From 87b0148bb6814171983b537a456f7b5004833529 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Thu, 30 Jul 2026 20:27:29 +0200
Subject: Ok, probably an init error again

---
 .../sim.cpp                                        |  65 +++++--------
 modules/core/c++/fplbm.hpp                         | 107 +++++++++++++++------
 2 files changed, 100 insertions(+), 72 deletions(-)

diff --git a/examples/moving_poiseulle_particles_2d_fplbm_gpu/sim.cpp b/examples/moving_poiseulle_particles_2d_fplbm_gpu/sim.cpp
index 3164945..42495c6 100644
--- a/examples/moving_poiseulle_particles_2d_fplbm_gpu/sim.cpp
+++ b/examples/moving_poiseulle_particles_2d_fplbm_gpu/sim.cpp
@@ -48,7 +48,8 @@ template<typename T, typename Desc>
 using MacroStruct = Struct<
 	Member<VelChunk<T,Desc>, "velocity">,
 	Member<RhoChunk<T>, "density">,
-	Member<ScalarChunk<T,Desc>, "porosity">
+	Member<ScalarChunk<T,Desc>, "porosity">,
+	Member<VelChunk<T,Desc>, "force">
 >;
 
 //template<typename T, typename Desc>
@@ -61,13 +62,12 @@ using ParticleSpheroidGroup = ParticleGroup<T,Desc::D,1u,coll::Spheroid<T>>;
 }
 
 template<typename T, typename Desc>
-saw::error_or<void> setup_initial_conditions(
+saw::error_or<void> init(
 	saw::data<sch::ChunkStruct<T,Desc>>& fields,
 	saw::data<sch::MacroStruct<T,Desc>>& macros,
 	saw::data<sch::ParticleSpheroidGroup<T,Desc>>& particles
 ){
 	auto& info_f = fields.template get<"info">();
-	auto& porous_f = macros.template get<"porosity">();
 	// Set everything as walls
 	iterator<Desc::D>::apply(
 		[&](auto& index){
@@ -107,42 +107,34 @@ saw::error_or<void> setup_initial_conditions(
 		{{0u,1u}}
 	);
 	//
-	auto& df_f = fields.template get<"dfs_old">();
+	auto& dfs_old_f = fields.template get<"dfs_old">();
+	auto& dfs_f = fields.template get<"dfs">();
 	auto& rho_f = macros.template get<"density">();
 	auto& vel_f = macros.template get<"velocity">();
 	auto& por_f = macros.template get<"porosity">();
+	auto& force_f = macros.template get<"force">();
 	
 	iterator<Desc::D>::apply(
 		[&](auto& index){
-			auto& df = df_f.at(index);
+			auto& dfs = dfs_f.at(index);
 			auto& rho = rho_f.at(index);
 			por_f.at(index).at({}) = {1};
 			rho.at({}) = {1};
 			auto& vel = vel_f.at(index);
-			auto eq = equilibrium<T,Desc>(rho,vel);
-
-			df = eq;
-		},
-		{},// 0-index
-		df_f.get_dims()
-	);
-
-	iterator<Desc::D>::apply(
-		[&](auto& index){
-			auto& df = df_f.at(index);
-			auto& rho = rho_f.at(index);
-			rho.at({}) = {1};
-			auto& vel = vel_f.at(index);
-			if(info_f.at(index).get() == 2u){
-				vel.at({{0u}}) = 0.0;
+			for(uint64_t i{0u}; i < Desc::D; ++i){
+				vel.at({{i}}).set(0);
 			}
 			auto eq = equilibrium<T,Desc>(rho,vel);
 
-			df = eq;
+			dfs = eq;
+			dfs_old_f.at(index) = dfs;
+			auto& force = force_f.at(index);
+			for(uint64_t i{0u}; i < Desc::D; ++i){
+				force.at({{i}}).set(0);
+			}
 		},
 		{},// 0-index
-		df_f.get_dims(),
-		{{1u,1u}}
+		df_f.get_dims()
 	);
 
 	saw::data<sch::Scalar<T>> rad;
@@ -181,19 +173,19 @@ saw::error_or<void> step(
 	auto& porous_f = macros.template get<"porosity">();
 
 	q.submit([&](acpp::sycl::handler& h){
-		component<T,Desc,cmpt::FplbmReset,encode::Sycl<saw::encode::Native>> hlbm_reset;
+		component<T,Desc,cmpt::FpLbmReset,encode::Sycl<saw::encode::Native>> fplbm_reset;
 		h.parallel_for(acpp::sycl::range<Desc::D>{dim_x,dim_y}, [=](acpp::sycl::id<Desc::D> idx){
 			saw::data<sch::FixedArray<sch::UInt64,Desc::D>> index;
 			for(uint64_t i = 0u; i < Desc::D; ++i){
 				index.at({{i}}).set(idx[i]);
 			}
 
-			hlbm_reset.apply(fields,macros,index,t_i);
+			fplbm_reset.apply(fields,macros,index,t_i);
 		});
 	}).wait();
 
 	q.submit([&](acpp::sycl::handler& h){
-		component<T,Desc,cmpt::FplbmOneParticle,encode::Sycl<saw::encode::Native>> hlbm_one_part;
+		component<T,Desc,cmpt::FpLbmOneParticle,encode::Sycl<saw::encode::Native>> fplbm_one_part;
 
 		h.parallel_for(acpp::sycl::range<1u>{particle_amount}, [=](acpp::sycl::id<1u> idx){
 			saw::data<sch::FixedArray<sch::UInt64,1u>> index;
@@ -201,13 +193,13 @@ saw::error_or<void> step(
 				index.at({{i}}).set(idx[i]);
 			}
 
-			hlbm_one_part.apply(fields,macros,particles,index,t_i,{16u});
+			fplbm_one_part.apply(fields,macros,particles,index,t_i,{1u});
 		});
 	}).wait();
 
 	// auto coll_ev = 
 	q.submit([&](acpp::sycl::handler& h){
-		component<T,Desc,cmpt::Fplbm,encode::Sycl<saw::encode::Native>> collision{0.8};
+		component<T,Desc,cmpt::FpLbm,encode::Sycl<saw::encode::Native>> collision{0.8};
 		component<T,Desc,cmpt::BounceBack,encode::Sycl<saw::encode::Native>> bb;
 
 		component<T,Desc,cmpt::ZouHeHorizontal<true>,encode::Sycl<saw::encode::Native>> flow_in{
@@ -221,7 +213,6 @@ saw::error_or<void> step(
 		};
 		component<T,Desc,cmpt::ZouHeHorizontal<false>,encode::Sycl<saw::encode::Native>> flow_out{1.0};
 
-
 		h.parallel_for(acpp::sycl::range<Desc::D>{dim_x,dim_y}, [=](acpp::sycl::id<Desc::D> idx){
 			saw::data<sch::FixedArray<sch::UInt64,Desc::D>> index;
 			for(uint64_t i = 0u; i < Desc::D; ++i){
@@ -253,14 +244,6 @@ saw::error_or<void> step(
 		});
 	}).wait();
 
-	
-	// Step
-	/*
-	q.submit([&](acpp::sycl::handler& h){
-		// h.depends_on(collision_ev);
-	}).wait();
-	*/
-
 	return saw::make_void();
 }
 }
@@ -278,7 +261,7 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 	}
 	auto& lbm_dir = eo_lbm_dir.get_value();
 
-	auto out_dir = lbm_dir / "moving_poiseulle_particles_2d_hlbm_gpu";
+	auto out_dir = lbm_dir / "moving_poiseulle_particles_2d_fplbm_gpu";
 
 	{
 		std::error_code ec;
@@ -327,7 +310,7 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 
 	sycl_q.wait();
 	{
-		auto eov = setup_initial_conditions<T,Desc>(*lbm_data_ptr,*lbm_macro_data_ptr,*lbm_parts_data_ptr);
+		auto eov = init<T,Desc>(*lbm_data_ptr,*lbm_macro_data_ptr,*lbm_parts_data_ptr);
 		if(eov.is_error()){
 			return eov;
 		}
@@ -421,6 +404,8 @@ saw::error_or<void> lbm_main(int argc, char** argv){
 				}
 			});
 		}).wait();
+	
+		// EPoll
 		wait.poll();
 		if(print_status){
 			std::cout<<"Status: "<<i.get()<<" of "<<time_steps.get()<<" - "<<(i.template cast_to<sch::Float64>().get() * 100 / time_steps.get())<<"%"<<std::endl;
diff --git a/modules/core/c++/fplbm.hpp b/modules/core/c++/fplbm.hpp
index 31b66c4..3c8e173 100644
--- a/modules/core/c++/fplbm.hpp
+++ b/modules/core/c++/fplbm.hpp
@@ -1,6 +1,9 @@
 #pragma once
 
 #include "common.hpp"
+#include "particle/aabb.hpp"
+#include "particle/porosity.hpp"
+#include "iterator.hpp"
 
 namespace kel {
 namespace lbm {
@@ -28,6 +31,24 @@ public:
 
 		auto& por = por_f.at(index);
 		por.at({}) = 1.0;
+
+		auto& force_f = macros.template get<"force">();
+		auto& force = force_f.at(index);
+		for(uint64_t i{0u}; i < Descriptor::D; ++i){
+			force.at({{i}}) = 0.0;
+		}
+
+		bool is_even = ((time_step.get() % 2) == 0);
+
+		auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">();
+		auto& dfs = dfs_old_f.at(index);
+
+		auto& rho_f = macros.template get<"density">();
+		auto& rho = rho_f.at(index);
+		auto& vel_f = macros.template get<"velocity">();
+		auto& vel = vel_f.at(index);
+
+		compute_rho_u<T,Descriptor>(dfs,rho,vel);
 	}
 };
 
@@ -52,19 +73,18 @@ public:
 
 	template<typename CellFieldSchema, typename MacroFieldSchema>
 	void apply(const saw::data<CellFieldSchema, Encode>& field, const saw::data<MacroFieldSchema,Encode>& macros, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, saw::data<sch::UInt64> time_step) const {
-	// void apply(saw::data<CellFieldSchema, Encode>& field, saw::data<sch::FixedArray<sch::UInt64, Descriptor::D>> index, saw::data<sch::UInt64> time_step){
 		bool is_even = ((time_step.get() % 2) == 0);
 
 		auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">();
 		auto& dfs = dfs_old_f.at(index);
 
 		auto& rho_f = macros.template get<"density">();
-		auto& vel_f = macros.template get<"velocity">();
-
 		saw::data<sch::Scalar<T>>& rho = rho_f.at(index);
+
+		auto& vel_f = macros.template get<"velocity">();
 		saw::data<sch::Vector<T,Descriptor::D>>& vel = vel_f.at(index);
 
-		compute_rho_u<T,Descriptor>(dfs_old_f.at(index),rho,vel);
+		compute_rho_u<T,Descriptor>(dfs,rho,vel);
 		auto eq = equilibrium<T,Descriptor>(rho,vel);
 
 		using dfi = df_info<T,Descriptor>;
@@ -72,36 +92,34 @@ public:
 		auto& force_f = macros.template get<"force">();
 		auto& force = force_f.at(index);
 
-		auto& porosity_f = macros.template get<"porosity">();
-		auto& porosity = porosity_f.at(index);
+		auto& por_f = macros.template get<"porosity">();
+		auto& por = por_f.at(index);
 
 		saw::data<sch::Scalar<T>> dfi_inv_cs2;
 		dfi_inv_cs2.at({}).set(dfi::inv_cs2);
 
-		for(uint64_t i = 0u; i < Descriptor::Q; ++i){
-			// saw::data<T> ci_min_u{0};
+		for(uint64_t i{0u}; i < Descriptor::Q; ++i){
 			saw::data<sch::Vector<T,Descriptor::D>> ci;
-			for(uint64_t d = 0u; d < Descriptor::D; ++d){
+			for(uint64_t d{0u}; d < Descriptor::D; ++d){
 				ci.at({{d}}).set(static_cast<typename saw::native_data_type<T>::type>(dfi::directions[i][d]));
 			}
 			auto ci_dot_u = saw::math::dot(ci,vel);
 
-			// saw::data<sch::Vector<T,Descriptor::D>> F_i;
-			// F_i = f * (c_i - u * ics2  + <c_i,u> * c_i * ics2 * ics2) * w_i;
 			saw::data<sch::Scalar<T>> w;
 			w.at({}).set(dfi::weights[i]);
 
-			auto F_i_d = saw::math::dot(force * w, (ci - vel * dfi_inv_cs2 + ci * ci_dot_u * dfi_inv_cs2 * dfi_inv_cs2 ));
-			/*
-			saw::data<sch::Scalar<T>> F_i_sum;
-			for(uint64_t d = 0u; d < Descriptor::D; ++d){
-				saw::data<sch::Scalar<T>> F_i_d;
-				F_i_d.at({}) = F_i.at({{d}});
-				F_i_sum = F_i_sum + F_i_d;
-			}
-			*/
+			auto term1 = (ci-vel) * dfi_inv_cs2;
+			auto term2 = ci * (ci_dot_u * dfi_inv_cs2 * dfi_inv_cs2);
+
+			auto force_projection = saw::math::dot(term1 + term2, force);
+
+			auto F_i = w * force_projection;
 
-			dfs.at({i}) = dfs.at({i}) + frequency_ * (eq.at(i) - dfs.at({i}) ) + F_i_d.at({}) * (saw::data<T>{1} - saw::data<T>{0.5f} * frequency_);
+			dfs.at({i}) = dfs.at({i})
+									+ frequency_
+										* (eq.at(i) - dfs.at({i}) )
+									+ F_i.at({})
+										* (saw::data<T>{1} - saw::data<T>{0.5f} * frequency_);
 		}
 	}
 };
@@ -119,14 +137,12 @@ public:
 	// void apply(saw::data<CellFieldSchema, Encode>& field, saw::data<sch::FixedArray<sch::UInt64, Descriptor::D>> index, saw::data<sch::UInt64> time_step){
 		bool is_even = ((time_step.get() % 2) == 0);
 
-		auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">();
-		auto& dfs = dfs_old_f.at(index);
+		//auto& dfs_old_f = (is_even) ? field.template get<"dfs_old">() : field.template get<"dfs">();
+		// auto& dfs = dfs_old_f.at(index);
 
 		auto& rho_f = macros.template get<"density">();
 		auto& vel_f = macros.template get<"velocity">();
 		auto& por_f = macros.template get<"porosity">();
-
-		// Temporary find a better way
 		auto& force_f = macros.template get<"force">();
 
 		/**
@@ -136,8 +152,19 @@ public:
 		// TODO - Change to tuple later
 		auto parts = pg.template get<"particles">();
 
-		auto parts_size = parts.meta.at({0u});
-		auto pi = parts.at(index);
+		auto parts_size = parts.meta().at({0u});
+		auto pi = parts.at(index);		
+
+		auto& pirb = pi.template get<"rigid_body">();
+		auto& pirb_pos = pirb.template get<"position">();
+		auto& pirb_pos_old = pirb.template get<"position_old">();
+		
+		saw::data<sch::Scalar<T>> sss;
+		sss.at({}) = sub_steps.template cast_to<T>();
+		auto vel_s = (pirb_pos-pirb_pos_old) / sss;
+
+		auto& p_coll = pg.template get<"collision">().at({});
+		auto& p_rad = p_coll.template get<"radius">();
 
 		auto eo_aabb = particle_aabb<typename ParticleSchema::ValueType>::calculate(pg,{{0u}},vel_f.meta());
 		if(eo_aabb.is_error()){
@@ -145,9 +172,28 @@ public:
 		}
 		auto& aabb = eo_aabb.get_value();
 
-		iterator<Desc::D>::apply([&](const auto& index_f) -> void {
+		saw::data<sch::Scalar<T>> two;
+		two.at({}).set(2);
 
-		}, start, stop);
+		saw::data<sch::Scalar<T>> one;
+		one.at({}) = 1.0;
+		
+		saw::data<sch::Scalar<T>> eps;
+		eps.at({}) = 1.5f;
+
+		iterator<Descriptor::D>::apply([&](const auto& index_f) -> void {
+			auto& force = force_f.at(index_f);
+			auto& vel = vel_f.at(index_f);
+			auto& por = por_f.at(index_f);
+			auto& rho = rho_f.at(index_f);
+
+			saw::data<sch::Vector<T,Descriptor::D>> rel_dist = saw::math::vectorize_data(index_f).template cast_to<T>() - pirb_pos;
+
+			por = particle_porosity<T,Descriptor::D,1u,por::ParticleSpheroid<T>>::calculate(rel_dist,p_rad,eps);
+			auto flip_por = one - por;
+
+			force = ( vel_s * rho -  vel * rho ) * two * flip_por;
+		}, aabb.template get<"a">(), aabb.template get<"b">());
 	}
 };
 
@@ -208,15 +254,12 @@ public:
 		saw::data<sch::Scalar<T>> min_two;
 		min_two.at({}).set(-2);
 
-		// Maybe ? 
 		auto& force = force_f.at(index);
 		force = vel * rho * min_two * flip_porosity;
 
 		saw::data<sch::Scalar<T>> dfi_inv_cs2;
 		dfi_inv_cs2.at({}).set(dfi::inv_cs2);
 
-		// auto vel = vel_f.at(index);
-
 		for(uint64_t i = 0u; i < Descriptor::Q; ++i){
 			// saw::data<T> ci_min_u{0};
 			saw::data<sch::Vector<T,Descriptor::D>> ci;
-- 
cgit v1.2.3