From 1afcf370b571a350ce58d49ecd3e7fc577b5d878 Mon Sep 17 00:00:00 2001
From: snyke7 <ikemulder@hotmail.com>
Date: Mon, 21 Jan 2013 14:27:38 +0100
Subject: [PATCH] Fix fuel burning mechanic in EngineIron

Old implementation was not as intended I think. For example, lava as fuel should have outputted 20000 MJ, but actually outputted 20980 MJ.
This was because burnTime's value went 20,19,...2,1,0,20 - so that it had actually outputted 21 MJ for each amount of fuel.
Also, when the last amount of fuel was burned, burnTime would be 20 but fuel would be null, and so would currentFuel so that the last cycle was skipped.
So the actual output of some fuel was:
powerPerCycle * ((amount - 1) * (totalBurnTime/1000 + 1) + 1).
There probably are better ways to fix it but this is what seemed best to me.
---
 common/buildcraft/energy/EngineIron.java | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/common/buildcraft/energy/EngineIron.java b/common/buildcraft/energy/EngineIron.java
index b42fdd67..6373bd6b 100644
--- a/common/buildcraft/energy/EngineIron.java
+++ b/common/buildcraft/energy/EngineIron.java
@@ -37,6 +37,7 @@ public class EngineIron extends Engine {
 	int heat = 0;
 	private LiquidTank fuelTank;
 	private LiquidTank coolantTank;
+	private IronEngineFuel currentFuel = null;
 
 	public int penaltyCooling = 0;
 
@@ -92,7 +93,9 @@ public class EngineIron extends Engine {
 	public void burn() {
 		currentOutput = 0;
 		LiquidStack fuel = this.fuelTank.getLiquid();
-		IronEngineFuel currentFuel = IronEngineFuel.getFuelForLiquid(fuel);
+		if(currentFuel == null) {
+			currentFuel = IronEngineFuel.getFuelForLiquid(fuel);
+		}
 
 		if (currentFuel == null)
 			return;
@@ -104,20 +107,25 @@ public class EngineIron extends Engine {
 			if (burnTime > 0 || fuel.amount > 0) {
 				if (burnTime > 0) {
 					burnTime--;
-				} else {
-					if (--fuel.amount <= 0) {
-						fuelTank.setLiquid(null);
+				} 
+				if (burnTime <= 0) {
+					if(fuel != null) {
+						if (--fuel.amount <= 0) {
+							fuelTank.setLiquid(null);
+						}
+						burnTime = currentFuel.totalBurningTime / LiquidContainerRegistry.BUCKET_VOLUME;
+					} else {
+						currentFuel = null;
+						return;
 					}
-					burnTime = currentFuel.totalBurningTime / LiquidContainerRegistry.BUCKET_VOLUME;
 				}
-
 				currentOutput = currentFuel.powerPerCycle;
 				addEnergy(currentFuel.powerPerCycle);
 				heat += currentFuel.powerPerCycle;
 			}
 		} else if (penaltyCooling <= 0) {
 			if (lastPowered) {
-				lastPowered = false;
+				lastPowered = false; 
 				penaltyCooling = 30 * 20;
 				// 30 sec of penalty on top of the cooling
 			}