minecraft-src/net/minecraft/client/renderer/LightTexture.java

package net.minecraft.client.renderer;

import com.mojang.blaze3d.platform.NativeImage;
import com.mojang.blaze3d.systems.RenderSystem;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.Minecraft;
import net.minecraft.client.multiplayer.ClientLevel;
import net.minecraft.client.renderer.texture.DynamicTexture;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.Mth;
import net.minecraft.world.effect.MobEffectInstance;
import net.minecraft.world.effect.MobEffects;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.level.dimension.DimensionType;
import org.joml.Vector3f;

@Environment(EnvType.CLIENT)
public class LightTexture implements AutoCloseable {
	public static final int FULL_BRIGHT = 15728880;
	public static final int FULL_SKY = 15728640;
	public static final int FULL_BLOCK = 240;
	private final DynamicTexture lightTexture;
	private final NativeImage lightPixels;
	private final ResourceLocation lightTextureLocation;
	private boolean updateLightTexture;
	private float blockLightRedFlicker;
	private final GameRenderer renderer;
	private final Minecraft minecraft;

	public LightTexture(GameRenderer renderer, Minecraft minecraft) {
		this.renderer = renderer;
		this.minecraft = minecraft;
		this.lightTexture = new DynamicTexture(16, 16, false);
		this.lightTextureLocation = this.minecraft.getTextureManager().register("light_map", this.lightTexture);
		this.lightPixels = this.lightTexture.getPixels();

		for (int i = 0; i < 16; i++) {
			for (int j = 0; j < 16; j++) {
				this.lightPixels.setPixelRGBA(j, i, -1);
			}
		}

		this.lightTexture.upload();
	}

	public void close() {
		this.lightTexture.close();
	}

	public void tick() {
		this.blockLightRedFlicker = this.blockLightRedFlicker + (float)((Math.random() - Math.random()) * Math.random() * Math.random() * 0.1);
		this.blockLightRedFlicker *= 0.9F;
		this.updateLightTexture = true;
	}

	public void turnOffLightLayer() {
		RenderSystem.setShaderTexture(2, 0);
	}

	public void turnOnLightLayer() {
		RenderSystem.setShaderTexture(2, this.lightTextureLocation);
		this.minecraft.getTextureManager().bindForSetup(this.lightTextureLocation);
		RenderSystem.texParameter(3553, 10241, 9729);
		RenderSystem.texParameter(3553, 10240, 9729);
	}

	private float getDarknessGamma(float partialTick) {
		MobEffectInstance mobEffectInstance = this.minecraft.player.getEffect(MobEffects.DARKNESS);
		return mobEffectInstance != null ? mobEffectInstance.getBlendFactor(this.minecraft.player, partialTick) : 0.0F;
	}

	private float calculateDarknessScale(LivingEntity entity, float gamma, float partialTick) {
		float f = 0.45F * gamma;
		return Math.max(0.0F, Mth.cos((entity.tickCount - partialTick) * (float) Math.PI * 0.025F) * f);
	}

	public void updateLightTexture(float partialTicks) {
		if (this.updateLightTexture) {
			this.updateLightTexture = false;
			this.minecraft.getProfiler().push("lightTex");
			ClientLevel clientLevel = this.minecraft.level;
			if (clientLevel != null) {
				float f = clientLevel.getSkyDarken(1.0F);
				float g;
				if (clientLevel.getSkyFlashTime() > 0) {
					g = 1.0F;
				} else {
					g = f * 0.95F + 0.05F;
				}

				float h = this.minecraft.options.darknessEffectScale().get().floatValue();
				float i = this.getDarknessGamma(partialTicks) * h;
				float j = this.calculateDarknessScale(this.minecraft.player, i, partialTicks) * h;
				float k = this.minecraft.player.getWaterVision();
				float l;
				if (this.minecraft.player.hasEffect(MobEffects.NIGHT_VISION)) {
					l = GameRenderer.getNightVisionScale(this.minecraft.player, partialTicks);
				} else if (k > 0.0F && this.minecraft.player.hasEffect(MobEffects.CONDUIT_POWER)) {
					l = k;
				} else {
					l = 0.0F;
				}

				Vector3f vector3f = new Vector3f(f, f, 1.0F).lerp(new Vector3f(1.0F, 1.0F, 1.0F), 0.35F);
				float m = this.blockLightRedFlicker + 1.5F;
				Vector3f vector3f2 = new Vector3f();

				for (int n = 0; n < 16; n++) {
					for (int o = 0; o < 16; o++) {
						float p = getBrightness(clientLevel.dimensionType(), n) * g;
						float q = getBrightness(clientLevel.dimensionType(), o) * m;
						float s = q * ((q * 0.6F + 0.4F) * 0.6F + 0.4F);
						float t = q * (q * q * 0.6F + 0.4F);
						vector3f2.set(q, s, t);
						boolean bl = clientLevel.effects().forceBrightLightmap();
						if (bl) {
							vector3f2.lerp(new Vector3f(0.99F, 1.12F, 1.0F), 0.25F);
							clampColor(vector3f2);
						} else {
							Vector3f vector3f3 = new Vector3f(vector3f).mul(p);
							vector3f2.add(vector3f3);
							vector3f2.lerp(new Vector3f(0.75F, 0.75F, 0.75F), 0.04F);
							if (this.renderer.getDarkenWorldAmount(partialTicks) > 0.0F) {
								float u = this.renderer.getDarkenWorldAmount(partialTicks);
								Vector3f vector3f4 = new Vector3f(vector3f2).mul(0.7F, 0.6F, 0.6F);
								vector3f2.lerp(vector3f4, u);
							}
						}

						if (l > 0.0F) {
							float v = Math.max(vector3f2.x(), Math.max(vector3f2.y(), vector3f2.z()));
							if (v < 1.0F) {
								float u = 1.0F / v;
								Vector3f vector3f4 = new Vector3f(vector3f2).mul(u);
								vector3f2.lerp(vector3f4, l);
							}
						}

						if (!bl) {
							if (j > 0.0F) {
								vector3f2.add(-j, -j, -j);
							}

							clampColor(vector3f2);
						}

						float v = this.minecraft.options.gamma().get().floatValue();
						Vector3f vector3f5 = new Vector3f(this.notGamma(vector3f2.x), this.notGamma(vector3f2.y), this.notGamma(vector3f2.z));
						vector3f2.lerp(vector3f5, Math.max(0.0F, v - i));
						vector3f2.lerp(new Vector3f(0.75F, 0.75F, 0.75F), 0.04F);
						clampColor(vector3f2);
						vector3f2.mul(255.0F);
						int w = 255;
						int x = (int)vector3f2.x();
						int y = (int)vector3f2.y();
						int z = (int)vector3f2.z();
						this.lightPixels.setPixelRGBA(o, n, 0xFF000000 | z << 16 | y << 8 | x);
					}
				}

				this.lightTexture.upload();
				this.minecraft.getProfiler().pop();
			}
		}
	}

	private static void clampColor(Vector3f color) {
		color.set(Mth.clamp(color.x, 0.0F, 1.0F), Mth.clamp(color.y, 0.0F, 1.0F), Mth.clamp(color.z, 0.0F, 1.0F));
	}

	private float notGamma(float value) {
		float f = 1.0F - value;
		return 1.0F - f * f * f * f;
	}

	public static float getBrightness(DimensionType dimensionType, int lightLevel) {
		float f = lightLevel / 15.0F;
		float g = f / (4.0F - 3.0F * f);
		return Mth.lerp(dimensionType.ambientLight(), g, 1.0F);
	}

	public static int pack(int blockLight, int skyLight) {
		return blockLight << 4 | skyLight << 20;
	}

	public static int block(int packedLight) {
		return packedLight >> 4 & 65535;
	}

	public static int sky(int packedLight) {
		return packedLight >> 20 & 65535;
	}
}