/*
 * This file is part of Applied Energistics 2.
 * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
 *
 * Applied Energistics 2 is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Applied Energistics 2 is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
 */

package appeng.client.render;


import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
import net.minecraft.client.renderer.vertex.VertexFormat;
import net.minecraftforge.common.ForgeModContainer;
import net.minecraftforge.fml.client.FMLClientHandler;


/**
 * Utility for managing extended Vertex Formats without having to re-clone existing vertex formats over and over again.
 */
public final class VertexFormats
{

	// Standard item format extended with lightmap coordinates
	private static final VertexFormat itemFormatWithLightMap = new VertexFormat( DefaultVertexFormats.ITEM ).addElement( DefaultVertexFormats.TEX_2S );

	private VertexFormats() {
	}

	public static VertexFormat getFormatWithLightMap( VertexFormat format )
	{
		// Do not use this when Optifine is present or if the vanilla lighting pipeline is used
		if( FMLClientHandler.instance().hasOptifine() || !ForgeModContainer.forgeLightPipelineEnabled )
		{
			return format;
		}

		VertexFormat result;
		if( format == DefaultVertexFormats.BLOCK )
		{
			result = DefaultVertexFormats.BLOCK;
		}
		else if( format == DefaultVertexFormats.ITEM )
		{
			result = itemFormatWithLightMap;
		}
		else if( !format.hasUvOffset( 1 ) )
		{
			result = new VertexFormat( format );
			result.addElement( DefaultVertexFormats.TEX_2S );
		}
		else
		{
			result = format; // Already has the needed UV, so keep it
		}
		return result;
	}
}