float global_time;

void setup() {
	size(600, 600);
	colorMode(RGB);
	background(20,1,55);
	noStroke();
	smooth();
	global_time = 0;
}

void draw() {
	int i, j, box_size;
	int total_mesh = 20;
	float xx, yy, distance, wave;
	box_size = 600 / total_mesh;

	global_time = global_time + 0.1; // wave speed
	if (global_time > 3.1415926535*2){
		global_time = 0;
	}

	for(i=0; i < total_mesh; i++){
		for(j=0; j < total_mesh; j++){
			xx = (j+0.5) * box_size;
			yy = (i+0.5) * box_size;
			if( random(20) < 1 ){			
				fill(random(8,100)+50,10,40);
				ellipse(xx, yy, box_size, box_size);
			}
			distance = sqrt( sq(xx-mouseX) + sq(yy-mouseY) );
			if ( distance < box_size/2 ){
				fill(255,255,255);
				ellipse(xx, yy, box_size, box_size);			 
			}
			wave = distance - 100*(sin(global_time)+1) - 40;
			if ( (wave > box_size/2) && (wave-15 < box_size/2) ){
				fill(0,255,255);
				ellipse(xx, yy, box_size, box_size);			 
			}
		}
	}
}