CStruct matrix-t - cl-cffi-gtk3 API documentation

Package: cairo

CStruct cairo:matrix-t

Declaration

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

Values

xx: The double float for the xx component.
yx: The double float for the yx component.
xy: The double float for the xy component.
yy: The double float for the yy component.
x0: The double float for the x translation component.
y0: The double float for the y translation component.

Details

The 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:

xnew = xx * x + xy * y + x0
ynew = yx * x + yy * y + y0

The current transformation matrix (CTM) of a cairo:context-t instance, represented as a cairo:matrix-t structure, defines the transformation from user space coordinates to device space coordinates. See also the cairo:matrix function.