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-rw-r--r--examples/particles_gpu/particles_gpu.cpp15
-rw-r--r--lib/core/c++/particle/particle.hpp75
-rw-r--r--lib/core/tests/particles.cpp12
3 files changed, 59 insertions, 43 deletions
diff --git a/examples/particles_gpu/particles_gpu.cpp b/examples/particles_gpu/particles_gpu.cpp
index dfd5af3..abbc192 100644
--- a/examples/particles_gpu/particles_gpu.cpp
+++ b/examples/particles_gpu/particles_gpu.cpp
@@ -42,12 +42,15 @@ saw::error_or<void> lbm_main(int argc, char** argv){
}
}
+ saw::data<sch::Scalar<sch::Float32>> time_step;
+ time_step.at({}).set(0.05f);
+
for(saw::data<sch::UInt64> dt{0u}; dt < saw::data<sch::UInt64>{32ul}; ++dt){
// Do Verlet Step
for(saw::data<sch::UInt64> i{0u}; i < particles.size(); ++i){
auto& part_i = particles.at(i);
- verlet_step_lambda<sch::Float32,2u>(part_i,{0.05f});
+ verlet_step_lambda<sch::Float32,2u>(part_i,time_step);
auto& body_i = part_i.template get<"rigid_body">();
auto& acc_i = body_i.template get<"acceleration">();
@@ -70,23 +73,23 @@ saw::error_or<void> lbm_main(int argc, char** argv){
auto& pos_j = body_j.template get<"position">();
auto& pos_old_j = body_j.template get<"position_old">();
- auto res = broadphase_collision_distance<sch::Float32,2u>(part_i, part_j);
+ auto res = broadphase_collision_distance_squared<sch::Float32,2u>(part_i, part_j);
if(res.first){
//std::cout<<"Collision"<<std::endl;
// Do collision
- auto vel_i = pos_i - pos_old_i;
- auto vel_j = pos_j - pos_old_j;
+ auto vel_i = (pos_i - pos_old_i)/time_step;
+ auto vel_j = (pos_j - pos_old_j)/time_step;
auto vel_rel = vel_i - vel_j;
auto pos_rel = pos_i - pos_j;
auto vel_pos_rel_dot = saw::math::dot(vel_rel,pos_rel);
if(vel_pos_rel_dot.at({}).get() < 0.0){
-
+ auto pos_rel_normed = pos_rel / saw::math::sqrt(res.second);
}
- auto vel_ij = saw::math::dot(vel_i,vel_j);
+ // auto vel_ij = saw::math::dot(vel_i,vel_j);
}
}
diff --git a/lib/core/c++/particle/particle.hpp b/lib/core/c++/particle/particle.hpp
index 8a4ce5d..9bf310e 100644
--- a/lib/core/c++/particle/particle.hpp
+++ b/lib/core/c++/particle/particle.hpp
@@ -12,15 +12,30 @@ struct Spheroid{};
namespace sch {
using namespace saw::schema;
+namespace impl {
+template<typename T,uint64_t D>
+struct rotation_type_helper;
+
+template<typename T>
+struct rotation_type_helper<T,2u> {
+ using Schema = Scalar<T>;
+};
+
+template<typename T>
+struct rotation_type_helper<T,3u> {
+ using Schema = Vector<T,3u>;
+};
+}
+
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<typename impl::rotation_type_helper<T,D>::Schema, "rotation">,
+ Member<typename impl::rotation_type_helper<T,D>::Schema, "rotation_old">,
Member<Vector<T,D>, "acceleration">,
- Member<T, "rotational_acceleration">
+ Member<typename impl::rotation_type_helper<T,D>::Schema, "rotational_acceleration">
>;
template<typename T>
@@ -44,8 +59,8 @@ saw::data<sch::Particle<T,D>, sch::ParticleCollisionSpheroid<T>> create_spheroid
saw::data<sch::Vector<T,D>> rot_pos_p,
saw::data<sch::Vector<T,D>> rot_vel_p,
saw::data<sch::Vector<T,D>> rot_acc_p,
- saw::data<T> rad_p,
- saw::data<T> density_p
+ saw::data<sch::Scalar<T>> rad_p,
+ saw::data<sch::Scalar<T>> density_p
){
saw::data<sch::Particle<T,D>> part;
@@ -70,54 +85,48 @@ saw::data<sch::Particle<T,D>, sch::ParticleCollisionSpheroid<T>> create_spheroid
}
template<typename T,uint64_t D>
-constexpr auto verlet_step_lambda = [](saw::data<sch::Particle<T,D>>& particle, saw::data<T> time_step_delta){
- auto& body = particle.template get<"rigid_body">();
+constexpr auto verlet_step_lambda = [](saw::data<sch::Particle<T,D>>& particle, saw::data<sch::Scalar<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& 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& rot = body.template get<"rotation">();
+ auto& acc = body.template get<"acceleration">();
- auto tsd_squared = time_step_delta * time_step_delta;
+ 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;
- }
+ saw::data<sch::Vector<T,D>> pos_new;
+ // Actual step
+ saw::data<sch::Scalar<T>> two;
+ two.at({}).set(2.0);
+ pos_new = pos * two - pos_old + acc * tsd_squared;
- pos_old = pos;
- pos = pos_new;
+ pos_old = pos;
+ pos = pos_new;
};
template<typename T, uint64_t D>
-constexpr auto handle_collision = [](saw::data<sch::Particle<T,D>>& left, saw::data<sch::Particle<T,D>>& right, saw::data<sch::Vector<T,D>> unit_pos_rel, saw::data<sch::Vector<T,D>> vel_rel)
+constexpr auto handle_collision = [](saw::data<sch::Particle<T,D>>& left, saw::data<sch::Particle<T,D>>& right, saw::data<sch::Vector<T,D>> unit_pos_rel, saw::data<sch::Vector<T,D>> vel_rel, saw::data<sch::Scalar<T>> d_t)
{
auto& rb_l = left.template get<"rigid_body">();
auto& pos_l = rb_l.template get<"position">();
auto& pos_old_l = rb_l.template get<"position_old">();
- auto vel_l = pos_l - pos_old_l;
auto& mass_l = left.template get<"mass">();
+ auto vel_l = (pos_l-pos_old_l)/d_t;
auto& rb_r = right.template get<"rigid_body">();
auto& pos_r = rb_r.template get<"position">();
auto& pos_old_r = rb_r.template get<"position_old">();
- auto vel_r = pos_r - pos_old_r;
auto& mass_r = left.template get<"mass">();
+ auto vel_r = (pos_r-pos_old_r)/d_t;
- /**
- * E to 0
- */
-
- constexpr saw::data<sch::Scalar<T>> elasticity{0u};
- constexpr saw::data<sch::Scalar<T>> one{1.0};
-
- saw::data<sch::Scalar<T>> j = (e - one) / ((one / mass_l) + (one / mass_r));
-
- vel_l = vel_l + vel_rel * j;
- vel_r = vel_r - vel_rel * j;
+ auto vel_pos_rel_dot = saw::math::dot(unit_pos_rel,vel_rel);
+ if( vel_pos_rel_dot.at({{0u}}).get() < 0.0 ){
+ pos_l = pos_l + vel_rel * unit_pos_rel * d_t;
+ pos_r = pos_r - vel_rel * unit_pos_rel * d_t;
+ }
};
diff --git a/lib/core/tests/particles.cpp b/lib/core/tests/particles.cpp
index 366c2a2..b2581f7 100644
--- a/lib/core/tests/particles.cpp
+++ b/lib/core/tests/particles.cpp
@@ -22,7 +22,9 @@ SAW_TEST("Verlet step 2D - Planar"){
acc.at({{0}}).set({1.0});
- lbm::verlet_step_lambda<sch::T,2u>(particle,{0.5});
+ saw::data<sch::Scalar<sch::T>> dt;
+ dt.at({}).set(0.5);
+ lbm::verlet_step_lambda<sch::T,2u>(particle,dt);
SAW_EXPECT(pos.at({{0}}).get() == 0.25, std::string{"Incorrect Pos X: "} + std::to_string(pos.at({{0}}).get()));
SAW_EXPECT(pos.at({{1}}).get() == 0.0, std::string{"Incorrect Pos Y: "} + std::to_string(pos.at({{1}}).get()));
@@ -130,11 +132,13 @@ SAW_TEST("Moving particles 2D"){
pos_old = pos;
acc.at({{0u}}) = -0.1;
}
-
+
+ saw::data<sch::Scalar<sch::T>> dt;
+ dt.at({}).set(0.5);
bool has_collided = false;
for(uint64_t i = 0u; i < 32u; ++i){
- lbm::verlet_step_lambda<sch::T,2u>(part_a,{0.5});
- lbm::verlet_step_lambda<sch::T,2u>(part_b,{0.5});
+ lbm::verlet_step_lambda<sch::T,2u>(part_a,dt);
+ lbm::verlet_step_lambda<sch::T,2u>(part_b,dt);
has_collided = lbm::broadphase_collision_check<sch::T,2u>(part_a,part_b);
if(has_collided){
generated by cgit v1.2.3 (git 2.25.1) at 2026-01-27 22:26:20 +0000