# transform_distance

## Description:

Transforms the distance vector (`dx`

,`dy`

) by this.

This is similar to transform_point except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:

`dx2 = dx1 * xx + dy1 * xy;`

dy2 = dx1 * yx + dy1 * yy;

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`

.

## Parameters:

this |
a Matrix, or |

dx |
in/out X component of a distance vector |

dy |
in/out Y component of a distance vector |