[gtk/path-work-rebased: 1013/1045] testsuite: Add special-case curve tests

[Matthias Clasen <matthiasc src gnome org>]

commit 8917f61d23d7bb6e93181ca784f25a94976845af
Author: Matthias Clasen <mclasen redhat com>
Date:   Thu Apr 7 14:48:19 2022 -0400

    testsuite: Add special-case curve tests

 testsuite/gsk/curve-special-cases.c | 144 ++++++++++++++++++++++++++++++++++++
 testsuite/gsk/meson.build           |   2 +-
 2 files changed, 145 insertions(+), 1 deletion(-)
---
diff --git a/testsuite/gsk/curve-special-cases.c b/testsuite/gsk/curve-special-cases.c
index aac4976573..820cb73d59 100644
--- a/testsuite/gsk/curve-special-cases.c
+++ b/testsuite/gsk/curve-special-cases.c
@@ -120,6 +120,147 @@ test_curve_tangents (void)
   g_assert_true (graphene_vec2_near (&t, graphene_vec2_y_axis (), 0.0001));
 }
 
+static void
+test_errant_intersection (void)
+{
+  GskCurve c;
+  GskCurve l;
+  graphene_point_t p[4];
+  graphene_point_t q[2];
+  float t1[3], t2[3];
+  graphene_point_t s[3];
+  int n;
+
+  graphene_point_init (&p[0], 888, 482);
+  graphene_point_init (&p[1], 999.333313, 508.666687);
+  graphene_point_init (&p[2], 1080.83325, 544.333313);
+  graphene_point_init (&p[3], 1132.5, 589);
+  gsk_curve_init (&c, gsk_pathop_encode (GSK_PATH_CURVE, p));
+
+  graphene_point_init (&q[0], 886, 680);
+  graphene_point_init (&q[1], 642, 618);
+  gsk_curve_init (&l, gsk_pathop_encode (GSK_PATH_LINE, q));
+
+  n = gsk_curve_intersect (&l, &c, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 0);
+}
+
+static void
+test_errant_intersection2 (void)
+{
+  GskCurve c;
+  GskCurve l;
+  graphene_point_t p[4];
+  graphene_point_t q[2];
+  float t1[3], t2[3];
+  graphene_point_t s[3];
+  int n;
+
+  graphene_point_init (&p[0], 1119.5, 772);
+  graphene_point_init (&p[1], 1039.16675, 850.666687);
+  graphene_point_init (&p[2], 925.333313, 890);
+  graphene_point_init (&p[3], 778, 890);
+  gsk_curve_init (&c, gsk_pathop_encode (GSK_PATH_CURVE, p));
+
+  graphene_point_init (&q[0], 1052, 1430);
+  graphene_point_init (&q[1], 734, 762);
+  gsk_curve_init (&l, gsk_pathop_encode (GSK_PATH_LINE, q));
+
+  n = gsk_curve_intersect (&l, &c, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 1);
+
+  graphene_point_init (&q[0], 954, 762);
+  graphene_point_init (&q[1], 1292, 1430);
+  gsk_curve_init (&l, gsk_pathop_encode (GSK_PATH_LINE, q));
+
+  n = gsk_curve_intersect (&l, &c, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 1);
+
+  graphene_point_init (&p[0], 248, 142);
+  graphene_point_init (&p[1], 283, 103);
+  graphene_point_init (&p[2], 333, 80);
+  graphene_point_init (&p[3], 384, 80);
+  gsk_curve_init (&c, gsk_pathop_encode (GSK_PATH_CURVE, p));
+
+  graphene_point_init (&q[0], 256, 719);
+  graphene_point_init (&q[1], 256, 76);
+  gsk_curve_init (&l, gsk_pathop_encode (GSK_PATH_LINE, q));
+
+  n = gsk_curve_intersect (&l, &c, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 1);
+}
+
+static void
+test_line_intersection_parallel (void)
+{
+  GskCurve l1;
+  GskCurve l2;
+  graphene_point_t p1[1];
+  graphene_point_t p2[2];
+  float t1[3], t2[3];
+  graphene_point_t s[3];
+  int n;
+
+  graphene_point_init (&p1[0], 0, 100);
+  graphene_point_init (&p1[1], 100, 100);
+  gsk_curve_init (&l1, gsk_pathop_encode (GSK_PATH_LINE, p1));
+
+  graphene_point_init (&p2[0], 0, 110);
+  graphene_point_init (&p2[1], 100, 110);
+  gsk_curve_init (&l2, gsk_pathop_encode (GSK_PATH_LINE, p2));
+
+  n = gsk_curve_intersect (&l1, &l2, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 0);
+
+  graphene_point_init (&p2[0], 110, 100);
+  graphene_point_init (&p2[1], 210, 100);
+  gsk_curve_init (&l2, gsk_pathop_encode (GSK_PATH_LINE, p2));
+
+  n = gsk_curve_intersect (&l1, &l2, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 0);
+
+  graphene_point_init (&p2[0], 0, 100);
+  graphene_point_init (&p2[1], -100, 100);
+  gsk_curve_init (&l2, gsk_pathop_encode (GSK_PATH_LINE, p2));
+
+  n = gsk_curve_intersect (&l1, &l2, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 1);
+  g_assert_cmpfloat_with_epsilon (t1[0], 0, 0.001);
+  g_assert_cmpfloat_with_epsilon (t2[0], 0, 0.001);
+
+  graphene_point_init (&p2[0], 20, 100);
+  graphene_point_init (&p2[1], 80, 100);
+  gsk_curve_init (&l2, gsk_pathop_encode (GSK_PATH_LINE, p2));
+
+  n = gsk_curve_intersect (&l1, &l2, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 2);
+  g_assert_cmpfloat_with_epsilon (t1[0], 0.2, 0.001);
+  g_assert_cmpfloat_with_epsilon (t1[1], 0.8, 0.001);
+  g_assert_cmpfloat_with_epsilon (t2[0], 0, 0.001);
+  g_assert_cmpfloat_with_epsilon (t2[1], 1, 0.001);
+
+  graphene_point_init (&p2[0], 150, 100);
+  graphene_point_init (&p2[1], 50, 100);
+  gsk_curve_init (&l2, gsk_pathop_encode (GSK_PATH_LINE, p2));
+
+  n = gsk_curve_intersect (&l1, &l2, t1, t2, s, G_N_ELEMENTS (s));
+
+  g_assert_true (n == 2);
+  g_assert_cmpfloat_with_epsilon (t1[0], 1, 0.001);
+  g_assert_cmpfloat_with_epsilon (t1[1], 0.5, 0.001);
+  g_assert_cmpfloat_with_epsilon (t2[0], 0.5, 0.001);
+  g_assert_cmpfloat_with_epsilon (t2[1], 1, 0.001);
+
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -128,6 +269,9 @@ main (int   argc,
 
   g_test_add_func ("/curve/special/conic-segment", test_conic_segment);
   g_test_add_func ("/curve/special/tangents", test_curve_tangents);
+  g_test_add_func ("/curve/errant-intersection", test_errant_intersection);
+  g_test_add_func ("/curve/errant-intersection2", test_errant_intersection2);
+  g_test_add_func ("/curve/line-intersection-parallel", test_line_intersection_parallel);
 
   return g_test_run ();
 }
diff --git a/testsuite/gsk/meson.build b/testsuite/gsk/meson.build
index 32f4f702e9..35df1c24ed 100644
--- a/testsuite/gsk/meson.build
+++ b/testsuite/gsk/meson.build
@@ -208,7 +208,7 @@ endforeach
 
 tests = [
   ['curve', ['../../gsk/gskcurve.c', '../../gsk/gskcurveintersect.c'], ['-DGTK_COMPILATION']],
-  ['curve-special-cases', ['../../gsk/gskcurve.c'], ['-DGTK_COMPILATION']],
+  ['curve-special-cases', ['../../gsk/gskcurve.c', '../../gsk/gskcurveintersect.c'], ['-DGTK_COMPILATION']],
   ['dash'],
   ['path'],
   ['path-special-cases'],