[Freeciv-Dev] Re: the directional system

[Jason Dorje Short <jshort@xxxxxxxxxxxxx>]

Raimar Falke wrote:
> 

> DIR_DX2 is only used in
> client/tilespec.c:fill_tile_sprite_array_iso. Correct? Looking at it,
> it looks save for me to change the underlying direction
> system. Somebody has said that the graphics also depend on the
> direction system. It looks to me that the graphics only depend on
> INDEX_NSEW. Correct?

This particular file does; however this file uses the *new* directional
system whereas Ross says the graphics depend on the *old* system
(although I don't see this).

I think I may not have been clear in my previous letter: I'm not really
looking for a deep analysis of the patch itself.  My main questions are
these: does FreeCiv run correctly under this patch, and are there any
other places where "magic" code or constants are used?

Also, yes I know the magic numbers in tilespec need to be removed.  I
intend to submit a real patch that removes the DIR_D[XY]2 arrays as well
as fixing the locations that still have magic code (there are three of
them that I know of).  But, this patch will only be worthwhile if we
convert to the new directional system as I've suggested; if we do it as
Ross has suggested then I'm only doing work that he'll have to undo
later.

One other clarification: I've removed the DIR_D[XY]2 arrays, but I've
changed the DIR_D[XY] arrays to use that directional system so really
it's everything else that has changed.  Trying to find magic code by
searching for DIR_D[XY] usages is pretty futile; the use of DIR_D[XY]
itself is quite safe but the problem is when the code tries to
manipulate the directions directly.  This often occurs several levels
down (for instance in straightest_direction() and get_char() which don't
use the arrays at all).  So, it will be difficult to tell by inspecting
the code that all "magic" has been removed.

The question remains: does FreeCiv work correctly under this patch?

jason