From 5ea5b11902719226097188a7b0e7d3ac2341dc90 Mon Sep 17 00:00:00 2001
From: Anonimus <anonimus.srb2k@gmail.com>
Date: Wed, 24 Sep 2025 18:26:09 -0400
Subject: [PATCH] Bandaid: exaggerate AltInvinc legacy cluster distance checks
 Closes #89; this (hopefully) brings it more in line with the DtF checks
 Bagging may be a concern, not too sure yet

---
 src/k_kart.c | 19 +++++++++++++++++--
 src/k_odds.c |  5 +++--
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/src/k_kart.c b/src/k_kart.c
index 3360c2778..b0764ca24 100644
--- a/src/k_kart.c
+++ b/src/k_kart.c
@@ -2329,10 +2329,13 @@ static fixed_t K_InvincibilityEasing(fixed_t x)
         min(FRACUNIT, FixedMul(u - FRACUNIT, FRACUNIT/4)), (INVINMIDTIME/10), (INVINMAXTIME/10));
 }
 
+// 2.5 * FRACUNIT
+#define LEGACYALTINVINMUL 163840
 
 UINT16 K_GetInvincibilityTime(player_t *player)
 {
     UINT32 i, pingame;
+	fixed_t distmul = FRACUNIT;
 
     if (K_GetKartInvinType() == KARTINVIN_LEGACY)
         return BASEINVINTIME;
@@ -2351,12 +2354,24 @@ UINT16 K_GetInvincibilityTime(player_t *player)
     }
 
     if (pingame <= 1)
-        return BASEINVINTIME;
+    {
+		return BASEINVINTIME;
+	}
 
-    fixed_t clustermul = K_InvincibilityEasing(player->distancefromcluster);
+	if (K_UsingLegacyCheckpoints() && !(gametype == GT_BATTLE))
+	{
+		// Legacy waypointing is janky and finicky, so tack on a safety-net multiplier.
+		// If an invincible player gets ahead of the cluster player, bottlenecking activates
+		// regardless.
+		distmul = LEGACYALTINVINMUL;
+	}
+
+    fixed_t clustermul = K_InvincibilityEasing(FixedMul(player->distancefromcluster,distmul));
     return FixedMul(BASEINVINTIME, clustermul);
 }
 
+#undef LEGACYALTINVINMUL
+
 static fixed_t K_GetInvincibilitySpeed(UINT16 time)
 {
     if (K_GetKartInvinType() == KARTINVIN_LEGACY)
diff --git a/src/k_odds.c b/src/k_odds.c
index 984211800..e191fad79 100644
--- a/src/k_odds.c
+++ b/src/k_odds.c
@@ -719,8 +719,9 @@ INT32 K_KartGetLegacyItemOdds(UINT8 pos, SINT8 item, fixed_t clusterDist, fixed_
 				// Nonetheless, apply the start cooldown.
 				cooldownOnStart = true;
 
-				// Unique odds for Invincibility.
-				newodds = K_KartGetInvincibilityOdds(clusterDist);
+				// Unique odds for Invincibility. In legacy waypointing,
+				// its odds are doubled.
+				newodds = K_KartGetInvincibilityOdds(clusterDist) * 2;
                 
 				newodds *= BASEODDSMUL;
 				break;