code: public void setViewportTopLeft(float left, float top) {
          /**
           * Constrains within the scroll range. The scroll range is simply the viewport extremes (AXIS_X_MAX,
           * etc.) minus
           * the viewport size. For example, if the extrema were 0 and 10, and the viewport size was 2, the scroll range
           * would be 0 to 8.
           */
  
          final float curWidth = currentViewport.width();
          final float curHeight = currentViewport.height();
  
          left = Math.max(maxViewport.left, Math.min(left, maxViewport.right - curWidth));
          top = Math.max(maxViewport.bottom + curHeight, Math.min(top, maxViewport.top));
          constrainViewport(left, top, left + curWidth, top - curHeight);
      }
docs: Sets the current viewport (defined by {@link #currentViewport}) to the given X and Y positions.