archetype-file	NAME.arc

image-file	NAME.PDA

	where
		P - part number
		D - coding, or any other instance
		    coding in 
		A - animation phase
numbering, PDA
	- 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,...,Z
	- alphanumerics
	- can be thought as hexadecimals

name NAME:
	- maximum 10 characters long, so max file name is 14 characters,
	  that fit into portability requirements:

Part numbers
	3x3
		1 2 3
		4 5 6
		7 8 9
	2x2
		1 2
		3 4
	3x2
		1 2 3
		4 5 6
	2x3
		1 2
		3 4
		5 6
codings:
	direction:

		8  1  2
		 \ | /
		7- 0 -3
		 / | \
		6  5  4
	
	- same as in crossfire

	turnable (reflecting objects):
		0 to left, vertical
		1 to right, horizontal
	- also in gates,signs, ...

walls:
		   1
		   |
		8 -+- 2
		   |
		   4

	- bit-combination; eg. 8 + 4 + 2 + 1 = F is cross,
	  4 + 1 = 5 is vertical wall.

river:

    The non branched rivers are stored as river_XY.arc and river_XY.PDA
    The XY use the direction scheme above (that is, river_15 runs
    north/south).  As of now, D and A are always 1.  P will be up to
    3, as rivers that run diagonally have wedges for the corners of the
    adjacent spaces.  These wedges are stored as river_48.211, river_48.311,
    river_26.211 and river_26.311.  The archetypes for these are stored
    in river_48.arc and river_26.arc.

    Junctions are of the form branch_XYZ.[arc/111].  XYZ reperesent the
    three directions the river exits.  367 would be east,southwest, and
    west.  Junctions may also have multiple parts - this happens when
    the junction has a diagonal direction.

    By convention, all directions for the river parts are in ascending
    order.  That is to say if the exit locations are 2,6,3, that would
    be stored as branch_236.

cave:
	-complex

modified:
	93/08 hevi@lut.fi - created
	94/05 master@rahul.net - updated river definitions.

### end of README ###