[libgdx] Clipper assumes counter clockwise order, easier to adapt decomposition algorithm that way

spine-libgdx/spine-libgdx-tests/src/com/esotericsoftware/spine/SoftwareClippingTest.java

@@ -137,7 +137,7 @@ public class SoftwareClippingTest extends ApplicationAdapter {
 		// edge normals
 		shapes.setColor(Color.YELLOW);		
 		if (clippingPolygon.size > 2) {
-			boolean clockwise = SutherlandHodgmanClipper.clockwise(clippingPolygon);
+			boolean clockwise = SutherlandHodgmanClipper.counterClockwise(clippingPolygon);
 			for (int i = 0; i < clippingPolygon.size; i += 2) {
 				float x = clippingPolygon.get(i);
 				float y = clippingPolygon.get(i + 1);
@@ -183,7 +183,7 @@ public class SoftwareClippingTest extends ApplicationAdapter {
 		
 		// must duplicate first vertex at end of polygon
 		// so we can avoid module/branch in clipping code
-		SutherlandHodgmanClipper.makeClockwise(clippingPolygon);
+		SutherlandHodgmanClipper.makeCounterClockwise(clippingPolygon);
 		clippingPolygon.add(clippingPolygon.get(0));
 		clippingPolygon.add(clippingPolygon.get(1));
 		

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/SkeletonRenderer.java

@@ -406,9 +406,9 @@ public class SkeletonRenderer {
 			int n = clip.getWorldVerticesLength();
 			float[] vertices = this.clippingArea.setSize(n);
 			clip.computeWorldVertices(slot, 0, n, vertices, 0, 2);
-			clippingAreaClockwise = SutherlandHodgmanClipper.clockwise(this.clippingArea);
+			clippingAreaClockwise = SutherlandHodgmanClipper.counterClockwise(this.clippingArea);
 			if (!clippingAreaClockwise) {
-				SutherlandHodgmanClipper.makeClockwise(clippingArea);
+				SutherlandHodgmanClipper.makeCounterClockwise(clippingArea);
 			}
 			clippingArea.add(clippingArea.items[0]);
 			clippingArea.add(clippingArea.items[1]);

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/utils/SutherlandHodgmanClipper.java

@@ -35,10 +35,10 @@ public class SutherlandHodgmanClipper {
 		final float[] clippingVertices = clippingArea.items;
 		final int clippingVerticesLength = clippingArea.size - 2;
 		for (int i = 0; i < clippingVerticesLength; i += 2) {
-			float edgeX = clippingVertices[i];
-			float edgeY = clippingVertices[i + 1];
-			float edgeX2 = clippingVertices[i + 2];
-			float edgeY2 = clippingVertices[i + 3];
+			float edgeX2 = clippingVertices[i];
+			float edgeY2 = clippingVertices[i + 1];
+			float edgeX = clippingVertices[i + 2];
+			float edgeY = clippingVertices[i + 3];
 
 			final float deltaX = edgeX - edgeX2;
 			final float deltaY = edgeY - edgeY2;
@@ -129,8 +129,8 @@ public class SutherlandHodgmanClipper {
 		return clipped;
 	}
 	
-	public static void makeClockwise (FloatArray poly) {
-		if (clockwise(poly)) return;
+	public static void makeCounterClockwise (FloatArray poly) {
+		if (counterClockwise(poly)) return;
 		
 		int lastX = poly.size - 2;
 		final float[] polygon = poly.items;
@@ -145,8 +145,8 @@ public class SutherlandHodgmanClipper {
 		}
 	}
 
-	public static boolean clockwise (FloatArray poly) {
-		return area(poly) < 0;
+	public static boolean counterClockwise (FloatArray poly) {
+		return area(poly) > 0;
 	}
 
 	public static float area (FloatArray poly) {