1 ;;; Gacela, a GNU Guile extension for fast games development
2 ;;; Copyright (C) 2013 by Javier Sancho Fernandez <jsf at jsancho dot org>
4 ;;; This program is free software: you can redistribute it and/or modify
5 ;;; it under the terms of the GNU General Public License as published by
6 ;;; the Free Software Foundation, either version 3 of the License, or
7 ;;; (at your option) any later version.
9 ;;; This program is distributed in the hope that it will be useful,
10 ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
11 ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 ;;; GNU General Public License for more details.
14 ;;; You should have received a copy of the GNU General Public License
15 ;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
18 (define-module (gacela engine)
19 #:use-module (gacela system)
20 #:use-module (ice-9 receive)
21 #:use-module (ice-9 threads)
22 #:use-module (srfi srfi-9)
23 #:use-module (srfi srfi-9 gnu))
26 ;;; Engine definitions
28 (define-record-type engine
29 (make-engine-record entities mutex system)
31 (entities engine-entities set-engine-entities!)
32 (mutex engine-mutex set-engine-mutex!)
33 (system engine-system set-engine-system!))
35 (set-record-type-printer! engine
37 (format port "#<[engine] entities: ~a>"
38 (length (car (engine-entities record))))))
40 (define (make-engine . systems)
44 (if (not (= (length systems) 1))
45 (join-systems systems)
48 (define-syntax define-engine
52 (make-engine system ...)))))
58 ;;; Engine Access Protocol Interface
60 (define (with-engine engine . changes)
61 (with-mutex (engine-mutex engine)
62 (let ((entities (engine-entities engine)))
63 (receive (e c) (modify-entities changes (car entities) (cadr entities))
64 (set-engine-entities! engine (list e c))))))