From b14020c1a1fdf5bfed8b7898c2d25b9c70892228 Mon Sep 17 00:00:00 2001
From: "Sebastian Benjamin (aider)" <sebastiancbenjamin@gmail.com>
Date: Tue, 3 Jun 2025 18:26:05 -0700
Subject: [PATCH] feat: apply input once per tick and check death state for
 grace window

---
 server/game-modes/battle-royale/game-loop.go   | 18 ++++++------------
 .../game-modes/battle-royale/player-stage.go   |  7 +++++--
 2 files changed, 11 insertions(+), 14 deletions(-)

diff --git a/server/game-modes/battle-royale/game-loop.go b/server/game-modes/battle-royale/game-loop.go
index 2a16eb0..fdfaf81 100644
--- a/server/game-modes/battle-royale/game-loop.go
+++ b/server/game-modes/battle-royale/game-loop.go
@@ -38,26 +38,20 @@ func RespondToInput(lobbyState *MatchState, messages []runtime.MatchData, logger
 			continue
 		}
 
+		// Apply the input to the tick where it occurred
+		lobbyState.presences[msg.GetSessionId()].stageState.BoundsCheckedMove(update.X, update.Y)
+
 		// Check if the input is within the grace window
 		if update.Tick < tick && tick-update.Tick <= GRACE_WINDOW_TICKS {
-			// Replay the game state for the intervening ticks
+			// Check the player's death state for all subsequent ticks
 			for t := update.Tick; t < tick; t++ {
-				// Apply the input to the player's state
-				lobbyState.presences[msg.GetSessionId()].stageState.BoundsCheckedMove(update.X, update.Y)
-				// Check if the player survives after applying the input
 				if lobbyState.presences[msg.GetSessionId()].stageState.CheckDeathState(t) == PLAYER_ALIVE {
-					// Send a cancel death message to the client
-					cancelDeathMessage := map[string]any{
-						"cancelDeath": true,
-					}
-					data, _ := json.Marshal(cancelDeathMessage)
-					(*dispatcher).BroadcastMessage(CANCEL_DEATH, data, []runtime.Presence{msg.GetPresence()}, nil, true)
+					// Set a flag to cancel death
+					lobbyState.presences[msg.GetSessionId()].stageState.cancelDeath = true
 					break
 				}
 			}
 		}
-
-		lobbyState.presences[msg.GetSessionId()].stageState.BoundsCheckedMove(update.X, update.Y)
 	}
 }
 
diff --git a/server/game-modes/battle-royale/player-stage.go b/server/game-modes/battle-royale/player-stage.go
index 5bfc1ec..b4eb2dc 100644
--- a/server/game-modes/battle-royale/player-stage.go
+++ b/server/game-modes/battle-royale/player-stage.go
@@ -16,7 +16,7 @@ type PlayerStageState struct {
 	graze           int
 	score           int
 	deathTimer      int
-}
+	cancelDeath     bool
 
 func NewPlayerStage() *PlayerStageState {
 	return &PlayerStageState{
@@ -26,7 +26,10 @@ func NewPlayerStage() *PlayerStageState {
 		updatePlayerPos: true,
 		health:          3,
 		deathTimer:      -1,
-	}
+		if s.cancelDeath {
+			tickData.CancelDeath = true
+			s.cancelDeath = false
+		}
 }
 
 func (s *PlayerStageState) Delete() {