import processing.opengl.*; 
 
void setup() 
{ 
  size(800, 600, OPENGL); 
  noStroke(); 
  fill(0, 102, 153, 26); 
} 
 
void draw() 
{ 
  float x = mouseX - width/2; 
  background(255); 
  translate(width/2, height/2); 
  rotateZ(radians(mouseY/10)); 
  for(int i=-height/2; i<height/2; i+=10) { 
    for(int j=-width/2; j<width/2; j+=10) { 
      beginShape(QUADS); 
      vertex(x+j,   i,    0); 
      vertex(x+j, i+5,    0); 
      vertex(j-x, i+5, -400); 
      vertex(j-x,   i, -400); 
      endShape(); 
    } 
  } 
}