pattern:get-transform

pattern:get-transform

List of:	Scheme Extensions
Subjects:	Patterns
Contents:	Kernel

Action:

Returns the requested pattern transform.

Filename:

kern/kern_scm/pattern_scm.cxx

Syntax:

(pattern:get-transform pat [index1 [index2]])

Arg Types:

pat

pattern

index1

integer

index2

integer

Returns:

transform

Description:

This extension returns a transform associated with the pattern specified by pat. By default, the root transformation is returned.

pat specifies a pattern.

If index1 is given, the relative transformation for the pattern element indexed by its value is returned;

If both index1 and index2 are given, the transformation that generates the element indexed by index2 from the element indexed by index1 is returned.

Example:

; pattern:get-transform

; make a pattern

(define axis_start (position 0 -25 0))

;; axis_start

(define axis_end (position 0 25 0))

;; axis_end

(define start-dir (gvector 1 0 0))

;; start-dir

(define radius 5)

;; radius

(define thread_distance 10)

;; thread_distance

(define edge (edge:helix axis_start axis_end

start-dir radius thread_distance))

;; edge

(define num 50)

;; num

(define root (position 1 2 3))

;; root

(define on-endpoints #f)

;; on-endpoints

(define rail-dir (gvector 1 0 0))

;; rail-dir

(define tangent-dir (gvector 0 1 0))

;; tangent-dir

(define pat (pattern:edge edge num

root on-endpoints rail-dir tangent-dir))

;; pat

(entity:delete edge)

;; ()

; get the root transform

(define t_root (pattern:get-transform pat))

;; t_root

;get the first transform

(define t_0 (pattern:get-transform pat 0))

;; t_0

; print the two transforms

(transform:print t_root)

; rotation no reflection no shear not identity

; translation part:

; 4.111957 -27.965300 -0.288970

; affine part:

; 0.951057 0.000000 -0.309017

; -0.294459 0.303314 -0.906253

; 0.093729 0.952891 0.288469

; scaling part:

; 1.000000

;; #[transform 118280584]

(transform:print t_0)