| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments: position matrix
Transforms the given position with the supplied matrix, which is a 2 by 2 array (or larger 2-dimensional array -- extra cells of the array are ignored). Even if the elements of matrix are floats, the returned position will have rounded whole number components. The transform works as follows:
xnew = A(0,0)*xold + A(0,1)*yold ynew = A(1,0)*xold + A(1,1)*yold
For example:
(setq ar (make-array '(2 2) :initial-contents '((5.0 2.0) (3.0 1.0)))) (setq p1 (make-position 7 10)) (position-transform p1 ar) returns #.(make-position 55 31) ; = 5*7 + 2*10, 3*7 + 1*10
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |