ShaderCase.java

package blusunrize.immersiveengineering.api.shader;

import net.minecraft.item.ItemStack;
import net.minecraft.util.ResourceLocation;

import java.util.Collection;

/**
 * @author BluSunrize - 29.10.2015
 * Completely rewritten 29.10.2016
 *
 * To be extended for ShaderCases all items, entities and whatever else you use them for<br>
 * Pre-configured ones exist (ShaderCaseRevolver.class) but when a new, shader-ready thing is implemented, it'll need a shadercase.
 */
public abstract class ShaderCase
{
	/**An array of layers that this shader is comprised of.*/
	protected ShaderLayer[] layers;

	protected ShaderCase(ShaderLayer... layers)
	{
		this.layers = layers;
	}
	protected ShaderCase(Collection<ShaderLayer> layers)
	{
		this.layers = layers.toArray(new ShaderLayer[layers.size()]);
	}

	public ShaderLayer[] getLayers()
	{
		return this.layers;
	}
	public ShaderCase addLayers(ShaderLayer... addedLayers)
	{
		ShaderLayer[] newLayers = new ShaderLayer[layers.length+addedLayers.length];
		int insert = getLayerInsertionIndex();
		System.arraycopy(this.layers,0, newLayers,0, insert);
		System.arraycopy(addedLayers,0, newLayers,insert, addedLayers.length);
		System.arraycopy(this.layers,insert, newLayers,insert+addedLayers.length, this.layers.length-insert);
		this.layers = newLayers;
		return this;
	}

	public abstract int getLayerInsertionIndex();

	/**
	 * @return if the given part of the model renders on the pass
	 */
	public abstract boolean renderModelPartForPass(ItemStack shader, ItemStack item, String modelPart, int pass);

	/**
	 * @return A string representing which item this shader case applies to. e.g.: "immersiveengineering:revolver"
	 */
	public abstract String getShaderType();

	/**
	 * @return if the ResourceLocations of the layers should be stitched into the main texturemap<br>
	 *     defaults to true, since item and block textures are generally handled by that map<br
	 *     Minecarts return false here
	 */
	public boolean stitchIntoSheet()
	{
		return true;
	}

	/**
	 * @return which icon is to be used for the given pass and model part. These obviously need to be stitched on the given sheet (mind the revolvers!)
	 */
	public ResourceLocation getReplacementSprite(ItemStack shader, ItemStack item, String modelPart, int pass)
	{
		return getLayers()[pass].getTexture();
	}
	/**
	 * @return the ARGB values to be appleid to the given part in the given pass
	 */
	public int getARGBColourModifier(ItemStack shader, ItemStack item, String modelPart, int pass)
	{
		return getLayers()[pass].getColour();
	}

	/**
	 * @param pre indicates whether this is before or after the part was rendered
	 * @return make specific changes to the render, like GL calls
	 */
	public abstract void modifyRender(ItemStack shader, ItemStack item, String modelPart, int pass, boolean pre, boolean inventory);

	public static class ShaderLayer
	{
		/**A resource location pointing to a texture on the sheet*/
		private final ResourceLocation texture;
		/**An ARGB formatted colour*/
		private final int colour;
		/**An optional double array (uMin, vMin, uMax, vMax; values of 0-1) to define which part of the original texture is overriden<br>
		 * The model will then only render faces who's coords lie within that limited space.<br>
		 * Useful for keeping additional decorations (see Sponsor Shader) in smaller textures*/
		private double[] textureBounds;
		/**An optional double array (uMin, vMin, uMax, vMax; values of 0-1) for the parts of the texture to be used.<br>
		 * Useful when putting multiple shader textures into one file*/
		private double[] cutoutBounds;

		public ShaderLayer(ResourceLocation texture, int colour)
		{
			this.texture = texture;
			this.colour = colour;
		}

		public ShaderLayer setTextureBounds(double... bounds)
		{
			if(bounds==null)
				return this;
			assert(bounds.length==4);
			this.textureBounds = bounds;
			return this;
		}
		/**@return An optional double array (uMin, vMin, uMax, vMax; values of 0-1) to define which part of the original texture is overriden<br>
		 * The model will then only render faces who's coords lie within that limited space.<br>
		 * Useful for keeping additional decorations (see Sponsor Shader) in smaller textures*/
		public double[] getTextureBounds()
		{
			return this.textureBounds;
		}

		public ShaderLayer setCutoutBounds(double... bounds)
		{
			if(bounds==null)
				return this;
			assert(bounds.length==4);
			this.cutoutBounds = bounds;
			return this;
		}
		/** @return An optional double array (uMin, vMin, uMax, vMax; values of 0-1) for the parts of the texture to be used.<br>
		 * Useful when putting multiple shader textures into one file*/
		public double[] getCutoutBounds()
		{
			return this.cutoutBounds;
		}

		public ResourceLocation getTexture()
		{
			return texture;
		}

		public int getColour()
		{
			return colour;
		}
	}
}