[gtk/curve-ops: 17/17] Test splitting harder

[Matthias Clasen <matthiasc src gnome org>]

commit 93c63a1ef2c1520e9d14ed2d3b1eef225e89d298
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Dec 8 14:17:25 2020 -0500

    Test splitting harder
    
    Check that the points on the split curves are close
    to the original curve, as they should.

 testsuite/gsk/curve.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
---
diff --git a/testsuite/gsk/curve.c b/testsuite/gsk/curve.c
index 8bea03db8e..a04fa60634 100644
--- a/testsuite/gsk/curve.c
+++ b/testsuite/gsk/curve.c
@@ -227,6 +227,40 @@ test_curve_curve_intersection (void)
   g_assert_cmpfloat (t2[1], >, 0.5);
 }
 
+static void
+gsk_path_builder_pathop_to (GskPathBuilder *builder,
+                            gskpathop       op)
+{
+  const graphene_point_t *pts = gsk_pathop_points (op);
+
+  switch (gsk_pathop_op (op))
+  {
+    case GSK_PATH_MOVE:
+      gsk_path_builder_move_to (builder, pts[0].x, pts[0].y);
+      break;
+
+    case GSK_PATH_CLOSE:
+      gsk_path_builder_close (builder);
+      break;
+
+    case GSK_PATH_LINE:
+      gsk_path_builder_line_to (builder, pts[1].x, pts[1].y);
+      break;
+
+    case GSK_PATH_CURVE:
+      gsk_path_builder_curve_to (builder, pts[1].x, pts[1].y, pts[2].x, pts[2].y, pts[3].x, pts[3].y);
+      break;
+
+    case GSK_PATH_CONIC:
+      gsk_path_builder_conic_to (builder, pts[1].x, pts[1].y, pts[3].x, pts[3].y, pts[2].x);
+      break;
+
+    default:
+      g_assert_not_reached ();
+      break;
+  }
+}
+
 /* Some sanity checks for splitting curves.
  */
 static void
@@ -236,8 +270,21 @@ test_curve_split (void)
 
   for (int i = 0; i < 100; i++)
     {
+      GskPathBuilder *builder;
+      GskPath *path;
+      GskPathMeasure *measure;
+      const graphene_point_t *s;
+
       init_random_curve (&c);
 
+      builder = gsk_path_builder_new ();
+
+      s = gsk_curve_get_start_point (&c);
+      gsk_path_builder_move_to (builder, s->x, s->y);
+      gsk_curve_builder_to (&c, builder);
+      path = gsk_path_builder_free_to_path (builder);
+      measure = gsk_path_measure_new (path);
+
       for (int j = 1; j < 20; j++)
         {
           GskCurve c1, c2;
@@ -271,6 +318,19 @@ test_curve_split (void)
           gsk_curve_get_end_tangent (&c2, &t2);
           g_assert_true (graphene_vec2_near (&t1, &t2, 0.005));
 
+          for (int k = 0; k < 20; k++)
+            {
+              graphene_point_t q;
+              float dist;
+
+              gsk_curve_eval (&c1, k/19, &q, NULL);
+              dist = gsk_path_measure_get_closest_point (measure, &q, NULL);
+              g_assert_cmpint (dist, <=, 0.001);
+
+              gsk_curve_eval (&c2, k/19, &q, NULL);
+              dist = gsk_path_measure_get_closest_point (measure, &q, NULL);
+              g_assert_cmpint (dist, <=, 0.001);
+            }
         }
     }
 }