int lightMode = 0;
int lightDirection = 0;
void setup()
{
  size(600,600,P3D);
}
void draw()
{
  background( 0 );
switch ( lightMode ) {
case 0:
noLights();
break;
case 1:
lights();
break;
case 2:
if ( lightDirection == 0 ) {
directionalLight( 255, 128, 0, 0, -1, 0 ); // UP
} else if ( lightDirection == 1 ) {
directionalLight( 0, 255, 0, 1, 0, 0 ); // RIGHT
} else if ( lightDirection == 2 ) {
directionalLight( 255, 0, 255, 0, 1, 0 ); // DOWN
} else if ( lightDirection == 3 ) {
directionalLight( 0, 255, 255, -1, 0, 0 ); // LEFT
}
break;
case 3:
ambientLight( 0, 255, 255 );
break;
case 4:
pointLight( 255, 255, 0, 100, height*0.3, 100 );
break;
case 5:
spotLight( 128, 255, 128, 800, 20, 300, -1, .25, 0, PI, 
2 );
break;
default:
noLights();
}

pushMatrix();
translate( width/2, height/2, 0 );
pushMatrix();
rotateY( radians( frameCount ) );
fill( 255 );
noStroke();
sphere( 100 );
popMatrix();
pushMatrix();
rotateZ( radians( frameCount ) );
rotateX( radians( frameCount/2 ) );
fill( 255 );
noStroke();
box( 150 );
popMatrix();
popMatrix();
}

void keyPressed()
{
switch ( key ) {
case 'n':
lightMode = 0; // no lights
break;
case 'l':
lightMode = 1; // lights
break;
case 'd':
lightMode = 2; // directional light
break;
case 'a':
lightMode = 3; // ambient light
break;
case 'p':
lightMode = 4; // point light
break;
case 's':
lightMode = 5; // spot light
break;
}
if ( key == CODED ) {
switch ( keyCode ) {
case UP:
lightDirection = 0;
break;
case RIGHT:
lightDirection = 1;
break;
case DOWN:
lightDirection = 2;
break;
case LEFT: 
lightDirection = 3;
break;
}
}
}