diff options
| -rw-r--r-- | examples/tiled.scm | 65 |
1 files changed, 52 insertions, 13 deletions
diff --git a/examples/tiled.scm b/examples/tiled.scm index c64f7b6..0f7c4fa 100644 --- a/examples/tiled.scm +++ b/examples/tiled.scm @@ -1,6 +1,7 @@ (use-modules (chickadee) (chickadee math vector) (chickadee math rect) + (chickadee graphics color) (chickadee graphics font) (chickadee graphics tiled) (ice-9 format) @@ -8,35 +9,73 @@ (srfi srfi-11)) (define map #f) -(define camera #v(0.0 0.0)) -(define text-position #v(4.0 4.0)) +(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" + (/ 1000.0 avg-frame-time))) +(define start-time 0.0) +(define avg-frame-time 16) +(define stats-text (stats-message)) +(define stats-text-pos (vec2 4.0 464.0)) +(define last-update start-time) +(define scroll-speed 6.0) (define (load) (set! map (load-tile-map "maps/example.tmx"))) (define (draw alpha) - (draw-tile-map map #:position camera) - (draw-text text text-position)) + ;; 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 + (+ (* (vec2-x camera) alpha) + (* (vec2-x prev-camera) beta))) + (set-vec2-y! render-camera + (+ (* (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) 1000) + (set! stats-text (stats-message)) + (set! last-update current-time)))) + +(define (update dt) + (vec2-copy! camera prev-camera) + (set-vec2-x! camera + (+ (vec2-x camera) + (if (key-pressed? 'right) scroll-speed 0.0) + (if (key-pressed? 'left) (- scroll-speed) 0.0))) + (set-vec2-y! camera + (+ (vec2-y camera) + (if (key-pressed? 'up) scroll-speed 0.0) + (if (key-pressed? 'down) (- scroll-speed) 0.0)))) -(define inc 8.0) (define (key-press key modifiers repeat?) (match key - ('up (set-vec2-y! camera (- (vec2-y camera) inc))) - ('down (set-vec2-y! camera (+ (vec2-y camera) inc))) - ('right (set-vec2-x! camera (- (vec2-x camera) inc))) - ('left (set-vec2-x! camera (+ (vec2-x camera) inc))) - ('q (abort-game)) + ((or 'escape 'q) (abort-game)) (_ #t))) (define (mouse-move x y x-rel y-rel buttons) - (let-values (((tx ty) (point->tile map x y))) + (let-values (((tx ty) (point->tile map (- x (vec2-x camera)) (- y (vec2-y camera))))) (set! text (format #f "~d, ~d" tx ty)))) -(run-game #:window-width 320 - #:window-height 240 +(run-game #:window-width 640 + #:window-height 480 #:window-title "tile map demo" #:load load #:draw draw + #:update update #:key-press key-press #:mouse-move mouse-move) |