Getting a box to move around

game.lisp

@@ -0,0 +1,48 @@
+(ql:quickload :claw-raylib)
+(ql:quickload :cffi)
+
+(in-package :cffi)
+
+(rename-package (find-package :raylib) :rl)
+
+(defparameter *move-speed* 2.0)
+
+(defmacro is-key-down (key)
+  `(rl:is-key-down (foreign-enum-value 'rl:keyboard-key ,key)))
+
+(defun v2+ (v1 v2) (rl:vector2-add v1 v2))
+(defun v2- (v1 v2) (rl:vector2-subtract v1 v2))
+(defun v2* (v1 n) (rl:vector2-scale v1 n))
+
+(defstruct game-state
+  (player-pos (rl:make-vector2 :x 100.0 :y 100.0)))
+
+(defun game-input (state)
+  (with-slots ((pos player-pos)) state
+    (let ((dx 0.0) (dy 0.0))
+      (when (is-key-down :right) (incf dx 1))
+      (when (is-key-down :left)  (decf dx 1))
+      (when (is-key-down :up)    (decf dy 1))
+      (when (is-key-down :down)  (incf dy 1))
+      (setf pos (v2+ pos (v2* (rl:vector2-normalize (rl:make-vector2 :x dx :y dy))
+                              *move-speed*))))))
+
+(defun game-update (state)
+  (rl:draw-rectangle-v (game-state-player-pos state)
+                       (rl:make-vector2 :x 100.0 :y 100.0)
+                       rl:+skyblue+)
+  (rl:draw-fps 10 5))
+
+(defun basic-window ()
+  (let ((screen-width 800)
+        (screen-height 450)
+        (game-state (make-game-state)))
+    (rl:with-window ("CL Game" (screen-width screen-height))
+      (rl:set-target-fps 60)
+      (loop :until (rl:window-should-close)
+            :do (rl:with-drawing
+                  (rl:clear-background rl:+raywhite+)
+                  (game-input game-state)
+                  (game-update game-state))))))
+
+(basic-window)