Fix flag toggle waterfall crash when used with underwater switch controller

Author: maddie480

Entities/FlagToggleWaterfall.cs

@@ -12,6 +12,8 @@ class FlagToggleWaterfall : WaterFall {
         private string loopingSfxEvent;
         private string enteringSfxEvent;
 
+        private bool alreadyTurnedOnOnce = false;
+
         public FlagToggleWaterfall(EntityData data, Vector2 offset) : base(data, offset) {
             Add(toggle = new FlagToggleComponent(data.Attr("flag"), data.Bool("inverted"), () => {
                 // disable the waterfall sound.
@@ -35,10 +37,42 @@ public override void Awake(Scene scene) {
             enteringSfxEvent = enteringSfx.EventName;
 
             toggle.UpdateFlag();
+
+            if (toggle.Enabled) {
+                alreadyTurnedOnOnce = true;
+            }
         }
 
         public override void Update() {
             if (toggle.Enabled) {
+                // if we are turning the waterfall on for the first time, compute its height, now that other entities
+                // (pools of water, underwater switch controller) have been toggled to match as well.
+                if (!alreadyTurnedOnOnce) {
+                    DynData<WaterFall> self = new DynData<WaterFall>(this);
+                    float height = 8f;
+                    Water water = null;
+                    Solid solid = null;
+                    while (Y + height < SceneAs<Level>().Bounds.Bottom
+                        && (water = Scene.CollideFirst<Water>(new Rectangle((int) X, (int) (Y + height), 8, 8))) == null
+                        && ((solid = Scene.CollideFirst<Solid>(new Rectangle((int) X, (int) (Y + height), 8, 8))) == null || !solid.BlockWaterfalls)) {
+
+                        height += 8f;
+                        solid = null;
+                    }
+                    if (water != null && !Scene.CollideCheck<Solid>(new Rectangle((int) X, (int) (Y + height), 8, 16))) {
+                        enteringSfxEvent = "event:/env/local/waterfall_small_in_deep";
+                    } else {
+                        enteringSfxEvent = "event:/env/local/waterfall_small_in_shallow";
+                    }
+                    enteringSfx.Play(enteringSfxEvent);
+
+                    self["height"] = height;
+                    self["water"] = water;
+                    self["solid"] = solid;
+
+                    alreadyTurnedOnOnce = true;
+                }
+
                 // update the entity as usual
                 base.Update();
             } else {

Entities/UnderwaterSwitchController.cs

@@ -47,6 +47,7 @@ public IEnumerator Routine() {
                 }
 
                 // make water go away.
+                water.Collidable = false;
                 Scene.Remove(water);
                 water = null;
             }