1 ;;; Gacela, a GNU Guile extension for fast games development
2 ;;; Copyright (C) 2009 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 ;;; Default values for Gacela
19 (define *width-screen* 640)
20 (define *height-screen* 480)
21 (define *bpp-screen* 32)
22 (define *frames-per-second* 20)
25 ;;; SDL Initialization Subsystem
29 (let ((initialized #f))
32 (cond ((not initialized) (SDL_Init SDL_INIT_EVERYTHING) (set! initialized #t))
38 (set! initialized #f))))
42 (define init-video-mode #f)
43 (define resize-screen #f)
44 (define apply-mode-change #f)
45 (define quit-video-mode #f)
47 (let ((screen #f) (flags 0) (current-width *width-screen*) (current-height *height-screen*) (current-bpp *bpp-screen*))
49 (lambda* (#:optional (width current-width) (height current-height) (bpp current-bpp))
52 (SDL_GL_SetAttribute SDL_GL_DOUBLEBUFFER 1)
53 (set! flags (+ SDL_OPENGL SDL_GL_DOUBLEBUFFER SDL_HWPALETTE SDL_RESIZABLE
54 (if (= (assoc-ref (SDL_GetVideoInfo) 'hw_available) 0) SDL_SWSURFACE SDL_HWSURFACE)
55 (if (= (assoc-ref (SDL_GetVideoInfo) 'blit_hw) 0) 0 SDL_HWACCEL)))
56 (set! screen (SDL_SetVideoMode width height bpp flags))
58 (resize-screen-GL width height)
59 (set! current-width width)
60 (set! current-height height)
61 (set! current-bpp bpp))
65 (lambda* (width height #:optional (bpp current-bpp))
66 (cond (screen (set! screen (SDL_SetVideoMode width height bpp flags))
67 (resize-screen-GL width height)))
68 (set! current-width width)
69 (set! current-height height)))
71 (set! apply-mode-change
72 (lambda () (resize-screen-GL current-width current-height)))
75 (lambda () (set! screen #f))))
78 (cond ((not (3d-mode?))
80 (glDisable GL_DEPTH_TEST)
81 (apply-mode-change))))
87 (glEnable GL_DEPTH_TEST)
88 (glDepthFunc GL_LEQUAL)
89 (apply-mode-change))))
92 (eq? (assoc-ref (get-game-properties) 'mode) '3d))
95 (glShadeModel GL_SMOOTH)
96 (glClearColor 0 0 0 0)
98 ; (glDepthFunc GL_LEQUAL)
100 ; (glBlendFunc GL_SRC_ALPHA GL_ONE)
101 (glHint GL_PERSPECTIVE_CORRECTION_HINT GL_NICEST)
104 (define (init-lighting)
106 (glEnable GL_LIGHTING))
108 (define (resize-screen-GL width height)
109 (glViewport 0 0 width height)
110 (glMatrixMode GL_PROJECTION)
112 (cond ((3d-mode?) (let ((ratio (if (= height 0) width (/ width height))))
113 (gluPerspective 45 ratio 0.1 100))) ;0.1
114 (else (let* ((w (/ width 2)) (h (/ height 2)))
115 (glOrtho (- w) w (- h) h 0 1))))
116 (glMatrixMode GL_MODELVIEW)
120 (define get-current-color #f)
121 (define set-current-color #f)
123 (let ((current-color '(1 1 1 1)))
124 (set! get-current-color
128 (set! set-current-color
129 (lambda* (red green blue #:optional (alpha 1))
130 (set! current-color (list red green blue alpha))
131 (glColor4f red green blue alpha))))
133 (define* (load-image image-file #:key transparent-color)
135 (let ((loaded-image (IMG_Load image-file)))
136 (cond ((= loaded-image 0) #f)
137 (else (let ((optimized-image (SDL_DisplayFormat loaded-image)))
138 (SDL_FreeSurface loaded-image)
139 (cond ((= optimized-image 0) #f)
140 ((not transparent-color) optimized-image)
141 (else (SDL_SetColorKey optimized-image
143 (SDL_MapRGB (surface-format optimized-image)
144 (car transparent-color)
145 (cadr transparent-color)
146 (caddr transparent-color)))
147 optimized-image)))))))
151 (define init-audio #f)
152 (define quit-audio #f)
157 (cond ((not audio) (begin (init-sdl) (set! audio (Mix_OpenAudio 22050 MIX_DEFAULT_FORMAT 2 4096))))
167 (define set-frames-per-second #f)
168 (define init-frame-time #f)
169 (define delay-frame #f)
171 (let ((time 0) (time-per-frame (/ 1000.0 *frames-per-second*)))
172 (set! set-frames-per-second
174 (set! time-per-frame (/ 1000.0 fps))))
176 (set! init-frame-time
178 (set! time (SDL_GetTicks))))
182 (let ((frame-time (- (SDL_GetTicks) time)))
183 (cond ((< frame-time time-per-frame)
184 (SDL_Delay (- time-per-frame frame-time))))))))
187 (define set-game-properties #f)
188 (define get-game-properties #f)
190 (let ((ptitle "") (pwidth *width-screen*) (pheight *height-screen*) (pbpp *bpp-screen*) (pfps *frames-per-second*) (pmode '2d))
191 (set! set-game-properties
192 (lambda* (#:key title width height bpp fps mode)
194 (if title (begin (set! ptitle title) (SDL_WM_SetCaption title "")))
195 (if (or width height bpp)
197 (if width (set! pwidth width))
198 (if height (set! pheight height))
199 (if bpp (set! pbpp bpp))
200 (resize-screen pwidth pheight pbpp)))
201 (if fps (begin (set! pfps fps) (set-frames-per-second fps)))
202 (if mode (begin (set! pmode mode) (if (eq? mode '3d) (set-3d-mode) (set-2d-mode))))
203 (get-game-properties)))
205 (set! get-game-properties
207 `((title . ,ptitle) (width . ,pwidth) (height . ,pheight) (bpp . ,pbpp) (fps . ,pfps) (mode . ,pmode)))))
210 (define-macro (run-game . code)
211 `(let ((game-function ,(if (null? code)
213 `(lambda () ,@code))))
215 (set-game-code game-function)
216 (cond ((not (game-running?))
219 (define game-loop #f)
220 (define game-running? #f)
221 (define set-game-code #f)
223 (let ((running #f) (game-code #f))
230 ; (check-connections)
231 ; (eval-from-clients)
234 (glClear (+ GL_COLOR_BUFFER_BIT GL_DEPTH_BUFFER_BIT))
236 ; (refresh-active-objects)
237 (if (procedure? game-code) (game-code))
248 (lambda (game-function)
249 (set! game-code game-function))))