/// start
void setup() {
   size(600,600);
}

void draw(){
    background(255);

    int left_x = 0;
    int right_x = width;
    int top_y = 0;
    int bottom_y = height;
    int light_green = #99FF99;
    int light_blue = #66CCFF;
    int light_yellow = #FFCC66;
    int pale_red = #FF3366;
    
    for (int n=0; n < 100; n++) {
      int y_of_n = n * (bottom_y/100);
      int x_of_n = n * (right_x/100);
      
      stroke(pale_red);
      line(left_x,y_of_n,mouseX,mouseY);
      
      stroke(light_yellow);
      line(right_x,y_of_n,mouseX,mouseY);
      
      stroke(light_blue);
      line(x_of_n,0,mouseX,mouseY);
      
      stroke(light_green);
      line(x_of_n,bottom_y,mouseX,mouseY);
    }
}

/// end