Brightness
int barWidth = 20;
int lastBar = -1;
void setup() {
size(640, 360);
colorMode(HSB, width, 100, height);
noStroke();
background(0);
}
void draw() {
int whichBar = mouseX / barWidth;
if (whichBar != lastBar) {
int barX = whichBar * barWidth;
fill(barX, 100, mouseY);
rect(barX, 0, barWidth, height);
lastBar = whichBar;
}
}