84. Current transformation
matrix (CTM)
• Quartz accomplishes device independence with a
separate coordinate system - user space -
mapping it to the coordinate system of the output
device - device space - using the current
transformation matrix, or CTM.
• The current transformation matrix is a particular
type of matrix called an affine transform, which
maps points from one coordinate space to
another by applying translation, rotation, and
scaling operations. (move, rotate, resize)