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;; load the SDL module and some useful srfi's
(use-modules (srfi srfi-1)
(srfi srfi-9)
(2d game-loop)
(2d helpers)
(2d sprite)
(2d texture)
(2d vector)
(2d window))
(set! *random-state* (random-state-from-platform))
(init-2d)
;;;
;;; Particles
;;;
(define-record-type <particle>
(make-particle sprite position velocity)
particle?
(sprite particle-sprite)
(position particle-position set-particle-position!)
(velocity particle-velocity set-particle-velocity!))
(define (update-particle! particle)
(set-particle-position! particle
(v+ (particle-position particle)
(particle-velocity particle))))
;;;
;;; Demo
;;;
(define window-width 800)
(define window-height 600)
(open-window window-width window-height)
(define stars (load-sprite "images/stars.png" #:anchor #(0 0)))
(define particle-image (load-texture "images/bullet.png"))
(define particle-width (texture-width particle-image))
(define particle-height (texture-height particle-image))
(define particle-count 500)
(define particles
(list-tabulate particle-count
(lambda (n)
(make-particle (make-sprite particle-image)
(vector (random window-width)
(random window-height))
(vector (* (random:normal) 1)
(* (random:normal) 1))))))
(define batch (make-sprite-batch (* particle-count 4)))
(define (draw-particles particles)
(with-sprite-batch batch
(for-each
(lambda (p)
(let* ((sprite (particle-sprite p)))
(set-sprite-position! sprite (particle-position p))
(draw-sprite sprite)))
particles)))
(add-hook! on-render-hook (lambda () (render)))
(add-hook! on-update-hook (lambda () (update)))
(add-hook! on-key-down-hook (lambda (key mod unicode) (key-down key mod unicode)))
(define (key-down key mod unicode)
(cond ((any-equal? key 'escape 'q)
(close-window)
(quit))))
(define (render)
(draw-sprite stars)
(draw-particles particles))
(define (update)
(for-each update-particle! particles))
(run-game-loop)
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