ColorfulAbstractGradient.java
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1 /*
2 * A program to paint an abstract gradient in the vertical direction.
3 */
4
5 package npw;
6
7 import painter.SPainter;
8 import shapes.SCircle;
9
10 import javax.swing.*;
11 import java.awt.*;
12 import java.util.Random;
13 import java.util.Scanner;
14
15 public class ColorfulAbstractGradient {
16
17 public static void main(String[] args) {
18 SwingUtilities.invokeLater(ColorfulAbstractGradient::new);
19 }
20
21 public ColorfulAbstractGradient() {
22 paintTheImage();
23 }
24
25 private void paintTheImage(){
26 // Grab the input information
27 int width = getNumber("width");
28 int height = getNumber("height");
29 int dotSpace = getNumber("horizontal space between dots");
30 // Establish the painter
31 SPainter painter = new SPainter("Abstract Gradient", width, height);
32 SCircle dot = new SCircle(5);
33
34 // Move the painter to the upper left corner to get ready to paint the gradient
35 painter.mfd(height/2.0);
36 painter.tl();
37 painter.mfd(width/2.0);
38 painter.tl();
39
40 // Paint it!
41 paintGradient(painter, dot, height, width, dotSpace);
42 }
43
44 private static int getNumber(String prompt) {
45 String nss = JOptionPane.showInputDialog(null,prompt+"?");
46 Scanner scanner = new Scanner(nss);
47 return scanner.nextInt();
48 }
49
50 private void paintGradient(SPainter painter, SCircle dot, int height, int width, int dotSpace){
51 // Calculate the number of columns. We want to fill the screen, but don't want any columns half on the canvas.
52 // A column takes up the horizontal space of a dot's diameter plus the space between it and a neighbor.
53 double colWidth = dot.diameter() + dotSpace;
54 // We don't want a column all the way on the edge on the right side, so subtract 1.
55 int nrOfCols = (int) Math.floor(( width / colWidth )) - 1;
56
57 int cols = 0;
58 while (cols < nrOfCols){
59 nextCol(painter, dot, dotSpace);
60 paintColumn(painter, dot, height);
61 cols = cols + 1;
62 }
63 }
64
65 private void paintOneDot(SPainter painter, SCircle dot){
66 painter.setColor(randomColor());
67 painter.paint(dot);
68 }
69
70 private Color randomColor() {
71 int rv = (int)(Math.random()*256);
72 int gv = (int)(Math.random()*256);
73 int bv = (int)(Math.random()*256);
74 return new Color(rv,gv,bv);
75 }
76
77 // Dots are spaced more tightly together near the bottom of the canvas.
78 private void paintColumn(SPainter painter, SCircle dot, int height) {
79 int totalDistanceTraveled = 0;
80
81 // Paint a column with decreasing distance between dots.
82 while(totalDistanceTraveled < height - (dot.radius() * 3)) {
83 int travel = randomDistance((height - totalDistanceTraveled) / 4);
84 totalDistanceTraveled = totalDistanceTraveled + travel;
85 painter.mfd(travel);
86 paintOneDot(painter, dot);
87 }
88
89 // Make the method invariant with respect to painter position.
90 painter.mbk(totalDistanceTraveled);
91 }
92
93 // Moves the painter to the next column.
94 private void nextCol(SPainter painter, SCircle dot, int dotSpace){
95 painter.tl();
96 painter.mfd(dot.diameter() + dotSpace);
97 painter.tr();
98 }
99
100 private int randomDistance(int maxDistance){
101 Random rgen = new Random();
102 return rgen.nextInt(maxDistance);
103 }
104 }
105