From 77afc46bf0cb5169edbec626a7c60996c81b2154 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Tue, 3 Mar 2026 16:52:53 +0100
Subject: Confusion about Boundary conditions

---
 lib/core/c++/geometry.hpp                   | 13 -------------
 lib/core/c++/geometry/poiseulle_channel.hpp | 15 +++++++++++++++
 lib/core/c++/particle/blur.hpp              |  1 -
 3 files changed, 15 insertions(+), 14 deletions(-)

(limited to 'lib/core/c++')

diff --git a/lib/core/c++/geometry.hpp b/lib/core/c++/geometry.hpp
index c8a48a6..1c5d0a3 100644
--- a/lib/core/c++/geometry.hpp
+++ b/lib/core/c++/geometry.hpp
@@ -12,19 +12,6 @@ struct geometry {
 	}
 };
 */
-namespace cmpt {
-struct PoiseulleChannel;
-}
-
-template<typename Schema, typename Desc, typename Encode>
-class component<Schema, Desc, cmpt::PoiseulleChannel, Encode> final {
-private:
-public:
-	template<typename CellFieldSchema>
-	void apply(saw::data<CellFieldSchema,Encode>& field, const saw::data<sch::FixedArraysch::UInt64,Desc::D>){
-		auto& info_f = field.template get<"info">();
-	}
-};
 
 // Ghost - 0
 // Wall  - 1
diff --git a/lib/core/c++/geometry/poiseulle_channel.hpp b/lib/core/c++/geometry/poiseulle_channel.hpp
index f675a99..f719ec4 100644
--- a/lib/core/c++/geometry/poiseulle_channel.hpp
+++ b/lib/core/c++/geometry/poiseulle_channel.hpp
@@ -1,7 +1,22 @@
 #pragma once
 
+#include "../geometry.hpp"
+
 namespace kel {
 namespace lbm {
+namespace cmpt {
+struct PoiseulleChannel;
+}
+
+template<typename Schema, typename Desc, typename Encode>
+class component<Schema, Desc, cmpt::PoiseulleChannel, Encode> final {
+private:
+public:
+	template<typename CellFieldSchema>
+	void apply(saw::data<CellFieldSchema,Encode>& field, const saw::data<sch::FixedArraysch::UInt64,Desc::D>){
+		auto& info_f = field.template get<"info">();
+	}
+};
 
 }
 }
diff --git a/lib/core/c++/particle/blur.hpp b/lib/core/c++/particle/blur.hpp
index a304e8d..7b93ae9 100644
--- a/lib/core/c++/particle/blur.hpp
+++ b/lib/core/c++/particle/blur.hpp
@@ -31,7 +31,6 @@ void blur_mask(saw::data<sch::Array<T,D>>& p_mask){
 
 		p_mask = blurred_mask;
 	}
-
 }
 }
 }
-- 
cgit v1.2.3


From 75fda9a23cd30efa72bd212d5642c3d30ee34913 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Tue, 3 Mar 2026 19:03:05 +0100
Subject: Added CSV for simpler script processing

---
 lib/core/c++/lbm.hpp       |   1 +
 lib/core/c++/write_csv.hpp | 184 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 185 insertions(+)
 create mode 100644 lib/core/c++/write_csv.hpp

(limited to 'lib/core/c++')

diff --git a/lib/core/c++/lbm.hpp b/lib/core/c++/lbm.hpp
index a1e088e..d6a0976 100644
--- a/lib/core/c++/lbm.hpp
+++ b/lib/core/c++/lbm.hpp
@@ -17,6 +17,7 @@
 #include "memory.hpp"
 #include "psm.hpp"
 #include "stream.hpp"
+#include "write_csv.hpp"
 #include "write_vtk.hpp"
 #include "util.hpp"
 
diff --git a/lib/core/c++/write_csv.hpp b/lib/core/c++/write_csv.hpp
new file mode 100644
index 0000000..a60e208
--- /dev/null
+++ b/lib/core/c++/write_csv.hpp
@@ -0,0 +1,184 @@
+#pragma once
+
+#include <forstio/error.hpp>
+
+#include <forstio/codec/data.hpp>
+#include <forstio/codec/data_math.hpp>
+
+#include "descriptor.hpp"
+#include "flatten.hpp"
+#include "chunk.hpp"
+
+#include <fstream>
+#include <filesystem>
+
+namespace kel {
+namespace lbm {
+namespace impl {
+
+template<typename CellFieldSchema>
+struct lbm_csv_writer {
+};
+
+template<typename T, uint64_t D>
+struct lbm_csv_writer<sch::Primitive<T,D>> {
+	static saw::error_or<void> apply(std::ostream& csv_file, const saw::data<sch::Primitive<T,D>>& field){
+		if constexpr (std::is_same_v<T,sch::UnsignedInteger> and D == 1u) {
+			csv_file<<field.template cast_to<sch::UInt16>().get();
+		}else{
+			csv_file<<field.get();
+		}
+		return saw::make_void();
+	}
+};
+
+template<typename T, uint64_t D>
+struct lbm_csv_writer<sch::FixedArray<T,D>> {
+	static saw::error_or<void> apply(std::ostream& csv_file, const saw::data<sch::FixedArray<T,D>>& field){
+		saw::data<sch::FixedArray<sch::UInt64,D>> index;
+		for(saw::data<sch::UInt64> it{0}; it.get() < D; ++it){
+			index.at({0u}).set(0u);
+		}
+
+		// csv_file<<"VECTORS "<<name<<" float\n";
+		for(uint64_t i = 0u; i < D; ++i){
+			if(i > 0){
+				csv_file<<",";
+			}
+			csv_file<<field.at({i}).get();
+		}
+		return saw::make_void();
+	}
+};
+
+template<typename T, uint64_t Ghost, uint64_t... D>
+struct lbm_csv_writer<sch::Chunk<T,Ghost,D...>> {
+
+	template<uint64_t d>
+	static saw::error_or<void> apply_d(std::ostream& csv_file, const saw::data<sch::Chunk<T,Ghost,D...>>& field, saw::data<sch::FixedArray<sch::UInt64,sizeof...(D)>>& index){
+		// VTK wants to iterate over z,y,x instead of x,y,z
+		// So we do the same with CSV to stay consistent for now
+		// We could reorder the dimensions, but eh
+		if constexpr ( d > 0u){
+			for(index.at({d-1u}) = 0u; index.at({d-1u}) < field.get_dims().at({d-1u}); ++index.at({d-1u})){
+				auto eov = apply_d<d-1u>(csv_file, field, index);
+			}
+		}else{
+			auto eov = lbm_csv_writer<T>::apply(csv_file, field.at(index));
+			csv_file<<"\n";
+			if(eov.is_error()) return eov;
+		}
+		return saw::make_void();
+	}
+
+	static saw::error_or<void> apply(std::ostream& csv_file, const saw::data<sch::Chunk<T,Ghost,D...>>& field, std::string_view name){
+		saw::data<sch::FixedArray<sch::UInt64,sizeof...(D)>> index;
+		for(saw::data<sch::UInt64> it{0}; it.get() < sizeof...(D); ++it){
+			index.at({0u}).set(0u);
+		}
+
+		{
+			auto eov = apply_d<sizeof...(D)>(csv_file, field, index);
+			if(eov.is_error()){
+				return eov;
+			}
+		}
+
+		return saw::make_void();
+	}
+};
+
+template<typename T, uint64_t D>
+struct lbm_csv_writer<sch::Vector<T,D>> {
+	static saw::error_or<void> apply(std::ostream& csv_file, const saw::data<sch::Vector<T,D>>& field){
+		static_assert(D > 0, "Non-dimensionality is bad for velocity.");
+
+		// csv_file<<"VECTORS "<<name<<" float\n";
+		for(uint64_t i = 0u; i < D; ++i){
+			if(i > 0){
+				csv_file<<",";
+			}
+			{
+				auto eov = lbm_csv_writer<T>::apply(csv_file,field.at({{i}}));
+				if(eov.is_error()) return eov;
+			}
+		}
+		return saw::make_void();
+	}
+};
+
+template<typename T>
+struct lbm_csv_writer<sch::Scalar<T>> {
+	static saw::error_or<void> apply(std::ostream& csv_file, const saw::data<sch::Scalar<T>>& field){
+		return lbm_csv_writer<T>::apply(csv_file,field.at({}));
+	}
+};
+
+template<typename... MemberT, saw::string_literal... Keys, uint64_t... Ghost, uint64_t... Dims>
+struct lbm_csv_writer<sch::Struct<sch::Member<sch::Chunk<MemberT,Ghost,Dims...>,Keys>...>> final  {
+	template<uint64_t i>
+	static saw::error_or<void> iterate_i(
+			const std::filesystem::path& csv_dir, const std::string_view& file_base_name, uint64_t d_t, 
+			const saw::data<sch::Struct<sch::Member<sch::Chunk<MemberT,Ghost,Dims...>,Keys>...>>& field){
+
+		if constexpr ( i < sizeof...(MemberT) ) {
+			using MT = typename saw::parameter_pack_type<i,sch::Member<sch::Chunk<MemberT,Ghost,Dims...>,Keys>...>::type;
+			{
+				std::stringstream sstr;
+				sstr
+					<<file_base_name
+					<<"_"
+					<<MT::Key.view()
+					<<"_"
+					<<d_t
+					<<".csv"
+				;
+				std::ofstream csv_file{csv_dir / sstr.str() };
+
+				if( not csv_file.is_open() ){
+					return saw::make_error<saw::err::critical>("Could not open file.");
+				}
+				// 
+				auto eov = lbm_csv_writer<typename MT::ValueType>::apply(csv_file,field.template get<MT::KeyLiteral>(), MT::KeyLiteral.view());
+				if(eov.is_error()){
+					return eov;
+				}
+			}
+
+			return iterate_i<i+1u>(csv_dir, file_base_name, d_t,field);
+		}
+
+		return saw::make_void();
+	}
+
+
+	static saw::error_or<void> apply(
+			const std::filesystem::path& csv_dir, const std::string_view& file_base_name, uint64_t d_t, 
+			const saw::data<sch::Struct<sch::Member<sch::Chunk<MemberT,Ghost,Dims...>,Keys>...>>& field){
+		
+		auto& field_0 = field.template get<saw::parameter_key_pack_type<0u,Keys...>::literal>();	
+		auto meta = field_0.get_dims();
+		
+		return iterate_i<0u>(csv_dir,file_base_name, d_t, field);
+	}
+};
+
+}
+
+template<typename Sch>
+saw::error_or<void> write_csv_file(const std::filesystem::path& out_dir, const std::string_view& file_name, uint64_t d_t, const saw::data<Sch>& field){
+
+	auto csv_dir = out_dir / "csv";
+	{
+		std::error_code ec;
+		std::filesystem::create_directories(csv_dir,ec);
+		if(ec != std::errc{}){
+			return saw::make_error<saw::err::critical>("Could not create directory for write_csv_file function");
+		}
+	}
+	auto eov = impl::lbm_csv_writer<Sch>::apply(csv_dir, file_name, d_t, field);
+	return eov;
+}
+
+}
+}
-- 
cgit v1.2.3


From 16700f013886b8d8cb02e322c2d66c00179d9c89 Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Tue, 3 Mar 2026 19:46:31 +0100
Subject: Fixing ZouHe?

---
 lib/core/c++/boundary.hpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'lib/core/c++')

diff --git a/lib/core/c++/boundary.hpp b/lib/core/c++/boundary.hpp
index d5f3022..0a4ff4d 100644
--- a/lib/core/c++/boundary.hpp
+++ b/lib/core/c++/boundary.hpp
@@ -135,7 +135,7 @@ public:
 		for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
 			auto c_k = dfi::directions[k.get()];
 
-			if(c_k[0u]*known_dir <= 0){
+			if(c_k[0u]*known_dir >= 0){
 				sum_df += dfs_old.at({k});
 			}
 		}
@@ -147,7 +147,7 @@ public:
 
 		for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
 			auto c_k = dfi::directions[k.get()];
-			if(c_k[0u]*known_dir < 0){
+			if(c_k[0u]*known_dir > 0){
 				sum_unknown_dfs += dfs_old.at({k}) * c_k[0u];
 			}
 		}
-- 
cgit v1.2.3