CanisterItemRender.java

package buildcraftAdditions.client.render.items;

/**
 * Copyright (c) 2014-2015, AEnterprise
 * http://buildcraftadditions.wordpress.com/
 * Buildcraft Additions is distributed under the terms of GNU GPL v3.0
 * Please check the contents of the license located in
 * http://buildcraftadditions.wordpress.com/wiki/licensing-stuff/
 */

import org.lwjgl.opengl.GL11;

import net.minecraft.client.Minecraft;
import net.minecraft.client.renderer.ItemRenderer;
import net.minecraft.client.renderer.Tessellator;
import net.minecraft.item.ItemStack;
import net.minecraft.util.IIcon;

import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;

import net.minecraftforge.client.IItemRenderer;
import net.minecraftforge.fluids.Fluid;
import net.minecraftforge.fluids.FluidStack;

import buildcraftAdditions.items.ItemCanister;
import buildcraftAdditions.utils.RenderUtils;
import buildcraftAdditions.utils.Utils;

@SideOnly(Side.CLIENT)
public class CanisterItemRender implements IItemRenderer {

	public static final CanisterItemRender INSTANCE = new CanisterItemRender();

	private CanisterItemRender() {
	}

	@Override
	public boolean handleRenderType(ItemStack item, ItemRenderType type) {
		return true;
	}

	@Override
	public boolean shouldUseRenderHelper(ItemRenderType type, ItemStack item, ItemRendererHelper helper) {
		return type.equals(ItemRenderType.ENTITY);
	}

	@Override
	public void renderItem(ItemRenderType type, ItemStack item, Object... data) {
		if (item == null || item.getItem() == null || !(item.getItem() instanceof ItemCanister))
			return;

		ItemCanister canister = (ItemCanister) item.getItem();

		IIcon overlay = canister.getOverlay();
		IIcon canisterIcon = canister.getIconFromDamage(0);

		GL11.glPushMatrix();
		GL11.glEnable(GL11.GL_ALPHA_TEST);
		if (type.equals(ItemRenderType.EQUIPPED)) {
			GL11.glRotated(180, 0, 0, 1);
			GL11.glTranslated(-1, -1, 0);
		} else if (type.equals(ItemRenderType.ENTITY)) {
			GL11.glRotated(180, 0, 0, 1);
			GL11.glRotated(90, 0, 1, 0);
			GL11.glTranslated(-0.5, -0.9, 0);
			if (item.isOnItemFrame()) {
				GL11.glTranslated(0.075, 0.475, 0);
				GL11.glScaled(0.85, 0.85, 0.85);
			}
		} else if (type.equals(ItemRenderType.EQUIPPED_FIRST_PERSON)) {
			GL11.glTranslated(1, 1, 0);
			GL11.glRotated(180, 0, 0, 1);
		}

		FluidStack fluid = Utils.getFluidStackFromItemStack(item);
		if (fluid != null) {
			Fluid f = fluid.getFluid();
			if (f != null) {
				Minecraft.getMinecraft().renderEngine.bindTexture(RenderUtils.MC_ITEM_SHEET);
				renderMask(overlay, f.getIcon(), type);
			}
		}
		Minecraft.getMinecraft().renderEngine.bindTexture(RenderUtils.MC_ITEM_SHEET);

		if (type.equals(ItemRenderType.INVENTORY))
			renderIcon(canisterIcon, 0);
		else
			ItemRenderer.renderItemIn2D(Tessellator.instance, canisterIcon.getMinU(), canisterIcon.getMaxV(), canisterIcon.getMaxU(), canisterIcon.getMinV(), canisterIcon.getIconWidth(), canisterIcon.getIconHeight(), 0.0625F);


		GL11.glColor4f(1, 1, 1, 1);
		GL11.glPopMatrix();
	}

	private void renderMask(IIcon mask, IIcon subIcon, ItemRenderType type) {
		if (mask == null || subIcon == null)
			return;

		GL11.glEnable(GL11.GL_BLEND);
		GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
		GL11.glDisable(GL11.GL_CULL_FACE);
		Tessellator tessellator = Tessellator.instance;

		tessellator.startDrawingQuads();
		tessellator.setNormal(0, 0, 1);
		if (type.equals(ItemRenderType.INVENTORY))
			preRenderInvIcon(mask, 0.001);
		else
			preRenderWorldIcon(mask, 0.001);
		tessellator.draw();

		tessellator.startDrawingQuads();
		tessellator.setNormal(0, 0, -1);
		if (type.equals(ItemRenderType.INVENTORY))
			preRenderInvIcon(mask, -0.0635);
		else
			preRenderWorldIcon(mask, -0.0635);
		tessellator.draw();

		Minecraft.getMinecraft().renderEngine.bindTexture(RenderUtils.MC_BLOCK_SHEET);
		GL11.glDepthFunc(GL11.GL_EQUAL);
		GL11.glDepthMask(false);

		tessellator.startDrawingQuads();
		tessellator.setNormal(0, 0, 1);
		if (type.equals(ItemRenderType.INVENTORY))
			preRenderInvIcon(subIcon, 0.001);
		else
			preRenderWorldIcon(subIcon, 0.001);
		tessellator.draw();

		tessellator.startDrawingQuads();
		tessellator.setNormal(0, 0, -1);
		if (type.equals(ItemRenderType.INVENTORY))
			preRenderInvIcon(subIcon, -0.0635);
		else
			preRenderWorldIcon(subIcon, -0.0635);
		tessellator.draw();

		GL11.glDisable(GL11.GL_BLEND);
		GL11.glDepthMask(true);
		GL11.glDepthFunc(GL11.GL_LEQUAL);
		GL11.glEnable(GL11.GL_CULL_FACE);
		GL11.glColor4f(1, 1, 1, 1);
	}

	private void preRenderInvIcon(IIcon icon, double z) {
		Tessellator.instance.addVertexWithUV(16, 0, z, icon.getMaxU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 0, z, icon.getMinU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 16, z, icon.getMinU(), icon.getMaxV());
		Tessellator.instance.addVertexWithUV(16, 16, z, icon.getMaxU(), icon.getMaxV());
	}

	private void preRenderWorldIcon(IIcon icon, double z) {
		Tessellator.instance.addVertexWithUV(1, 0, z, icon.getMaxU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 0, z, icon.getMinU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 1, z, icon.getMinU(), icon.getMaxV());
		Tessellator.instance.addVertexWithUV(1, 1, z, icon.getMaxU(), icon.getMaxV());
	}

	private void renderIcon(IIcon icon, double z) {
		Tessellator.instance.startDrawingQuads();
		Tessellator.instance.addVertexWithUV(16, 0, z, icon.getMaxU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 0, z, icon.getMinU(), icon.getMinV());
		Tessellator.instance.addVertexWithUV(0, 16, z, icon.getMinU(), icon.getMaxV());
		Tessellator.instance.addVertexWithUV(16, 16, z, icon.getMaxU(), icon.getMaxV());
		Tessellator.instance.draw();
	}
}