Hello I'm creating a game engine. In order to draw everything correctly I need to sort a vector (vector<game_object*>) by each contents z value
I miserably failed to do it with std's sort() so Id like to know what's the most efficient way I could sort this vector [If its efficient , its likely complex so please post quite a bit of example code :icon_cheesygrin: ]
Use binary predicate :
template<typename Object>
struct PointerComp{
bool operator()(const Object* lhs, const Object* rhs)const{
return *lhs < *rhs;
}
};
//....
std::vector<game_object*> objects;
//...
std::sort(objects.begin(),object.end(),PointerComp<game_object>());how dose it sort the z valuse ... Should I add it so the code looks like this ?
template<typename Object>
struct PointerComp{
bool operator()(const Object* lhs, const Object* rhs)const{
return *lhs->z < *rhs->z;
}
};
//....
std::vector<game_object*> objects;
//...
std::sort(objects.begin(),object.end(),PointerComp<game_object>());If yor wan't to sort it based on its z-values then use this predicate:
template<typename Object>
struct PointerComp{
bool operator()(const Object* lhs, const Object* rhs)const{
return lhs->getZ() < rhs->getZ();
}
};template<typename Object>
struct PointerComp
{
bool operator()(const Object* lhs, const Object* rhs)const
{
return *lhs->z < *rhs->z;
}
};
// update objects
void update(SDL_Surface * screen)
{
std::sort(var::_objects_.begin(),var::_objects_.end(),PointerComp<game_object>()); // error
### error: invalid type argument of ‘unary *’ ###what am I doing wrong here ?
nvm I fixed it , Thanks firstperson !
We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.