Function ShowExtraViewportWindowForTileUnderCursor

src/viewport_gui.cpp:174–180

* Show a new Extra Viewport window. * Center it on the tile under the cursor, if the cursor is inside a viewport. * If that fails, center it on main viewport center. */

 * If that fails, center it on main viewport center.
 */
void ShowExtraViewportWindowForTileUnderCursor()
{
	/* Use tile under mouse as center for new viewport.
	 * Do this before creating the window, it might appear just below the mouse. */
	Point pt = GetTileBelowCursor();
	ShowExtraViewportWindow(pt.x != -1 ? TileVirtXY(pt.x, pt.y) : INVALID_TILE);
}