code: public void setColumns(float leftLine[], float rightLine[]) {
          maxY = -10e20f;
          minY = 10e20f;
          setYLine(Math.max(leftLine[1], leftLine[leftLine.length - 1]));
          rightWall = convertColumn(rightLine);
          leftWall = convertColumn(leftLine);
          rectangularWidth = -1;
          rectangularMode = false;
      }
docs: Sets the columns bounds. Each column bound is described by a
  <CODE>float[]</CODE> with the line points [x1,y1,x2,y2,...].
  The array must have at least 4 elements.
  
  @param leftLine the left column bound
  @param rightLine the right column bound