From d830e49510a781d71c4b406df71312c5050cbce7 Mon Sep 17 00:00:00 2001
From: Hannes Janetzek <hannes.janetzek@gmail.com>
Date: Sun, 30 Jun 2013 09:11:34 +0200
Subject: [PATCH] ExtrusionLayer utility for libtess

---
 .../org/oscim/utils/geom/Triangulator.java    | 84 +++++++++++++++++++
 1 file changed, 84 insertions(+)
 create mode 100644 vtm-gdx-html/src/org/oscim/gdx/emu/org/oscim/utils/geom/Triangulator.java

diff --git a/vtm-gdx-html/src/org/oscim/gdx/emu/org/oscim/utils/geom/Triangulator.java b/vtm-gdx-html/src/org/oscim/gdx/emu/org/oscim/utils/geom/Triangulator.java
new file mode 100644
index 00000000..5df2e4ab
--- /dev/null
+++ b/vtm-gdx-html/src/org/oscim/gdx/emu/org/oscim/utils/geom/Triangulator.java
@@ -0,0 +1,84 @@
+package org.oscim.utils.geom;
+
+import org.oscim.backend.Log;
+import org.oscim.renderer.sublayers.VertexItem;
+
+import com.google.gwt.core.client.JavaScriptException;
+import com.google.gwt.core.client.JavaScriptObject;
+import com.google.gwt.core.client.JsArrayInteger;
+import com.google.gwt.core.client.JsArrayNumber;
+import com.google.gwt.core.client.JsArrayUtils;
+import com.google.gwt.typedarrays.shared.Float32Array;
+import com.google.gwt.typedarrays.shared.Int32Array;
+
+public class Triangulator {
+
+	public static synchronized int triangulate(float[] points, int ppos, int plen, short[] index,
+			int ipos, int rings, int vertexOffset, VertexItem outTris) {
+
+		JavaScriptObject o;
+
+		try{
+		o = tessellate(JsArrayUtils.readOnlyJsArray(points), ppos, plen,
+				JsArrayUtils.readOnlyJsArray(index), ipos, rings);
+		} catch(JavaScriptException e){
+			e.printStackTrace();
+			return 0;
+		}
+
+		Float32Array vo = getPoints(o);
+		Int32Array io = getIndices(o);
+
+
+		if (vo.length() != plen) {
+			// TODO handle different output points
+			Log.d("", "other points out" + plen + ":" + vo.length() + ", " + io.length());
+
+			//for (int i = 0; i < vo.length(); i += 2)
+			//	Log.d("<", vo.get(i) + " " + vo.get(i + 1));
+			//for (int i = ppos; i < ppos + plen; i += 2)
+			//	Log.d(">",  points[i]+ " " + points[i + 1]);
+
+			return 0;
+		}
+
+		int numIndices = io.length();
+
+		for (int k = 0, cnt = 0; k < numIndices; k += cnt) {
+
+			if (outTris.used == VertexItem.SIZE) {
+				outTris.next = VertexItem.pool.get();
+				outTris = outTris.next;
+			}
+
+			cnt = VertexItem.SIZE - outTris.used;
+
+			if (k + cnt > numIndices)
+				cnt = numIndices - k;
+
+			for (int i = 0; i < cnt; i++){
+				int idx = (vertexOffset + io.get(k + i));
+				outTris.vertices[outTris.used + i] = (short) idx;
+			}
+			outTris.used += cnt;
+		}
+
+		return numIndices;
+	}
+
+	static native JavaScriptObject tessellate(JsArrayNumber points, int pOffset, int pLength,
+			JsArrayInteger bounds, int bOffset, int bLength)/*-{
+
+		return $wnd.tessellate(points, pOffset, pOffset + pLength, bounds,
+				bOffset, bOffset + bLength);
+	}-*/;
+
+	static native Float32Array getPoints(JavaScriptObject result)/*-{
+		return result.vertices;
+	}-*/;
+
+	static native Int32Array getIndices(JavaScriptObject result)/*-{
+		return result.triangles;
+	}-*/;
+
+}