Change polygon, store vertices in local coords, compute world coords …

…as needed.

git-svn-id: https://libgdx.googlecode.com/svn/trunk@4209 6c4fd544-2939-11df-bb46-9574ba5d0bfa

gdx/src/com/badlogic/gdx/math/Interpolation.java

@@ -1,7 +1,8 @@
 
 package com.badlogic.gdx.math;
 
-/** Takes a linear value in the range of 0-1 and outputs a (usually) non-linear, interpolated value. */
+/** Takes a linear value in the range of 0-1 and outputs a (usually) non-linear, interpolated value.
+ * @author Nathan Sweet */
 public abstract class Interpolation {
 	abstract public float apply (float a);
 

gdx/src/com/badlogic/gdx/math/Intersector.java

@@ -647,8 +647,8 @@ public static boolean overlapConvexPolygons (Polygon p1, Polygon p2) {
 	 * @param separation Normalized vector defining a direction of the separation axis (optional).
 	 * @return Whether polygons overlap. */
 	public static boolean overlapConvexPolygons (Polygon p1, Polygon p2, Vector2 separation) {
-		final float[] verts1 = p1.getVertices();
-		final float[] verts2 = p2.getVertices();
+		final float[] verts1 = p1.getWorldVertices();
+		final float[] verts2 = p2.getWorldVertices();
 		return !separateConvexPolygons(verts1, verts2, separation) && !separateConvexPolygons(verts2, verts1, separation);
 	}
 

gdx/src/com/badlogic/gdx/math/MathUtils.java

@@ -20,9 +20,10 @@
 
 import com.badlogic.gdx.utils.NumberUtils;
 
-/** Utility and fast math functions.<br>
- * <br>
- * Thanks to Riven on JavaGaming.org for sin/cos/atan2/floor/ceil.<br> */
+/** Utility and fast math functions.
+ * <p>
+ * Thanks to Riven on JavaGaming.org for the basis of sin/cos/atan2/floor/ceil.
+ * @author Nathan Sweet */
 public class MathUtils {
 	static public final float PI = 3.1415927f;
 

gdx/src/com/badlogic/gdx/math/Polygon.java

@@ -17,41 +17,51 @@
 package com.badlogic.gdx.math;
 
 public class Polygon {
-
-	private final float[] vertices;
+	private final float[] localVertices;
+	private float[] worldVertices;
 	private float x, y;
 	private float originX, originY;
 	private float rotation;
 	private float scaleX = 1, scaleY = 1;
-	private boolean dirty;
-	private Rectangle bounds = new Rectangle();
+	private boolean dirty = true;
+	private Rectangle bounds;
 
 	public Polygon (float[] vertices) {
 		if (vertices.length < 6) throw new IllegalArgumentException("polygons must contain at least 3 points.");
-		this.vertices = vertices;
+		this.localVertices = vertices;
 	}
 
-	public float[] getVertices () {
-		if (!dirty) return vertices;
+	/** Returns vertices without scaling or rotation and without being offset by the polygon position. */
+	public float[] getLocalVertices () {
+		return localVertices;
+	}
 
-		float[] vertices = this.vertices;
-		final int numFloats = vertices.length;
+	/** Returns vertices scaled, rotated, and offset by the polygon position. */
+	public float[] getWorldVertices () {
+		if (!dirty) return localVertices;
+		dirty = false;
 
-		final float translateX = x + originX;
-		final float translateY = y + originY;
+		final float[] localVertices = this.localVertices;
+		if (worldVertices == null || worldVertices.length < localVertices.length) worldVertices = new float[localVertices.length];
+
+		final float[] worldVertices = this.worldVertices;
+		final float positionX = x;
+		final float positionY = y;
+		final float originX = this.originX;
+		final float originY = this.originY;
+		final float scaleX = this.scaleX;
+		final float scaleY = this.scaleY;
+		final boolean scale = scaleX != 1 || scaleY != 1;
+		final float rotation = this.rotation;
 		final float cos = MathUtils.cosDeg(rotation);
 		final float sin = MathUtils.sinDeg(rotation);
-		float x, y;
-		for (int i = 0; i < numFloats; i += 2) {
-			x = vertices[i];
-			y = vertices[i + 1];
 
-			// move vertices to local coordinates
-			x -= translateX;
-			y -= translateY;
+		for (int i = 0, n = localVertices.length; i < n; i += 2) {
+			float x = localVertices[i] - originX;
+			float y = localVertices[i + 1] - originY;
 
 			// scale if needed
-			if (scaleX != 1 || scaleY != 1) {
+			if (scale) {
 				x *= scaleX;
 				y *= scaleY;
 			}
@@ -63,17 +73,10 @@ public float[] getVertices () {
 				y = sin * oldX + cos * y;
 			}
 
-			// move vertices back to world coordinates
-			x += translateX;
-			y += translateY;
-
-			vertices[i] = x;
-			vertices[i + 1] = y;
+			worldVertices[i] = positionX + x + originX;
+			worldVertices[i + 1] = positionY + y + originY;
 		}
-
-		dirty = false;
-
-		return vertices;
+		return worldVertices;
 	}
 
 	public void setOrigin (float originX, float originY) {
@@ -119,7 +122,7 @@ public void scale (float amount) {
 	public float area () {
 		float area = 0;
 
-		float[] vertices = getVertices();
+		float[] vertices = getWorldVertices();
 		final int numFloats = vertices.length;
 
 		int x1, y1, x2, y2;
@@ -137,8 +140,7 @@ public float area () {
 	}
 
 	public Rectangle getBoundingRectangle () {
-
-		float[] vertices = getVertices();
+		float[] vertices = getWorldVertices();
 
 		float minX = vertices[0];
 		float minY = vertices[1];
@@ -153,6 +155,7 @@ public Rectangle getBoundingRectangle () {
 			maxY = maxY < vertices[i + 1] ? vertices[i + 1] : maxY;
 		}
 
+		if (bounds == null) bounds = new Rectangle();
 		bounds.x = minX;
 		bounds.y = minY;
 		bounds.width = maxX - minX;
@@ -162,7 +165,7 @@ public Rectangle getBoundingRectangle () {
 	}
 
 	public boolean contains (float x, float y) {
-		final float[] vertices = getVertices();
+		final float[] vertices = getWorldVertices();
 		final int numFloats = vertices.length;
 		int intersects = 0;
 

gdx/src/com/badlogic/gdx/math/Vector2.java

@@ -28,6 +28,7 @@ public class Vector2 implements Serializable {
 	/** Static temporary vector. Use with care! Use only when sure other code will not also use this.
 	 * @see #tmp() **/
 	public final static Vector2 tmp = new Vector2();
+
 	public final static Vector2 X = new Vector2(1, 0);
 	public final static Vector2 Y = new Vector2(0, 1);
 	public final static Vector2 Zero = new Vector2(0, 0);
@@ -39,7 +40,6 @@ public class Vector2 implements Serializable {
 
 	/** Constructs a new vector at (0,0) */
 	public Vector2 () {
-
 	}
 
 	/** Constructs a vector with the given components

gdx/src/com/badlogic/gdx/math/Vector3.java

@@ -20,21 +20,28 @@
 
 import com.badlogic.gdx.utils.NumberUtils;
 
-/** Encapsulates a 3D vector. Allows chaining operations by returning a reference to it self in all modification methods.
- * 
+/** Encapsulates a 3D vector. Allows chaining operations by returning a reference to itself in all modification methods.
  * @author badlogicgames@gmail.com */
 public class Vector3 implements Serializable {
 	private static final long serialVersionUID = 3840054589595372522L;
+
 	/** the x-component of this vector **/
 	public float x;
 	/** the x-component of this vector **/
 	public float y;
 	/** the x-component of this vector **/
 	public float z;
 
-	private static Vector3 tmp = new Vector3();
-	private static Vector3 tmp2 = new Vector3();
-	private static Vector3 tmp3 = new Vector3();
+	/** Static temporary vector. Use with care! Use only when sure other code will not also use this.
+	 * @see #tmp() **/
+	public final static Vector3 tmp = new Vector3();
+	/** Static temporary vector. Use with care! Use only when sure other code will not also use this.
+	 * @see #tmp() **/
+	public final static Vector3 tmp2 = new Vector3();
+	/** Static temporary vector. Use with care! Use only when sure other code will not also use this.
+	 * @see #tmp() **/
+	public final static Vector3 tmp3 = new Vector3();
+
 	public final static Vector3 X = new Vector3(1, 0, 0);
 	public final static Vector3 Y = new Vector3(0, 1, 0);
 	public final static Vector3 Z = new Vector3(0, 0, 1);
@@ -45,7 +52,6 @@ public Vector3 () {
 	}
 
 	/** Creates a vector with the given components
-	 * 
 	 * @param x The x-component
 	 * @param y The y-component
 	 * @param z The z-component */
@@ -54,7 +60,6 @@ public Vector3 (float x, float y, float z) {
 	}
 
 	/** Creates a vector from the given vector
-	 * 
 	 * @param vector The vector */
 	public Vector3 (Vector3 vector) {
 		this.set(vector);