code: function() {
  		var sprites = this.sprites,
  		    background = this.background;
  
  		if ( this.inRenderScanline ) {
  			if ( this.enabled ) {
  				background.evaluate();
  				sprites.evaluate();
  			}
  
  			if ( this.pixelInRange ) {
  				if ( 
  					this.pixelInRange &&
  					sprites.sprite0InRange &&
  					sprites.scanlineSprite0[ this.lineCycle - 1 ] &&
  					!this.sprite0Hit
  				) {
  					this.sprite0Hit = !!background.scanlineColors[ this.lineCycle - 1 ];
  				}
  			}
  
  			this.incrementRenderCycle();
  		} else {
  			this.incrementIdleCycle();
  		}
  	}
docs: A single PPU tick.