001/**
002 * Copyright (c) 2011, The University of Southampton and the individual contributors.
003 * All rights reserved.
004 *
005 * Redistribution and use in source and binary forms, with or without modification,
006 * are permitted provided that the following conditions are met:
007 *
008 *   *  Redistributions of source code must retain the above copyright notice,
009 *      this list of conditions and the following disclaimer.
010 *
011 *   *  Redistributions in binary form must reproduce the above copyright notice,
012 *      this list of conditions and the following disclaimer in the documentation
013 *      and/or other materials provided with the distribution.
014 *
015 *   *  Neither the name of the University of Southampton nor the names of its
016 *      contributors may be used to endorse or promote products derived from this
017 *      software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
020 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
021 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
022 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
023 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
026 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
028 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package org.openimaj.demos.core;
031
032import java.util.Random;
033
034import org.openimaj.demos.Demo;
035import org.openimaj.image.DisplayUtilities;
036import org.openimaj.image.FImage;
037import org.openimaj.image.renderer.FImageRenderer;
038import org.openimaj.math.geometry.point.Point2d;
039import org.openimaj.math.geometry.point.Point2dImpl;
040import org.openimaj.math.geometry.shape.Triangle;
041
042/**
043 * Draw a Sierpinski Triangle into an FImage using two
044 * different techniques. 
045 * 
046 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
047 */
048@Demo(
049        author = "Jonathon Hare", 
050        description = "Demonstrates some of the core drawing tools within " +
051                        "OpenIMAJ by drawing a Sierpinski triangle using two different " +
052                        "techniques.", 
053        keywords = { "sierpinski", "triangle", "render", "point", "drawing" }, 
054        title = "Sierpinski Triangle",
055        icon = "/org/openimaj/demos/icons/core/sierpinski-icon.png"
056)
057public class SierpinskiTriangle {
058        /**
059         * Draw a Sierpinski Triangle by plotting random points
060         * @return image with triangle
061         */
062        public static FImage randomPointTriangle() {
063                FImage image = new FImage(500, 500);
064                FImageRenderer renderer = image.createRenderer();
065                
066                Point2d [] vertices = {
067                        new Point2dImpl(0, 500),
068                        new Point2dImpl(250, 0),
069                        new Point2dImpl(500, 500),
070                };
071                
072                Point2d p = new Point2dImpl(75, 450);
073                
074                Random random = new Random();
075                
076                for (int i=0; i<5000; i++) {
077                        int j = random.nextInt(3);
078                        
079                        p.setX((p.getX() + vertices[j].getX()) / 2);
080                        p.setY((p.getY() + vertices[j].getY()) / 2);
081                        
082                        renderer.drawPoint(p, 1.0f, 1);
083                }
084                
085                return image;
086        }
087
088        protected static void divideTriangle(Point2d a, Point2d b, Point2d c, int k, FImageRenderer renderer) {
089                if (k>0) {
090                        Point2d ab = new Point2dImpl((a.getX() + b.getX()) / 2, (a.getY() + b.getY()) / 2);
091                        Point2d ac = new Point2dImpl((a.getX() + c.getX()) / 2, (a.getY() + c.getY()) / 2);
092                        Point2d bc = new Point2dImpl((b.getX() + c.getX()) / 2, (b.getY() + c.getY()) / 2);
093                        
094                        divideTriangle(a, ab, ac, k-1, renderer);
095                        divideTriangle(c, ac, bc, k-1, renderer);
096                        divideTriangle(b, bc, ab, k-1, renderer);
097                } else {
098                        renderer.drawShapeFilled(new Triangle(a, b, c), 1.0f);
099                }
100        }
101        
102        /**
103         * Draw a Sierpinski Triangle by recursively drawing sub-triangles
104         * @return image with triangle
105         */
106        public static FImage polygonTriangle() {
107                FImage image = new FImage(500, 500);
108                FImageRenderer renderer = image.createRenderer();
109                
110                Point2d [] v = new Point2d[] {
111                                new Point2dImpl(0, 500),
112                                new Point2dImpl(500, 500),
113                                new Point2dImpl(250, 0),
114                };
115                
116                divideTriangle(v[0], v[1], v[2], 4, renderer);
117                
118                return image;
119        }
120        
121        /**
122         *      Default main
123         *  @param args Command-line arguments
124         */
125        public static void main(String [] args) {
126                DisplayUtilities.display(randomPointTriangle());
127                DisplayUtilities.display(polygonTriangle());
128        }
129}