Since Empire 3 made option NEWPAF mandatory, checkabort is always
non-zero, and show implies checkabort != 1 and other == 0. Drop
unreachable code, and remove unused parameters checkabort and other.
Pass the more obviously correct plane_owner instead of player->cnum.
They're the same, actually.
When deities could still fly foreign planes (before commit 2023b47c),
they weren't. ac_encounter() updated the plane owner's in-memory
bmap, but wrote the current player's bmap to disk.
satdisp_sect() updated the in-memory bmap, but failed to write the
updates to disk. Its callers already update bmap from other sources,
so move this update there, and connect it to the existing write back.
The only user is reco(), so the restriction is fine. Several
functions called on behalf of mission_flags assumed it already:
plane_sweep(), sathead(), satdisp_sect(), satdisp_units(). Simplify
the rest accordingly: plane_sona() and ac_encounter() itself.
These were leftovers from Chainsaw, and their only remaining effect
was a flak bonus.
The got replaced except for flak by plane selector stealth under
Chainsaw option STEALTHV, which became mandatory in Empire 2. It is
unclear why STEALTHV didn't cover flak. No planes with these
capabilities have existed in the stock game since Empire 2.
pln_arm(), pln_equip(), mission_pln_arm() mission_pln_equip() took a
mission parameter encoding the kind of sortie (strategic bomb,
pinpoint bomb, transport, ...), a flag parameter to further specify
the plane's role, and a parameter ip to specify the load.
The flags argument was always either P_F (intercept), P_F | P_ESC
(escort), or zero (any other role).
With non-zero flags, mission and ip argument were not used in any way.
Use mission 'e' and null load for escorts, and remove flags.
Intercept can still be identified by mission zero.
Also change pln_mobcost() to take a mission parameter instead of
flags, so that pln_arm() and mission_pln_arm() can simply pass on
their mission.
4.0.9 changed flak not to use up shells, but they still had to be
present. Drop that, because it doesn't really provide any value.
Moreover, this gets rid of the buggy flak shell supply code (seqno
mismatch oopses, lost supplies).
The ancients designed interception dead simple: when you overfly a
sector, you get intercepted by the sector owner. Fine print
interception rules govern which planes intercept.
Then complexity got piled on top of it.
Chainsaw 2 added an extra interception by surface ship owners, in the
target sector only.
Chainsaw 3 added an extra interception by land unit owners, in the
target sector only (Empire 4 later merged this extra land unit
interception with the extra surface ship interception).
Chainsaw 3 added an entirely separate kind of interception: air
defense missions. When you enter a sector in some air defense op
area, you get intercepted. Fine print air defense rules govern which
planes intercept. These rules differ significantly from the
interception fine print.
Additional complexity comes from these facts:
* Air defense mission interception happens in addition to non-mission
interception. You can boost your total interception by setting up
air defense. Which means you must set it up, or forgo an advantage.
* Air defense planes are not available for non-mission interception
duty. You need to decide on a split.
* In contrast to non-mission interception, interceptors flying air
defense get intercepted.
Moreover, the air defense code breaks one of the plane code's design
assumptions, namely that just one plane sortie is active at a time.
The air defense sortie runs while the sortie it intercepts is in
progress. This leads to two interceptions being active at the same
time: the one intercepting the original sortie, and the one
intercepting the air defense sortie. The same plane can fly in both
interceptions, and damage received in the interception of the air
defense sortie is wiped out, triggering a seqno mismatch oops.
The previous commit already simplified non-mission interception: you
get intercepted by anyone who owns the sector, or a surface ship or a
land unit there, whether it's the target sector or not.
Now simplify mission interception, by merging air defense back into
ordinary interception: when you overfly a sector, you get intercepted
by anyone who owns the sector, or a surface ship or land unit there,
or has an air defense mission covering the sector. That's all. No
multiple interceptions, no separate air defense rules.
Remove air_defense(). Simplify ac_encounter() and sam_intercept()
accordingly; both lose their last parameter.
Change sam_intercept() and ac_intercept() to intercept in mission op
areas. New parameter only_mission to suppress non-mission
interception. Pass zero when the intercepting country owns the sector
or a surface ship or land unit in the sector.
ac_encounter() can't efficiently predict whether a country intercepts,
so it needs to call ac_intercept() unconditionally. This kills the
optimization to collect interceptors only when needed; simplify
accordingly, replacing getilist() by getilists().
In each sector, any country owning the sector, a surface ship or a
land unit gets to intercept.
Before, only the sector owner got to intercept, except for the target
sector. There, any country owning surface ships or land units got to
intercept in addition to the sector owner. Thus, a sector owner with
surface ships or land units there got to intercept twice.
Info Intercept claimed you get to intercept once for ships and once
again for land units, which was wrong since 4.0.9.
Info bomb suggested that flak fires only in the target sector, which
was wrong since 4.2.8. Drop that.
Sectors already spotted overflying planes in every sector along the
flight path, but ships and land units did that only in the target
sector, once if you got any ships there, in ac_encounter(), once if
you got any land units there, in ac_encounter(), once for ships firing
flak, in ac_shipflak(), and once for land units firing flak, in
ac_landflak(). Remove all that, and generalize ac_encounter()'s code
for sectors to spot planes to include ships and land units. Unlike
before, ships and land units don't spot allied planes.
Planes now spot ships and land units only when flying recon or sweep,
and along all of their flight path instead of just the target sector.
It still takes a spy plane to identify ships and land units.
Before, non-spy planes spotted ships and land units only in the target
sector, regardless of type of sortie, once for all ships and land
units, in ac_encounter(), once for ships firing flak, in
ac_shipflak(), and once for land units firing flak, in ac_landflak().
Remove all that.
Change ac_encounter() to start intercepting and running air defense
missions at the assembly point instead of the first sector entered
from there.
This also fixes a coding bug: when the flight path was empty, evaded
was used uninitialized when checking whether to intercept over the
target. The compiler even warned about that. Since the uninitialized
evaded typically read non-zero, interception triggered by ships and
land units didn't work. Abusable: if you managed to make your target
sector an assembly point, e.g. by placing an own or allied ship there,
you could bomb it without getting intercepted or taking flak.
A country's SAMs launched only in the first interception of a sortie.
That was because ac_intercept() made sam_intercept() delete all SAMs
from the list of available interceptors. sam_intercept() also deleted
any SAMs out of range. Don't do that, delete unused SAMs along with
other unused interceptors on return from ac_encounter().
Planes were not subject to air defense and flak over allied sectors.
Air defense was broken when Empire 2 changed it to happen after
spotting.
Flak was broken when 4.2.8 made ships and land units fire flak in
every sector, not just the target sector. Although an allied sector
doesn't fire flak, it may still contain hostile ships and land units.
Also makes use of ilist[] more robust: before, if relations somehow
went sour after unfriendly[] was initialized, the sector intercept
would run with an invalid interceptor list, and crash.
Chainsaw had missiles flying missions together with planes, and to
make that work, aircombat.c got code for coping with missiles. Since
Empire 2, missiles fly separately and don't go through aircombat.c
anymore. The missile code there has been useless for more than a
decade. Remove it.
This simplifies ac_encounter(), sam_intercept(), ac_intercept(),
ac_airtoair(), and gets rid of count_non_missiles(), all_missiles().
ac_encounter() passed MAXNOC instead of the sector owner to setcont(),
and setcont() does nothing for such an argument. Screwed up from the
start, in commit 144c7cb5, v4.2.22.
ac_encounter() lets all owners of ships and land units in the target
sector intercept, but not more than once.
Move the interception code behind reporting of both ships and land
units. Before, it was duplicated for ships and land units. Land
units didn't get reported when no bombers got through interception
triggered by ships.
A reconnaissance patrol (recon and sweep) uses sonar when ASW planes
participate. ac_encounter() enabled sonar when P_A was in
mission_flags. These get computed by pln_arm() and callers. However,
they set P_A only when *all* planes were capable, including escorts.
Fix by checking actual plane capabilities instead. Closes#1389451.
A reconnaissance patrol (recon and sweep) reports much more detail
when spy planes participate. However, ac_encounter() didn't stop
doing that after all spy planes were shot down or aborted.
Fix by recalculating plane capabilities for every sector.
Interception and missions launch planes automatically. The plane
owner (and for missions, the base sector owner) gets a message.
Destination coordinates are often obvious from the context, but not
always, e.g. when flying in support of allies, or when the mission
gets interepted and aborts. Include the destination coordinates in
the messages. Reported by Ulrich Hannemann.
Commit 7ca4f412 fixed tracking of planes flying a sortie by marking
them with flag PLN_LAUNCHED. It failed to write SAMs and planes
flying missions back to the plane file, in sam_intercept() and
mission_pln_arm(). The only known problem with that is fairly
harmless: when the mission damages planes on the ground, the planes
flying it get damaged as if they were still sitting in their bases,
but the damage gets wiped out when they land.
The same issue applies to missiles. So they need to be tracked as
well. Do that in msl_hit().
While there, remove a few redundant PLN_LAUNCHED sanity checks.
Planes normally sit in their base (sector or carrier), where they can
be spied, damaged, captured, loaded, unloaded, upgraded and so forth.
All this must not be possible while they fly. There are two kinds of
flying planes: satellites in orbit, and planes flying a sortie.
Satellites in orbit have always been marked with flag PLN_LAUNCHED.
Works. What didn't work was tracking planes flying a sortie.
If you look at one sortie in isolation, up to three groups of planes
can be flying at any point of time: the primary group, which carries
out the sortie's mission (bomb, transport, ...), their escorts, and a
group of hostile planes flying interception or air defense.
The old code attempted to track these planes by passing those groups
to the places that need to know whether a plane is flying. This was
complex and incomplete, and broke down completely for the pin-bombing
command.
It was complex, because the plane code needs to keep track of all the
call chains that can lead to a place that needs to know whether a
plane flies, and pass the groups down the call chains. This leads to
a rather ugly passing of plane groups all over the place.
It was incomplete, because it generally failed to pass the escorts.
And the whole scheme broke down for the pin-bombing command. That's
because pin-bombing asks the player for targets while his planes are
loitering above the target sector. This yields the processor and lets
other code run. Which does not get the flying planes passed.
The new code marks planes and SAMs (but not other missiles) flying a
sortie with flag PLN_LAUNCHED (the previous commit laid the groundwork
for that), and does away with passing around groups of flying planes.
This fixes the following bugs:
* Many commands could interact with foreign planes flying for a
pin-bombing command as if they were sitting in their base. This
includes spying, damaging, capturing, loading, or upgrading them,
and even getting intercepted by them. Any changes to those planes
were wiped out when they landed. Abusable.
* The bomb command could bomb its own escorts, directly (pin-bomb
planes) or through collateral damage, strategic sector damage,
collapsing bridges or nuke damage. The damage to the escorts was
wiped out when they landed.
* If you asked for a plane to fly both in the primary group and the
escort group, you got charged fuel for two sorties instead of one.
* pln_put1() and pln_put() now recognize planes that didn't take off,
and refrain from making them land. Intercept (since commit
c64e2149) and air defense can do that. Making them land had no
ill-effects, but it was still wrong.
There's one new problem: if PLN_LAUNCHED doesn't get reset properly,
due to game crash during flight or some other bug, the plane gets
stuck in the air. Catch and fix that on game start in ef_verify().
Use it in pln_put() and ac_planedamage().
This changes ac_planedamage() to deal with a destroyed airbase.
Before, aborted planes happily landed there. This bug could not
actually bite, because the code neither yields nor does damage to
potential airbases between checking the landing airbase before takeoff
and aborting planes in ac_planedamage().
It changes pln_put() to cope with dead planes. Before, it made them
land as if they lived, fortunately without ill effects (complaints
about not being able to land were suppressed for dead planes).
ac_planedamage() removes dead planes, but pinflak_planedamage()
doesn't, and these end up in pln_put(). pinflak_planedamage() no
longer has to take shot down planes off their carriers, because
pln_put() now takes care of that.
Interception builds lists of planes that could intercept. Only list
nodes for missiles were freed. Broken since BSD Empire 1.1.
The fix frees interceptors that actually intercepted when
ac_intercept() returns, and the interceptors that didn't when
ac_encounter() returns.
The latter introduces a small bug: it passes planes that didn't fly to
pln_put(). pln_put() expects only planes that actually took off.
Same bug exists in air defense missions. Luckily, it has no ill
effects. To be fixed soon.
New lnd_att(), lnd_def(), lnd_vul(), lnd_spd(), lnd_vis(), lnd_frg(),
lnd_acc(), lnd_dam(), lnd_aaf() replace the struct lndstr members with
the same names.
Make land unit selectors att, def, vul, spd, vis, frg, acc, dam, aaf
virtual.
New pln_att(), pln_def(), pln_acc(), pln_range_max(), pln_load()
replace the struct plnstr members with the same names.
Make plane selectors att and def virtual.
