--- /dev/null
+#!/usr/bin/env guile
+!#
+
+;;; Gacela, a GNU Guile extension for fast games development
+;;; Copyright (C) 2017 by Javier Sancho Fernandez <jsf at jsancho dot org>
+;;;
+;;; This program is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation, either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+(use-modules (gacela))
+
+(define (tick) (* 3000000 (get-internal-real-time)))
+(define (waggle) (* 200 (cos (* pi (tick)))))
+(define (wiggle) (* 300 (sin (* pi (tick)))))
+(define (swaggle) (cos (* pi (tick))))
+(define (swiggle) (sin (* pi (tick))))
+
+(define homer (image "homer.png"))
+(define marge (image "marge.png"))
+
+(define (hv-dance image1 image2)
+ (over (move image1 wiggle 0)
+ (move image2 0 waggle)))
+
+(define homer-marge-dance
+ (hv-dance homer marge))
+
+(display-scene
+ (window ((resolution '(640 480)))
+ homer-marge-dance))
+
+(display-scene
+ (window ((resolution '(640 480)))
+ (let ((small (scale homer-marge-dance 0.5)))
+ (hv-dance small small))))
+
+(display-scene
+ (window ((resolution '(640 480)))
+ (scale homer-marge-dance (lambda () (abs (swiggle))))))
+
+(display-scene
+ (window ((resolution '(640 480)))
+ (hv-dance (scale homer swiggle)
+ (scale marge swaggle))))
+
+(display-scene
+ (window ((resolution '(640 480)))
+ (over (scale homer swiggle)
+ (move marge wiggle waggle))))
(define %gl-context #f)
(define (init-window)
- (sdl2:sdl-init)
- (sdl2:set-gl-attribute! 'context-major-version 3)
- (sdl2:set-gl-attribute! 'context-minor-version 2)
- (sdl2:set-gl-attribute! 'double-buffer 1)
- (sdl2:set-gl-attribute! 'depth-size 24)
- (set! %sdl-window (sdl2:make-window #:opengl? #t #:show? #t))
- (set! %sdl-renderer (sdl2:make-renderer %sdl-window))
- (set! %gl-context (sdl2:make-gl-context %sdl-window))
- (sdl2:set-gl-swap-interval! 'vsync)
+ (when (not %sdl-window)
+ (sdl2:sdl-init)
+ (sdl2:set-gl-attribute! 'context-major-version 3)
+ (sdl2:set-gl-attribute! 'context-minor-version 2)
+ (sdl2:set-gl-attribute! 'double-buffer 1)
+ (sdl2:set-gl-attribute! 'depth-size 24)
+ (set! %sdl-window (sdl2:make-window #:opengl? #t #:show? #t))
+ (set! %sdl-renderer (sdl2:make-renderer %sdl-window))
+ (set! %gl-context (sdl2:make-gl-context %sdl-window))
+ (sdl2:set-gl-swap-interval! 'vsync))
(init-gl))
(define (init-gl)
(sdl2:show-window! %sdl-window))
(define (close-window)
- (sdl2:hide-window! %sdl-window)
- (sdl2:sdl-quit))
+ (sdl2:hide-window! %sdl-window))
(define (resize-window width height)
(gl-viewport 0 0 width height)
#:use-module (gl)
#:export (image
move
- scale))
+ scale
+ over))
(define (calculate proc-or-value)
(if (procedure? proc-or-value)
(set! h/2 (/ (sdl2:surface-height image) 2)))
(gl-enable (oes-framebuffer-object texture-2d))
(sdl2:bind-texture texture)
+ (gl-enable (oes-framebuffer-object blend))
+ (set-gl-blend-function (blending-factor-src src-alpha)
+ (blending-factor-dest one-minus-src-alpha))
(gl-begin (begin-mode quads)
(gl-texture-coordinates 0 0)
(gl-vertex (- w/2) h/2 0)
(gl-vertex w/2 (- h/2) 0)
(gl-texture-coordinates 0 1)
(gl-vertex (- w/2) (- h/2) 0))
+ (gl-disable (oes-framebuffer-object blend))
(gl-disable (oes-framebuffer-object texture-2d))))))
(define* (move scene x y #:optional (z 0))
(make-scene
"scale"
(lambda ()
- (gl-scale x y z)
+ (gl-scale (calculate x)
+ (calculate y)
+ (calculate z))
(display-scene scene))))
+
+(define (over . scenes)
+ (make-scene
+ "over"
+ (lambda ()
+ (let display ((sc scenes))
+ (cond ((not (null? sc))
+ (with-gl-push-matrix
+ (display-scene (car sc)))
+ (display (cdr sc))))))))