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#pragma once
#include <forstio/codec/data.hpp>
#include <forstio/codec/data_math.hpp>
namespace kel {
namespace lbm {
namespace sch {
using namespace saw::schema;
template<typename T, uint64_t D>
using ParticleRigidBody = Struct<
Member<Vector<T,D>, "position">,
Member<Vector<T,D>, "position_old">,
Member<T, "rotation">,
Member<T, "rotation_old">,
Member<Vector<T,D>, "acceleration">,
Member<T, "rotational_acceleration">
>;
template<typename T, uint64_t D>
using ParticleMask = Struct<
Member<Array<T,D>, "grid">
>;
template<typename T, uint64_t D>
using Particle = Struct<
Member<ParticleRigidBody<T,D>, "rigid_body">,
Member<ParticleMask<T,D>, "mask">,
Member<T, "size">
>;
}
template<typename T, uint64_t D, typename ParticleCollision = sch::ParticleMask<T,D> >
class particle_system {
private:
saw::data<sch::Array<sch::Particle<T,D>>> particles_;
void verlet_step(saw::data<sch::Particle<T,D>>& particle, saw::data<T> time_step_delta){
auto& body = particle.template get<"rigid_body">();
auto& pos = body.template get<"position">();
auto& pos_old = body.template get<"position_old">();
// auto& rot = body.template get<"rotation">();
auto& acc = body.template get<"acceleration">();
auto tsd_squared = time_step_delta * time_step_delta;
saw::data<sch::Vector<T,D>> pos_new;
// Actual step
for(uint64_t i = 0u; i < D; ++i){
pos_new.at({{i}}) = saw::data<T>{2.0} * pos.at({{i}}) - pos_old.at({{i}}) + acc.at({{i}}) * tsd_squared;
}
pos_old = pos;
pos = pos_new;
}
public:
/**
* Add particle to this class and return an id representing this particle
*/
saw::error_or<saw::data<sch::UInt64>> add_particle(saw::data<sch::Particle<T,D>> particle__){
auto size = particles_.size();
auto eov = particles_.add(std::move(particle__));
if(eov.is_error()){
return std::move(eov.get_error());
}
return size;
}
/*
saw::data<sch::Particle<T,D>>& get_particle(saw::data<sch::UInt64> id){
}
*/
void step(saw::data<T> time_step_delta){
for(saw::data<sch::UInt64> i{0u}; i < particles_.size(); ++i){
verlet_step(particles_.at(i), time_step_delta);
}
}
template<typename LbmLattice>
void update_particle_border(saw::data<LbmLattice>& latt){
(void) latt;
for(auto& iter : particles_){
auto& par = iter;
auto& body = par.template get<"rigid_body">();
auto& size = par.template get<"size">();
}
}
saw::data<sch::UInt64> size() const {
return particles_.size();
}
/**
* Mostly meant for unforeseen use cases.
*/
saw::data<sch::Particle<T,D>>& at(saw::data<sch::UInt64> i){
return particles_.at(i);
}
};
}
}
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