IndustrialWires/src/main/java/malte0811/industrialWires/client/render/TileRenderMarx.java

/*
 * This file is part of Industrial Wires.
 * Copyright (C) 2016-2017 malte0811
 *
 * Industrial Wires is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Industrial Wires 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Industrial Wires.  If not, see <http://www.gnu.org/licenses/>.
 */

package malte0811.industrialWires.client.render;

import blusunrize.immersiveengineering.common.util.chickenbones.Matrix4;
import malte0811.industrialWires.blocks.IWProperties;
import malte0811.industrialWires.blocks.hv.TileEntityMarx;
import malte0811.industrialWires.util.MiscUtils;
import net.minecraft.client.Minecraft;
import net.minecraft.client.renderer.GlStateManager;
import net.minecraft.client.renderer.Tessellator;
import net.minecraft.client.renderer.VertexBuffer;
import net.minecraft.client.renderer.tileentity.TileEntitySpecialRenderer;
import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.Vec3i;
import net.minecraft.world.World;
import org.lwjgl.opengl.GL11;
import org.lwjgl.util.vector.Vector3f;

public class TileRenderMarx extends TileEntitySpecialRenderer<TileEntityMarx> {
	@Override
	public void renderTileEntityAt(TileEntityMarx te, double x, double y, double z, float partialTicks, int destroyStage) {
		final boolean debug = false;
		//noinspection ConstantConditions,PointlessBooleanExpression
		if (te.type== IWProperties.MarxType.BOTTOM&&(debug||te.state== TileEntityMarx.FiringState.FIRE)) {
			prepare(x, y, z, te);
			Tessellator tes = Tessellator.getInstance();
			VertexBuffer vb = tes.getBuffer();

			drawDischarge(te.dischargeData, vb, tes);
			GlStateManager.popMatrix();
			GlStateManager.pushMatrix();
			Vec3i offset = MiscUtils.offset(BlockPos.ORIGIN, te.facing, te.mirrored, 1, 1, 0);
			GlStateManager.translate(x+offset.getX(), y+offset.getY()+.75, z+offset.getZ());
			Vec3i facing = te.facing.getDirectionVec();
			final float pos = .6875F;
			GlStateManager.translate(-facing.getX()*pos, 0, -facing.getZ()*pos);
			//draw firing spark gaps
			for (int i = 0;i<te.getStageCount()-1;i++) {
				GlStateManager.pushMatrix();
				GlStateManager.translate(0, i, 0);
				GlStateManager.rotate(-45, facing.getX(), facing.getY(), facing.getZ());
				GlStateManager.rotate(-Minecraft.getMinecraft().player.rotationYaw+180, 0, 1, 0);
				vb.begin(GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR);
				drawDischargeSection(new Vector3f(0, -.2F, 0), new Vector3f(0, .2F, 0), .25F, vb);
				tes.draw();
				GlStateManager.popMatrix();
			}
			cleanUp();
			te.state = TileEntityMarx.FiringState.CHARGING;
		}
	}
	private void prepare(double x, double y, double z, TileEntityMarx te) {
		setLightmapDisabled(true);
		GlStateManager.pushMatrix();
		Vec3i offset = MiscUtils.offset(BlockPos.ORIGIN, te.facing, te.mirrored, 1, 4, 1);
		GlStateManager.translate(x+offset.getX()+.5, y+offset.getY(), z+offset.getZ()+.5);
		GlStateManager.disableTexture2D();
		GlStateManager.disableLighting();
		GlStateManager.shadeModel(GL11.GL_SMOOTH);
		GlStateManager.color(1, 1, 1, 1);
		GlStateManager.enableBlend();
		GlStateManager.blendFunc(GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA);
		GlStateManager.rotate(-Minecraft.getMinecraft().player.rotationYaw+180, 0, 1, 0);
	}
	private void cleanUp() {
		setLightmapDisabled(false);
		GlStateManager.popMatrix();
		GlStateManager.enableTexture2D();
		GlStateManager.enableLighting();
		GlStateManager.shadeModel(GL11.GL_FLAT);
		GlStateManager.disableBlend();
	}
	private static final float[] WHITE = {1, 1, 1, 1};
	private static final float[] WHITE_TRANSPARENT = {1, 1, 1, 0};
	private void drawDischarge(Discharge d, VertexBuffer vb, Tessellator tes) {
		if (d!=null&&d.vertices!=null) {
			vb.begin(GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR);
			for (int i = 0;i<d.vertices.length-1;i++) {
				drawDischargeSection(d.vertices[i], d.vertices[i+1], d.diameter, vb);
			}
			tes.draw();
		}
	}
	private void drawDischargeSection(Vector3f start, Vector3f end, float diameter, VertexBuffer vb) {
		drawPart(start, end, diameter/3, diameter/3, WHITE_TRANSPARENT, WHITE, vb);
		drawPart(start, end, 0, diameter/3, WHITE, WHITE, vb);
		drawPart(start, end, -diameter/3, diameter/3, WHITE, WHITE_TRANSPARENT, vb);
	}
	private void drawPart(Vector3f start, Vector3f end, float offset, float width, float[] color1, float[] color2, VertexBuffer vb) {
		vb.setTranslation(-offset-width/2, 0, 0);
		vb.pos(start.x, start.y, start.z).color(color1[0], color1[1], color1[2], color1[3]).endVertex();
		vb.pos(start.x+width, start.y, start.z).color(color2[0], color2[1], color2[2], color2[3]).endVertex();
		vb.pos(end.x+width, end.y, end.z).color(color2[0], color2[1], color2[2], color2[3]).endVertex();
		vb.pos(end.x, end.y, end.z).color(color1[0], color1[1], color1[2], color1[3]).endVertex();
		vb.setTranslation(0, 0, 0);
	}
	public static final class Discharge {
		public float energy;
		public Vector3f[] vertices;
		public float diameter = .25F;
		public final int stageCount;
		public Discharge(int stages) {
			stageCount = stages;
			int count = 1;
			while (count<stageCount) {
				count <<= 1;
			}
			count = 8;
			vertices = new Vector3f[2*count];
			vertices[0] = new Vector3f(0, -.5F, 0);
			for (int i = 1;i<vertices.length;i++) {
				vertices[i] = new Vector3f();
			}
			vertices[vertices.length-1] = new Vector3f(0, stageCount-1.9375F, 0);

		}

		// Meant to be const
		private final Vector3f up = new Vector3f(0, 1, 0);
		private final Vector3f side = new Vector3f(0, 0, 1);
		//used for calculation buffering
		private final Vector3f diff = new Vector3f();
		private final Vector3f center = new Vector3f();
		private final Vector3f v0 = new Vector3f();
		private final Matrix4 transform = new Matrix4();
		/**
		 * @param min The first point of the discharge section to be generated. has to be pre-populated
		 * @param max The last point of the discharge section to be generated. has to be pre-populated
		 */
		public void genMarxPoint(int min, int max) {
			World world = Minecraft.getMinecraft().world;
			int toGenerate = (min+max)/2;
			Vector3f.sub(vertices[max], vertices[min], diff);
			Vector3f.cross(diff, side, v0);
			transform.setIdentity();
			double noise = Math.sqrt(diff.length())*world.rand.nextDouble()*1/(1+Math.abs(stageCount/2.0-toGenerate))*.75;
			if ((max-min)%2==1) {
				noise *= (toGenerate-min)/(double)(max-min);
			}
			v0.scale((float) (noise/v0.length()));
			diff.scale(1/diff.length());
			transform.rotate(Math.PI*2*world.rand.nextDouble(), diff.x, diff.y, diff.z);
			Vector3f.add(vertices[max], vertices[min], center);
			center.scale(.5F);
			vertices[toGenerate] = transform.apply(v0);
			//IELogger.info(toGenerate+" with noise "+noise+" shift-to-noise "+vertices[toGenerate].length()/noise);
			Vector3f.add(vertices[toGenerate], center, vertices[toGenerate]);

			if (toGenerate-min>1) {
				genMarxPoint(min, toGenerate);
			}
			if (max-toGenerate>1) {
				genMarxPoint(toGenerate, max);
			}
		}
	}
}