Matrix

A #cairo_matrix_t 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: <programlisting> x_new = xx * x + xy * y + x0; y_new = yx * x + yy * y + y0; </programlisting>

Members

Functions

initIdentity void initIdentity(): Modifies matrix to be an identity transformation.
initRotate void initRotate(double radians): Initialized matrix to a transformation that rotates by radians.
initScale void initScale(double sx, double sy): Initializes matrix to a transformation that scales by sx and sy in the X and Y dimensions, respectively.
initTranslate void initTranslate(double tx, double ty): Initializes matrix to a transformation that translates by tx and ty in the X and Y dimensions, respectively.
init_ void init_(double xx, double yx, double xy, double yy, double x0, double y0): Sets matrix to be the affine transformation given by xx, yx, xy, yy, x0, y0. The transformation is given by: <programlisting> x_new = xx * x + xy * y + x0; y_new = yx * x + yy * y + y0; </programlisting>
invert cairo.types.Status invert(): Changes matrix to be the inverse of its original value. Not all transformation matrices have inverses; if the matrix collapses points together (it is <firstterm>degenerate</firstterm>), then it has no inverse and this function will fail.
multiply void multiply(cairo.matrix.Matrix a, cairo.matrix.Matrix b): Multiplies the affine transformations in a and b together and stores the result in result. The effect of the resulting transformation is to first apply the transformation in a to the coordinates and then apply the transformation in b to the coordinates.
rotate void rotate(double radians): Applies rotation by radians to the transformation in matrix. The effect of the new transformation is to first rotate the coordinates by radians, then apply the original transformation to the coordinates.
scale void scale(double sx, double sy): Applies scaling by sx, sy to the transformation in matrix. The effect of the new transformation is to first scale the coordinates by sx and sy, then apply the original transformation to the coordinates.
transformDistance void transformDistance(double dx, double dy): Transforms the distance vector (dx,dy) by matrix. This is similar to cairo.matrix.Matrix.transformPoint except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:
transformPoint void transformPoint(double x, double y): Transforms the point (x, y) by matrix.
translate void translate(double tx, double ty): Applies a translation by tx, ty to the transformation in matrix. The effect of the new transformation is to first translate the coordinates by tx and ty, then apply the original transformation to the coordinates.

Properties

_gType GType _gType [@property getter]

Static functions

_getGType GType _getGType()

Variables

x0 double x0;: X translation component of the affine transformation
xx double xx;: xx component of the affine transformation
xy double xy;: xy component of the affine transformation
y0 double y0;: Y translation component of the affine transformation
yx double yx;: yx component of the affine transformation
yy double yy;: yy component of the affine transformation

cairo matrix structs

Matrix