Why upgrade? I'm not a lawyer, but here's my take on the differences
to version 2:
* Software patents: better protection against abuse of patents to
prevent users from exercising the rights under the GPL. I doubt
we'll get hit with a patent suit, but it's a good move just on
general principles.
* License compatibility: compatible with more free licenses, i.e. can
"steal" more free software for use in Empire. I don't expect to steal
much, but it's nice to have the option.
* Definition of "source code": modernization of some details for today's
networked world, to make it easier to distribute the software. Not
really relevant to us now, as we normally distribute full source code.
* Tivoization: this is about putting GPL-licensed software in hardware,
then make the hardware refuse to run modified software. "Neat" trick
to effectively deny its users their rights under the GPL. Abuse was
"pioneered" by TiVo (popular digital video recorders). GPLv3 forbids
it. Unlikely to become a problem for us.
* Internationalization: more careful wording, to harden the license
outside the US. The lawyers tell us it better be done that way.
* License violations: friendlier way to deal with license violations.
This has come out of past experience enforcing the GPL.
* Additional permissions: Probably not relevant to us.
Also include myself in the list of principal authors.
radmap() is now radmap2()'s only caller. Inline radmap2() and
simplify. This cleans up a suspicious-looking use of xyas(): it
relied on the fact that owner == player->cnum if pr_flag.
The correct method to compute indexes into a map buffer for a struct
range is deltx(), delty().
path() used deltax(), deltay() instead, which yield correct results
only for indexes up to half the world size. Pathes spanning larger
areas were screwed up.
sona(), radmap2(), satmap() also used deltax(), deltay(), but only
with arguments where those yield correct results.
draw_map() used xnorm(), ynorm() instead, which is correct, but less
clear and less efficient.
Use new pln_is_in_orbit() when we want to test for orbit specifically,
and test PLN_LAUNCHED when we want to test whether the plane not
sitting in the sector (because it is flying). This distinction is
pointless at this time, because the only way PLN_LAUNCHED gets set is
when a satellite goes into orbit. It will become useful in a later
commit, which will use PLN_LAUNCHED to mark flying planes.
other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
(map_char): New.
(draw_map): Use it. Wilderness and plains owned by other players are
now displayed as '?'.
(radmap2): Display wilderness and plains as '?'.
(satmap): Call satdisp() for all sectors owned by other players.
effect. Replace calls by struct assignment where possible. Replace
clear buffer, copy string to buffer by strncpy(). Use assignment to
clear when that's clearer. Replace overlapping copy through bounce
buffer by memmove(). Replace rest by standard memset() and memcpy().
Also use sizeof() instead of literal array sizes for robustness, and
instead of symbolic array sizes for clarity.