Ring Shooter: add a 2 second cooldown after respawning before you can touch a Ring Shooter

This does not prevent you from using the respawn button to
summon a Ring Shooter.

- Ring Shooter only tracks the last player who touched it,
  to prevent that player from reusing it
- If another player touches the Ring Shooter, it loses
  track of the original user
- Near a Block Lightsnake waypoint, this would enter an
  endless loop where both players are able to touch the
  Ring Shooter and use it to respawn, placing them right
  above the Ring Shooter (and the cycle repeats)

src/d_player.h

@@ -952,6 +952,7 @@ struct player_t
 	UINT16 infinitether; // Generic infinitether time, used for infinitether leniency.
 
 	UINT8 finalfailsafe; // When you can't Ringshooter, force respawn as a last ditch effort!
+	UINT8 freeRingShooterCooldown; // Can't use a free Ring Shooter again too soon after respawning.
 
 	UINT8 lastsafelap;
 	UINT8 lastsafecheatcheck;

src/k_kart.c

@@ -8738,6 +8738,9 @@ void K_KartPlayerThink(player_t *player, ticcmd_t *cmd)
 		player->finalfailsafe = 0;
 	}
 
+	if (player->freeRingShooterCooldown && !player->mo->hitlag)
+		player->freeRingShooterCooldown--;
+
 	if (player->superring)
 	{
 		player->nextringaward++;

src/k_respawn.c

@@ -885,6 +885,9 @@ static void K_HandleDropDash(player_t *player)
 		player->respawn.state = RESPAWNST_NONE;
 
 		player->mo->flags &= ~(MF_NOCLIPTHING);
+
+		// Don't touch another Ring Shooter (still lets you summon a Ring Shooter yourself)
+		player->freeRingShooterCooldown = 2*TICRATE;
 	}
 }
 

src/p_inter.c

@@ -915,7 +915,10 @@ void P_TouchSpecialThing(mobj_t *special, mobj_t *toucher, boolean heightcheck)
 			return;
 
 		case MT_RINGSHOOTER:
-			Obj_PlayerUsedRingShooter(special, player);
+			if (player->freeRingShooterCooldown)
+				player->pflags |= PF_CASTSHADOW; // you can't use this right now!
+			else
+				Obj_PlayerUsedRingShooter(special, player);
 			return;
 
 		case MT_SUPER_FLICKY: