+++ /dev/null
-;;; Gacela, a GNU Guile extension for fast games development
-;;; Copyright (C) 2009 by Javier Sancho Fernandez <jsf at jsancho dot org>
-;;;
-;;; This program is free software: you can redistribute it and/or modify
-;;; it under the terms of the GNU General Public License as published by
-;;; the Free Software Foundation, either version 3 of the License, or
-;;; (at your option) any later version.
-;;;
-;;; This program is distributed in the hope that it will be useful,
-;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;;; GNU General Public License for more details.
-;;;
-;;; You should have received a copy of the GNU General Public License
-;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
-
-
-(define-module (gacela math)
- #:export (*pi*
- degrees-to-radians
- radians-to-degrees
- distance-between-points
- nearest-power-of-two))
-
-
-;;; Constants
-
-(define *pi* (* (asin 1) 2))
-
-
-;;; Geometry
-
-(define (degrees-to-radians angle)
- (/ (* angle *pi*) 180))
-
-(define (radians-to-degrees angle)
- (/ (* angle 180) *pi*))
-
-(define (distance-between-points p1 p2)
- (define (add-power-of-two p1 p2)
- (cond ((null? p1)
- 0)
- (else
- (+ (expt (- (car p1) (car p2)) 2)
- (add-power-of-two (cdr p1) (cdr p2))))))
-
- (cond ((not (= (length p1) (length p2)))
- #f)
- (else
- (sqrt (add-power-of-two p1 p2)))))
-
-
-;;; Functions
-
-(define (nearest-power-of-two n)
- (define (power p n)
- (cond ((> (* p 2) n) p)
- (else (power (* p 2) n))))
- (power 1 n))