int box_height = 20;
int box_width = 20;
int base_color = 50;
int y_color = 200;
int row_nb, col_nb;
float max_dist;

void setup() {
	size(500, 500);
	colorMode(RGB);
	background(20, 1, 55);
	noStroke();
	smooth();
	frameRate(16);
	row_nb = height / box_height;
	col_nb = width / box_width;
	max_dist = sqrt(width * width + height * height); 
}

void draw() {
	background(10,2,64);
	for (int c = 0; c < col_nb; c++) {
		for (int r = 0; r < row_nb; r++) {
			float e = random(3);
			float distance = dist(c * box_width, r * box_height, mouseX, mouseY) / max_dist;
			if (distance < 0.2 && e < 0.5) {
				fill(base_color + random(8, y_color / 2) + 2.5 * y_color * (0.2 - distance), 10, 40);
				ellipse(c * box_width, r * box_height, box_width, box_height);
			}
		}
	}
}