Hi all,
Hopefully this is the correct way to post a question, If not I apologize as I
haven't used mailing lists before.
Anyways, here is my problem:
I have some class functions that takes in parameters by pointer. However, when
I expose and override this class/these functions in boost::python, any changes
I make to the parameters are not reflected back to the original, meaning it
isn't being passed by pointer as I expect. I previously had them as
pass-by-reference, but the same problem still occurred. For an example of what
I mean, here's some of my code with unimportant functions and details omitted.
class StatusEffect
{
public:
virtual void TickCharacter(Character::BaseCharacter* character,
Battles::BattleField *field, int ticks = 1);
}
//In my Scripting Code header file
struct StatusEffectWrapper : Game::StatusEffects::StatusEffect
{
virtual void TickCharacter(Game::Character::BaseCharacter* character,
Game::Battles::BattleField *field, int ticks = 1);
virtual void TickCharacterDefault(Game::Character::BaseCharacter*
character, Game::Battles::BattleField *field, int ticks = 1);
}
//In the actual scripting code
void StatusEffectWrapper::TickCharacter(Game::Character::BaseCharacter*
character, Game::Battles::BattleField *field, int ticks)
{
call_method<void>(self, "TickCharacter", character, field, ticks);
}
void
StatusEffectWrapper::TickCharacterDefault(Game::Character::BaseCharacter*
character, Game::Battles::BattleField *field, int ticks)
{
this->StatusEffect::TickCharacter(character, field, ticks);
}
class_<StatusEffects::StatusEffect,
boost::shared_ptr<StatusEffectWrapper> >("StatusEffect")
.def("TickCharacter", &StatusEffect::TickCharacter,
&StatusEffectWrapper::TickCharacterDefault)
and finally in my Python file, I try and do something like this
class StatCreepEffect(StatusEffect):
def __init__(self, name, stat_, rate_, descript, uid, turns, prior,
canrefresh, poseffect, cats, conds, flgs, sep, pers):
StatusEffect.__init__(self, name, descript, uid, turns, prior,
canrefresh, poseffect, cats, conds, flgs, sep, pers)
self.rate = rate_
self.stat = stat_
def TickCharacter(self, Character, Field, Ticks):
if (self.stat == Stat.HP):
Character.SetHP(int(round(Character.GetHP() +
Character.GetInBattleStat(self.stat) * self.rate)))
print("HP Regenerated on character " + Character.GetName() + "
New HP: " + str(Character.GetHP()))
elif (self.stat == Stat.MP):
Character.SetMP(int(round(Character.GetMP() +
Character.GetInBattleStat(self.stat) * self.rate)))
elif (self.stat == Stat.SP):
Character.SetSP(int(round(Character.SetSP() +
Character.GetInBattleStat(self.stat) * self.rate)))
Regen = StatCreepEffect("Regen", Stat.HP, 0.05, "Regenerates a small amount
of HP every turn", PrimaryEngine.GetUID(), 14, 0, True, True,
StatusCategories.SC_Regen, 0, StatusFlags.TickEffect, True,
StatusPersistence.SP_Timer_Cure)
SELibrary.AddPythonEffect(Regen);
If it matters, the AddPythonEffect is defined as follows:
void StatusEffectsLibrary::AddPythonEffect(boost::shared_ptr<StatusEffect>
effect)
{
if (effect.get() != nullptr)
{
NameToSEMap[effect->GetName()] = effect;
IDToSEMap[effect->GetUID()] = effect;
}
}
I call the effect like so in my C++ code
StatusEffect* regen =
game.GetSELibrary().GetStatusEffect(std::string("Regen")); //This simply does a
lookup to the NameToSEMap inside the StatusEffectLibrary and does a .get() on
the shared_ptr
while(character->GetHP() < 600)
{
regen->TickCharacter(character, field, 1);
std::cout << "Character HP: " << character->GetHP() << std::endl;
}
The script compiles and the effect is added correctly. The print line in the
python script prints the correct value. The character object starts with 400 HP
and the print line outputs 430. However, the std::cout line in my C++ code
always outputs 400, meaning the extra 30 HP added by the script is not
reflected back in the original object. For clarity, here's the console output
from the above C++ code fragment:
HP Regenerated on character Arian New HP: 430
Character HP: 400
I've tried adding boost::non_copyable to the class wrapper but to no effect.
I've replaced my pointers with pass by reference to no effect. I've switched
between shared_ptr, auto_ptr, and a straight reference for the HeldType to no
effect. I can confirm using shared_ptrs over regular pointers in the function
does work, but I'd prefer to avoid using them unless there really isn't another
way as it would be tedious and time consuming to do so.
Can someone tell me how to get the behaviour I expect?
To be clear, I'm not looking for the python script to take ownership of any of
the parameters, nor will I be returning anything. I just want the changes made
in the function to be reflected back to the passed in object.
Thanks
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