A cairo-matrix-t structure holds an affine transformation, such as a scale, rotation, shear, or a combination of those. The transformation of a point (x, y) is given by:

x_new = xx * x + xy * y + x0;
y_new = yx * x + yy * y + y0;  

The current transformation matrix of a cairo-t context, represented as a cairo-matrix-t structure, defines the transformation from user space coordinates to device space coordinates. See the functions cairo-get-matrix and cairo-set-matrix.

(defcstruct cairo-matrix-t
  (xx :double)
  (yx :double)
  (xy :double)
  (yy :double)
  (x0 :double)
  (y0 :double))  

xx

A double float xx component of the affine transformation.

yx

A double float yx component of the affine transformation.

xy

A double float xy component of the affine transformation.

yy

A double float yy component of the affine transformation.

x0

A double float x translation component of the affine transformation.

y0

A double float y translation component of the affine transformation.