feat: re implement onMovementStep to be able to affect actor movement

msu/hooks/entity/tactical/actor.nut

@@ -21,14 +21,7 @@
 
 	q.onMovementStep = @(__original) function( _tile, _levelDifference )
 	{
-		local ret = __original(_tile, _levelDifference);
-
-		if (ret)
-		{
-			this.m.Skills.onMovementStep(_tile, _levelDifference);
-		}
-
-		return ret;
+		return __original(_tile, _levelDifference) && this.m.Skills.onMovementStep(_tile, _levelDifference);
 	}
 
 	// VANILLAFIX: http://battlebrothersgame.com/forums/topic/oncombatstarted-is-not-called-for-ai-characters/

msu/hooks/skills/skill_container.nut

@@ -132,10 +132,56 @@
 
 	q.onMovementStep <- function( _tile, _levelDifference )
 	{
-		this.callSkillsFunction("onMovementStep", [
-			_tile,
-			_levelDifference
-		], false);
+		local wasUpdating = this.m.IsUpdating;
+		this.m.IsUpdating = true;
+
+		local callback = null;
+
+		local skill, skill_callback; // cache vars for foreach loop
+		foreach (s in this.m.Skills)
+		{
+			if (s.isGarbage())
+				continue;
+
+			skill_callback = s.onMovementStep(_tile, _levelDifference);
+			if (callback == null)
+			{
+				switch (skill_callback)
+				{
+					// null is for legacy support, because older versions didn't have a return
+					// for `onMovementStep` and weren't meant to be able to interrupt movement.
+					case null:
+					case true:
+						break;
+
+					// skill_callback is either `false` or a function in this case.
+					// In this case the skill wants to interrupt the movement.
+					// We will only take skill_callback from the first skill that gives it,
+					// so SkillOrder is important.
+					// The skill_callback can be useful to do functionality after the interruption
+					// e.g. refunding AP or triggering an effect etc.
+					default:
+						callback = skill_callback;
+						skill = s;
+						break;
+				}
+			}
+		}
+
+		this.m.IsUpdating = wasUpdating;
+
+		// callback being null means no skill returned `false` or a function
+		// therefore no skill is interrupting this movement. So we return `true`.
+		if (callback == null)
+			return true;
+
+		// If any skill returned `false` or a function it means it wants to
+		// stop the movement. So, we call the skill's provided callback (if any)
+		// and then return `false`.
+		if (callback != false)
+			callback.call(skill, _tile, _levelDifference);
+
+		return false;
 	}
 
 	q.onAnySkillExecuted <- function( _skill, _targetTile, _targetEntity, _forFree )