anagram.client.Ball.java Source code

Introduction

Here is the source code for anagram.client.Ball.java

Source

/*
 * Copyright 2011 Google Inc.
 *
 * 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 anagram.client;

import com.google.gwt.canvas.dom.client.Context2d;
import com.google.gwt.canvas.dom.client.CssColor;

public class Ball extends SpringObject {
    public CssColor color;
    public double posZ, velZ, goalZ;
    public double radius;
    public Vector startPos;
    public double startPosZ;
    public double startRadius;

    public Ball(Vector start, double startPosZ, double radius, CssColor color) {
        super(start);
        this.color = color;
        this.posZ = startPosZ;
        this.velZ = 0;
        this.goalZ = startPosZ;
        this.radius = radius;
        this.startPos = new Vector(start);
        this.startPosZ = startPosZ;
        this.startRadius = radius;
    }

    public Ball(double x, double y, double z, double radius, String color) {
        this(new Vector(x, y), z, radius, CssColor.make(color));
    }

    public void update() {
        super.update();

        Vector dh = Vector.sub(startPos, pos);
        double dist = dh.mag();
        goalZ = dist / 100.0 + 1.0;
        double dgZ = goalZ - posZ;
        double aZ = dgZ * springStrength;
        velZ += aZ;
        velZ *= friction;
        posZ += velZ;

        radius = startRadius * posZ;
        radius = radius < 1 ? 1 : radius;
    }

    public void draw(Context2d context) {
        context.setFillStyle(color);
        context.beginPath();
        context.arc(pos.x, pos.y, radius, 0, Math.PI * 2.0, true);
        context.closePath();
        context.fill();
    }
}