public class InGameOverlay extends Gui
{
	private final Minecraft mc = Minecraft.getMinecraft();
	private final ResourceLocation rivenOverlay = new ResourceLocation(RivenMod.MODID + ":textures/gui/rivengui.png");
	private final FontRenderer fontRendererObj = mc.fontRendererObj;

	private ArrayList<ISkill> skillListInstance;

	private int zCooldownTicks;
	private boolean isZUseable;

	public InGameOverlay() {
		skillListInstance = RivenMod.skillList;
		zCooldownTicks = 0;
		isZUseable = true;
	}

	@SubscribeEvent
	public void renderGameOverlay(RenderGameOverlayEvent.Post event) {
		if(event.isCancelable() || event.type != ElementType.EXPERIENCE)
			return;

		ScaledResolution sr = new ScaledResolution(mc, mc.displayWidth, mc.displayHeight);
		int width = sr.getScaledWidth();
		int height = sr.getScaledHeight();

		GL11.glColor4f(1.0F, 1.0F, 1.0F, 1.0F);
		GL11.glDisable(GL11.GL_LIGHTING);

		GL11.glPushMatrix();
		mc.renderEngine.bindTexture(rivenOverlay);
		drawTexturedModalRect(0, height / 2 - 61, 0, 0, 30, 74); //Skill Icon Holder

		for(int i = 0; i < skillListInstance.size(); i++) {
			drawTexturedModalRect(2, height / 2 - 61 + 2 + (18 * i), 16 + (16 * i), 74, 16, 16);
		}

		if(zCooldownTicks > 0) drawCenteredString(this.fontRendererObj, "" + (zCooldownTicks / 20), 10, 10, 0xFFFFFFFF);

		GL11.glPopMatrix();
	}
.....
}