add code to make enemy fall when attacked by projectile (assuming health is enough)

fcore/game-type.sml

@@ -102,7 +102,7 @@ struct
         , health = 1
         , xAxis = EntityType.MOVE_RIGHT
         , yAxis = EntityType.FALLING
-        , variant = EnemyType.STRAIGHT_BAT
+        , variant = EnemyType.PATROL_SLIME
         , batDirY = EnemyType.UP
         , platID = ~1
         , nextPlatID = ~1
@@ -110,7 +110,22 @@ struct
         , batMaxY = 485
         , batMinY = 625
         }
-      val enemies = enemyMapFromList ([enemy1], EnemyMap.empty)
+      val enemy2 =
+        { id = 2
+        , x = 351
+        , y = 555
+        , health = 1
+        , xAxis = EntityType.MOVE_RIGHT
+        , yAxis = EntityType.FALLING
+        , variant = EnemyType.PATROL_SLIME
+        , batDirY = EnemyType.UP
+        , platID = ~1
+        , nextPlatID = ~1
+        , batRest = 0
+        , batMaxY = 485
+        , batMinY = 625
+        }
+      val enemies = enemyMapFromList ([enemy1, enemy2], EnemyMap.empty)
       val graph = Graph.fromPlatforms (platforms, platformTree)
     in
       { player = player

fcore/game-update.sml

@@ -21,6 +21,11 @@ struct
       val (player, enemies) =
         PlayerAttack.attackEnemies (player, enemies, enemyTree)
 
+      val projectiles = #projectiles player
+      val (fallingEnemies, enemies) =
+        PlayerAttack.projectileHitEnemy
+          (projectiles, enemies, enemyTree, fallingEnemies)
+
       val enemies = Enemy.update
         (enemies, walls, wallTree, platforms, platformTree, player, graph)
 

fcore/player/player-attack.sml

@@ -8,33 +8,24 @@ struct
 
          open EnemyType
 
-         fun onAttacked (enemyID, enemy, enemyMap, defeatedList) =
+         fun defeatEnemy (enemyID, enemyMap, defeatedList) =
+           let
+             val defeatedList = {angle = 1} :: defeatedList
+             val enemyMap = EnemyMap.remove (enemyID, enemyMap)
+           in
+             (defeatedList, enemyMap)
+           end
+
+         fun onPlayerAttack (enemyID, enemy, enemyMap, defeatedList) =
            case #variant enemy of
-             PATROL_SLIME =>
+             PATROL_SLIME => defeatEnemy (enemyID, enemyMap, defeatedList)
-               let
+           | FOLLOW_SLIME => defeatEnemy (enemyID, enemyMap, defeatedList)
-                 val defeatedList = {angle = 1} :: defeatedList
+           | STRAIGHT_BAT => defeatEnemy (enemyID, enemyMap, defeatedList)
-                 val enemyMap = EnemyMap.remove (enemyID, enemyMap)
-               in
-                 (defeatedList, enemyMap)
-               end
-           | FOLLOW_SLIME =>
-               let
-                 val defeatedList = {angle = 1} :: defeatedList
-                 val enemyMap = EnemyMap.remove (enemyID, enemyMap)
-               in
-                 (defeatedList, enemyMap)
-               end
-           | STRAIGHT_BAT =>
-               let
-                 val defeatedList = {angle = 1} :: defeatedList
-                 val enemyMap = EnemyMap.remove (enemyID, enemyMap)
-               in
-                 (defeatedList, enemyMap)
-               end
 
          fun fold (enemyID, (), (defeatedList, enemyMap)) =
            case EnemyMap.get (enemyID, enemyMap) of
-             SOME enemy => onAttacked (enemyID, enemy, enemyMap, defeatedList)
+             SOME enemy =>
+               onPlayerAttack (enemyID, enemy, enemyMap, defeatedList)
            | NONE => (defeatedList, enemyMap)
        end)
 
@@ -66,4 +57,60 @@ struct
           end
       | _ => (player, enemyMap)
     end
+
+  structure ProjectileHitEnemy =
+    MakeQuadTreeFold
+      (struct
+         type env = unit
+         type state = EnemyType.falling_enemy list * EnemyMap.t
+
+         open EnemyType
+
+         fun onDefeated (enemyID, enemy, enemyMap, fallingList) =
+           let
+             val {x, y, variant, ...} = enemy
+             val fallingList = {x = x, y = y, variant = variant} :: fallingList
+             val enemyMap = EnemyMap.remove (enemyID, enemyMap)
+           in
+             (fallingList, enemyMap)
+           end
+
+         fun onProjectileAttack (enemyID, enemy, enemyMap, fallingList) =
+           case #variant enemy of
+             PATROL_SLIME => onDefeated (enemyID, enemy, enemyMap, fallingList)
+           | FOLLOW_SLIME => onDefeated (enemyID, enemy, enemyMap, fallingList)
+           | STRAIGHT_BAT => onDefeated (enemyID, enemy, enemyMap, fallingList)
+
+         fun fold (enemyID, (), (fallingList, enemyMap)) =
+           case EnemyMap.get (enemyID, enemyMap) of
+             SOME enemy =>
+               onProjectileAttack (enemyID, enemy, enemyMap, fallingList)
+           | NONE => (fallingList, enemyMap)
+       end)
+
+  fun helpProjectileHitEnemy (pos, projectiles, enemyTree, enemyMap, newFalling) =
+    if pos = Vector.length projectiles then
+      (newFalling, enemyMap)
+    else
+      let
+        val {x, y, ...}: PlayerType.player_projectile =
+          Vector.sub (projectiles, pos)
+        val size = Constants.projectileSizeInt
+        val (newFalling, enemyMap) = ProjectileHitEnemy.foldRegion
+          (x, y, size, size, (), (newFalling, enemyMap), enemyTree)
+      in
+        helpProjectileHitEnemy
+          (pos + 1, projectiles, enemyTree, enemyMap, newFalling)
+      end
+
+  fun projectileHitEnemy (projectiles, enemyMap, enemyTree, oldFalling) =
+    let
+      val (newFalling, enemyMap) = helpProjectileHitEnemy
+        (0, projectiles, enemyTree, enemyMap, [])
+
+      val newFalling = Vector.fromList newFalling
+      val allFalling = Vector.concat [newFalling, oldFalling]
+    in
+      (allFalling, enemyMap)
+    end
 end