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authorDavid Thompson <dthompson2@worcester.edu>2021-04-09 22:37:49 -0400
committerDavid Thompson <dthompson2@worcester.edu>2021-04-09 22:45:33 -0400
commite05aa45f672eb49312449d359a9e345223741b19 (patch)
tree1a00e89b1116546c2fb93e294870f9005fea46dc /examples/tile-map.scm
parent5c919ae2dfaee36d689b2c2bedee1d2745bd2d6d (diff)
graphics: Rewrite tile map module.
Diffstat (limited to 'examples/tile-map.scm')
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diff --git a/examples/tile-map.scm b/examples/tile-map.scm
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+(use-modules (chickadee)
+ (chickadee math vector)
+ (chickadee math rect)
+ (chickadee graphics color)
+ (chickadee graphics font)
+ (chickadee graphics tile-map)
+ (ice-9 format)
+ (ice-9 match)
+ (srfi srfi-11))
+
+(define window-width 960)
+(define window-height 540)
+(define map #f)
+(define prev-camera (vec2 0.0 0.0))
+(define camera (vec2 0.0 0.0))
+(define render-camera (vec2 0.0 0.0))
+(define text-position (vec2 4.0 4.0))
+(define text "0, 0")
+(define (stats-message)
+ (format #f "fps: ~1,2f"
+ (/ 1.0 avg-frame-time)))
+(define start-time 0.0)
+(define avg-frame-time 16)
+(define stats-text (stats-message))
+(define stats-text-pos (vec2 4.0 (- window-height 16.0)))
+(define last-update start-time)
+(define scroll-speed 6.0)
+
+(define (load)
+ (set! map (load-tile-map "maps/example3.tmx")))
+
+(define (draw alpha)
+ ;; Linearly interpolate between the current camera position and the
+ ;; previous camera position based on the alpha value. This makes
+ ;; the scrolling appear much smoother because the Chickadee game
+ ;; loop does not render in lock-step with updates.
+ (let ((beta (- 1.0 alpha)))
+ (set-vec2-x! render-camera
+ (round
+ (+ (* (vec2-x camera) alpha)
+ (* (vec2-x prev-camera) beta))))
+ (set-vec2-y! render-camera
+ (round
+ (+ (* (vec2-y camera) alpha)
+ (* (vec2-y prev-camera) beta)))))
+ (draw-tile-map map #:camera render-camera)
+ (draw-text text text-position #:color black)
+ (draw-text stats-text stats-text-pos #:color black)
+ (let ((current-time (elapsed-time)))
+ (set! avg-frame-time
+ (+ (* (- current-time start-time) 0.1)
+ (* avg-frame-time 0.9)))
+ (set! start-time current-time)
+ (when (>= (- current-time last-update) 1.0)
+ (set! stats-text (stats-message))
+ (set! last-update current-time))))
+
+(define (refresh-tile-coords x y)
+ (call-with-values (lambda ()
+ (point->tile map
+ (+ x (vec2-x camera))
+ (+ y (vec2-y camera))))
+ (lambda (tx ty)
+ (set! text (format #f "~d, ~d" tx ty)))))
+
+(define (update dt)
+ (vec2-copy! camera prev-camera)
+ (set-vec2! camera
+ (min (max (+ (vec2-x camera)
+ (if (key-pressed? 'right) scroll-speed 0.0)
+ (if (key-pressed? 'left) (- scroll-speed) 0.0))
+ 0.0)
+ (- (* (tile-map-width map) (tile-map-tile-width map))
+ window-width))
+ (min (max (+ (vec2-y camera)
+ (if (key-pressed? 'up) scroll-speed 0.0)
+ (if (key-pressed? 'down) (- scroll-speed) 0.0))
+ 0.0)
+ (- (* (tile-map-height map) (tile-map-tile-height map))
+ window-height)))
+ (when (or (key-pressed? 'left) (key-pressed? 'right)
+ (key-pressed? 'down) (key-pressed? 'up))
+ (refresh-tile-coords (mouse-x) (mouse-y))))
+
+(define (key-press key modifiers repeat?)
+ (match key
+ ((or 'escape 'q) (abort-game))
+ (_ #t)))
+
+(define (mouse-move x y x-rel y-rel buttons)
+ (refresh-tile-coords x y))
+
+(run-game #:window-width window-width
+ #:window-height window-height
+ #:window-title "tile map demo"
+ #:load load
+ #:draw draw
+ #:update update
+ #:key-press key-press
+ #:mouse-move mouse-move)