From 822cb31184875def0b2cc0d5d66e0f65bacff226 Mon Sep 17 00:00:00 2001
From: Gene Pasquet <dev@etenil.net>
Date: Tue, 19 May 2026 07:09:00 +0100
Subject: First attempt!?

---
 game.scm | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 87 insertions(+), 1 deletion(-)

(limited to 'game.scm')

diff --git a/game.scm b/game.scm
index 54ee68c..b125852 100644
--- a/game.scm
+++ b/game.scm
@@ -1,2 +1,88 @@
-(import (downstroke engine))
+(import scheme
+        (chicken base)
+        (chicken process-context)
+	(srfi 197)
+        (only (list-utils alist) plist->alist)
+        (prefix sdl2 "sdl2:")
+        (prefix sdl2-ttf "ttf:")
+        (prefix sdl2-image "img:")
+        (downstroke engine)
+        (downstroke world)
+        (downstroke input)
+        (downstroke physics)
+        (downstroke assets)
+        (downstroke entity)
+        (downstroke sound)
+	(downstroke tween)
+        (downstroke scene-loader))
+
+(define +debug?+ (and (member "--debug" (command-line-arguments)) #t))
+;; Momentum, number of pixels/s a movement accelerates after pressing/release
+(define +horizontal-momentum+ 0.01)
+(define +wind-force+ 0.1)
+(define +max-leaf-speed+ 3)
+
+(set! *gravity* 0.1)
+
+(define (make-leaf)
+  (plist->alist (list #:type 'leaf
+                      #:x 100 #:y 200
+                      #:width 32 #:height 32
+		      #:ax 0 #:ay 0
+                      #:vx 0 #:vy 0
+                      #:gravity? #t #:on-ground? #f
+                      #:tile-id 41 #:tags '(leaf)
+		      ;; #:tween (make-tween '((#:x . 100) (#:y . 200))
+		      ;; 			  props: '((#:x . 120))
+		      ;; 			  duration: 500
+		      ;; 			  ease: 'linear
+		      ;; 			  repeat: -1
+		      ;; 			  yoyo?: #t)
+		      )))
+
+(define (clamp value maximum . args)
+  (let ((minimum (if (null? args) (- maximum) (car args))))
+    (max (min value maximum) minimum)))
+
+(define (leaf-ax vx input)
+  (cond ((input-held? input 'left) (- +wind-force+))
+        ((input-held? input 'right)  +wind-force+)
+        ((> vx 0.1) (- +horizontal-momentum+))
+	((< vx -0.1) +horizontal-momentum+)
+	(else 0)))
+
+(define (update-leaf leaf input dt)
+  (let ((ax (leaf-ax (entity-ref leaf #:vx) input)))
+    (chain leaf
+     (entity-set _ #:vx (clamp
+			    (+ (entity-ref leaf #:vx) (* ax dt))
+			    +max-leaf-speed+))
+     ;; Clamp gravity
+     (entity-set _ #:vy (clamp (entity-ref leaf #:vy) +max-leaf-speed+)))))
+
+(define (scene-get-leaf scene)
+  ;; leaf is being added as the first entity in the scene, so we can cheat here.
+  (car (scene-entities scene)))
+
+(define *game*
+  (make-game
+   title: "Free Fall" width: 320 height: 240
+   debug?: +debug?+
+   scale: 2
+
+   preload: (lambda (game) game)
+
+   create: (lambda (game)
+	     (game-scene-set! game (chain (game-load-scene! game "level0.tmx")
+					  (scene-add-entity _ (make-leaf))
+					  (update-scene _ camera-target: 'leaf)
+					  (update-scene _ background: '(173 216 230 255)))))
+
+   update: (lambda (game dt)
+             (let* ((input  (game-input game))
+                    (scene  (game-scene game))
+                    (leaf (update-leaf (scene-get-leaf scene) input dt)))
+               (game-scene-set! game (update-scene scene entities: (list leaf)))))))
+
+;; (game-run! *game*)
 
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