From f4483e4f516916c7d3ce44c034525c2849e70583 Mon Sep 17 00:00:00 2001
From: flan <flan@flande.re>
Date: Mon, 14 Jul 2025 08:32:56 +0200
Subject: [PATCH] Treat multiple flashes sent in the same frame as repeating

Prevents connection issues caused by large amounts of fl packets
(sometimes thousands per frame) being sent in several maps, including:

 - Yume 2kki: Whispery Sewers remake (as of 0.127i patch 5)
 - Yume 2kki: older versions of Lush Cells
 - Deep Dreams: Alien Ocean
---
 src/multiplayer/game_multiplayer.cpp | 6 ++++--
 src/multiplayer/game_multiplayer.h   | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/multiplayer/game_multiplayer.cpp b/src/multiplayer/game_multiplayer.cpp
index 767454353..5e4dca07a 100644
--- a/src/multiplayer/game_multiplayer.cpp
+++ b/src/multiplayer/game_multiplayer.cpp
@@ -112,7 +112,7 @@ static bool MovePlayerToPos(Game_PlayerOther& player, int x, int y) {
 }
 
 void Game_Multiplayer::ResetRepeatingFlash() {
-	frame_index = -1;
+	frame_index = 0;
 	last_flash_frame_index = -1;
 	last_frame_flash.reset();
 	repeating_flashes.clear();
@@ -591,7 +591,9 @@ void Game_Multiplayer::MainPlayerJumped(int x, int y) {
 
 void Game_Multiplayer::MainPlayerFlashed(int r, int g, int b, int p, int f) {
 	std::array<int, 5> flash_array = std::array<int, 5>{ r, g, b, p, f };
-	if (last_flash_frame_index == frame_index - 1 && (last_frame_flash.get() == nullptr || *last_frame_flash == flash_array)) {
+	if (last_flash_frame_index > -1
+			&& frame_index - last_flash_frame_index <= 1
+			&& (last_frame_flash.get() == nullptr || *last_frame_flash == flash_array)) {
 		if (last_frame_flash.get() == nullptr) {
 			last_frame_flash = std::make_unique<std::array<int, 5>>(flash_array);
 			connection.SendPacketAsync<RepeatingFlashPacket>(r, g, b, p, f);
diff --git a/src/multiplayer/game_multiplayer.h b/src/multiplayer/game_multiplayer.h
index 37c4c1a58..dc52d7ed3 100644
--- a/src/multiplayer/game_multiplayer.h
+++ b/src/multiplayer/game_multiplayer.h
@@ -68,7 +68,7 @@ class Game_Multiplayer {
 	int host_id{-1};
 	std::string session_token; // non-null if the user has an ynoproject account logged in
 	int room_id{-1};
-	int frame_index{-1};
+	int frame_index{0};
 	std::map<int, int> map_server_variables;
 
 	enum class NametagMode {