cairoMatrixTransformDistance: cairoMatrixTransformDistance
Description
Transforms the distance vector (dx
,dy
) by matrix
. This is
similar to cairo() except that the translation
components of the transformation are ignored. The calculation of
the returned vector is as follows:
cairoMatrixTransformDistance(matrix, dx, dy)
matrix
{[CairoMatrix
] a cairo.matrix.t
}
dx
{[numeric] X component of a distance vector. An in/out parameter}
dy
{[numeric] Y component of a distance vector. An in/out parameter}
dx2 = dx1 * a + dy1 * c;
dy2 = dx1 * b + dy1 * d;
Affine transformations are position invariant, so the same vector
always transforms to the same vector. If (x1
,y1
) transforms
to (x2
,y2
) then (x1
+dx1
,y1
+dy1
) will transform to
(x1
+dx2
,y1
+dy2
) for all values of x1
and x2
.
[object Object]
internal