content: /*
   * Copyright (c) 2012 Jason Polites
   * 
   * 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.polites;
  
  import android.graphics.PointF;
  import android.util.FloatMath;
  import android.view.MotionEvent;
  
  public class MathUtils {
  	
  	public static float distance(MotionEvent event) {
  		float x = event.getX(0) - event.getX(1);
  		float y = event.getY(0) - event.getY(1);
  		return FloatMath.sqrt(x * x + y * y);
  	}
  	
  	public static float distance(PointF p1, PointF p2) {
  		float x = p1.x - p2.x;
  		float y = p1.y - p2.y;
  		return FloatMath.sqrt(x * x + y * y);
  	}
  	
  	public static float distance(float x1, float y1, float x2, float y2) {
  		float x = x1 - x2;
  		float y = y1 - y2;
  		return FloatMath.sqrt(x * x + y * y);
  	}
  
  	public static void midpoint(MotionEvent event, PointF point) {
  		float x1 = event.getX(0);
  		float y1 = event.getY(0);
  		float x2 = event.getX(1);
  		float y2 = event.getY(1);
  		midpoint(x1, y1, x2, y2, point);
  	}
  
  	public static void midpoint(float x1, float y1, float x2, float y2, PointF point) {
  		point.x = (x1 + x2) / 2.0f;
  		point.y = (y1 + y2) / 2.0f;
  	}
  	/**
  	 * Rotates p1 around p2 by angle degrees.
  	 * @param p1
  	 * @param p2
  	 * @param angle
  	 */
  	public void rotate(PointF p1, PointF p2, float angle) {
  		float px = p1.x;
  		float py = p1.y;
  		float ox = p2.x;
  		float oy = p2.y;
  		p1.x = (FloatMath.cos(angle) * (px-ox) - FloatMath.sin(angle) * (py-oy) + ox);
  		p1.y = (FloatMath.sin(angle) * (px-ox) + FloatMath.cos(angle) * (py-oy) + oy);
  	}
  	
  	public static float angle(PointF p1, PointF p2) {
  		return angle(p1.x, p1.y, p2.x, p2.y);
  	}	
  	
  	public static float angle(float x1, float y1, float x2, float y2) {
  		return (float) Math.atan2(y2 - y1, x2 - x1);
  	}
  }
  