fix spells interaction with walls

[Zbizu]

Pull Request Prelude

• I have followed proper The Forgotten Server code styling.
• I have read and understood the contribution guidelines before making this PR.
• I am aware that this PR may be closed if the above-mentioned criteria are not fulfilled.

Changes Proposed

• remove the check for toPos for instant spells
• move the centerPos for isSightClear checks to avoid casting waves through walls

Issues addressed: #2891

Note: Not tested yet, side effects unknown.

[Zbizu]

tested, doesn't fix the issue for clarity: already fixed

the problem is that check for instant spells calls canDoCombat

forgottenserver/src/spells.cpp

Line 699 in aa6d358

ReturnValue ret = Combat::canDoCombat(player, tile, aggressive);

which checks for blockprojectile

forgottenserver/src/combat.cpp

Line 280 in aa6d358

if (tile->hasProperty(CONST_PROP_BLOCKPROJECTILE)) {

but in order to remove it, I need to make sure that onAreaCombat gets executed somehow

edit: gets called later, can safely be removed

[Zbizu]

removing the check for possibility to cast the spell made it also possible to cast the spell through wall because isSightClear was checking the tile in front of the player instead of the player himself so I fixed that as well

spells such as ue work normally, just tested

edit: breaks diagonal wall spells, needs some fixing
edit2: was already broken, just tested other builds

[MillhioreBT]

I'm a little concerned about Combat::canDoCombat why should it be removed from here? Doesn't this prevent the spell from doing unnecessary checks?

At first glance it seems a simple solution, but not very pretty

[Zbizu]

@MillhioreBT canDoCombat is checking the first tile in front of the caster. Removing that check from canDoCombat can bug some other function that uses it. Removing canDoCombat from this place doesn't bug anything as other checks were perfomed earlier and pz check will be performed when checking isAggressive parameter.

[Zbizu]

Tested my changes on a build from November 2020 now, works fine with diagonal fire/poison/energy wall runes.

[nekiro]

What if you throw field rune at stairs (floorchange item) or so, wont it go down/up?

[Zbizu]

What if you throw field rune at stairs (floorchange item) or so, wont it go down/up?

not enough room error
rune doesn't disappear
rl: fires shooteffect, this pr: doesn't
both send poff

fire bomb doesn't change floors (both servers)

you can aim fire bomb at stairs tile, not sure if this pr allows that, will test tomorrow

[Zbizu]

testing update (rl):
spells can be fired to any place that doesn't block projectile, this includes fences and windows (so blocksolid = true, blockprojectile = false)

field spells launch shoot effect, but return "there is not enough room", poff and don't consume the rune when they can't be placed (eg. when you click on opened window)

area spells can be thrown to any tile that doesn't block projectile, the charge is consumed regardless of spell area

going to look into the code later

[Zbizu]

Looks like spells and isSightClear are directly tied. This limits my ability to work on them separately. I'll give that a closer look when working with #3487.

[Zbizu]

Delayed until new isSightClear gets merged. Files conflict very likely to happen so I'll rebase this one after isSightClear gets merged.

[Zbizu]

new isSightClear was merged, resuming work on that

update: merged commits from main repo
update: wave spells interaction with walls should be fixed now (local tests show me that it works)

[Zbizu]

Something is stuck in github mergability verification. I addressed the requested changes with a commit already.

[ranisalt]

Something is stuck in github mergability verification

My blessing was required, Github doesn't automatically dismiss change requests