Diffusing a color in java Draw

Question

I am trying to diffuse a color in java Draw (which doesn't have the capability to diffuse normally) but I ran into an error and I can't seem to spot it. The way I went about diffusing was by writing a small script that would draw my shape hundreds of times, each time smaller and slightly varying in color. This is my snippet:

import javax.swing.*;
import java.awt.*;
public class DiffuseDraw extends JFrame
{
  //set size of window here
  final int length = 350;
  final int height = 370;

  public DiffuseDraw()
  { 
    super("Graphics Project Window");
    Container container = getContentPane(); 
    setBackground(new Color(0,0,0));
    setSize(length, height);
    setVisible(true);
  }


// my problem comes here:

  public void paint(Graphics g)
  {

    Draw.fillRectangle(g,0,0,length,height,new Color(19,24,32));

    int rad = 325; // size of the biggest circle

    float floatGreen = 0; // Color components for black
    float floatBlue = 0;
    float floatRed = 0;

    int counter = 0; // the counter
    while (counter < 290) {
       rad = rad - 1; // Here we shrink the by a small incriment

       floatRed = floatRed + 87/290;  //red component slowly goes brighter
       floatBlue = floatBlue + 178/290; // blue component slowly goes brighter
       floatGreen = floatGreen + 211/290; // green component slowly goes brighter
       int intRed = (int)Math.round(floatRed);
       int intBlue = (int)Math.round(floatBlue);
       int intGreen = (int)Math.round(floatGreen);

       Draw.fillCircle(g,173,307,rad,new Color(intRed,intBlue,intGreen));
       counter = counter + 1;
    }

  }

  public static void main(String args[]) {
    DiffuseDraw prog = new DiffuseDraw();
    prog.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  }  
}

When I compile and run, I only get a black screen. I am guessing that the problem is coming from the colors not changing. The number I am adding the float red blue and green by came from me wanting to diffuse a type of blue, so I took the the brightest color of blue that would appear and divided it by 290, the number of times the loop would run.

You might try working in the HSB color space, seen in the examples cited [here](http://stackoverflow.com/a/13709785/230513). — trashgod, Dec 12 '12 at 03:21

score 1 · Accepted Answer · answered Dec 12 '12 at 03:29

Instead of

87/290, 178/290, and 211/290,

try using

(float)87/290, (float)178/290, and (float)211/290.

That will, at least, add some color to the window- the problem is that by default, a number like 87/290 will be evaluated to 0; casting it to a float will give the desired result of 0.3 instead.

Diffusing a color in java Draw

1 Answers1