Fix walking path calc.

Author: bladecoder

blade-engine/src/com/bladecoder/engine/model/ObstacleActor.java

@@ -15,6 +15,10 @@
  ******************************************************************************/
 package com.bladecoder.engine.model;
 
+import com.badlogic.gdx.utils.Json;
+import com.bladecoder.engine.util.PolygonUtils;
+import com.bladecoder.engine.util.SerializationHelper;
+import com.bladecoder.engine.util.SerializationHelper.Mode;
 
 /**
  * An Obstacle actor is used to restrict the walk zone in the scene
@@ -51,4 +55,14 @@ public void setPosition(float x, float y) {
 			scene.getPolygonalNavGraph().addDinamicObstacle(bbox);
 		}
 	}
+	
+	@Override
+	public void write(Json json) {
+		if (SerializationHelper.getInstance().getMode() == Mode.MODEL) {
+			PolygonUtils.ensureClockWise(bbox.getVertices(), 0, bbox.getVertices().length);
+			bbox.dirty();			
+		}
+		
+		super.write(json);
+	}
 }

blade-engine/src/com/bladecoder/engine/polygonalpathfinder/PolygonalNavGraph.java

@@ -320,8 +320,12 @@ public boolean removeDinamicObstacle(Polygon poly) {
 
 	@Override
 	public void write(Json json) {
+		PolygonUtils.ensureClockWise(walkZone.getVertices(), 0, walkZone.getVertices().length);
+		walkZone.dirty();
+		
 		Polygon p = new Polygon(walkZone.getVertices());
 		p.setPosition(walkZone.getX() / walkZone.getScaleX(), walkZone.getY() / walkZone.getScaleY());
+		
 		json.writeValue("walkZone", p);
 	}
 

blade-engine/src/com/bladecoder/engine/util/PolygonUtils.java

@@ -15,6 +15,7 @@
  ******************************************************************************/
 package com.bladecoder.engine.util;
 
+import com.badlogic.gdx.math.GeometryUtils;
 import com.badlogic.gdx.math.Intersector;
 import com.badlogic.gdx.math.Polygon;
 import com.badlogic.gdx.math.Vector2;
@@ -254,7 +255,7 @@ public static boolean inLineOfSight(Vector2 p1, Vector2 p2, Polygon polygon, boo
 		return obstacle?!result:result;
 	}
 
-	private static float TOLERANCE_LINE_SEGMENTS_CROSS = 0.1f;
+	private static float TOLERANCE_LINE_SEGMENTS_CROSS = 0.01f;
 
 	public static boolean lineSegmentsCross(float ax, float ay, float bx,
 			float by, float cx, float cy, float dx, float dy) {
@@ -277,4 +278,18 @@ public static boolean lineSegmentsCross(float ax, float ay, float bx,
 
 		return (r > TOLERANCE_LINE_SEGMENTS_CROSS && r < 1 - TOLERANCE_LINE_SEGMENTS_CROSS) && (s > TOLERANCE_LINE_SEGMENTS_CROSS && s < 1 - TOLERANCE_LINE_SEGMENTS_CROSS);
 	}
+	
+	static public void ensureClockWise (float[] polygon, int offset, int count) {
+		if (GeometryUtils.isClockwise(polygon, offset, count)) return;
+		int lastX = offset + count - 2;
+		for (int i = offset, n = offset + count / 2; i < n; i += 2) {
+			int other = lastX - i;
+			float x = polygon[i];
+			float y = polygon[i + 1];
+			polygon[i] = polygon[other];
+			polygon[i + 1] = polygon[other + 1];
+			polygon[other] = x;
+			polygon[other + 1] = y;
+		}
+	}
 }