[shapedef.txt 4/95 Digital Insight]

This file describes how to define custom object shapes and arrow 
types for Robochart. 

--- Where To Define Shapes

The complete default library of shapes and arrows are defined in the
file named in environment variable RCHT_SHAPES. Normally, this is the
file "shapedef" in the Robochart installation directory. To replace
this library, create your own version of the shapedef file and point
RCHT_SHAPES to that file before starting Robochart. To override individual
shape (but not arrow) definitions, you can put them into your configuration
file (normally ~/.rchart) - this happens automatically when you use the
online shape definition window.

--- File Format

Blank lines and comments (starting with "#") are ignored. Vector shape 
definitions require five consecutive lines:

	shape <ID> v <atm> <wid> <ht> [<options>]
	icon data
	attach points
	outline definition
	fill definition

Image shape definitions require four lines:

	shape <ID> i <atm> [<options>]
	icon data
	attach points
	image filename

Arrow definitions require three lines:

	arrow <ID>
	icon data
	definition

<ID> = 0-255 for shapes, 0-29 for arrows
<atm> = a (automatic), m (manual), or b (bus) attachment mode
<wid> and <ht> are default width and height in pixels. Default size
	for image shapes is the original image size.
<options> = n for numberable objects

--- Icon Data

Icons are defined as a string of 64 hex characters indicating the
16x16-pixel X11-style bitmap image. The rcicon utility can be used
to generate bitmaps in this format (using the X11 bitmap program).

--- Coordinate Space

Object attach points, outlines, and fill are defined in terms of a 
128-unit wide by 128-unit high region, with the origin at the upper 
left corner. This region is scaled to fit the width and height of each 
object. For example, if a certain diagram object is exactly 64 pixels 
wide and 64 pixels high, each unit in definition space corresponds to 
a half-pixel of screen space for that object. 

          (0,0) --------------- (128,0)
	    |                       |
	    |                       |
	    |                       |
	    |                       |
	    |                       |
	    |                       |
	    |                       |
	    |                       |
	    |                       |
          (0,128) ------------- (128,128)

Arrow definitions are in pixel units, defined in terms of a line
approaching from the right (positive X) reaching an object at the
origin, with positive Y going down.

	   ---+
	      |   (10,10)
	      | / 
	      |/
	      +-------------------
	    (0,0)
	      | \
	      |   (10,-10)
	   ---+

--- Attach Points

Attach points form a list of X,Y coordinate pairs, separated by white space
and/or commas, terminated by a newline or "#". If no attach points are
defined for a shape, a default set of 16 points spaced around the rectangular
boundary are used. The standard shape library includes shapes with a reduced
number of attach points, which are convenient for drawing objects on a
rigid grid. 

--- Outline Commands

Vector shape outline commands are a list of single-character (upper-case)
commands followed by numeric parameters, separated by white space
and/or commas, terminated by a newline or "#". The commands are:

	M x,y		- move to x,y
	L x,y		- draw line to x,y
	P x,y [x,y]...  - draw closed polygon with specified vertices
	A x,y w,h a1 a2 - draw elliptical arc inside the bounding rectangle
		(x,y) [upper left] + (w,h) [width, height]; starting at
		angle a1 (degrees counterclockwise from "3 o-clock") and 
		continuing for a2 degrees counterclockwise.

--- Fill Commands

Vector shape fill commands are a list of single-character (upper-case)
commands followed by numeric parameters, separated by white space
and/or commas, terminated by a newline or "#". The commands are:

	P x,y [x,y]...  - fill closed polygon with specified vertices
	A x,y w,h a1 a2 - fill elliptical arc (see above for parameters)
	C x,y w,h a1 a2 - clip elliptical arc (see above for parameters)
		This is used "cut away" a curved region. It may not
		work correctly in MIF or HPGL output formats.

--- Image Files

Image shape filenames are pathnames for monochrome image files in any
of the following formats:

	X11 ASCII bitmap file
	XView/IconEdit ASCII bitmap file
	Sun raster file (raw or compressed)

--- Arrow Commands

Arrow (flow end) commands are a list of single-character (upper-case)
commands followed by numeric parameters, separated by white space
and/or commas, terminated by a newline or "#". The commands are:

	M x,y		- move to x,y
	L x,y		- draw line to x,y
	P x,y [x,y]...  - draw closed hollow polygon with specified vertices
	F x,y [x,y]...  - draw closed filled polygon with specified vertices
	H x,y r         - draw hollow circle, center at x,y, radius r
	S x,y r         - draw solid (filled) circle, center at x,y, radius r