2.3 DUIM-Geometry Module
make-rotation-transform
Function
Summary
Returns a transform that rotates all points by angle around the point specified by coordinates origin-x and origin-y or the point object origin.
Signature
make-rotation-transformangle#keyorigin-x origin-y => transform
make-rotation-transform* angle #key origin => transform
Arguments
- angle
- An instance of type
<real>.
The following arguments are specific to make-rotation-transform.
- origin-x
- An instance of type
<real>. Default value:0. - origin-y
- An instance of type
<real>. Default value:0.
The following argument is specific to make-reflection-transform*.
- origin
- An instance of type
<point>. Default value: (0, 0).
Values
- transform
- An instance of type
<transform>.
Library
duim-geometry
Module
duim-geometry
Description
Returns a transform that rotates all points by angle around the point specified by coordinates origin-x and origin-y or the point object origin. The angle must be expressed in radians.
A rotation is a transform that preserves length and angles of all geometric entities. Rotations also preserve one point (the origin) and the distance of all entities from that point.
The function make-rotation-transform* is identical to make-rotation-transform, except that it passes composite objects, rather than separate coordinates, in its arguments. You should be aware that using this function may lead to a loss of performance.
See also
make-reflection-transform, page 37