Function ScrollWindowTo

src/viewport.cpp:2546–2572

* Scrolls the viewport in a window to a given location. * @param x Desired x location of the map to scroll to (world coordinate). * @param y Desired y location of the map to scroll to (world coordinate). * @param z Desired z location of the map to scroll to (world coordinate). Use \c -1 to scroll to the height of the map at the \a x, \a y location. * @param w %Window co

 * @return Destination of the viewport was changed (to activate other actions when the viewport is already at the desired position).
 */
bool ScrollWindowTo(int x, int y, int z, Window *w, bool instant)
{
	/* The slope cannot be acquired outside of the map, so make sure we are always within the map. */
	if (z == -1) {
		if ( x >= 0 && x <= (int)Map::SizeX() * (int)TILE_SIZE - 1
				&& y >= 0 && y <= (int)Map::SizeY() * (int)TILE_SIZE - 1) {
			z = GetSlopePixelZ(x, y);
		} else {
			z = TileHeightOutsideMap(x / (int)TILE_SIZE, y / (int)TILE_SIZE);
		}
	}

	Point pt = MapXYZToViewport(*w->viewport, x, y, z);
	w->viewport->CancelFollow(*w);

	if (w->viewport->dest_scrollpos_x == pt.x && w->viewport->dest_scrollpos_y == pt.y) return false;

	if (instant) {
		w->viewport->scrollpos_x = pt.x;
		w->viewport->scrollpos_y = pt.y;
		RebuildViewportOverlay(w);
	}

	w->viewport->dest_scrollpos_x = pt.x;
	w->viewport->dest_scrollpos_y = pt.y;
	return true;
}

/**
 * Scrolls the viewport in a window to a given location.