nWall

Height of a wall. Walls are slices of a line that are too wide to be considered part of the line. Examples of walls include a character that a line passes through or a perpendicular line. If the image contains lines that pass through characters, set nWall to be equal to or a little larger than nMaxLineWidth. If LINE_USE_DPI is set in uProcessFlags, units are in thousandths of an inch, otherwise units are in pixels.