code: function(corner, size, scale) {
  		scale = scale || 1;
  		size = size || this.size;
  
  		var width = size[0] * scale,
  			height = size[1] * scale,
  			width2 = Math.ceil(width / 2), height2 = Math.ceil(height / 2),
  
  		// Define tip coordinates in terms of height and width values
  		tips = {
  			br:	[0,0,		width,height,	width,0],
  			bl:	[0,0,		width,0,		0,height],
  			tr:	[0,height,	width,0,		width,height],
  			tl:	[0,0,		0,height,		width,height],
  			tc:	[0,height,	width2,0,		width,height],
  			bc:	[0,0,		width,0,		width2,height],
  			rc:	[0,0,		width,height2,	0,height],
  			lc:	[width,0,	width,height,	0,height2]
  		};
  
  		// Set common side shapes
  		tips.lt = tips.br; tips.rt = tips.bl;
  		tips.lb = tips.tr; tips.rb = tips.tl;
  
  		return tips[ corner.abbrev() ];
  	}
docs: Tip coordinates calculator