distant-horizons-sharded/src/main/java/com/backsun/lod/renderer/LodRenderer.java

package com.backsun.lod.renderer;

import java.awt.Color;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.lwjgl.opengl.GL11;

import com.backsun.lod.builders.LodBufferBuilder;
import com.backsun.lod.handlers.ReflectionHandler;
import com.backsun.lod.objects.LodChunk;
import com.backsun.lod.objects.LodDimension;
import com.backsun.lod.objects.NearFarBuffer;
import com.backsun.lod.util.LodConfig;
import com.backsun.lod.util.enums.ColorDirection;
import com.backsun.lod.util.enums.FogDistance;
import com.backsun.lod.util.enums.FogQuality;
import com.backsun.lod.util.enums.LodCorner;
import com.mojang.blaze3d.matrix.MatrixStack;
import com.mojang.blaze3d.platform.GlStateManager;
import com.mojang.blaze3d.systems.RenderSystem;

import net.minecraft.client.Minecraft;
import net.minecraft.client.entity.player.ClientPlayerEntity;
import net.minecraft.client.renderer.ActiveRenderInfo;
import net.minecraft.client.renderer.BufferBuilder;
import net.minecraft.client.renderer.FogRenderer;
import net.minecraft.client.renderer.GameRenderer;
import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
import net.minecraft.client.renderer.vertex.VertexBuffer;
import net.minecraft.client.renderer.vertex.VertexFormat;
import net.minecraft.profiler.IProfiler;
import net.minecraft.util.math.AxisAlignedBB;
import net.minecraft.util.math.vector.Matrix4f;
import net.minecraft.util.math.vector.Vector3d;
import net.minecraft.util.math.vector.Vector3f;


/**
 * @author James Seibel
 * @version 2-24-2021
 */
public class LodRenderer
{
	/** this is the light used when rendering the LODs,
	 * it should be something different than what is used by Minecraft */
	private static final int LOD_GL_LIGHT_NUMBER = GL11.GL_LIGHT2;

	/** If true the LODs colors will be replaced with
	 * a checkerboard, this can be used for debugging. */
	public boolean debugging = false;
	
	private Minecraft mc;
	private GameRenderer gameRender;
	private IProfiler profiler;
	private float farPlaneDistance;
	/** this is the radius of the LODs */
	private static final int LOD_CHUNK_DISTANCE_RADIUS = 6;
	
	private ReflectionHandler reflectionHandler;
	
	public LodDimension lodDimension = null;
	
	
	/** This is used to generate the buildable buffers */
	private LodBufferBuilder lodBufferBuilder = null;
	
	/** The buffers that are used to draw LODs using near fog */
	private volatile BufferBuilder drawableNearBuffer = null;
	/** The buffers that are used to draw LODs using far fog */
	private volatile BufferBuilder drawableFarBuffer = null;
	
	/** The buffers that are used to create LODs using near fog */
	private volatile BufferBuilder buildableNearBuffer = null;
	/** The buffers that are used to create LODs using far fog */
	private volatile BufferBuilder buildableFarBuffer = null;
	
	/** This is the VertexBuffer used to draw any LODs that use near fog */
	private volatile VertexBuffer nearVbo = null;
	/** This is the VertexBuffer used to draw any LODs that use far fog */
	private volatile VertexBuffer farVbo = null;
	public static final VertexFormat LOD_VERTEX_FORMAT = DefaultVertexFormats.POSITION_COLOR;
	
	/** This holds the thread used to generate new LODs off the main thread. */
	private ExecutorService genThread = Executors.newSingleThreadExecutor();
	
	/** This is used to determine if the LODs should be regenerated */
	private int previousChunkRenderDistance = 0;
	/** This is used to determine if the LODs should be regenerated */
	private int prevChunkX = 0;
	/** This is used to determine if the LODs should be regenerated */
	private int prevChunkZ = 0;
	/** This is used to determine if the LODs should be regenerated */
	private FogDistance prevFogDistance = FogDistance.NEAR_AND_FAR;
	
	/** if this is true the LOD buffers should be regenerated,
	 * provided they aren't already being regenerated. */
	private boolean regen = false;
	/** if this is true the LOD buffers are currently being
	 * regenerated. */
	private volatile boolean regenerating = false;
	/** if this is true new LOD buffers have been generated 
	 * and are waiting to be swapped with the drawable buffers*/
	private volatile boolean switchBuffers = false;
	
	
	
	
	
	
	public LodRenderer()
	{
		mc = Minecraft.getInstance();
		gameRender = mc.gameRenderer;
		
		reflectionHandler = new ReflectionHandler();
	}
	
	
	/**
	 * Besides drawing the LODs this method also starts
	 * the async process of generating the Buffers that hold those LODs.
	 * 
	 * @param newDimension The dimension to draw, if null doesn't replace the current dimension.
	 * @param partialTicks how far into the current tick this method was called.
	 */
	@SuppressWarnings("deprecation")
	public void drawLODs(LodDimension newDimension, float partialTicks, IProfiler newProfiler)
	{		
		if (lodDimension == null && newDimension == null)
		{
			// if there aren't any loaded LodChunks
			// don't try drawing anything
			return;
		}
		
		
		
		
		
		
		//===============//
		// initial setup //
		//===============//
		
		
		// used for debugging and viewing how long different processes take
		profiler = newProfiler;
		profiler.endSection();
		profiler.startSection("LOD");
		profiler.startSection("LOD setup");
		
		ClientPlayerEntity player = mc.player;
		
		// should LODs be regenerated?
		if ((int)player.getPosX() / LodChunk.WIDTH != prevChunkX ||
			(int)player.getPosZ() / LodChunk.WIDTH != prevChunkZ ||
			previousChunkRenderDistance != mc.gameSettings.renderDistanceChunks ||
			prevFogDistance != LodConfig.COMMON.fogDistance.get() ||
			lodDimension != newDimension)
		{
			// yes
			regen = true;
			
			prevChunkX = (int)player.getPosX() / LodChunk.WIDTH;
			prevChunkZ = (int)player.getPosZ() / LodChunk.WIDTH;
			prevFogDistance = LodConfig.COMMON.fogDistance.get();
		}
		else
		{
			// nope, the player hasn't moved, the
			// render distance hasn't changed, and
			// the dimension is the same
			regen = false;
		}
		
		lodDimension = newDimension;
		if (lodDimension == null)
		{
			// if there aren't any loaded LodChunks
			// don't try drawing anything
			return;
		}
		
		if (LodConfig.COMMON.drawCheckerBoard.get())
		{
			if (debugging != LodConfig.COMMON.drawCheckerBoard.get())
				regen = true;
			debugging = true;
		}
		else
		{
			if (debugging != LodConfig.COMMON.drawCheckerBoard.get())
				regen = true;
			debugging = false;
		}
		
		
		
		// determine how far the game's render distance is currently set
		int renderDistWidth = mc.gameSettings.renderDistanceChunks;
		farPlaneDistance = renderDistWidth * LodChunk.WIDTH;
		
		// set how big the LODs will be and how far they will go
		int totalLength = (int) farPlaneDistance * LOD_CHUNK_DISTANCE_RADIUS * 2;
		int numbChunksWide = (totalLength / LodChunk.WIDTH);
		
		
		
		
		
		
		//=================//
		// create the LODs //
		//=================//
		
		// only regenerate the LODs if:
		// 1. we want to regenerate LODs
		// 2. we aren't already regenerating the LODs
		// 3. we aren't waiting for the build and draw buffers to swap
		//		(this is to prevent thread conflicts)
		if (regen && !regenerating && !switchBuffers)
		{
			profiler.endStartSection("LOD generation");
			regenerating = true;
			
			if (lodBufferBuilder == null)
				lodBufferBuilder = new LodBufferBuilder();
			
			// this will mainly happen when the view distance is changed
			if (drawableNearBuffer == null || drawableFarBuffer == null || 
				previousChunkRenderDistance != mc.gameSettings.renderDistanceChunks)
				setupBuffers(numbChunksWide);
			
			// generate the LODs on a separate thread to prevent stuttering or freezing
			genThread.execute(createLodBufferGenerationThread(player.getPosX(), player.getPosZ(), numbChunksWide));
		}
		
		// replace the buffers used to draw and build,
		// this is only done when the createLodBufferGenerationThread
		// has finished executing on a parallel thread.
		if (switchBuffers)
		{
			swapBuffers();
			switchBuffers = false;
		}
		
		
		
		
		
		//===========================//
		// GL settings for rendering //
		//===========================//
		
		// set the required open GL settings
		GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_FILL);
		GL11.glBlendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
		GL11.glDisable(GL11.GL_TEXTURE_2D);
		GL11.glEnable(GL11.GL_CULL_FACE);
		GL11.glEnable(GL11.GL_COLOR_MATERIAL);
		GL11.glEnable(GL11.GL_DEPTH_TEST);
		
		Matrix4f modelViewMatrix = generateModelViewMatrix();
		
		setupProjectionMatrix(partialTicks);
//		setupLighting(partialTicks);
		
		
		
		
		
		
		
		
		
		
		//===========//
		// rendering //
		//===========//
		
		switch(LodConfig.COMMON.fogDistance.get())
		{
		case NEAR_AND_FAR:
			// when drawing NEAR_AND_FAR fog we need 2 draw
			// calls since fog can only go in one direction at a time
			
			setupFog(FogDistance.NEAR, reflectionHandler.getFogQuality());
			sendLodsToGpuAndDraw(nearVbo, modelViewMatrix);
			
			setupFog(FogDistance.FAR, reflectionHandler.getFogQuality());
			sendLodsToGpuAndDraw(farVbo, modelViewMatrix);
			break;
			
		case NEAR:
			setupFog(FogDistance.NEAR, reflectionHandler.getFogQuality());
			sendLodsToGpuAndDraw(nearVbo, modelViewMatrix);
			break;
			
		case FAR:
			setupFog(FogDistance.FAR, reflectionHandler.getFogQuality());
			sendLodsToGpuAndDraw(farVbo, modelViewMatrix);
			break;
		}
		
		
		
		
		//=========//
		// cleanup //
		//=========//
		
		profiler.endStartSection("LOD cleanup");
		
		// this must be done otherwise other parts of the screen may be drawn with a fog effect
		// IE the GUI
		FogRenderer.resetFog();
		RenderSystem.disableFog();
		
		GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_FILL);
		GL11.glEnable(GL11.GL_TEXTURE_2D);
		GL11.glDisable(LOD_GL_LIGHT_NUMBER);
		GL11.glDisable(GL11.GL_COLOR_MATERIAL);
		GL11.glDisable(GL11.GL_DEPTH_TEST);
		
		// this can't be called until after the buffers are built
		// because otherwise the buffers may be set to the wrong size
		previousChunkRenderDistance = mc.gameSettings.renderDistanceChunks;
		
		
		// end of profiler tracking
		profiler.endSection();
	}
	
	
	private Matrix4f generateModelViewMatrix()
	{
		// get all relevant camera info
		ActiveRenderInfo renderInfo = mc.gameRenderer.getActiveRenderInfo();
        Vector3d projectedView = renderInfo.getProjectedView();
		double cameraX = projectedView.x;
		double cameraY = projectedView.y;
		double cameraZ = projectedView.z;
		
		
		// generate the model view matrix
		MatrixStack matrixStack = new MatrixStack();
        matrixStack.push();
        // translate and rotate to the current camera location
        matrixStack.rotate(Vector3f.XP.rotationDegrees(renderInfo.getPitch()));
        matrixStack.rotate(Vector3f.YP.rotationDegrees(renderInfo.getYaw() + 180));
        matrixStack.translate(-cameraX, -cameraY, -cameraZ);
        
        return matrixStack.getLast().getMatrix();
	}


	/**
	 * This is where the actual drawing happens.
	 * 
	 * @param buffers the buffers sent to the GPU to draw
	 */
	private void sendLodsToGpuAndDraw(VertexBuffer vbo, Matrix4f modelViewMatrix)
	{
		if (vbo == null)
			return;
		
		profiler.endStartSection("LOD draw setup");
        vbo.bindBuffer();
        LOD_VERTEX_FORMAT.setupBufferState(0L); // TODO what does this do?
        
        profiler.endStartSection("LOD draw");
        vbo.draw(modelViewMatrix, 7); // TODO what is 7?
        
        profiler.endStartSection("LOD draw cleanup");
        VertexBuffer.unbindBuffer();
        LOD_VERTEX_FORMAT.clearBufferState();
	}
	
	
	
	
	
	
	
	//=================//
	// Setup Functions //
	//=================//
	
	@SuppressWarnings("deprecation")
	private void setupFog(FogDistance fogDistance, FogQuality fogQuality)
	{
		if(fogQuality == FogQuality.OFF)
		{
			FogRenderer.resetFog();
			RenderSystem.disableFog();
			return;
		}
		
		if(fogDistance == FogDistance.NEAR_AND_FAR)
		{
			throw new IllegalArgumentException("setupFog doesn't accept the NEAR_AND_FAR fog distance.");
		}

		// the multipliers are percentages
		// of the regular view distance.
		
		if(fogDistance == FogDistance.NEAR)
		{
			// the reason that I wrote fogEnd then fogStart backwards
			// is because we are using fog backwards to how
			// it is normally used, with it hiding near objects
			// instead of far objects.
			
			if (fogQuality == FogQuality.FANCY)
			{
				RenderSystem.fogEnd(farPlaneDistance * 0.3f * LOD_CHUNK_DISTANCE_RADIUS);
				RenderSystem.fogStart(farPlaneDistance * 0.35f * LOD_CHUNK_DISTANCE_RADIUS);
			}
			else if(fogQuality == FogQuality.FAST)
			{
				// for the far fog of the normal chunks
				// to start right where the LODs' end use:
				// end = 0.8f, start = 1.5f
				
				RenderSystem.fogEnd(farPlaneDistance * 1.5f);
				RenderSystem.fogStart(farPlaneDistance * 2.0f);
			}
		}
		else if(fogDistance == FogDistance.FAR)
		{
			if (fogQuality == FogQuality.FANCY)
			{
				RenderSystem.fogStart(farPlaneDistance * 0.78f * LOD_CHUNK_DISTANCE_RADIUS);
				RenderSystem.fogEnd(farPlaneDistance * 1.0f * LOD_CHUNK_DISTANCE_RADIUS);
			}
			else if(fogQuality == FogQuality.FAST)
			{
				RenderSystem.fogStart(farPlaneDistance * 0.5f * LOD_CHUNK_DISTANCE_RADIUS);
				RenderSystem.fogEnd(farPlaneDistance * 0.75f * LOD_CHUNK_DISTANCE_RADIUS);
			}
		}
		
		RenderSystem.fogMode(GlStateManager.FogMode.LINEAR);
		RenderSystem.enableFog();
	}
	

	/**
	 * create a new projection matrix and send it over to the GPU
	 * @param partialTicks how many ticks into the frame we are
	 */
	private void setupProjectionMatrix(float partialTicks)
	{
		ActiveRenderInfo activeRenderInfoIn = mc.gameRenderer.getActiveRenderInfo();
		
		Matrix4f projectionMatrix = 
				Matrix4f.perspective(
				gameRender.getFOVModifier(activeRenderInfoIn, partialTicks, true), 
				(float)this.mc.getMainWindow().getFramebufferWidth() / (float)this.mc.getMainWindow().getFramebufferHeight(), 
				0.5F, 
				this.farPlaneDistance * LOD_CHUNK_DISTANCE_RADIUS * 2);
		
		gameRender.resetProjectionMatrix(projectionMatrix);
		
		return;
	}
	
	
	/**
	 * setup the lighting to be used for the LODs
	 */
	@SuppressWarnings({ "unused", "deprecation" })
	private void setupLighting(float partialTicks)
	{
		GL11.glEnable(GL11.GL_COLOR_MATERIAL); // set the color to be used as the material (this allows lighting to be enabled)
		
		// FIXME
		// this isn't perfect right now, but it looks pretty good at 50% brightness
		float sunBrightness = mc.world.getSunBrightness(partialTicks); // * mc.world.provider.getSunBrightnessFactor(partialTicks);
		float skyHasLight = 1.0f; //mc.world.provider.hasSkyLight()? 1.0f : 0.15f;
		float gammaMultiplyer = (float) mc.gameSettings.gamma * 0.5f + 0.5f;
		float lightStrength = sunBrightness * skyHasLight * gammaMultiplyer;
		float lightAmbient[] = {lightStrength, lightStrength, lightStrength, 1.0f};
        
		ByteBuffer temp = ByteBuffer.allocateDirect(16);
		temp.order(ByteOrder.nativeOrder());
		GL11.glLightfv(LOD_GL_LIGHT_NUMBER, GL11.GL_AMBIENT, (FloatBuffer) temp.asFloatBuffer().put(lightAmbient).flip());
		GL11.glEnable(LOD_GL_LIGHT_NUMBER); // Enable the above lighting
		
		RenderSystem.enableLighting();
	}
	
	/**
	 * Create all buffers that will be used.
	 */
	private void setupBuffers(int numbChunksWide)
	{
		// calculate the max amount of storage needed (in bytes)
		int bufferMaxCapacity = (numbChunksWide * numbChunksWide * (6 * 4 * (3 + 4)));
		// (numbChunksWide * numbChunksWide * 
		// (sidesOnACube * pointsInASquare * (positionPoints + colorPoints)))
		
		// TODO complain or do something when memory is too low
		// currently the VM will just crash and complain there is no more memory
		// issue #4
		drawableNearBuffer = new BufferBuilder(bufferMaxCapacity);
		drawableFarBuffer = new BufferBuilder(bufferMaxCapacity);
		
		buildableNearBuffer = new BufferBuilder(bufferMaxCapacity);
		buildableFarBuffer = new BufferBuilder(bufferMaxCapacity);
	}
	
	
	
	
	
	
	
	//======================//
	// Other Misc Functions // 
	//======================//
	
	
	/**
	 * @Returns -1 if there are no valid points
	 */
	private int getValidHeightPoint(short[] heightPoints)
	{
		if (heightPoints[LodCorner.NE.value] != -1)
			return heightPoints[LodCorner.NE.value];
		if (heightPoints[LodCorner.NW.value] != -1)
			return heightPoints[LodCorner.NW.value];
		if (heightPoints[LodCorner.SE.value] != -1)
			return heightPoints[LodCorner.NE.value];
		return heightPoints[LodCorner.NE.value];
	}
	
	
	/**
	 * Create a thread to asynchronously generate LOD buffers
	 * centered around the given camera X and Z.
	 * <br>
	 * This thread will write to the drawableNearBuffers and drawableFarBuffers.
	 * <br>
	 * After the buildable buffers have been generated they must be
	 * swapped with the drawable buffers to be drawn.
	 */
	private Thread createLodBufferGenerationThread(double playerX, double playerZ,
			int numbChunksWide)
	{
		// this is where we store the points for each LOD object
		AxisAlignedBB lodArray[][] = new AxisAlignedBB[numbChunksWide][numbChunksWide];
		// this is where we store the color for each LOD object
		Color colorArray[][] = new Color[numbChunksWide][numbChunksWide];
		
		int alpha = 255; // 0 - 255
		Color red = new Color(255, 0, 0, alpha);
		Color black = new Color(0, 0, 0, alpha);
		Color white = new Color(255, 255, 255, alpha);
		@SuppressWarnings("unused")
		Color invisible = new Color(0,0,0,0);
		@SuppressWarnings("unused")
		Color error = new Color(255, 0, 225, alpha); // bright pink
		
		// this seemingly useless math is required,
		// just using (int) camera doesn't work
		int playerXChunkOffset = ((int) playerX / LodChunk.WIDTH) * LodChunk.WIDTH;
		int playerZChunkOffset = ((int) playerZ / LodChunk.WIDTH) * LodChunk.WIDTH;
		// this is where we will start drawing squares
		// (exactly half the total width)
		int startX = (-LodChunk.WIDTH * (numbChunksWide / 2)) + playerXChunkOffset;
		int startZ = (-LodChunk.WIDTH * (numbChunksWide / 2)) + playerZChunkOffset;
		
		Thread t = new Thread(()->
		{
			// x axis
			for (int i = 0; i < numbChunksWide; i++)
			{
				// z axis
				for (int j = 0; j < numbChunksWide; j++)
				{
					// skip the middle
					// (As the player moves some chunks will overlap or be missing,
					// this is just how chunk loading/unloading works. This can hopefully
					// be hidden with careful use of fog)
					int middle = (numbChunksWide / 2);
					if (isCoordInCenterArea(i, j, middle))
					{
						continue;
					}
					
					
					// set where this square will be drawn in the world
					double xOffset = (LodChunk.WIDTH * i) + // offset by the number of LOD blocks
									startX; // offset so the center LOD block is centered underneath the player
					double yOffset = 0;
					double zOffset = (LodChunk.WIDTH * j) + startZ;
					
					int chunkX = i + (startX / LodChunk.WIDTH);
					int chunkZ = j + (startZ / LodChunk.WIDTH);
					
					LodChunk lod = lodDimension.getLodFromCoordinates(chunkX, chunkZ);
					if (lod == null)
					{
						// note: for some reason if any color or lod objects are set here
						// it causes the game to use 100% gpu; 
						// undefined in the debug menu
						// and drop to ~6 fps.
						colorArray[i][j] = null;
						lodArray[i][j] = null;
						
						continue;
					}
					
					Color c = new Color(
							(lod.colors[ColorDirection.TOP.value].getRed()),
							(lod.colors[ColorDirection.TOP.value].getGreen()),
							(lod.colors[ColorDirection.TOP.value].getBlue()),
							lod.colors[ColorDirection.TOP.value].getAlpha());
										
					if (!debugging)
					{
						// add the color to the array
						colorArray[i][j] = c;
					}
					else
					{
						// if debugging draw the squares as a black and white checker board
						if ((chunkX + chunkZ) % 2 == 0)
							c = white;
						else
							c = black;
						// draw the first square as red
						if (i == 0 && j == 0)
							c = red;
						
						colorArray[i][j] = c;
					}
					
					
					// add the new box to the array
					int topPoint = getValidHeightPoint(lod.top);
					int bottomPoint = getValidHeightPoint(lod.bottom);
					
					// don't draw an LOD if it is empty
					if (topPoint == -1 && bottomPoint == -1)
						continue;
					
					lodArray[i][j] = new AxisAlignedBB(0, bottomPoint, 0, LodChunk.WIDTH, topPoint, LodChunk.WIDTH).offset(xOffset, yOffset, zOffset);
				}
			}
			
			// generate our new buildable buffers
			NearFarBuffer nearFarBuffers = lodBufferBuilder.createBuffers(
					buildableNearBuffer, buildableFarBuffer, 
					LodConfig.COMMON.fogDistance.get(), lodArray, colorArray);
			
			// update our buffers
			buildableNearBuffer = nearFarBuffers.nearBuffer;
			buildableFarBuffer = nearFarBuffers.farBuffer;
			
			// mark the buildable buffers as ready to swap
			regenerating = false;
			switchBuffers = true;
		});
		return t;
	}
	
	
	
	/**
	 * Swap buildable and drawable buffers.
	 */
	private void swapBuffers()
	{
		// swap the BufferBuilders
		BufferBuilder tmp = buildableNearBuffer;
		buildableNearBuffer = drawableNearBuffer;
		drawableNearBuffer = tmp;
		
		tmp = buildableFarBuffer;
		buildableFarBuffer = drawableFarBuffer;
		drawableFarBuffer = tmp;
		
		
		// bind the buffers with their respective VBOs
		if (nearVbo != null)
			nearVbo.close();
		
		nearVbo = new VertexBuffer(LOD_VERTEX_FORMAT);
		nearVbo.upload(drawableNearBuffer);
		
		
		if (farVbo != null)
			farVbo.close();
		
		farVbo = new VertexBuffer(LOD_VERTEX_FORMAT);
		farVbo.upload(drawableFarBuffer);
	}
	
	
	/**
	 * Returns if the given coordinate is in the loaded area of the world.
	 * @param centerCoordinate the center of the loaded world
	 */
	private boolean isCoordInCenterArea(int i, int j, int centerCoordinate)
	{
		return (i >= centerCoordinate - mc.gameSettings.renderDistanceChunks 
				&& i <= centerCoordinate + mc.gameSettings.renderDistanceChunks) 
				&& 
				(j >= centerCoordinate - mc.gameSettings.renderDistanceChunks 
				&& j <= centerCoordinate + mc.gameSettings.renderDistanceChunks);
	}
	
	
	public double getFov(float partialTicks, boolean useFovSetting)
	{
		return mc.gameRenderer.getFOVModifier(mc.gameRenderer.getActiveRenderInfo(), partialTicks, useFovSetting);
	}
	
	
	
}