anchor: love.graphics.newQuad
  Creates a new Quad.
  
  The purpose of a Quad is to use a fraction of an image to draw objects, as opposed to drawing entire image. It is most useful for sprite sheets and atlases: in a sprite atlas, multiple sprites reside in same image, quad is used to draw a specific sprite from that image; in animated sprites with all frames residing in the same image, quad is used to draw specific frame from the animation.
  quad = love.graphics.newQuad( x, y, width, height, sw, sh )
  x number The top-left position in the Image along the x-axis.
  y number The top-left position in the Image along the y-axis.
  width number The width of the Quad in the Image. (Must be greater than 0.)
  height number The height of the Quad in the Image. (Must be greater than 0.)
  sw number The reference width, the width of the Image. (Must be greater than 0.)
  sh number The reference height, the height of the Image. (Must be greater than 0.)
  quad Quad The new Quad.
  quad = love.graphics.newQuad( x, y, width, height, texture )
  x number The top-left position in the Image along the x-axis.
  y number The top-left position in the Image along the y-axis.
  width number The width of the Quad in the Image. (Must be greater than 0.)
  height number The height of the Quad in the Image. (Must be greater than 0.)
  texture Texture The texture whose width and height will be used as the reference width and height.
  quad Quad The new Quad.