From 2b6da538ac15fabeb50cf3053aa3c528c973c40b Mon Sep 17 00:00:00 2001
From: AJ Martinez <aj@worldsbe.st>
Date: Sun, 2 Jul 2023 04:28:19 -0700
Subject: [PATCH] UFO not CBT

---
 src/objects/ufo.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/objects/ufo.c b/src/objects/ufo.c
index dacce52e6..bf1857072 100644
--- a/src/objects/ufo.c
+++ b/src/objects/ufo.c
@@ -35,6 +35,9 @@
 #define UFO_DAMAGED_SPEED (UFO_BASE_SPEED >> 1) // Speed to add when UFO takes damage.
 #define UFO_START_SPEED (UFO_BASE_SPEED << 1) // Speed when the map starts.
 
+#define UFO_PITY_DIST (10000) // Let's aim for an exciting finish! Try to stick closer to the player once they're past this threshold.
+#define UFO_PITY_BRAKES (600 * FRACUNIT) // Subtract this amount from UFO_SFACING, starting at UFO_PITY_DIST and ending at the finish line.
+
 #define UFO_NUMARMS (3)
 #define UFO_ARMDELTA (ANGLE_MAX / UFO_NUMARMS)
 
@@ -52,6 +55,8 @@
 #define ufo_piece_next(o) ((o)->hnext)
 #define ufo_piece_prev(o) ((o)->hprev)
 
+#define ufo_intangible(o) ((o)->cusval)
+
 enum
 {
 	UFO_PIECE_TYPE_POD,
@@ -168,9 +173,11 @@ static void UFOUpdateDistanceToFinish(mobj_t *ufo)
 static void UFOUpdateSpeed(mobj_t *ufo)
 {
 	const fixed_t baseSpeed = FixedMul(UFO_BASE_SPEED, K_GetKartGameSpeedScalar(gamespeed));
-	const UINT32 spacing = FixedMul(FixedMul(UFO_SPACING, mapobjectscale), K_GetKartGameSpeedScalar(gamespeed)) >> FRACBITS;
 	const UINT32 deadzone = FixedMul(FixedMul(UFO_DEADZONE, mapobjectscale), K_GetKartGameSpeedScalar(gamespeed)) >> FRACBITS;
 
+	UINT32 spacing = FixedMul(FixedMul(UFO_SPACING, mapobjectscale), K_GetKartGameSpeedScalar(gamespeed)) >> FRACBITS;
+	UINT32 distanceNerf = FixedMul(FixedMul(UFO_PITY_BRAKES, mapobjectscale), K_GetKartGameSpeedScalar(gamespeed)) >> FRACBITS;
+
 	// Best values of all of the players.
 	UINT32 bestDist = UINT32_MAX;
 	fixed_t bestSpeed = 0;
@@ -223,6 +230,13 @@ static void UFOUpdateSpeed(mobj_t *ufo)
 	{
 		INT32 distDelta = 0;
 
+		if (bestDist < UFO_PITY_DIST && UFOEmeraldChase(ufo))
+		{
+			INT32 brakeDelta = UFO_PITY_DIST - bestDist;
+			INT32 distPerNerf = UFO_PITY_DIST / distanceNerf; // Doing this in the sensible way integer overflows. Sorry.
+			spacing = spacing - (brakeDelta / distPerNerf);
+		}
+
 		if (bestDist > spacing)
 		{
 			wantedDist = bestDist - spacing;
@@ -495,6 +509,9 @@ void Obj_SpecialUFOThinker(mobj_t *ufo)
 	UFOUpdateSpeed(ufo);
 	UFOUpdateSound(ufo);
 
+	if (ufo_intangible(ufo))
+		ufo_intangible(ufo)--;
+
 	if (UFOEmeraldChase(ufo) == true)
 	{
 		// Spawn emerald sparkles
@@ -768,6 +785,7 @@ boolean Obj_SpecialUFODamage(mobj_t *ufo, mobj_t *inflictor, mobj_t *source, UIN
 			SetRandomFakePlayerSkin(source->player, true);
 	}
 
+	ufo_intangible(ufo) = 30;
 
 	// Speed up on damage!
 	ufo_speed(ufo) += addSpeed;
@@ -819,6 +837,11 @@ void Obj_PlayerUFOCollide(mobj_t *ufo, mobj_t *other)
 		return; // underneath
 	}
 
+	if (ufo_intangible(ufo))
+	{
+		return; // We were just hit!
+	}
+
 	if ((other->player->sneakertimer > 0)
 		&& !P_PlayerInPain(other->player)
 		&& (other->player->flashing == 0))