Map files describe what should be displayed our output for any given line type.

The basic syntax of the map command is:

MAP <line_type> COLOR <red> <green> <blue> STYLE <style> DASH <dash1> <gap1> <dash2> <gap2>

The style argument is defined as follows:

	Windows line styles:

	   PS_SOLID           0
	   PS_DASH            1        -------
	   PS_DOT             2        .......
	   PS_DASHDOT         3        _._._._
	   PS_DASHDOTDOT      4        _.._.._

	Cimex line styles:
						  10   Dash (or dot)
						  11   Dash dot
						  12   Dash dot dot
						  13   Dash dot dot dot
						  ...

						  20+  Same as above, but dash lengths refer to
								 the design, not the paper (i.e. they scale
								 up or down with the plot scale)
 
	The dash argument is defined as follows:
	(dash indices):   0 Length of main dash
					  1 Length of main gap
					  2 Length of dot (secondary dash)
					  3 Length of gap between dots (secondary gap)

For example:	

map 1 color   0   0 255 style  0 dash 0 0 0 0     ; * indicates that line type 1 should be displayed as a bright blue, using style 0 (PS_SOLID), and because this is a Windows style, the dash elements are ignored (and here they're all specified as zeros anyway).
map 2 color   0   0   0 style 11 dash .1 .1 0 0   ; * indicates type 2 maps to a black dash dot pattern of .1" long dash, and .1" long gap before the dot.


If you use style 2, the dash numbers are ignored. This just generates a
PS_DOT line using whatever the Windows printer driver decided to do.
If you use any of the Cimex styles (10 or higher), then we do look at the
dash numbers, and use these to tell Windows to draw lots of short solid
lines. So we have full control over the length of the dashes.
Line style 11 is exactly the same as line style 21, but ONLY if the drawing
is at scale 1:1. At any other scale, style 11 defines the length of the dash
on the paper (or on the screen), and style 21 defines the length of the dash
in the design's coordinates. So as you zoom in, style 21 will always draw
the same number of dashes, style 11 will draw more dashes.
