Method IsDraggingDiagonal

src/viewport.cpp:2656–2659

* Is the user dragging a 'diagonal rectangle'? * @return User is dragging a rotated rectangle. */

 * @return User is dragging a rotated rectangle.
 */
bool TileHighlightData::IsDraggingDiagonal()
{
	return (this->place_mode & HT_DIAGONAL) != 0 && _ctrl_pressed && _left_button_down;
}

/**
 * Get the window that started the current highlighting.