroke->miter_limit))
+ {
+ gsk_path_builder_line_to (builder, op->le[0].x, op->le[0].y);
+ gsk_path_builder_line_to (builder, op1->l[op1->n_pts - 1].x, op1->l[op1->n_pts - 1].y);
+ }
+ else if (stroke->line_join == GSK_LINE_JOIN_MITER_CLIP)
+ {
+ graphene_point_t p, q, p1, p2;
+ graphene_vec2_t t, n;
+
+ direction_vector (&op->pts[0], &op->le[0], &t);
+ scale_point (&op->pts[0], &t, stroke->line_width * stroke->miter_limit / 2, &p);
+
+ normal_vector (&op->pts[0], &op->le[0], &n);
+ scale_point (&p, &n, 1, &q);
+
+ line_intersection (&p, &q, &op->l[0], &op->le[0], &p1);
+ line_intersection (&p, &q, &op1->l[op1->n_pts - 1], &op->le[0], &p2);
+
+ gsk_path_builder_line_to (builder, p1.x, p1.y);
+ gsk_path_builder_line_to (builder, p2.x, p2.y);
+ gsk_path_builder_line_to (builder, op1->l[op1->n_pts - 1].x, op1->l[op1->n_pts - 1].y);
+ }
+ else
+ {
+ gsk_path_builder_line_to (builder, op1->l[op1->n_pts - 1].x, op1->l[op1->n_pts - 1].y);
+ }
+ break;
+
+ case GSK_LINE_JOIN_BEVEL:
+ gsk_path_builder_line_to (builder, op1->l[op1->n_pts - 1].x, op1->l[op1->n_pts - 1].y);
+ break;
+
+ case GSK_LINE_JOIN_ROUND:
+ gsk_path_builder_svg_arc_to (builder,
+ stroke->line_width / 2, stroke->line_width / 2,
+ 0, 0, 0,
+ op1->l[op1->n_pts - 1].x, op1->l[op1->n_pts - 1].y);
+ break;
+
+ default:
+ g_assert_not_reached ();
+ }
+ }
+ }
+ }
+
+ if (draw_caps)
+ {
+ /* Deal with the cap at the beginning */
+
+ if (ops)
+ {
+ op = ops->data;
+ add_cap (builder, &op->le[0], &op->re[0], stroke);
+ }
+ else
+ {
+ graphene_point_t s, e;
+
+ /* an isolated point, we have it in start */
+ e = s = start;
+ s.y -= stroke->line_width / 2;
+ e.y += stroke->line_width / 2;
+ add_cap (builder, &s, &e, stroke);
+ }
+ }
+
+ gsk_path_builder_close (builder);
+
+#ifdef STROKE_DEBUG
+ emit_debug (builder, ops);
+#endif
+
+ g_list_free_full (ops, g_free);
+}
diff --git a/gsk/meson.build b/gsk/meson.build
index 00274374bd..99ba18b472 100644
--- a/gsk/meson.build
+++ b/gsk/meson.build
@@ -27,6 +27,7 @@ gsk_public_sources = files([
'gskpath.c',
'gskpathbuilder.c',
'gskpathmeasure.c',
+ 'gskpathstroke.c',
'gskrenderer.c',
'gskrendernode.c',
'gskrendernodeimpl.c',
diff --git a/testsuite/gsk/path-special-cases.c b/testsuite/gsk/path-special-cases.c
index 04a575ac1f..8f97eaa17c 100644
--- a/testsuite/gsk/path-special-cases.c
+++ b/testsuite/gsk/path-special-cases.c
@@ -306,6 +306,45 @@ test_serialize_custom_contours (void)
gsk_path_unref (path1);
}
+/* Test that single-point contours don't crash the stroker */
+static void
+test_point_to_stroke (void)
+{
+ GskPathBuilder *builder;
+ GskPath *path;
+ GskPathMeasure *measure;
+ GskStroke *stroke;
+ GskPath *path1;
+ char *string;
+
+ builder = gsk_path_builder_new ();
+ gsk_path_builder_move_to (builder, 100, 100);
+ gsk_path_builder_curve_to (builder, 190, 110,
+ 200, 120,
+ 210, 210);
+ gsk_path_builder_curve_to (builder, 220, 210,
+ 230, 200,
+ 230, 100);
+ gsk_path_builder_move_to (builder, 200, 200);
+
+ path = gsk_path_builder_free_to_path (builder);
+
+ string = gsk_path_to_string (path);
+ g_assert_cmpstr (string, ==, "M 100 100 C 190 110, 200 120, 210 210 C 220 210, 230 200, 230 100 M 200
200");
+ g_free (string);
+
+ stroke = gsk_stroke_new (20.f);
+ measure = gsk_path_measure_new (path);
+ path1 = gsk_path_measure_stroke (measure, stroke);
+ gsk_path_measure_unref (measure);
+ gsk_stroke_free (stroke);
+
+ g_assert_nonnull (path1);
+ gsk_path_unref (path1);
+
+ gsk_path_unref (path);
+}
+
int
main (int argc,
char *argv[])
@@ -314,6 +353,8 @@ main (int argc,
g_test_add_func ("/path/rsvg-parse", test_rsvg_parse);
g_test_add_func ("/path/serialize-custom-contours", test_serialize_custom_contours);
+ g_test_add_func ("/path/point_to_stroke", test_point_to_stroke);
+
return g_test_run ();
}
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