From 1897f9d1e74a548753585759d3ea758b26cf9fd6 Mon Sep 17 00:00:00 2001
From: NepDisk <nepdisk@noreply.codeberg.org>
Date: Sun, 18 May 2025 18:52:45 -0400
Subject: [PATCH] Fix weird stacking speed dropoff issue

Thanks so much Indev!
---
 src/d_player.h | 1 +
 src/k_kart.c   | 8 ++++----
 src/p_saveg.c  | 2 ++
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/d_player.h b/src/d_player.h
index 73b6550d4..a08cc392a 100644
--- a/src/d_player.h
+++ b/src/d_player.h
@@ -635,6 +635,7 @@ struct player_t
 	
 	fixed_t boostpower;		// Base boost value, for offroad
 	fixed_t speedboost;		// Boost value smoothing for max speed
+	fixed_t prevspeedboost;	// Max speed boost value from the last frame
 	fixed_t accelboost;		// Boost value smoothing for acceleration
 	angle_t boostangle;		// angle set when not spun out OR boosted to determine what direction you should keep going at if you're spun out and boosted.
 	boostinfo_t boostinfo;	// Stores values used for setting speed and accel boosts.
diff --git a/src/k_kart.c b/src/k_kart.c
index 33e7aff26..2f5c67dc8 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -3589,7 +3589,6 @@ static void K_GetKartBoostPower(player_t *player)
 	fixed_t finalspeedboost = 0;
 	fixed_t finalaccelboost = 0;
 	UINT8 finalgrade = 0;
-	fixed_t prevspeedboost = player->speedboost;
 
 	if (player->spinouttimer && player->wipeoutslow == 1) // Slow down after you've been bumped
 	{
@@ -3686,19 +3685,19 @@ static void K_GetKartBoostPower(player_t *player)
 			player->speedboost = max(finalspeedboost, player->speedboost)/2;
 			player->accelboost = max(finalaccelboost, player->accelboost)/2;
 		}
-		else if (finalspeedboost >= prevspeedboost)
+		else if (finalspeedboost >= player->prevspeedboost)
 		{
 			player->speedboost = max(player->speedboost, finalspeedboost);
 			player->accelboost = max(player->accelboost, finalaccelboost);
 		}
 		else if ((player->aizdriftstrat && abs((player->drift) < 5)) || (K_GetKartButtons(player) & BT_BRAKE))
 		{
-			player->speedboost = max(prevspeedboost - SPEEDBOOSTDROPOFF_BRAKE, min(player->speedboost, MAXVANILLABOOST));
+			player->speedboost = max(player->prevspeedboost - SPEEDBOOSTDROPOFF_BRAKE, min(player->speedboost, MAXVANILLABOOST));
 			player->accelboost = finalaccelboost;
 		}
 		else
 		{
-			player->speedboost = prevspeedboost - SPEEDBOOSTDROPOFF;
+			player->speedboost = max(player->speedboost + (finalspeedboost - player->speedboost) / (TICRATE/2), player->speedboost - SPEEDBOOSTDROPOFF);
 			player->accelboost = finalaccelboost;
 		}
 	}
@@ -3718,6 +3717,7 @@ static void K_GetKartBoostPower(player_t *player)
 
 	player->numboosts = finalgrade;
 	K_ClearBoost(player);
+	player->prevspeedboost = player->speedboost;
 }
 
 // Returns value based on being Grown or Shrunk otherwise returns FRACUNIT
diff --git a/src/p_saveg.c b/src/p_saveg.c
index 94edc68fd..2040d4e8c 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -277,6 +277,7 @@ static void P_NetArchivePlayers(savebuffer_t *save)
 
 		WRITEFIXED(save->p, players[i].boostpower);
 		WRITEFIXED(save->p, players[i].speedboost);
+		WRITEFIXED(save->p, players[i].prevspeedboost);
 		WRITEFIXED(save->p, players[i].accelboost);
 		WRITEANGLE(save->p, players[i].boostangle);
 		WRITEUINT8(save->p, players[i].numsneakers);
@@ -605,6 +606,7 @@ static void P_NetUnArchivePlayers(savebuffer_t *save)
 
 		players[i].boostpower = READFIXED(save->p);
 		players[i].speedboost = READFIXED(save->p);
+		players[i].prevspeedboost = READFIXED(save->p);
 		players[i].accelboost = READFIXED(save->p);
 		players[i].boostangle = READANGLE(save->p);
 		players[i].numsneakers = READUINT8(save->p);