Method UpdateDeltaXY

src/roadveh_cmd.cpp:405–457

}

void RoadVehicle::UpdateDeltaXY()
{
	/* Set common defaults. */
	this->bounds = {{-1, -1, 0}, {3, 3, 6}, {}};

	if (!IsDiagonalDirection(this->direction)) {
		static const Point _sign_table[] = {
			/* x, y */
			{-1, -1}, // DIR_N
			{-1,  1}, // DIR_E
			{ 1,  1}, // DIR_S
			{ 1, -1}, // DIR_W
		};

		int half_shorten = (VEHICLE_LENGTH - this->gcache.cached_veh_length) / 2;

		/* For all straight directions, move the bound box to the centre of the vehicle, but keep the size. */
		this->bounds.offset.x -= half_shorten * _sign_table[DirToDiagDir(this->direction)].x;
		this->bounds.offset.y -= half_shorten * _sign_table[DirToDiagDir(this->direction)].y;
	} else {
		/* Unlike trains, road vehicles do not have their offsets moved to the centre. */
		switch (this->direction) {
				/* Shorten southern corner of the bounding box according the vehicle length. */
			case DIR_NE:
				this->bounds.origin.x = -3;
				this->bounds.extent.x = this->gcache.cached_veh_length;
				this->bounds.offset.x = 1;
				break;

			case DIR_NW:
				this->bounds.origin.y = -3;
				this->bounds.extent.y = this->gcache.cached_veh_length;
				this->bounds.offset.y = 1;
				break;

				/* Move northern corner of the bounding box down according to vehicle length. */
			case DIR_SW:
				this->bounds.origin.x = -3 + (VEHICLE_LENGTH - this->gcache.cached_veh_length);
				this->bounds.extent.x = this->gcache.cached_veh_length;
				this->bounds.offset.x = 1 - (VEHICLE_LENGTH - this->gcache.cached_veh_length);
				break;

			case DIR_SE:
				this->bounds.origin.y = -3 + (VEHICLE_LENGTH - this->gcache.cached_veh_length);
				this->bounds.extent.y = this->gcache.cached_veh_length;
				this->bounds.offset.y = 1 - (VEHICLE_LENGTH - this->gcache.cached_veh_length);
				break;

			default:
				NOT_REACHED();
		}
	}
}

/**
 * Calculates the maximum speed of the vehicle under its current conditions.