V10/cmd/ideal/RAW_FORMAT

The IDEAL program puts out a code that is intended to be device-independent.
It looks like TROFF comments so that IDEAL output may be NROFFed safely,
or it may be filtered to produce TROFF commands to draw the picture.
It may also be run through filters that throw away all text but what
appears between .IS and .IE, in which case only the pictures in the
document will be run through the plot filter.

Elements of the output:

.IS
	start a picture;

...minx x
	x becomes the logical x-coordinate of the upper left corner
...maxy y
	y becomes the logical y-coordinate of the upper left corner
...maxx x
	x becomes the logical x-coordinate of the lower right corner
...miny y
	y becomes the logical y-coordinate of the lower right corner
...width w
	scale the picture to be w inches wide
...colwid w
	center the picture in a column w inches wide
...line x1 y1 x2 y2
	draw a line segment from (x1,y1) to (x2,y2)
...circle x0 y0 r
	draw a circle of radius r centered at (x0,y0)
...arc x0 y0 x1 y1 x2 y2 theta1 theta2 r
	draw a counterclockwise arc of radius r centered at (x0,y0),
	starting at (x1,y1), at an angle theta1,
	ending at (x2,y2), at an angle theta2
...spline x0 y0 x1 y1 x2 y2 ...
	draw a spline through the points named
...left x0 y0 'string
	write string so it starts at (x0,y0)
...center x0 y0 'string
	write string so it is centered at (x0,y0)
...right x0 y0 'string
	write string so it ends at (x0,y0)
.IE
	end picture
.IF
	end picture