From 508cc0d4c7f8eae26f0d3755492feae042c04bf9 Mon Sep 17 00:00:00 2001
From: sanderd17 <sanderd17@wildfiregames.com>
Date: Wed, 11 Sep 2013 17:50:49 +0000
Subject: [PATCH] Add preferred classes to BuildingAI. Patch by jammus. Fixes
 #1985

This was SVN commit r13823.
---
 .../simulation/components/BuildingAI.js       | 31 +++++++-----
 .../public/simulation/helpers/WeightedList.js | 47 +++++++++++++++++++
 2 files changed, 66 insertions(+), 12 deletions(-)
 create mode 100644 binaries/data/mods/public/simulation/helpers/WeightedList.js

diff --git a/binaries/data/mods/public/simulation/components/BuildingAI.js b/binaries/data/mods/public/simulation/components/BuildingAI.js
index 840588044f..dd50f9bc2f 100644
--- a/binaries/data/mods/public/simulation/components/BuildingAI.js
+++ b/binaries/data/mods/public/simulation/components/BuildingAI.js
@@ -169,16 +169,11 @@ BuildingAI.prototype.OnRangeUpdate = function(msg)
 	else if (msg.tag != this.enemyUnitsQuery)
 		return;
 
-	const restrictedClasses = cmpAttack.GetRestrictedClasses(attackType);
-
 	if (msg.added.length > 0)
 	{
 		for each (var entity in msg.added)
 		{
-			var cmpIdentity = Engine.QueryInterface(entity, IID_Identity);
-			var targetClasses = cmpIdentity.GetClassesList();
-
-			if (!targetClasses.some(function(c){return restrictedClasses.indexOf(c) > -1;}))
+			if (cmpAttack.CanAttack(entity))
 				this.targetUnits.push(entity);
 		}
 	}
@@ -285,20 +280,32 @@ BuildingAI.prototype.FireArrows = function()
 		    this.arrowsLeft 
 		);
 	}
-	var clonedTargets = this.targetUnits.slice();
+	if (arrowsToFire <= 0)
+	{
+		this.currentRound++;
+		return;
+	}
+	var targets = new WeightedList();
+	for (var i = 0; i < this.targetUnits.length; i++)
+	{
+		var target = this.targetUnits[i],
+		    weight = (cmpAttack.GetPreference(target) || 0) + 1
+		targets.add(target, weight);
+	}
 	for (var i = 0;i < arrowsToFire;i++)
 	{
-		var target = clonedTargets[Math.floor(Math.random() * this.targetUnits.length)];
-		if (target && this.CheckTargetVisible(target)) 
+		var selectedIndex = targets.randomIndex(),
+		    selectedTarget = targets.itemAt(selectedIndex);
+		if (selectedTarget && this.CheckTargetVisible(selectedTarget))
 		{
-			cmpAttack.PerformAttack(attackType, target);
+			cmpAttack.PerformAttack(attackType, selectedTarget);
 			PlaySound("attack", this.entity);
 		}
 		else 
 		{
-			clonedTargets.splice(clonedTargets.indexOf(target),1);
+			targets.removeAt(selectedIndex);
 			i--; // one extra arrow left to fire
-			if(clonedTargets.length < 1) 
+			if(targets.length() < 1)
 			{
 				this.arrowsLeft += arrowsToFire;
 				// no targets found in this round, save arrows and go to next round
diff --git a/binaries/data/mods/public/simulation/helpers/WeightedList.js b/binaries/data/mods/public/simulation/helpers/WeightedList.js
new file mode 100644
index 0000000000..5fe0646b17
--- /dev/null
+++ b/binaries/data/mods/public/simulation/helpers/WeightedList.js
@@ -0,0 +1,47 @@
+var WeightedList = function()
+{
+    this.elements = [ ];
+    this.totalWeight = 0;
+};
+
+WeightedList.prototype.length = function()
+{
+	return this.elements.length;
+};
+
+WeightedList.prototype.push = function(item, weight)
+{
+	if (weight === undefined)
+		weight = 1;
+	this.totalWeight += weight;
+	this.elements.push({ "item": item, "weight": weight });
+};
+
+WeightedList.prototype.removeAt = function(index)
+{
+	var element = this.elements.splice(index, 1)[0];
+	if (element)
+		this.totalWeight -= element.weight;
+};
+
+WeightedList.prototype.itemAt = function(index)
+{
+	var element = this.elements[index];
+	return element ? element.item : null;
+};
+
+WeightedList.prototype.randomIndex = function() {
+	var element,
+	targetWeight = Math.random() * this.totalWeight,
+	cumulativeWeight = 0;
+	for (var index = 0; index < this.elements.length; index++)
+	{
+		element = this.elements[index];
+		cumulativeWeight += element.weight;
+		if (cumulativeWeight >= targetWeight)
+			return index;
+	}
+	return -1;
+};
+
+Engine.RegisterGlobal("WeightedList", WeightedList);