add RF API and add concept of energy usage to machines + controllers

src/main/java/cofh/api/energy/ItemEnergyContainer.java

@@ -0,0 +1,110 @@
+package cofh.api.energy;
+
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.nbt.NBTTagCompound;
+
+/**
+ * Reference implementation of {@link IEnergyContainerItem}. Use/extend this or implement your own.
+ * 
+ * @author King Lemming
+ * 
+ */
+public class ItemEnergyContainer extends Item implements IEnergyContainerItem {
+
+	protected int capacity;
+	protected int maxReceive;
+	protected int maxExtract;
+
+	public ItemEnergyContainer() {
+
+	}
+
+	public ItemEnergyContainer(int capacity) {
+
+		this(capacity, capacity, capacity);
+	}
+
+	public ItemEnergyContainer(int capacity, int maxTransfer) {
+
+		this(capacity, maxTransfer, maxTransfer);
+	}
+
+	public ItemEnergyContainer(int capacity, int maxReceive, int maxExtract) {
+
+		this.capacity = capacity;
+		this.maxReceive = maxReceive;
+		this.maxExtract = maxExtract;
+	}
+
+	public ItemEnergyContainer setCapacity(int capacity) {
+
+		this.capacity = capacity;
+		return this;
+	}
+
+	public void setMaxTransfer(int maxTransfer) {
+
+		setMaxReceive(maxTransfer);
+		setMaxExtract(maxTransfer);
+	}
+
+	public void setMaxReceive(int maxReceive) {
+
+		this.maxReceive = maxReceive;
+	}
+
+	public void setMaxExtract(int maxExtract) {
+
+		this.maxExtract = maxExtract;
+	}
+
+	/* IEnergyContainerItem */
+	@Override
+	public int receiveEnergy(ItemStack container, int maxReceive, boolean simulate) {
+
+		if (container.stackTagCompound == null) {
+			container.stackTagCompound = new NBTTagCompound();
+		}
+		int energy = container.stackTagCompound.getInteger("Energy");
+		int energyReceived = Math.min(capacity - energy, Math.min(this.maxReceive, maxReceive));
+
+		if (!simulate) {
+			energy += energyReceived;
+			container.stackTagCompound.setInteger("Energy", energy);
+		}
+		return energyReceived;
+	}
+
+	@Override
+	public int extractEnergy(ItemStack container, int maxExtract, boolean simulate) {
+
+		if (container.stackTagCompound == null || !container.stackTagCompound.hasKey("Energy")) {
+			return 0;
+		}
+		int energy = container.stackTagCompound.getInteger("Energy");
+		int energyExtracted = Math.min(energy, Math.min(this.maxExtract, maxExtract));
+
+		if (!simulate) {
+			energy -= energyExtracted;
+			container.stackTagCompound.setInteger("Energy", energy);
+		}
+		return energyExtracted;
+	}
+
+	@Override
+	public int getEnergyStored(ItemStack container) {
+
+		if (container.stackTagCompound == null || !container.stackTagCompound.hasKey("Energy")) {
+			return 0;
+		}
+		return container.stackTagCompound.getInteger("Energy");
+	}
+
+	@Override
+	public int getMaxEnergyStored(ItemStack container) {
+
+		return capacity;
+	}
+
+}