/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * JavaWorld Library, Copyright 2011 Bryan Chadwick * * * * FILE: ./universe/world/test/FallingWorld.java * * * * This file is part of JavaWorld. * * * * JavaWorld is free software: you can redistribute it and/or * * modify it under the terms of the GNU General Public License * * as published by the Free Software Foundation, either version * * 3 of the License, or (at your option) any later version. * * * * JavaWorld is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU General Public License for more details. * * * * You should have received a copy of the GNU General Public License * * along with JavaWorld. If not, see . * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ package universe.world.test; import image.*; import universe.Package; import universe.world.World; import universe.world.None; /** Falling Balls Demo in World style. When the mouse is dragged, balls * are created with a random upward velocity and then fall off the bottom of * the screen */ public class FallingWorld extends World{ public static void main(String[] s){ new FallingWorld().bigBang(); } Random rand = new Random(); LoB balls; /** Construct an empty World */ FallingWorld(){ this(new ELoB()); } /** Construct a World with the given list-of Balls */ FallingWorld(LoB lob){ this.balls = lob; } /** In order to draw the World, draw the balls into an EmptyScene */ public Scene onDraw(){ return this.balls.draw(new EmptyScene(400,400)); } /** When the mouse is dragged, we add a new random Ball */ public Package onMouse(int x, int y, String me){ if(!me.equals("drag"))return new Package(this); return new Package( new FallingWorld(new CLoB(this.rand.randBall(x,y), this.balls))); } /** On each tick, we apply gravity, move them, and filter out * those off screen */ public Package onTick(){ return new Package( new FallingWorld(this.balls.gravity().move().filter())); } } /** Represents a Ball with a location and velocity */ class Ball{ int x, y, vx, vy; String color; Ball(int x, int y, int vx, int vy, String color){ this.x = x; this.y = y; this.vx = vx; this.vy = vy; this.color = color; } /** Move this Ball in the direction it's going */ Ball move(){ return new Ball(this.x+this.vx, this.y+this.vy, this.vx, this.vy, this.color); } /** Gravitize (increase Y velocity) of this Ball */ Ball gravity(){ return new Ball(this.x, this.y, this.vx, this.vy+3, this.color); } /** Draw this Ball into the given Scene */ Scene draw(Scene scn){ return scn.placeImage(new Circle(10, "solid", this.color) .overlay(new Circle(10, "outline", "black")), this.x, this.y); } /** Is this Ball off the screen? */ boolean offscreen(){ return (this.x > 400 || this.y > 400 || this.x < 0 || this.y < 0); } } /** Represents a List of Balls */ abstract class LoB{ /** Move all the balls in this LoB */ abstract LoB move(); /** Gravitize (increase Y velocity) all the balls in this LoB */ abstract LoB gravity(); /** Draw all the balls in this LoB into the given Scene */ abstract Scene draw(Scene scn); /** Filter out the offscreen Balls */ abstract LoB filter(); } /** Represents an empty List of Balls */ class ELoB extends LoB{ /** Construct a (the) Empty list of Balls*/ ELoB(){} /** Move all the balls in this LoB (None) */ LoB move(){ return this; } /** Gravitize (increase Y velocity) all the balls (None) */ LoB gravity(){ return this; } /** Draw all the balls in this LoB (None) */ Scene draw(Scene scn){ return scn; } /** Filter out the offscreen Balls (None) */ LoB filter(){ return this; } } /** Represents a non-empty List of Balls */ class CLoB extends LoB{ Ball first; LoB rest; /** Construct a Cons LoB (with a first and rest) */ CLoB(Ball first, LoB rest){ this.first = first; this.rest = rest; } /** Move all the balls in this LoB */ LoB move(){ return new CLoB(this.first.move(), this.rest.move()); } /** Gravitize (increase Y velocity) all the balls in this LoB */ LoB gravity(){ return new CLoB(this.first.gravity(), this.rest.gravity()); } /** Draw all the balls in this LoB into the given Scene */ Scene draw(Scene scn){ return this.first.draw(this.rest.draw(scn)); } /** Filter out the offscreen Balls */ LoB filter(){ if(this.first.offscreen())return this.rest.filter(); return new CLoB(this.first, this.rest.filter()); } } /** Class for creating random objects (Colors and Balls) */ class Random{ /** Random Integer */ int rand(int i){ return (int)(Math.random()*i); } /** Color for a given number */ String colorFor(int i){ if(i == 0)return "red"; else if(i == 1)return "blue"; else if(i == 2)return "green"; else if(i == 3)return "orange"; else if(i == 4)return "yellow"; else if(i == 5)return "purple"; else return "black"; } /** Random Ball at X/Y */ Ball randBall(int x, int y){ return new Ball(x,y,rand(11)-5, -10-rand(10), colorFor(rand(6))); } }