From 74c556af867b941e92d631e95cf270527fd2a516 Mon Sep 17 00:00:00 2001
From: p2r3 <p2r3@p2r3.com>
Date: Thu, 14 Aug 2025 08:13:33 +0300
Subject: [PATCH] precalculate networked block palette buffer

---
 build_registries.js | 16 ++++++++++++++++
 src/packets.c       | 13 ++++++-------
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/build_registries.js b/build_registries.js
index 7559c1a..bcd7ca9 100644
--- a/build_registries.js
+++ b/build_registries.js
@@ -194,6 +194,14 @@ function serializeTags (tags) {
   return Buffer.concat([lengthBuf, fullData]);
 }
 
+function toVarIntBuffer (array) {
+  const parts = [];
+  for (const num of array) {
+    parts.push(writeVarInt(num));
+  }
+  return Buffer.concat(parts);
+}
+
 // Convert to C-style hex byte array string
 function toCArray (buffer) {
   const hexBytes = [...buffer].map(b => `0x${b.toString(16).padStart(2, "0")}`);
@@ -267,6 +275,8 @@ async function convert () {
     }
   });
 
+  const networkBlockPalette = toVarIntBuffer(Object.values(itemsAndBlocks.palette));
+
   const sourceCode = `\
 #include <stdint.h>
 #include "registries.h"
@@ -282,6 +292,11 @@ ${toCArray(tagBuffer)}
 
 // Block palette
 uint16_t block_palette[] = { ${Object.values(itemsAndBlocks.palette).join(", ")} };
+// Block palette as VarInt buffer
+uint8_t network_block_palette[] = {
+${toCArray(networkBlockPalette)}
+};
+
 // Block-to-item mapping
 uint16_t B_to_I[] = { ${itemsAndBlocks.mappingWithOverrides.join(", ")} };
 // Item-to-block mapping
@@ -305,6 +320,7 @@ extern uint8_t registries_bin[${fullRegistryBuffer.length}];
 extern uint8_t tags_bin[${tagBuffer.length}];
 
 extern uint16_t block_palette[256]; // Block palette
+extern uint8_t network_block_palette[${networkBlockPalette.length}]; // Block palette as VarInt buffer
 extern uint16_t B_to_I[256]; // Block-to-item mapping
 uint8_t I_to_B (uint16_t item); // Item-to-block mapping
 
diff --git a/src/packets.c b/src/packets.c
index 19d6dcb..9b5b8dd 100644
--- a/src/packets.c
+++ b/src/packets.c
@@ -284,10 +284,7 @@ int sc_setCenterChunk (int client_fd, int x, int y) {
 // S->C Chunk Data and Update Light
 int sc_chunkDataAndUpdateLight (int client_fd, int _x, int _z) {
 
-  int palette_size = 0;
-  for (int i = 0; i < 256; i ++) palette_size += sizeVarInt(block_palette[i]);
-
-  const int chunk_data_size = (4101 + sizeVarInt(256) + palette_size) * 24;
+  const int chunk_data_size = (4101 + sizeVarInt(256) + sizeof(network_block_palette)) * 24;
 
   writeVarInt(client_fd, 17 + sizeVarInt(chunk_data_size) + chunk_data_size);
   writeByte(client_fd, 0x27);
@@ -306,13 +303,15 @@ int sc_chunkDataAndUpdateLight (int client_fd, int _x, int _z) {
     y = i * 16 - 64;
     writeUint16(client_fd, 4096); // block count
     writeByte(client_fd, 8); // bits per entry
-    writeVarInt(client_fd, 256);
-    for (int j = 0; j < 256; j ++) writeVarInt(client_fd, block_palette[j]);
+    writeVarInt(client_fd, 256); // block palette length
+    // block palette as varint buffer
+    send(client_fd, network_block_palette, sizeof(network_block_palette), 0);
+    // chunk section buffer
     buildChunkSection(x, y, z);
     send(client_fd, chunk_section, 4096, 0);
     // biome data
     writeByte(client_fd, 0); // bits per entry
-    writeByte(client_fd, W_plains); // palette
+    writeByte(client_fd, W_plains); // biome palette
     // reset watchdog and yield
     wdt_reset();
   }