[orx-triangulation] Improve triangulation, add kotlin/js support

orx-triangulation/src/commonTest/kotlin/TestVoronoiDiagram.kt

@@ -0,0 +1,53 @@
+import org.openrndr.extra.triangulation.Delaunay
+import org.openrndr.extra.triangulation.delaunayTriangulation
+import org.openrndr.math.Vector2
+import org.openrndr.shape.Circle
+import org.openrndr.shape.Rectangle
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class TestVoronoiDiagram {
+    @Test
+    fun testNeighbors() {
+        val c = Circle(200.0, 200.0, 150.0).contour.equidistantPositions(20).take(20)
+        val d = Delaunay.from(c)
+        val v = d.voronoi(Rectangle(0.0, 0.0, 400.0, 400.0))
+        for (j in c.indices) {
+            assertTrue(v.neighbors(j).toList().isNotEmpty())
+        }
+    }
+
+    @Test
+    fun testEmpty() {
+        val dt = listOf<Vector2>().delaunayTriangulation()
+        val v = dt.voronoiDiagram(Rectangle(0.0, 0.0, 400.0, 400.0))
+        assertEquals(0, dt.triangles().size)
+        assertEquals(0, v.cellPolygons().size)
+    }
+
+    @Test
+    fun testOnePoint() {
+        val dt = listOf(Vector2(100.0, 100.0)).delaunayTriangulation()
+        val v = dt.voronoiDiagram(Rectangle(0.0, 0.0, 400.0, 400.0))
+        assertEquals(0, dt.triangles().size)
+        assertEquals(1, v.cellPolygons().size)
+    }
+
+
+    @Test
+    fun testTwoPoints() {
+        val dt = listOf(Vector2(100.0, 100.0), Vector2(300.0, 300.0)).delaunayTriangulation()
+        val v = dt.voronoiDiagram(Rectangle(0.0, 0.0, 400.0, 400.0))
+        assertEquals(1, dt.triangles().size)
+        assertEquals(2, v.cellPolygons().size)
+    }
+
+    @Test
+    fun testThreePointsCollinear() {
+        val dt = listOf(Vector2(100.0, 100.0), Vector2(200.0, 200.0), Vector2(300.0, 300.0)).delaunayTriangulation()
+        val v = dt.voronoiDiagram(Rectangle(0.0, 0.0, 400.0, 400.0))
+        assertEquals(1, dt.triangles().size)
+        assertEquals(3, v.cellPolygons().size)
+    }
+}