Gimp Image Pipe Format

	The gih format is use to store a series of pixmap brushes,
and some extra info for how to use them. 

Basically, the format is real simple. It is a text header, followed
by a series of gpb files, all concatenated together.

An image pipe can be thought of as an n-dimensional array of pixmap
brushes.  Each dimension is indexed when the pipe is used in painting
by some parameter, eg an incremental counter, a random value, pointing
device pen pressure,tilt or velocity , etc.

An idea for how to implement editing of image pipes (with the GIMP) is
that each layer of the edited image representing the pipe is divided
conceptually (and visualized by guides) into equal-sized elements,
each element containing one pixmap brush. The typical cases are only
one layer, with an array of brushes, or many layers, with just one
brush per layer. (For instance something produced by some animator.)

The header format
================

First line is the name of the pipe.
Second line is the number of brushes in file, followed by the contents of
the gimp-image-pipe-parameters parasite (a text string)

ie
===========================
Fire
6 ncells:6 step:20 dim:1 cols:3 rows:2 rank0:6 selection:incremental
===========================

The rest is just gpb files catted in.

Making a gih file:

	1. Create a series of gpb files. Note these do not
	need to be the same size.

	2. Create a text header like above.

	3. Combine them all together:

		cat header brush1.gpb brush2.gpb brush3.gpb > foo.gih


Thats about it for now.


Other bits:
==========

The spacing for the pipe is currently based on the spacing
for the last brush in the pipe. 

WARNING:
=======

The header file format, and possible the entire file format
is likely to change.


Adrian Likins
aug 18, 1999