/* * A program to paint, centered on the canvas, a circle of randomly colored dots. */ package npw; import painter.SPainter; import shapes.SCircle; import shapes.SSquare; import javax.swing.*; import java.awt.*; import java.util.Random; import java.util.Scanner; public class HirstDots { private void paintTheImage(){ //Get the input information int radius = getNumber("circle radius"); int side = getNumber("square side length"); //Establish the painter SPainter painter = new SPainter("Circle of Squares",radius*2+50,radius*2+50); painter.setBrushWidth(3); SCircle circle = new SCircle(radius); SSquare square = new SSquare(side); //Paint the squares paintCircleOfSquares(painter,circle,square); } private void paintCircleOfSquares(SPainter painter, SCircle circle, SSquare square) { //Position the painter to begin the rows painter.mfd(circle.radius()); painter.tr(); //Paint the circle of squares double moved = 0; while (moved < circle.diameter()){ double chord = chordLength(circle.radius()-moved,circle); int squares = squaresOnLineCount(chord,square.side()); paintRow(painter,square,squares); nextRow(painter,square.side()); moved = moved + square.side(); } //Make the method invariant with respect to painter position painter.tl(); painter.mfd(circle.radius()); } //Move to the next row private void nextRow(SPainter painter,double rowHeight){ painter.tr(); painter.mfd(rowHeight); painter.tl(); } //Assumes the painter is at the center of the row to paint, facing right. private void paintRow(SPainter painter,SSquare square,int squaresToPaint){ //Move backward 1/2 of the length we're painting to get ready to paint the row. double centerOffset = ((squaresToPaint)*square.side()/2)-square.side()/2; painter.mbk(centerOffset); //Paint the row of squares. int painted = 0; while (painted < squaresToPaint){ paintOneSquare(painter,square); painter.mfd(square.side()); painted = painted + 1; } //Make the method invariant with respect to painter position. painter.mbk(centerOffset+square.side()); } private void paintOneSquare(SPainter painter, SSquare square){ square.s2(); SCircle dots = square.inscribingCircle(); painter.setColor(randomColor()); painter.paint(dots); square.x2(); } private static int squaresOnLineCount(double lineLength,double sideLength){ int squares = ((int)Math.ceil((lineLength-sideLength)/sideLength)+1); return squares; } private double chordLength(double yOffset,SCircle circle){ double xLength = Math.sqrt(Math.pow(circle.radius(),2)-Math.pow(yOffset,2)); double chordLength = xLength*2; return chordLength; } private static int getNumber(String prompt){ String nss = JOptionPane.showInputDialog(null,prompt+"?"); Scanner scanner = new Scanner(nss); return scanner.nextInt(); } private static Color randomColor(){ Random rgen = new Random(); int r = rgen.nextInt(256); int g = rgen.nextInt(256); int b = rgen.nextInt(256); return new Color(r,g,b); } public HirstDots(){ paintTheImage(); } public static void main(String[] args){ SwingUtilities.invokeLater(new Runnable(){ public void run(){ new HirstDots(); } }); } }