Better blaze head rotation

src/main/java/com/simibubi/create/content/contraptions/processing/HeaterRenderer.java

@@ -1,21 +1,18 @@
 package com.simibubi.create.content.contraptions.processing;
 
+import java.util.HashMap;
+
 import com.mojang.blaze3d.matrix.MatrixStack;
 import com.simibubi.create.AllBlockPartials;
 import com.simibubi.create.foundation.tileEntity.renderer.SafeTileEntityRenderer;
 import com.simibubi.create.foundation.utility.SuperByteBuffer;
 
-import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.IRenderTypeBuffer;
 import net.minecraft.client.renderer.RenderType;
-import net.minecraft.client.renderer.Vector3f;
 import net.minecraft.client.renderer.tileentity.TileEntityRendererDispatcher;
 import net.minecraft.util.Direction;
 
-import java.util.HashMap;
-
 public class HeaterRenderer extends SafeTileEntityRenderer<HeaterTileEntity> {
-	private static final Minecraft INSTANCE = Minecraft.getInstance();
 	private static final HashMap<HeaterBlock.HeatLevel, AllBlockPartials> blazeModelMap = new HashMap<>();
 
 	public HeaterRenderer(TileEntityRendererDispatcher dispatcher) {
@@ -31,22 +28,8 @@ public class HeaterRenderer extends SafeTileEntityRenderer<HeaterTileEntity> {
 		AllBlockPartials blazeModel =
 			blazeModelMap.getOrDefault(te.getHeatLevel(), AllBlockPartials.BLAZE_HEATER_BLAZE_ONE);
 		
-		float angle;
-		if (INSTANCE.player == null) {
-			angle = 0;
-		} else {
-			Vector3f difference = new Vector3f(INSTANCE.player.getPositionVector()
-				.subtract(te.getPos()
-					.getX() + 0.5, 0,
-					te.getPos()
-						.getZ() + 0.5)
-				.mul(1, 0, 1));
-			difference.normalize();
-			angle = (float) ((difference.getX() < 0 ? 1 : -1) * Math.acos(Direction.NORTH.getUnitVector()
-				.dot(difference)));
-		}
 		SuperByteBuffer blazeBuffer = blazeModel.renderOn(te.getBlockState());
-		blazeBuffer.rotateCentered(Direction.UP, angle);
+		blazeBuffer.rotateCentered(Direction.UP, (float) Math.toRadians(-te.rot + (te.speed * partialTicks)));
-		blazeBuffer.renderInto(ms, buffer.getBuffer(RenderType.getSolid()));
+		blazeBuffer.light(0xF000F0).renderInto(ms, buffer.getBuffer(RenderType.getSolid()));
 	}
 }

src/main/java/com/simibubi/create/content/contraptions/processing/HeaterTileEntity.java

@@ -10,12 +10,15 @@ import com.simibubi.create.content.contraptions.particle.CubeParticleData;
 import com.simibubi.create.foundation.tileEntity.SmartTileEntity;
 import com.simibubi.create.foundation.tileEntity.TileEntityBehaviour;
 import com.simibubi.create.foundation.utility.ColorHelper;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.entity.player.ClientPlayerEntity;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.entity.projectile.EggEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompoundNBT;
-import net.minecraft.tileentity.TileEntity;
 import net.minecraft.particles.IParticleData;
+import net.minecraft.tileentity.TileEntity;
 import net.minecraft.tileentity.TileEntityType;
 import net.minecraft.util.SoundCategory;
 import net.minecraft.util.math.BlockPos;
@@ -43,6 +46,9 @@ public class HeaterTileEntity extends SmartTileEntity {
 	private int remainingBurnTime;
 	private FuelType activeFuel;
 	
+	// Rendering state
+	float rot, speed;
+
 	public HeaterTileEntity(TileEntityType<? extends HeaterTileEntity> tileEntityTypeIn) {
 		super(tileEntityTypeIn);
 		activeFuel = FuelType.NONE;
@@ -53,6 +59,9 @@ public class HeaterTileEntity extends SmartTileEntity {
 	@Override
 	public void tick() {
 		super.tick();
+		if (world.isRemote) {
+			tickRotation();
+		}
 
 		spawnParticles(getHeatLevel());
 
@@ -72,6 +81,68 @@ public class HeaterTileEntity extends SmartTileEntity {
 		markDirty();
 	}
 	
+	private static final float MAX_ROT_SPEED = 5;
+	private static final float ROT_DAMPING = 15;
+	
+	private void tickRotation() {
+		ClientPlayerEntity player = Minecraft.getInstance().player;
+		Angle target;
+		if (player == null) {
+			target = new Angle(360, 0);
+		} else {
+			double dx = player.getX() - (getPos().getX() + 0.5);
+			double dz = player.getZ() - (getPos().getZ() + 0.5);
+			target = new Angle(360, (float) (MathHelper.atan2(dz, dx) * 180.0 / Math.PI + 90));
+		}
+
+		Angle current = new Angle(360, rot);
+		float diff = new Angle(180, current.get() - target.get()).get();
+		if (diff > 0.1 || diff < -0.1) {
+			// Inverse function https://www.desmos.com/calculator/kiaberb6sf
+			speed = MAX_ROT_SPEED + (-MAX_ROT_SPEED / ((Math.abs(diff) / ROT_DAMPING) + 1));
+			if (diff > 0) {
+				current.add(-Math.min(diff, speed));
+				speed = Math.min(diff, speed);
+			} else {
+				current.add(Math.min(-diff, speed));
+				speed = Math.min(-diff, -speed);
+			}
+		} else {
+			speed = 0;
+		}
+		
+		rot = current.get();
+	}
+	
+	// From EnderIO with <3
+	private static class Angle {
+		private final float offset;
+		private float a;
+
+		Angle(float offset, float a) {
+			this.offset = offset;
+			set(a);
+		}
+
+		void set(float a) {
+			while (a >= offset) {
+				a -= 360;
+			}
+			while (a < (offset - 360)) {
+				a += 360;
+			}
+			this.a = a;
+		}
+
+		void add(float b) {
+			set(a + b);
+		}
+
+		float get() {
+			return a;
+		}
+	}
+
 	@Override
 	public void lazyTick() {
 		super.lazyTick();