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(import scheme
(chicken base)
(only (list-utils alist) plist->alist)
(prefix sdl2 "sdl2:")
(prefix sdl2-ttf "ttf:")
downstroke-engine
downstroke-world
downstroke-entity
downstroke-input
downstroke-renderer
downstroke-assets)
;; Logical resolution: 320×240, displayed at 640×480 via scale: 2
(define +width+ 320)
(define +height+ 240)
(define +box-size+ 16)
(define +speed+ 2)
(define *game*
(make-game
title: "Demo: Scaling (2×)"
width: +width+ height: +height+
scale: 2
create: (lambda (game)
(game-scene-set! game
(make-scene
entities: (list (plist->alist (list #:type 'box
#:x (/ +width+ 2)
#:y (/ +height+ 2)
#:width +box-size+
#:height +box-size+
#:vx 0 #:vy 0
#:color '(255 200 0))))
tilemap: #f
camera: (make-camera x: 0 y: 0)
tileset-texture: #f
camera-target: #f
background: '(30 30 50)
engine-update: 'none)))
update: (lambda (game dt)
(let* ((input (game-input game))
(scene (game-scene game))
(box (car (scene-entities scene)))
(vx (cond ((input-held? input 'left) (- +speed+))
((input-held? input 'right) +speed+)
(else 0)))
(vy (cond ((input-held? input 'up) (- +speed+))
((input-held? input 'down) +speed+)
(else 0)))
(nx (max 0 (min (- +width+ +box-size+)
(+ (entity-ref box #:x 0) vx))))
(ny (max 0 (min (- +height+ +box-size+)
(+ (entity-ref box #:y 0) vy))))
(box (entity-set (entity-set box #:x nx) #:y ny)))
(game-scene-set! game
(update-scene scene entities: (list box)))))
render: (lambda (game)
(let* ((renderer (game-renderer game))
(scene (game-scene game))
(box (car (scene-entities scene)))
(bx (inexact->exact (floor (entity-ref box #:x 0))))
(by (inexact->exact (floor (entity-ref box #:y 0)))))
;; Draw the colored box
(set! (sdl2:render-draw-color renderer) (sdl2:make-color 255 200 0))
(sdl2:render-fill-rect! renderer
(sdl2:make-rect bx by +box-size+ +box-size+))
;; Draw a border around the logical viewport
(set! (sdl2:render-draw-color renderer) (sdl2:make-color 100 100 100))
(sdl2:render-draw-rect! renderer
(sdl2:make-rect 0 0 +width+ +height+))
;; Draw crosshair at center
(set! (sdl2:render-draw-color renderer) (sdl2:make-color 60 60 80))
(sdl2:render-draw-line! renderer (/ +width+ 2) 0 (/ +width+ 2) +height+)
(sdl2:render-draw-line! renderer 0 (/ +height+ 2) +width+ (/ +height+ 2))))))
(game-run! *game*)
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