From 3ce979504ada2ab420868218b01222fe4007f1c9 Mon Sep 17 00:00:00 2001
From: Duncan Frost <duncans_pumpkin@hotmail.co.uk>
Date: Sat, 21 Mar 2015 12:26:28 +0000
Subject: [PATCH] Small tidy up of vehicles related to using in pairs

---
 src/peep/peep.c    | 18 +++++++++---------
 src/ride/vehicle.c |  5 +++++
 src/ride/vehicle.h | 10 +++++-----
 3 files changed, 19 insertions(+), 14 deletions(-)

diff --git a/src/peep/peep.c b/src/peep/peep.c
index f1a77835a8..327c3f7aa7 100644
--- a/src/peep/peep.c
+++ b/src/peep/peep.c
@@ -883,7 +883,7 @@ static void peep_choose_seat_from_car(rct_peep* peep, rct_ride* ride, rct_vehicl
 		ride->mode == RIDE_MODE_BACKWARD_ROTATION){
 
 		chosen_seat = (((~vehicle->var_1F + 1) >> 3) & 0xF) * 2;
-		if (vehicle->var_B4 & 1){
+		if (vehicle->next_free_seat & 1){
 			chosen_seat++;
 		}
 	}
@@ -1014,17 +1014,17 @@ static void peep_update_ride_sub_state_0(rct_peep* peep){
 			i++){
 			vehicle = GET_VEHICLE(vehicle_id);
 
-			uint8 al = vehicle->num_seats;
-			if (al & 0x80){
-				al &= ~0x80;
-				if (vehicle->var_B4 & 1){
+			uint8 num_seats = vehicle->num_seats;
+			if (vehicle_is_used_in_pairs(vehicle)){
+				num_seats &= VEHICLE_SEAT_NUM_MASK;
+				if (vehicle->next_free_seat & 1){
 					peep->current_car = i;
 					peep_choose_seat_from_car(peep, ride, vehicle);
 					peep_go_to_ride_entrance(peep, ride);
 					return;
 				}
 			}
-			if (al == vehicle->next_free_seat)
+			if (num_seats == vehicle->next_free_seat)
 				continue;
 
 			if (ride->mode == RIDE_MODE_FORWARD_ROTATION ||
@@ -1481,7 +1481,7 @@ static void peep_update_ride_sub_state_2(rct_peep* peep){
 		}
 	}
 
-	if (!(vehicle->num_seats & 0x80)){
+	if (!vehicle_is_used_in_pairs(vehicle)){
 		peep_update_ride_sub_state_2_enter_ride(peep, ride);
 		return;
 	}
@@ -1489,7 +1489,7 @@ static void peep_update_ride_sub_state_2(rct_peep* peep){
 	if (ride->mode == RIDE_MODE_FORWARD_ROTATION ||
 		ride->mode == RIDE_MODE_BACKWARD_ROTATION){
 		if (peep->current_seat & 1 || 
-			!(vehicle->var_B4 & 1)){
+			!(vehicle->next_free_seat & 1)){
 			peep_update_ride_sub_state_2_enter_ride(peep, ride);
 			return;
 		}
@@ -1534,7 +1534,7 @@ static void peep_update_ride_sub_state_5(rct_peep* peep){
 			return;
 	}
 
-	if (vehicle->num_seats & 0x80){
+	if (vehicle_is_used_in_pairs(vehicle)){
 		rct_peep* seated_peep = GET_PEEP(vehicle->peep[peep->current_seat ^ 1]);
 		if (seated_peep->sub_state != 5)
 			return;
diff --git a/src/ride/vehicle.c b/src/ride/vehicle.c
index 6894c4fe9a..7d3070fe8b 100644
--- a/src/ride/vehicle.c
+++ b/src/ride/vehicle.c
@@ -632,4 +632,9 @@ rct_vehicle *vehicle_get_head(rct_vehicle *vehicle)
 	}
 
 	return vehicle;
+}
+
+int vehicle_is_used_in_pairs(rct_vehicle *vehicle)
+{
+	return vehicle->num_seats & VEHICLE_SEAT_PAIR_FLAG;
 }
\ No newline at end of file
diff --git a/src/ride/vehicle.h b/src/ride/vehicle.h
index 7af0aa24db..4121b22570 100644
--- a/src/ride/vehicle.h
+++ b/src/ride/vehicle.h
@@ -71,10 +71,7 @@ typedef struct {
 	uint8 peep_tshirt_colours[32];	// 0x92
 	uint8 num_seats;				// 0xB2
 	uint8 num_peeps;				// 0xB3
-	union{
-		uint8 var_B4; // When Forward/Backward rotation this variable is used differently
-		uint8 next_free_seat;		// 0xB4
-	};
+	uint8 next_free_seat;		// 0xB4
 	uint8 pad_B5[0x06];
 	uint8 sound1_id;				// 0xBB
 	uint8 sound1_volume;			// 0xBC
@@ -129,13 +126,16 @@ enum {
 	VEHICLE_STATUS_STOPPED_BY_BLOCK_BRAKES
 };
 
+#define VEHICLE_SEAT_PAIR_FLAG	0x80
+#define VEHICLE_SEAT_NUM_MASK	0x7F
+
 void vehicle_update_all();
 int sub_6BC2F3(rct_vehicle* vehicle);
 void sub_6BB9FF(rct_vehicle* vehicle);
 void vehicle_sounds_update();
 void vehicle_get_g_forces(rct_vehicle *vehicle, int *verticalG, int *lateralG);
 void vehicle_set_map_toolbar(rct_vehicle *vehicle);
-
+int vehicle_is_used_in_pairs(rct_vehicle *vehicle);
 rct_vehicle *vehicle_get_head(rct_vehicle *vehicle);
 
 /** Helper macro until rides are stored in this module. */