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 (define-macro (with-color color . code)
20 `(let ((original-color (get-current-color))
22 (apply set-current-color ,color)
23 (set! result (begin ,@code))
24 (apply set-current-color original-color)
26 (else `(begin ,@code))))
28 (define-macro (progn-textures . code)
31 (glEnable GL_TEXTURE_2D)
32 (set! result (begin ,@code))
33 (glDisable GL_TEXTURE_2D)
36 (define (draw . vertexes)
37 (begin-draw (length vertexes))
38 (draw-vertexes vertexes)
41 (define (begin-draw number-of-points)
42 (cond ((= number-of-points 2) (glBegin GL_LINES))
43 ((= number-of-points 3) (glBegin GL_TRIANGLES))
44 ((= number-of-points 4) (glBegin GL_QUADS))))
46 (define (draw-vertexes vertexes)
47 (cond ((not (null? vertexes))
48 (draw-vertex (car vertexes))
49 (draw-vertexes (cdr vertexes)))))
51 (define* (draw-vertex vertex #:key texture-coord)
52 (cond ((list? (car vertex))
53 (with-color (car vertex)
54 (apply simple-draw-vertex (cadr vertex))))
56 (cond (texture-coord (apply glTexCoord2f texture-coord)))
57 (apply simple-draw-vertex vertex))))
59 (define* (simple-draw-vertex x y #:optional (z 0))
60 (cond ((3d-mode?) (glVertex3f x y z))
61 (else (glVertex2f x y))))
63 (define (load-image filename)
65 (let ((image (IMG_Load filename)))
67 (SDL_DisplayFormatAlpha image)))))
69 (define (load-image-for-texture filename)
71 (let ((image (load-image filename)))
73 (let* ((width (surface-w image)) (height (surface-h image))
74 (power-2 (nearest-power-of-two (min width height)))
76 (cond ((and (= width power-2) (= height power-2)) (values image width height))
77 (else (set! resized-image (resize-surface image power-2 power-2))
78 (if resized-image (values resized-image width height))))))
82 (define (resize-surface surface width height)
83 (let ((old-width (surface-w surface)) (old-height (surface-h surface)))
84 (cond ((and (= width old-width) (= height old-height)) surface)
85 (else (let ((zoomx (/ (+ width 0.5) old-width)) (zoomy (/ (+ height 0.5) old-height)))
86 (zoomSurface surface zoomx zoomy 0))))))
88 (define* (load-texture filename #:key (min-filter GL_LINEAR) (mag-filter GL_LINEAR))
89 (let* ((key (list filename min-filter mag-filter))
90 (res (get-resource-from-cache key)))
95 (image real-w real-h) (load-image-for-texture filename)
97 (let ((width (surface-w image)) (height (surface-h image))
98 (byteorder (if (= SDL_BYTEORDER SDL_LIL_ENDIAN)
99 (if (= (surface-format-BytesPerPixel image) 3) GL_BGR GL_BGRA)
100 (if (= (surface-format-BytesPerPixel image) 3) GL_RGB GL_RGBA)))
101 (texture (car (glGenTextures 1))))
103 (glBindTexture GL_TEXTURE_2D texture)
104 (glTexImage2D GL_TEXTURE_2D 0 4 width height 0 byteorder GL_UNSIGNED_BYTE (surface-pixels image))
105 (glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MIN_FILTER min-filter)
106 (glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MAG_FILTER mag-filter)
107 (set-texture-size! texture real-w real-h)
108 (insert-resource-into-cache key texture)
111 (define* (draw-image filename #:optional (zoom 1))
112 (let ((texture (load-texture filename)))
113 (cond (texture (draw-texture texture zoom)))))
115 (define* (draw-texture texture #:optional (zoom 1))
117 (let ((width (texture-w texture))
118 (height (texture-h texture)))
119 (draw-rectangle (* zoom width) (* zoom height) #:texture texture)))))
121 (define* (draw-line length #:optional color)
122 (let ((l (/ length 2)))
124 (with-color color (draw (list 0 l) (list 0 (- l)))))
126 (draw (list 0 l) (list 0 (- l)))))))
128 (define* (draw-quad v1 v2 v3 v4 #:key texture color)
131 (glBindTexture GL_TEXTURE_2D texture)
133 (draw-vertex v1 #:texture-coord '(0 0))
134 (draw-vertex v2 #:texture-coord '(1 0))
135 (draw-vertex v3 #:texture-coord '(1 1))
136 (draw-vertex v4 #:texture-coord '(0 1))
139 (with-color color (draw v1 v2 v3 v4)))
141 (draw v1 v2 v3 v4))))
143 (define* (draw-rectangle width height #:key texture color)
144 (let ((w (/ width 2)) (h (/ height 2)))
145 (draw-quad (list (- w) h 0)
152 (define* (draw-square #:key (size 1) texture color)
153 (draw-rectangle size size #:texture texture #:color color))
155 (define* (draw-cube #:key (size 1)
156 texture texture-1 texture-2 texture-3 texture-4 texture-5 texture-6
157 color color-1 color-2 color-3 color-4 color-5 color-6)
158 (let ((-size (- size)))
161 (draw-quad (list -size size size) (list size size size) (list size -size size) (list -size -size size) #:texture (or texture-1 texture) #:color (or color-1 color))
163 (draw-quad (list -size -size -size) (list size -size -size) (list size size -size) (list -size size -size) #:texture (or texture-2 texture) #:color (or color-2 color))
165 (draw-quad (list size size size) (list -size size size) (list -size size -size) (list size size -size) #:texture (or texture-3 texture) #:color (or color-3 color))
167 (draw-quad (list -size -size size) (list size -size size) (list size -size -size) (list -size -size -size) :texture (or texture-4 texture) #:color (or color-4 color))
169 (draw-quad (list size -size -size) (list size -size size) (list size size size) (list size size -size) :texture (or texture-5 texture) #:color (or color-5 color))
171 (draw-quad (list -size -size size) (list -size -size -size) (list -size size -size) (list -size size size) :texture (or texture-6 texture) #:color (or color-6 color)))))
173 (define* (add-light #:key light position ambient (id GL_LIGHT1) (turn-on t))
175 (and light (glLightfv id GL_DIFFUSE (first light) (second light) (third light) (fourth light)))
176 (and light position (glLightfv GL_POSITION (first position) (second position) (third position) (fourth position)))
177 (and ambient (glLightfv id GL_AMBIENT (first ambient) (second ambient) (third ambient) (fourth ambient)))
178 (and turn-on (glEnable id))
181 (define* (translate x y #:optional (z 0))
182 (glTranslatef x y z))
184 (define* (rotate #:rest rot)
185 (cond ((3d-mode?) (apply 3d-rotate rot))
186 (else (apply 2d-rotate rot))))
188 (define (3d-rotate xrot yrot zrot)
189 (glRotatef xrot 1 0 0)
190 (glRotatef yrot 0 1 0)
191 (glRotatef zrot 0 0 1))
193 (define (2d-rotate rot)
194 (glRotatef rot 0 0 1))
198 (cond ((3d-mode?) (camera-look))))
200 (define set-camera #f)
201 (define camera-look #f)
203 (let ((camera-eye '(0 0 0)) (camera-center '(0 0 -100)) (camera-up '(0 1 0)))
205 (lambda* (#:key eye center up)
206 (cond (eye (set! camera-eye eye)))
207 (cond (center (set! camera-center center)))
208 (cond (up (set! camera-up up)))))
212 (apply gluLookAt (append camera-eye camera-center camera-up)))))