From af525c88fae8a09862f78cb8f97cad2828e227fe Mon Sep 17 00:00:00 2001
From: LabyStudio <labystudio@gmail.com>
Date: Mon, 31 Jan 2022 20:24:53 +0100
Subject: [PATCH] use bulk drawing

---
 .../net/minecraft/client/render/BlockRenderer.js   |  2 --
 src/js/net/minecraft/client/render/Tessellator.js  | 14 +++++++++++++-
 src/js/net/minecraft/client/world/ChunkSection.js  |  3 +++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/js/net/minecraft/client/render/BlockRenderer.js b/src/js/net/minecraft/client/render/BlockRenderer.js
index 695e6ef..9679958 100644
--- a/src/js/net/minecraft/client/render/BlockRenderer.js
+++ b/src/js/net/minecraft/client/render/BlockRenderer.js
@@ -10,9 +10,7 @@ window.BlockRenderer = class {
         let boundingBox = new BoundingBox(0.0, 0.0, 0.0, 1.0, 1.0, 1.0);
 
         for (let face = 0; face < 6; face++) {
-            this.tessellator.startDrawing();
             this.renderFace(world, typeId, boundingBox, face, x, y, z);
-            this.tessellator.draw(group);
         }
     }
 
diff --git a/src/js/net/minecraft/client/render/Tessellator.js b/src/js/net/minecraft/client/render/Tessellator.js
index dfb3046..115f0ca 100644
--- a/src/js/net/minecraft/client/render/Tessellator.js
+++ b/src/js/net/minecraft/client/render/Tessellator.js
@@ -14,22 +14,34 @@ window.Tessellator = class {
     startDrawing() {
         this.verticies = [];
         this.uv = [];
+        this.index = [];
     }
 
     addVertexWithUV(x, y, z, u, v) {
+        // Add vertex
         this.verticies.push(x);
         this.verticies.push(y);
         this.verticies.push(z);
 
+        // Add UV
         this.uv.push(u);
         this.uv.push(v);
+
+        // Add index
+        let index = this.index.length / 6;
+        this.index.push(index + 0);
+        this.index.push(index + 2);
+        this.index.push(index + 1);
+        this.index.push(index + 0);
+        this.index.push(index + 3);
+        this.index.push(index + 2);
     }
 
     draw(group) {
         let geometry = new THREE.BufferGeometry();
         geometry.setAttribute('position', new THREE.BufferAttribute(new Float32Array(this.verticies), 3));
         geometry.setAttribute('uv', new THREE.BufferAttribute(new Float32Array(this.uv), 2));
-        geometry.setIndex(new THREE.BufferAttribute(new Uint32Array([0, 2, 1, 0, 3, 2]), 1));
+        geometry.setIndex(new THREE.BufferAttribute(new Uint32Array(this.index), 1));
 
         let mesh = new THREE.Mesh(geometry, this.material);
         group.add(mesh);
diff --git a/src/js/net/minecraft/client/world/ChunkSection.js b/src/js/net/minecraft/client/world/ChunkSection.js
index d049675..44e678f 100644
--- a/src/js/net/minecraft/client/world/ChunkSection.js
+++ b/src/js/net/minecraft/client/world/ChunkSection.js
@@ -27,6 +27,7 @@ window.ChunkSection = class {
         this.dirty = false;
         this.group.clear();
 
+        renderer.blockRenderer.tessellator.startDrawing();
 
         for (let x = 0; x < ChunkSection.SIZE; x++) {
             for (let y = 0; y < ChunkSection.SIZE; y++) {
@@ -43,6 +44,8 @@ window.ChunkSection = class {
                 }
             }
         }
+
+        renderer.blockRenderer.tessellator.draw(this.group);
     }
 
     getBlockAt(x, y, z) {