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 system)
19 #:use-module (ice-9 receive)
20 #:use-module (srfi srfi-1)
21 #:use-module (srfi srfi-9))
24 ;;; Component definitions
26 (define (symbol-concatenate . args)
29 (map (lambda (a) (if (symbol? a) (symbol->string a) a)) args))))
31 (define-macro (define-component name . args)
33 (use-modules (srfi srfi-9) (srfi srfi-9 gnu))
34 (define-record-type ,name
35 (,(symbol-concatenate "make-" name) ,@args)
36 ,(symbol-concatenate name "?")
37 ,@(map (lambda (a) (list a (symbol-concatenate name "-" a) (symbol-concatenate "set-" name "-" a "!"))) args))
38 (set-record-type-printer! ,name
40 (format port "#<[~a]" ',name)
41 ,@(map (lambda (a) `(format port " ~a: ~a" ',a (,(symbol-concatenate name "-" a) record))) args)
45 (define (export-component component)
46 (let ((name (record-type-name component))
48 (module-export! m (list
49 (symbol-concatenate "make-" name)
50 (symbol-concatenate name "?")))
53 (module-export! (current-module)
55 (symbol-concatenate name "-" a)
56 (symbol-concatenate "set-" name "-" a "!"))))
57 (record-type-fields component))))
59 (define (get-component-type component)
60 (record-type-name (record-type-descriptor component)))
62 (export define-component
67 ;;; Entities and components
69 (define (normalize-components components)
73 `(,(get-component-type c) . ,c)
77 (define (register-components entity components clist)
78 (cond ((null? components) clist)
80 (let* ((type (car components))
81 (elist (assoc-ref clist type)))
82 (register-components entity (cdr components)
83 (assoc-set! clist type
85 (lset-adjoin eq? elist entity))
89 (define (unregister-components entity components clist)
90 (cond ((null? components) clist)
92 (let* ((type (car components))
93 (elist (lset-difference eq? (assoc-ref clist type) (list entity))))
94 (unregister-components entity (cdr components)
96 (assoc-remove! clist type))
98 (assoc-set! clist type elist))))))))
100 (define (new-entity . new-components)
101 (lambda (entities components)
103 (nc (normalize-components new-components)))
105 (acons key nc entities)
106 (register-components key
107 (map (lambda (c) (car c)) nc)
111 (define (remove-entity key)
112 (lambda (entities components)
113 (let ((clist (map (lambda (c) (car c)) (assoc-ref entities key))))
115 (assoc-remove! entities key)
116 (unregister-components key clist components)))))
118 (define (set-entity key . new-components)
119 (lambda (entities components)
120 (let* ((nc (normalize-components new-components))
121 (clist (map (lambda (c) (car c)) (assoc-ref entities key)))
122 (nclist (map (lambda (c) (car c)) nc)))
124 (assoc-set! entities key nc)
125 (register-components key (lset-difference eq? nclist clist)
126 (unregister-components key (lset-difference eq? clist nclist) components))))))
128 (define (set-entity-components key . new-components)
129 (lambda (entities components)
130 (let ((nc (normalize-components new-components))
131 (clist (alist-copy (assoc-ref entities key))))
134 (assoc-set! clist (car c) (cdr c)))
137 (assoc-set! entities key clist)
138 (register-components key (map (lambda (c) (car c)) nc) components)))))
140 (define (remove-entity-components key . old-components)
141 (lambda (entities components)
142 (let ((clist (alist-copy (assoc-ref entities key))))
145 (assoc-remove! clist c))
148 (assoc-set! entities key clist)
149 (unregister-components key old-components components)))))
151 (define (modify-entities changes entities components)
152 (cond ((null? changes)
153 (values entities components))
155 (receive (e c) ((car changes) entities components)
156 (modify-entities (cdr changes) e c)))))
161 set-entity-components
162 remove-entity-components
168 (define* (find-entities-by-components c t)
169 (cond ((null? t) '())
171 (let* ((e (assoc-ref c (car t)))
173 (cond ((null? (cdr t)) e*)
175 (lset-intersection eq? e* (find-entities-by-components c (cdr t)))))))))
178 (define (make-system component-types system-fun)
179 (lambda (entities components)
180 (let* ((e (find-entities-by-components components component-types))
181 (e* (map (lambda (x) (assoc x entities)) e))
182 (e** (map (lambda (x) (cons (car x) (filter (lambda (x) (memq (car x) component-types)) (cdr x)))) e*))
183 (res (system-fun e**)))
184 (lambda* (#:optional (entities2 #f) (components2 #f))
185 (let ((e (if (and entities2 components2) entities2 entities))
186 (c (if (and entities2 components2) components2 components)))
187 (modify-entities res e c))))))
190 (define (join-systems . systems)
191 (lambda (entities components)
192 (let run ((s systems) (e entities) (c components))
196 (receive (e2 c2) (((car s) e c))
197 (run (cdr s) e2 c2)))))))
200 (define (threaded-systems . systems)
201 (lambda (entities components)
205 (call-with-new-thread
206 (lambda () (s entities components))))
208 (e entities) (c components))
212 (receive (e2 c2) ((join-thread (car thd)) e c)
213 (run-wait (cdr thd) e2 c2)))))))
216 (export find-entities-by-components