1 /* 2 * A program to paint, centered on the canvas, a circle of randomly colored, black-framed squares with 3 * spaces inbetween them 4 */ 5 6 package npw; 7 8 import painter.SPainter; 9 import shapes.SCircle; 10 import shapes.SSquare; 11 12 import javax.swing.*; 13 import java.awt.*; 14 import java.util.Random; 15 import java.util.Scanner; 16 17 public class HirstDots { 18 19 private void paintTheImage(){ 20 // Get the input information 21 int radius = getNumber("circle radius length"); 22 int side = getNumber("dot radius length"); 23 24 // Establish the painter 25 SPainter painter = new SPainter("Circle of Squares", radius*2+50, radius*2+50); 26 painter.setBrushWidth(3); 27 SCircle circle = new SCircle(radius); 28 SCircle dot = new SCircle(side); 29 30 // Paint the squares 31 paintHirstDots(painter, circle, dot); 32 } 33 34 private void paintHirstDots(SPainter painter, SCircle circle, SCircle dot){ 35 // Position the painter to begin drawing the rows 36 painter.mfd(circle.radius()); 37 painter.tr(); 38 // Paint the circle of squares 39 double moved = 0; 40 while (moved < circle.diameter()) { 41 double chord = chordLength(circle.radius() - moved, circle); 42 int squares = squaresOnLineCount(chord, dot.radius()); 43 paintRow(painter, dot , squares); 44 nextRow(painter, dot.radius()); 45 moved = moved + dot.radius(); 46 } 47 // Make the method invariant with respect to painter position 48 painter.tl(); 49 painter.mfd(circle.radius()); 50 } 51 52 // Move to the next row 53 private void nextRow(SPainter painter, double rowHeight){ 54 painter.tr(); 55 painter.mfd(rowHeight); 56 painter.tl(); 57 } 58 59 // Assumes the painter is at the center of the row to paint, facing right. 60 private void paintRow(SPainter painter, SCircle dot, int dotsToPaint){ 61 // Move backward 1/2 of the length we're painting to get ready to paint the row. 62 double centerOffset = ( (dotsToPaint * dot.radius()) / 2) - dot.radius()/2; 63 painter.mbk(centerOffset); 64 65 // Paint the row of squares. 66 int painted = 0; 67 while (painted < dotsToPaint){ 68 paintOneSquare(painter, dot); 69 painter.mfd(dot.radius()); 70 painted = painted + 1; 71 } 72 73 // Make the method invariant with respect to painter position. 74 painter.mbk(centerOffset + dot.radius()); 75 } 76 77 private void paintOneSquare(SPainter painter, SCircle dot){ 78 painter.setColor(randomColor()); 79 dot.s3(); 80 painter.paint(dot); 81 dot.x3(); 82 } 83 84 private static int squaresOnLineCount(double lineLength, double sideLength){ 85 int squares = ( (int)Math.ceil( ( lineLength - sideLength ) / sideLength ) + 1); 86 return squares; 87 } 88 89 private double chordLength(double yOffset, SCircle circle){ 90 double xLength = Math.sqrt(Math.pow(circle.radius(), 2) - Math.pow(yOffset, 2)); 91 double chordLength = xLength * 2; 92 return chordLength; 93 } 94 95 private static int getNumber(String prompt) { 96 String nss = JOptionPane.showInputDialog(null,prompt+"?"); 97 Scanner scanner = new Scanner(nss); 98 return scanner.nextInt(); 99 } 100 101 private static Color randomColor() { 102 Random rgen = new Random(); 103 int r = rgen.nextInt(256); 104 int g = rgen.nextInt(256); 105 int b = rgen.nextInt(256); 106 return new Color(r,g,b); 107 } 108 109 public HirstDots() { 110 paintTheImage(); 111 } 112 113 public static void main(String[] args) { 114 SwingUtilities.invokeLater(new Runnable() { 115 public void run() { 116 new HirstDots(); 117 } 118 }); 119 } 120 }