Method UpdateBoundingBoxCoordinates

src/vehicle.cpp:1671–1710

* Update the bounding box co-ordinates of the vehicle * @param update_cache Update the cached values for previous co-ordinate values */

 * @param update_cache Update the cached values for previous co-ordinate values
 */
void Vehicle::UpdateBoundingBoxCoordinates(bool update_cache) const
{
	Rect new_coord;
	this->sprite_cache.sprite_seq.GetBounds(&new_coord);

	/* z-bounds are not used. */
	Point pt = RemapCoords(this->x_pos + this->bounds.origin.x + this->bounds.offset.x, this->y_pos + this->bounds.origin.y + this->bounds.offset.y, this->z_pos);
	new_coord.left   += pt.x;
	new_coord.top    += pt.y;
	new_coord.right  += pt.x + 2 * ZOOM_BASE;
	new_coord.bottom += pt.y + 2 * ZOOM_BASE;

	extern bool _draw_bounding_boxes;
	if (_draw_bounding_boxes) {
		int x = this->x_pos + this->bounds.origin.x;
		int y = this->y_pos + this->bounds.origin.y;
		int z = this->z_pos + this->bounds.origin.z;
		new_coord.left   = std::min(new_coord.left, RemapCoords(x + bounds.extent.x, y, z).x);
		new_coord.right  = std::max(new_coord.right, RemapCoords(x, y + bounds.extent.y, z).x + 1);
		new_coord.top    = std::min(new_coord.top, RemapCoords(x, y, z + bounds.extent.z).y);
		new_coord.bottom = std::max(new_coord.bottom, RemapCoords(x + bounds.extent.x, y + bounds.extent.y, z).y + 1);
	}

	if (update_cache) {
		/*
		 * If the old coordinates are invalid, set the cache to the new coordinates for correct
		 * behaviour the next time the coordinate cache is checked.
		 */
		this->sprite_cache.old_coord = this->coord.left == INVALID_COORD ? new_coord : this->coord;
	}
	else {
		/* Extend the bounds of the existing cached bounding box so the next dirty window is correct */
		this->sprite_cache.old_coord.left   = std::min(this->sprite_cache.old_coord.left,   this->coord.left);
		this->sprite_cache.old_coord.top    = std::min(this->sprite_cache.old_coord.top,    this->coord.top);
		this->sprite_cache.old_coord.right  = std::max(this->sprite_cache.old_coord.right,  this->coord.right);
		this->sprite_cache.old_coord.bottom = std::max(this->sprite_cache.old_coord.bottom, this->coord.bottom);
	}

	this->coord = new_coord;
}

/**
 * Update the vehicle on the viewport, updating the right hash and setting the new coordinates.