begin parameterising level so that it fits into larger type (with different modes like TITLE, LEVEL, SETTINGS, etc.)

fcore/level/level-update.sml

@@ -0,0 +1,46 @@
+structure LevelUpdate =
+struct
+  fun update (game, input) =
+    let
+      val
+        { player
+        , walls
+        , wallTree
+        , platforms
+        , platformTree
+        , enemies
+        , graph
+        , fallingEnemies
+        , userKeys
+        } = game
+
+      val player = Player.runPhysicsAndInput (game, input)
+
+      val enemyTree = Enemy.generateTree enemies
+      val player = Player.checkEnemyCollisions (player, enemies, enemyTree)
+
+      val (player, enemies, fallingEnemies) =
+        PlayerAttack.attackEnemies (player, enemies, enemyTree, fallingEnemies)
+
+      val projectiles = #projectiles player
+      val (fallingEnemies, enemies) =
+        PlayerAttack.projectileHitEnemy
+          (projectiles, enemies, enemyTree, fallingEnemies)
+
+      val enemies = Enemy.update
+        (enemies, walls, wallTree, platforms, platformTree, player, graph)
+
+      val fallingEnemies = FallingEnemies.update fallingEnemies
+    in
+      { player = player
+      , walls = walls
+      , wallTree = wallTree
+      , platforms = platforms
+      , platformTree = platformTree
+      , enemies = enemies
+      , graph = graph
+      , fallingEnemies = fallingEnemies
+      , userKeys = userKeys
+      }
+    end
+end