PgMatrix.transformDistance

Transforms the distance vector (dx,dy) by matrix. This is similar to Matrix.transformPoint except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:

<programlisting> dx2 = dx1 * xx + dy1 * xy; dy2 = dx1 * yx + dy1 * yy; </programlisting>

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.

class PgMatrix
void
transformDistance
(
ref double dx
,
ref double dy
)

Parameters

dx double

in/out X component of a distance vector

dy double

in/out Y component of a distance vector

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Since

1.16