implement player poses (sneak/sprint)

* Added sending player metadata with poses to everyone

* Renamed sendPlayerMetadataToAll to broadcastPlayerMetadata

* Made entity metadata system flexible

* Made broadcastPlayerMetadata create new metadata instead of using a global one

* Moved writeEntityData, sizeEntityData and sizeEntityMetadata to procedures

* style nitpicks

---------

Co-authored-by: p2r3 <p2r3@p2r3.com>

src/packets.c

@@ -764,6 +764,10 @@ int cs_setPlayerMovementFlags (int client_fd, uint8_t *on_ground) {
 
   *on_ground = readByte(client_fd) & 0x01;
 
+  PlayerData *player;
+  if (!getPlayerData(client_fd, &player))
+    broadcastPlayerMetadata(player);
+
   return 0;
 }
 
@@ -910,6 +914,26 @@ int sc_spawnEntity (
   return 0;
 }
 
+// S->C Set Entity Metadata
+int sc_setEntityMetadata (int client_fd, int id, EntityData *metadata, size_t length) {
+  int entity_metadata_size = sizeEntityMetadata(metadata, length);
+  if (entity_metadata_size == -1) return 1;
+
+  writeVarInt(client_fd, 2 + sizeVarInt(id) + entity_metadata_size);
+  writeByte(client_fd, 0x5C);
+
+  writeVarInt(client_fd, id); // Entity ID
+
+  for (size_t i = 0; i < length; i ++) {
+    EntityData *data = &metadata[i];
+    writeEntityData(client_fd, data);
+  }
+
+  writeByte(client_fd, 0xFF); // End
+
+  return 0;
+}
+
 // S->C Spawn Entity (from PlayerData)
 int sc_spawnEntityPlayer (int client_fd, PlayerData player) {
   return sc_spawnEntity(
@@ -1198,6 +1222,8 @@ int cs_playerInput (int client_fd) {
   if (flags & 0x20) player->flags |= 0x04;
   else player->flags &= ~0x04;
 
+  broadcastPlayerMetadata(player);
+
   return 0;
 }
 
@@ -1215,6 +1241,8 @@ int cs_playerCommand (int client_fd) {
   if (action == 1) player->flags |= 0x08;
   else if (action == 2) player->flags &= ~0x08;
 
+  broadcastPlayerMetadata(player);
+
   return 0;
 }