From a76507e17ffc4a363479a8496947e011045431cc Mon Sep 17 00:00:00 2001
From: AJ Martinez <aj@worldsbe.st>
Date: Sat, 13 Jan 2024 20:30:20 -0700
Subject: [PATCH] Slow down top if player's out of control

---
 src/d_player.h |  2 ++
 src/g_game.c   |  2 ++
 src/k_kart.c   | 25 +++++++++++++++++++++++--
 src/k_kart.h   |  3 +++
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/d_player.h b/src/d_player.h
index 4cb1b1539..70220414b 100644
--- a/src/d_player.h
+++ b/src/d_player.h
@@ -953,6 +953,8 @@ struct player_t
 
 	UINT8 lastsafelap;
 
+	fixed_t topAccel; // Reduced on straight wall collisions to give players extra recovery time
+
 	mobj_t *stumbleIndicator;
 	mobj_t *wavedashIndicator;
 	mobj_t *trickIndicator;
diff --git a/src/g_game.c b/src/g_game.c
index 231b94f18..fdffd4459 100644
--- a/src/g_game.c
+++ b/src/g_game.c
@@ -2362,6 +2362,8 @@ void G_PlayerReborn(INT32 player, boolean betweenmaps)
 
 	p->ringvolume = 255;
 
+	p->topAccel = MAXTOPACCEL;
+
 	p->botvars.rubberband = FRACUNIT;
 
 	p->spectatorReentry = spectatorReentry;
diff --git a/src/k_kart.c b/src/k_kart.c
index b17241488..69712001f 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -3531,7 +3531,7 @@ fixed_t K_GetKartAccel(const player_t *player)
 	// Marble Garden Top gets 1200% accel
 	if (player->curshield == KSHIELD_TOP)
 	{
-		k_accel *= 12;
+		k_accel = FixedMul(k_accel, player->topAccel);
 	}
 
 	if (K_PodiumSequence() == true)
@@ -3651,7 +3651,17 @@ SINT8 K_GetForwardMove(const player_t *player)
 		}
 		else
 		{
-			forwardmove = MAXPLMOVE;
+			// forwardmove = MAXPLMOVE;
+
+			UINT8 minmove = MAXPLMOVE/10;
+			fixed_t assistmove = (MAXPLMOVE - minmove) * FRACUNIT;
+
+			angle_t topdelta = player->mo->angle - K_MomentumAngle(player->mo);
+			fixed_t topmult = FINECOSINE(topdelta >> ANGLETOFINESHIFT);
+			topmult = (topmult/2) + (FRACUNIT/2);
+			assistmove = FixedMul(topmult, assistmove);
+
+			forwardmove = minmove + FixedInt(assistmove);
 		}
 	}
 
@@ -8723,6 +8733,17 @@ void K_KartPlayerThink(player_t *player, ticcmd_t *cmd)
 		}
 	}
 
+	// Players that bounce far off walls get reduced Top accel, to give them some time to get their bearings.
+	if ((player->mo->eflags & MFE_JUSTBOUNCEDWALL) && player->curshield == KSHIELD_TOP)
+	{
+		angle_t topdelta = player->mo->angle - K_MomentumAngle(player->mo);
+		fixed_t topmult = FINECOSINE(topdelta >> ANGLETOFINESHIFT);
+		topmult = (topmult/2) + (FRACUNIT/2); // 0 to original
+		player->topAccel = FixedMul(topmult, player->topAccel);
+	}
+
+	player->topAccel = min(player->topAccel + TOPACCELREGEN, MAXTOPACCEL);
+
 	if (player->stealingtimer == 0
 		&& player->rocketsneakertimer
 		&& onground == true)
diff --git a/src/k_kart.h b/src/k_kart.h
index 698cec3c5..b1f631044 100644
--- a/src/k_kart.h
+++ b/src/k_kart.h
@@ -52,6 +52,9 @@ Make sure this matches the actual number of states
 #define RINGVOLUMEUSEPENALTY 15
 #define RINGVOLUMEREGEN 1
 
+#define MAXTOPACCEL (12*FRACUNIT)
+#define TOPACCELREGEN (FRACUNIT/16)
+
 // Mispredicted turns can generate phantom sliptide inputs for a few tics.
 // Delay the wavedash visuals until we're reasonably sure that it's a deliberate turn.
 #define HIDEWAVEDASHCHARGE (60)