Bug: Railgun, Force Lance, Station graphics

[sven]

Correct me if I'm wrong, but if you define

Code: Select all

function WeaponProperty.foo(w)
  --return stuff
end

Then any time you evaluate w.foo it will call the foo function to determine what value results?

Not exactly... The property values can be overwritten by values defined in the weapon or the weapon's weapon info table. So, for example, if we're evaluating the shield_piercing_level of a Force Lance, we should always return 2 (because that's the value defined in the Force Lance entry in WEAPONS.lua). If you have a weapon that has the "Shield Piercing" property, but no shield_piercing_level defined (like a Coilgun), you'll w.get shield_piercing_level == 1, because of the property function logic.

Re: siyoa's year-old bug, I'm *guessing* what happened was that I had a typo or missing data entry in the WEAPONS.lua entry for Force Lance. But, I think that should be fixed now...

[siyoa]

hi Sven,

this should be what is in current build code (I am at work and only have a copy of Lua State folder, it is about a week old, so latest released build, I think)

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define_weapon "Force Lance" {
  tier=3,
  sound_fun = "FORCE_LANCE",
  type = "kinetic",
  power_mult=3,
  drawer_type = 'force_beam',
  damage_fun = dmg_range(25,35),
  beam_color=("pink"),
  desc = df([=[
    Uses rapidly oscillating gravity fields to tear apart the target,
    causing large amounts of damage without the use of particles or
    projectiles that could be intercepted via energy shields.  The Shield
    Piercing ability of Force Lances is stronger than that of other kinetic
    weapons, capable of fully bypassing both [[Battle Shields]] and
    [[Force Fields]].
  ]=]),

  shield_piercing_level = 2,
  specials =set("Shield Piercing"),
--  mods = set("Rapid Fire"),
}

function WeaponProperty.shield_piercing_level(w) 
  if not w:special 'Shield Piercing'
    return 0
  end
  return 1
end

so, I think what happens is that the function after Force Lance overwrites Force Lance shield_piercing_level to 1 because Force Lance has specials =set("Shield Piercing") ... I cannot upload save game at the moment, but Force Lance with this vanilla file was not piercing Force Fields and as soon as I added my "SP2" shenanigans it was piercing it ... I will try to remove specials =set("Shield Piercing") from Force Lance and just leave shield_piercing_level = 2, in Force Lance definition, then I would revert function WeaponProperty.shield_piercing_level(w) back to vanilla (i.e., remove that "SP2" if section of mine) and see if it works ... when I get home

EDIT: hmm, thinking about it more, it may not work, if Force Lance is missing specials =set("Shield Piercing"), than that function will overwrite Force Lance shield_piercing_level property to 0 ... do that function needs to exist at all ? isn't it enough to define shield_piercing_level for each weapon that needs it and be done with it ?

EDIT2: this should be able to read shield_piercing_level directly from the weapon, right ? so the function function WeaponProperty.shield_piercing_level(w) in WEAPONS.lua is not necessary ?

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function deal_damage(weapon, damage, ship, shield)

  -- shield damage logic

  --print('hrm', ..ship.resists_shield_piercing)

  local shield_damage_p = 1.0-
    saturate(weapon.shield_piercing_level -  ship.resists_shield_piercing)

  if shield_damage_p > 0

    local shield_damage = round | damage*shield_damage_p
    local direct_damage = damage - shield_damage

    if (ship.max_shields > 0) and ship[shield]
    
      if( weapon:special "Enveloping" )
        local d0 = damage_shield(shield_damage,ship,SHIELD_NAMES[1])
        local d1 = damage_shield(shield_damage,ship,SHIELD_NAMES[2])
        d0=max(d0,d1)
        local d1 = damage_shield(shield_damage,ship,SHIELD_NAMES[3])
        d0=max(d0,d1)
        local d1 = damage_shield(shield_damage,ship,SHIELD_NAMES[4])
        shield_damage=max(d0,d1)
      else
        shield_damage=damage_shield(shield_damage,ship,shield)
      end
  

    elseif(ship.planetary_shield)

      ship.planetary_shield_damage = ship.planetary_shield_damage or 0

      shield_damage=damage_shield(shield_damage,ship,"planetary_shield_damage")
    end

    -- recombine the direct and shield damage levels
    damage = direct_damage + shield_damage

  end

[siyoa]

Not exactly... The property values can be overwritten by values defined in the weapon or the weapon's weapon info table. So, for example, if we're evaluating the shield_piercing_level of a Force Lance, we should always return 2 (because that's the value defined in the Force Lance entry in WEAPONS.lua). If you have a weapon that has the "Shield Piercing" property, but no shield_piercing_level defined (like a Coilgun), you'll w.get shield_piercing_level == 1, because of the property function logic.

Re: siyoa's year-old bug, I'm *guessing* what happened was that I had a typo or missing data entry in the WEAPONS.lua entry for Force Lance. But, I think that should be fixed now...

just re-reading this, so the value in weapon's definition has a precedent over the function which is setting the property ? if that is the case my previous post is moot point

[sven]

just re-reading this, so the value in weapon's definition has a precedent over the function which is setting the property ? if that is the case my previous post is moot point

Yes, it has precedence. (The details are a bit complex, but, basically, WeaponProperty is hooking into a Lua technique called "metamethods", and those methods tend to have very low-precedence -- in particular, an __index metamethod, like WeaponProperty, will only be triggered if the value we're trying to read doesn't actually exist in the underlying table.)

[siyoa]

sooo, I removed this function from WEAPONS.lua and added a bit of a code (in shipdamage.lua or what ever the name of the file is) that if shield_piercing_level is nil, it is set to 0

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function WeaponProperty.shield_piercing_level(w) 
  if not w:special 'Shield Piercing'
    return 0
  end
  return 1
end

now this shield_piercing_level = 2 has proper effect for Force Lance

I know what you said about precedence Sven, but it seems that that function was overwriting it

[sven]

sooo, I removed this function from WEAPONS.lua and added a bit of a code (in shipdamage.lua or what ever the name of the file is) that if shield_piercing_level is nil, it is set to 0
I know what you said about precedence Sven, but it seems that that function was overwriting it

Oh no. I think you're right. The complete precedence chain when evaluating weapon fields is actually this:

1. Variables inside the weapon itself.
2. Any defined WeaponProperty functions.
3. Variables inside the weapon's associated info table (the thing in WEAPONS.lua).
4. Any defined WeaponInfo_Property functions.
5. Any defined WeaponMethod functions.

So, um, yes, that code is definitely buggy. I'll push an official fix in the next patch

edit: The patched code I'm currently considering looks like this:

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function WeaponProperty.shield_piercing_level(w) 
  local shield_piercing_level in w.info
  if shield_piercing_level
    return shield_piercing_level
  end
  if not w:special 'Shield Piercing'
    return 0
  end
  return 1
end

[Chasm]

Sven, tested your code, and force lances do pierce force fields with it used. Haven't checked to see it there are unintended results though.

[sven]

Sven, tested your code, and force lances do pierce force fields with it used. Haven't checked to see it there are unintended results though.

Thanks for the testing. Sadly, it does appear to be buggy in the case of damage done via reactor explosions. That's fixable as well, but, the patch isn't quite as clean as the code I posted

[siyoa]

So, um, yes, that code is definitely buggy. I'll push an official fix in the next patch

no worries, Sven, you guys are doing great job and we are here all together to make this game the best of them all