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

package net.minecraft.client.renderer;

import com.mojang.blaze3d.platform.GlStateManager;
import com.mojang.blaze3d.systems.RenderSystem;
import com.mojang.blaze3d.vertex.BufferBuilder;
import com.mojang.blaze3d.vertex.BufferUploader;
import com.mojang.blaze3d.vertex.DefaultVertexFormat;
import com.mojang.blaze3d.vertex.MeshData;
import com.mojang.blaze3d.vertex.Tesselator;
import com.mojang.blaze3d.vertex.VertexFormat;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.Util;
import net.minecraft.client.Minecraft;
import net.minecraft.resources.ResourceLocation;
import net.minecraft.util.ARGB;
import net.minecraft.util.Mth;
import net.minecraft.world.level.border.WorldBorder;
import net.minecraft.world.phys.Vec3;

@Environment(EnvType.CLIENT)
public class WorldBorderRenderer {
	private static final ResourceLocation FORCEFIELD_LOCATION = ResourceLocation.withDefaultNamespace("textures/misc/forcefield.png");

	public void render(WorldBorder worldBorder, Vec3 cameraPosition, double renderDistance, double farPlaneDepth) {
		double d = worldBorder.getMinX();
		double e = worldBorder.getMaxX();
		double f = worldBorder.getMinZ();
		double g = worldBorder.getMaxZ();
		if (!(cameraPosition.x < e - renderDistance)
			|| !(cameraPosition.x > d + renderDistance)
			|| !(cameraPosition.z < g - renderDistance)
			|| !(cameraPosition.z > f + renderDistance)) {
			double h = 1.0 - worldBorder.getDistanceToBorder(cameraPosition.x, cameraPosition.z) / renderDistance;
			h = Math.pow(h, 4.0);
			h = Mth.clamp(h, 0.0, 1.0);
			double i = cameraPosition.x;
			double j = cameraPosition.z;
			float k = (float)farPlaneDepth;
			RenderSystem.enableBlend();
			RenderSystem.enableDepthTest();
			RenderSystem.blendFuncSeparate(
				GlStateManager.SourceFactor.SRC_ALPHA, GlStateManager.DestFactor.ONE, GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ZERO
			);
			RenderSystem.setShaderTexture(0, FORCEFIELD_LOCATION);
			RenderSystem.depthMask(Minecraft.useShaderTransparency());
			int l = worldBorder.getStatus().getColor();
			float m = ARGB.red(l) / 255.0F;
			float n = ARGB.green(l) / 255.0F;
			float o = ARGB.blue(l) / 255.0F;
			RenderSystem.setShaderColor(m, n, o, (float)h);
			RenderSystem.setShader(CoreShaders.POSITION_TEX);
			RenderSystem.polygonOffset(-3.0F, -3.0F);
			RenderSystem.enablePolygonOffset();
			RenderSystem.disableCull();
			float p = (float)(Util.getMillis() % 3000L) / 3000.0F;
			float q = (float)(-Mth.frac(cameraPosition.y * 0.5));
			float r = q + k;
			BufferBuilder bufferBuilder = Tesselator.getInstance().begin(VertexFormat.Mode.QUADS, DefaultVertexFormat.POSITION_TEX);
			double s = Math.max(Mth.floor(j - renderDistance), f);
			double t = Math.min(Mth.ceil(j + renderDistance), g);
			float u = (Mth.floor(s) & 1) * 0.5F;
			if (i > e - renderDistance) {
				float v = u;

				for (double w = s; w < t; v += 0.5F) {
					double x = Math.min(1.0, t - w);
					float y = (float)x * 0.5F;
					bufferBuilder.addVertex((float)(e - i), -k, (float)(w - j)).setUv(p - v, p + r);
					bufferBuilder.addVertex((float)(e - i), -k, (float)(w + x - j)).setUv(p - (y + v), p + r);
					bufferBuilder.addVertex((float)(e - i), k, (float)(w + x - j)).setUv(p - (y + v), p + q);
					bufferBuilder.addVertex((float)(e - i), k, (float)(w - j)).setUv(p - v, p + q);
					w++;
				}
			}

			if (i < d + renderDistance) {
				float v = u;

				for (double w = s; w < t; v += 0.5F) {
					double x = Math.min(1.0, t - w);
					float y = (float)x * 0.5F;
					bufferBuilder.addVertex((float)(d - i), -k, (float)(w - j)).setUv(p + v, p + r);
					bufferBuilder.addVertex((float)(d - i), -k, (float)(w + x - j)).setUv(p + y + v, p + r);
					bufferBuilder.addVertex((float)(d - i), k, (float)(w + x - j)).setUv(p + y + v, p + q);
					bufferBuilder.addVertex((float)(d - i), k, (float)(w - j)).setUv(p + v, p + q);
					w++;
				}
			}

			s = Math.max(Mth.floor(i - renderDistance), d);
			t = Math.min(Mth.ceil(i + renderDistance), e);
			u = (Mth.floor(s) & 1) * 0.5F;
			if (j > g - renderDistance) {
				float v = u;

				for (double w = s; w < t; v += 0.5F) {
					double x = Math.min(1.0, t - w);
					float y = (float)x * 0.5F;
					bufferBuilder.addVertex((float)(w - i), -k, (float)(g - j)).setUv(p + v, p + r);
					bufferBuilder.addVertex((float)(w + x - i), -k, (float)(g - j)).setUv(p + y + v, p + r);
					bufferBuilder.addVertex((float)(w + x - i), k, (float)(g - j)).setUv(p + y + v, p + q);
					bufferBuilder.addVertex((float)(w - i), k, (float)(g - j)).setUv(p + v, p + q);
					w++;
				}
			}

			if (j < f + renderDistance) {
				float v = u;

				for (double w = s; w < t; v += 0.5F) {
					double x = Math.min(1.0, t - w);
					float y = (float)x * 0.5F;
					bufferBuilder.addVertex((float)(w - i), -k, (float)(f - j)).setUv(p - v, p + r);
					bufferBuilder.addVertex((float)(w + x - i), -k, (float)(f - j)).setUv(p - (y + v), p + r);
					bufferBuilder.addVertex((float)(w + x - i), k, (float)(f - j)).setUv(p - (y + v), p + q);
					bufferBuilder.addVertex((float)(w - i), k, (float)(f - j)).setUv(p - v, p + q);
					w++;
				}
			}

			MeshData meshData = bufferBuilder.build();
			if (meshData != null) {
				BufferUploader.drawWithShader(meshData);
			}

			RenderSystem.enableCull();
			RenderSystem.polygonOffset(0.0F, 0.0F);
			RenderSystem.disablePolygonOffset();
			RenderSystem.disableBlend();
			RenderSystem.defaultBlendFunc();
			RenderSystem.setShaderColor(1.0F, 1.0F, 1.0F, 1.0F);
			RenderSystem.depthMask(true);
		}
	}
}