/*******************************************************************************
 * Copyright 2011 See AUTHORS file.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package com.badlogic.gdx.physics.box2d;

import com.badlogic.gdx.math.Vector2;

public class PolygonShape extends Shape {
	/**
	 * Constructs a new polygon
	 */
	public PolygonShape () {
		addr = newPolygonShape();
	}

	protected PolygonShape (long addr) {
		this.addr = addr;
	}

	private native long newPolygonShape ();

	/**
	 * {@inheritDoc}
	 */
	@Override public Type getType () {
		return Type.Polygon;
	}

	/**
	 * Copy vertices. This assumes the vertices define a convex polygon. It is assumed that the exterior is the the right of each
	 * edge.
	 */
	public void set (Vector2[] vertices) {
		float[] verts = new float[vertices.length * 2];
		for (int i = 0, j = 0; i < vertices.length * 2; i += 2, j++) {
			verts[i] = vertices[j].x;
			verts[i + 1] = vertices[j].y;
		}
		jniSet(addr, verts);
	}

	private native void jniSet (long addr, float[] verts);

	/**
	 * Build vertices to represent an axis-aligned box.
	 * @param hx the half-width.
	 * @param hy the half-height.
	 */
	public void setAsBox (float hx, float hy) {
		jniSetAsBox(addr, hx, hy);
	}

	private native void jniSetAsBox (long addr, float hx, float hy);

	/**
	 * Build vertices to represent an oriented box.
	 * @param hx the half-width.
	 * @param hy the half-height.
	 * @param center the center of the box in local coordinates.
	 * @param angle the rotation of the box in local coordinates.
	 */
	public void setAsBox (float hx, float hy, Vector2 center, float angle) {
		jniSetAsBox(addr, hx, hy, center.x, center.y, angle);
	}

	private native void jniSetAsBox (long addr, float hx, float hy, float centerX, float centerY, float angle);

	/**
	 * Set this as a single edge.
	 */
	public void setAsEdge (Vector2 v1, Vector2 v2) {
		jniSetAsEdge(addr, v1.x, v1.y, v2.x, v2.y);
	}

	private native void jniSetAsEdge (long addr, float v1x, float v1y, float v2x, float v2y);

	/**
	 * @return the number of vertices
	 */
	public int getVertexCount () {
		return jniGetVertexCount(addr);
	}

	private native int jniGetVertexCount (long addr);

	private static float[] verts = new float[2];

	/**
	 * Returns the vertex at the given position.
	 * @param index the index of the vertex 0 <= index < getVertexCount( )
	 * @param vertex vertex
	 */
	public void getVertex (int index, Vector2 vertex) {
		jniGetVertex(addr, index, verts);
		vertex.x = verts[0];
		vertex.y = verts[1];
	}

	private native void jniGetVertex (long addr, int index, float[] verts);
}