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 3) (glBegin GL_TRIANGLES))
43 ((= number-of-points 4) (glBegin GL_QUADS))))
45 (define (draw-vertexes vertexes)
46 (cond ((not (null? vertexes))
47 (draw-vertex (car vertexes))
48 (draw-vertexes (cdr vertexes)))))
50 (define* (draw-vertex vertex #:key texture-coord)
51 (cond ((list? (car vertex))
52 (with-color (car vertex)
53 (apply simple-draw-vertex (cadr vertex))))
55 (cond (texture-coord (apply glTexCoord2f texture-coord)))
56 (apply simple-draw-vertex vertex))))
58 (define* (simple-draw-vertex x y #:optional (z 0))
59 (cond ((3d-mode?) (glVertex3f x y z))
60 (else (glVertex2f x y))))
62 (define (load-image-for-texture filename)
64 (let ((image (IMG_Load filename)))
66 (SDL_SetAlpha image 0 0)
67 (let* ((width (surface-w image)) (height (surface-h image))
68 (power-2 (nearest-power-of-two (min width height)))
70 (cond ((and (= width power-2) (= height power-2)) (values image width height))
71 (else (set! resized-image (resize-surface image power-2 power-2))
72 (if resized-image (values resized-image width height))))))
76 (define (resize-surface surface width height)
77 (let ((old-width (surface-w surface)) (old-height (surface-h surface)))
78 (cond ((and (= width old-width) (= height old-height)) surface)
79 (else (let ((zoomx (/ (+ width 0.5) old-width)) (zoomy (/ (+ height 0.5) old-height)))
80 (zoomSurface surface zoomx zoomy 0))))))
82 (define* (load-texture filename #:key (min-filter GL_LINEAR) (mag-filter GL_LINEAR))
85 (image real-w real-h) (load-image-for-texture filename)
87 (let ((width (surface-w image)) (height (surface-h image))
88 (byteorder (if (= SDL_BYTEORDER SDL_LIL_ENDIAN)
89 (if (= (surface-format-BytesPerPixel image) 3) GL_RGB GL_RGBA)
90 (if (= (surface-format-BytesPerPixel image) 3) GL_BGR GL_BGRA)))
91 (texture (car (glGenTextures 1))))
93 (glBindTexture GL_TEXTURE_2D texture)
94 (glTexImage2D GL_TEXTURE_2D 0 3 width height 0 byteorder GL_UNSIGNED_BYTE (surface-pixels image))
95 (glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MIN_FILTER min-filter)
96 (glTexParameteri GL_TEXTURE_2D GL_TEXTURE_MAG_FILTER mag-filter)
97 (set-texture-size! texture real-w real-h)
100 (define* (draw-image filename #:optional (zoom 1))
101 (let ((texture (load-texture filename)))
102 (cond (texture (draw-texture texture zoom)))))
104 (define* (draw-texture texture #:optional (zoom 1))
106 (let ((width (texture-w texture))
107 (height (texture-h texture)))
108 (draw-rectangle (* zoom width) (* zoom height) #:texture texture)))))
110 (define* (draw-quad v1 v2 v3 v4 #:key texture color)
113 (glBindTexture GL_TEXTURE_2D texture)
115 (draw-vertex v1 #:texture-coord '(0 0))
116 (draw-vertex v2 #:texture-coord '(1 0))
117 (draw-vertex v3 #:texture-coord '(1 1))
118 (draw-vertex v4 #:texture-coord '(0 1))
121 (with-color color (draw v1 v2 v3 v4)))
123 (draw v1 v2 v3 v4))))
125 (define* (draw-rectangle width height #:key texture color)
126 (let ((w (/ width 2)) (h (/ height 2)))
127 (draw-quad (list (- w) h 0)
134 (define* (draw-square #:key (size 1) texture color)
135 (draw-rectangle size size #:texture texture #:color color))
137 (define* (draw-cube #:key (size 1)
138 texture texture-1 texture-2 texture-3 texture-4 texture-5 texture-6
139 color color-1 color-2 color-3 color-4 color-5 color-6)
140 (let ((-size (- size)))
143 (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))
145 (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))
147 (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))
149 (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))
151 (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))
153 (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)))))
155 (define* (add-light #:key light position ambient (id GL_LIGHT1) (turn-on t))
157 (and light (glLightfv id GL_DIFFUSE (first light) (second light) (third light) (fourth light)))
158 (and light position (glLightfv GL_POSITION (first position) (second position) (third position) (fourth position)))
159 (and ambient (glLightfv id GL_AMBIENT (first ambient) (second ambient) (third ambient) (fourth ambient)))
160 (and turn-on (glEnable id))
163 (define* (translate x y #:optional (z 0))
164 (glTranslatef x y z))
166 (define* (rotate #:rest rot)
167 (cond ((3d-mode?) (apply 3d-rotate rot))
168 (else (apply 2d-rotate rot))))
170 (define (3d-rotate xrot yrot zrot)
171 (glRotatef xrot 1 0 0)
172 (glRotatef yrot 0 1 0)
173 (glRotatef zrot 0 0 1))
175 (define (2d-rotate rot)
176 (glRotatef rot 0 0 1))
180 (cond ((3d-mode?) (camera-look))))
182 (define set-camera #f)
183 (define camera-look #f)
185 (let ((camera-eye '(0 0 0)) (camera-center '(0 0 -100)) (camera-up '(0 1 0)))
187 (lambda* (#:key eye center up)
188 (cond (eye (set! camera-eye eye)))
189 (cond (center (set! camera-center center)))
190 (cond (up (set! camera-up up)))))
194 (apply gluLookAt (append camera-eye camera-center camera-up)))))