[runtime] Drop support of triangulation with holes, remove dependency…

… to earcut and poly2tri in favor of a port of libgdx's `EarClippingTriangulator.java`

.gitmodules

@@ -25,9 +25,6 @@
 [submodule "git/generate"]
 	path = git/generate
 	url = https://github.com/jeremyfa/generate.git
-[submodule "git/earcut"]
-	path = git/earcut
-	url = https://github.com/ceramic-engine/earcut.git
 [submodule "git/format-tiled"]
 	path = git/format-tiled
 	url = https://github.com/ceramic-engine/format-tiled.git
@@ -56,9 +53,6 @@
 [submodule "git/linc_dialogs"]
 	path = git/linc_dialogs
 	url = https://github.com/ceramic-engine/linc_dialogs.git
-[submodule "git/poly2tri"]
-	path = git/poly2tri
-	url = https://github.com/ceramic-engine/poly2tri.git
 [submodule "git/clay"]
 	path = git/clay
 	url = https://github.com/ceramic-engine/clay.git

README.md

@@ -52,7 +52,7 @@ Ceramic was created by **[Jérémy Faivre](https://github.com/jeremyfa)**, as we
 
 * **[Extrude Polyline](https://github.com/mattdesl/extrude-polyline) by Matt DesLauriers**, via Haxe port used in Ceramic to draw lines.
 
-* **[Earcut](https://github.com/mapbox/earcut) from Mapbox**, via Haxe port to triangulate shapes.
+* **[LibGDX](https://github.com/libgdx/libgdx)**, used as a reference for polygon triangulation.
 
 * **[Haxe Format Tiled](https://github.com/Yanrishatum/haxe-format-tiled) by Pavel Alexandrov** to parse Tiled Map Editor's TMX format.
 

runtime/src/ceramic/GeometryUtils.hx

@@ -165,4 +165,32 @@ class GeometryUtils {
 
     }
 
+    /**
+     * Returns whether the polygon vertices are ordered clockwise or counterclockwise.
+     * @param vertices Array of polygon vertices as [x,y,x,y,...]
+     * @param offset Starting index in the array
+     * @param count Number of array indices to use
+     * @return true if clockwise, false if counterclockwise
+     */
+    public static function isClockwise(vertices:Array<Float>, offset:Int, count:Int):Bool {
+        if (count <= 2) return false;
+
+        var area:Float = 0;
+        var last:Int = offset + count - 2;
+        var x1:Float = vertices[last];
+        var y1:Float = vertices[last + 1];
+
+        var i:Int = offset;
+        while (i <= last) {
+            var x2:Float = vertices[i];
+            var y2:Float = vertices[i + 1];
+            area += x1 * y2 - x2 * y1;
+            x1 = x2;
+            y1 = y2;
+            i += 2;
+        }
+
+        return area < 0;
+    }
+
 }

runtime/src/ceramic/Shape.hx

@@ -29,29 +29,6 @@ class Shape extends Mesh {
         return points;
     }
 
-    public var triangulation(default, set):TriangulateMethod = POLY2TRI;
-    inline function set_triangulation(triangulation:TriangulateMethod) {
-        if (this.triangulation != triangulation) {
-            this.triangulation = triangulation;
-            contentDirty = true;
-        }
-        return triangulation;
-    }
-
-    /**
-     * An array of hole indices, if any.
-     * (e.g. `[5, 8]` for a 12-vertex input would mean
-     * one hole with vertices 5–7 and another with 8–11).
-     * Note: when editing array content without reassigning it,
-     * `contentDirty` must be set to `true` to let the shape being updated accordingly.
-     */
-    public var holes:Array<Int> = null;
-    inline function set_holes(holes:Array<Int>):Array<Int> {
-        this.holes = holes;
-        contentDirty = true;
-        return holes;
-    }
-
     /**
      * If set to `true`, width and heigh will be computed from shape points.
      */
@@ -85,12 +62,7 @@ class Shape extends Mesh {
             if (indices == null)
                 indices = [];
 
-            if (holes != null && holes.length > 0) {
-                Triangulate.triangulate(vertices, indices, holes, triangulation);
-            }
-            else {
-                Triangulate.triangulate(vertices, indices, triangulation);
-            }
+            Triangulate.triangulate(vertices, indices);
         }
 
         if (autoComputeSize)