From 24bf28a8fb9cc8c3a90b77de9b60728bece7885d Mon Sep 17 00:00:00 2001
From: "Claudius \"keldu\" Holeksa" <mail@keldu.de>
Date: Sat, 18 Oct 2025 18:01:14 +0200
Subject: Moving project structure for more less compilation

---
 lib/c++/boundary.hpp | 154 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 lib/c++/boundary.hpp

(limited to 'lib/c++/boundary.hpp')

diff --git a/lib/c++/boundary.hpp b/lib/c++/boundary.hpp
new file mode 100644
index 0000000..5cc7705
--- /dev/null
+++ b/lib/c++/boundary.hpp
@@ -0,0 +1,154 @@
+#pragma once
+
+#include "component.hpp"
+#include "equilibrium.hpp"
+
+namespace kel {
+namespace lbm {
+namespace cmpt {
+struct BounceBack {};
+
+template<bool East>
+struct ZouHeHorizontal{};
+
+template<bool North>
+struct ZouHeVertical{};
+}
+
+/**
+ * Full-Way BounceBack.
+ */
+template<typename T, typename Descriptor, typename Encode>
+class component<T, Descriptor, cmpt::BounceBack, Encode> {
+private:
+public:
+	component() = default;
+
+	using Component = cmpt::BounceBack;
+
+	/**
+	 * Thoughts regarding automating order setup
+	 */
+	using access = cmpt::access_tuple<
+		cmpt::access<"dfs", 1, true, true, true>
+	>;
+
+	/**
+	 * Thoughts regarding automating order setup
+	 */
+	static constexpr saw::string_literal name = "full_way_bounce_back";
+	static constexpr saw::string_literal after = "";
+	static constexpr saw::string_literal before = "streaming";
+
+	/**
+	 * Raw setup
+	 */
+	template<typename CellFieldSchema>
+	void apply(saw::data<CellFieldSchema, Encode>& field, const saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>>& index, uint64_t time_step){
+		bool is_even = ((time_step % 2u) == 0u);
+
+		// This is a ref
+		auto& cell = field(index);
+
+		auto& dfs_old = (is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+		// auto& dfs = (not is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+
+		using dfi = df_info<T,Descriptor>;
+
+		// Technically use .copy()
+		auto df_cpy = dfs_old.copy();
+
+		for(uint64_t i = 1u; i < Descriptor::Q; ++i){
+			dfs_old({i}) = df_cpy({dfi::opposite_index.at(i)});
+		}
+	}
+};
+
+/**
+ * This is massively hacky and expects a lot of conditions
+ * Either this or mirrored along the horizontal line works
+ *
+ * 0 - 2 - 2
+ * 0 - 3 - 1
+ * 0 - 3 - 1
+ * .........
+ * 0 - 3 - 1
+ * 0 - 2 - 2
+ *
+ */
+template<typename FP, typename Descriptor, bool Dir, typename Encode>
+class component<FP, Descriptor, cmpt::ZouHeHorizontal<Dir>, Encode> final {
+private:
+	saw::data<FP> pressure_setting_;
+	saw::data<FP> rho_setting_;
+public:
+	component(const saw::data<FP>& pressure_setting__):
+		pressure_setting_{pressure_setting__},
+		rho_setting_{pressure_setting__ * df_info<FP,Descriptor>::inv_cs2}
+	{}
+
+	template<typename CellFieldSchema>
+	void apply(saw::data<CellFieldSchema, Encode>& field, saw::data<sch::FixedArray<sch::UInt64,Descriptor::D>> index, uint64_t time_step){
+		using dfi = df_info<FP,Descriptor>;
+
+		bool is_even = ((time_step % 2) == 0);
+		auto& cell = field(index);
+
+		auto& info = cell.template get<"info">();
+		if(info({0u}).get() == 0u){
+			return;
+		}
+		auto& dfs_old = (is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+		// auto& dfs = (not is_even) ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
+
+		/**
+		 * Sum all known DFs
+		 */
+		saw::data<FP> sum_df{0};
+		for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
+			auto c_k = dfi::directions[k.get()];
+			auto& cell_n = field({{index.at({0u})+c_k[0u], index.at({1u})+c_k[1u]}});
+			auto& info_n = cell_n.template get<"info">();
+			auto info_n_val = info_n({0u});
+			auto k_opp = dfi::opposite_index[k.get()];
+
+			if(info_n_val.get() > 0u){
+				sum_df += dfs_old({k_opp});
+			}
+		}
+
+		/**
+		 * Get the sum of the unknown dfs and precalculate the direction
+		 */
+		constexpr int known_dir = Dir ? 1 : -1;
+		auto sum_unknown_dfs = (rho_setting_ - sum_df) * saw::data<FP>{known_dir};
+
+		for(saw::data<sch::UInt64> k{0u}; k < saw::data<sch::UInt64>{Descriptor::Q}; ++k){
+			auto c_k = dfi::directions[k.get()];
+			auto& cell_n = field({{index.at({0u})+c_k[0u], index.at({1u})+c_k[1u]}});
+			auto& info_n = cell_n.template get<"info">();
+			auto info_n_val = info_n({0u});
+			// auto k_opp = dfi::opposite_index[k.get()];
+
+			if(info_n_val.get() > 0u){
+				sum_unknown_dfs += dfs_old({k}) * c_k[0u];
+			}
+		}
+
+		auto vel_x = sum_unknown_dfs / rho_setting_;
+
+		static_assert(Descriptor::D == 2u and Descriptor::Q == 9u, "Some parts are hard coded sadly");
+
+		if constexpr (Dir) {
+			dfs_old({2u}) = dfs_old({1u}) + saw::data<FP>{2.0 / 3.0} * rho_setting_ * vel_x;
+			dfs_old({6u}) = dfs_old({5u}) + saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({4u}) - dfs_old({3u}));
+			dfs_old({8u}) = dfs_old({7u}) + saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({3u}) - dfs_old({4u}));
+		}else if constexpr (not Dir){
+			dfs_old({1u}) = dfs_old({2u}) - saw::data<FP>{2.0 / 3.0} * rho_setting_ * vel_x;
+			dfs_old({5u}) = dfs_old({6u}) - saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({3u}) - dfs_old({4u}));
+			dfs_old({7u}) = dfs_old({8u}) - saw::data<FP>{1.0 / 6.0} * rho_setting_ * vel_x + saw::data<FP>{0.5} * (dfs_old({4u}) - dfs_old({3u}));
+		}
+	}
+};
+}
+}
-- 
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