Can someone explain this color wheel code to me?
- by user1869438
I just started doing java and i need some help with understanding this code. I got it from a this website. This is supposed to be code for a color wheel but i don't really understand how it works, especially the final ints STEPS and SLICES.
import java.awt.Color;
import objectdraw.*;
public class ColorWheel extends WindowController {
private double brightness;
private Text text;
private FilledRect swatch;
private Location center;
private int size;
private FilledRect brightnessOverlay;
private static final int SLICES = 96;
private static final int STEPS = 16;
public void begin() {
canvas.setBackground(Color.BLACK);
brightness = 1.;
size = Math.min(canvas.getWidth(), canvas.getHeight() - 20);
center = new Location(canvas.getWidth() / 2, size / 2);
for(int j = STEPS; j >= 1; j--) {
int arcSize = size * j / STEPS;
int x = center.getX() - arcSize / 2;
int y = center.getY() - arcSize / 2;
for(int i = 0; i < SLICES; i++) {
Color c = Color.getHSBColor((float)i / SLICES, (float)j / STEPS, (float)brightness);
new FilledArc(x, y, arcSize, arcSize, i * 360. / SLICES, 360. / SLICES + .5, c, canvas);
}
}
swatch = new FilledRect(0, canvas.getHeight() - 20, canvas.getWidth(), 20, Color.BLACK, canvas);
brightnessOverlay = new FilledRect(0, 0, canvas.getWidth(), canvas.getHeight() - 20, new Color(0, 0, 0, 0), canvas);
text = new Text("", canvas.getWidth() / 2, canvas.getHeight() - 18, canvas);
text.setAlignment(Text.CENTER, Text.TOP);
text.setBold(true);
}
public void onMouseDrag(Location point) {
brightness = (canvas.getHeight() - point.getY()) / (double)(canvas.getHeight());
if(brightness < 0) {
brightness = 0;
} else if(brightness > 1) {
brightness = 1;
}
if(brightness < .5) {
text.setColor(Color.WHITE);
} else {
text.setColor(Color.BLACK);
}
brightnessOverlay.setColor(new Color(0f, 0f, 0f, (float)(1 - brightness)));
}
public void onMouseMove(Location point) {
double saturation = 2 * center.distanceTo(point) / size;
if(saturation > 1) {
text.setText("");
swatch.setColor(Color.BLACK);
return;
}
double hue = -Math.atan2(point.getY() - center.getY(), point.getX() - center.getX()) / (2 * Math.PI);
if(hue < 0) {
hue += 1;
}
swatch.setColor(Color.getHSBColor((float)hue, (float)saturation, (float)brightness));
text.setText("Color.getHSBColor(" + Text.formatDecimal(hue, 2) + "f, " +
Text.formatDecimal(saturation, 2) + "f, " + Text.formatDecimal(brightness, 2) + "f)");
}
}
