Moved examples and added some fun rendering

1 files changed, 0 insertions, 531 deletions

diff --git a/c++/examples/cavity_2d.cpp b/c++/examples/cavity_2d.cpp
deleted file mode 100644
index 00c1741..0000000
--- a/c++/examples/cavity_2d.cpp
+++ /dev/null
@@ -1,531 +0,0 @@
-#include "../descriptor.hpp"
-
-/**
- */
-#include <forstio/codec/data.hpp>
-
-#include <iostream>
-#include <fstream>
-#include <cmath>
-
-namespace kel {
-namespace lbm {
-namespace sch {
-using namespace saw::schema;
-
-/**
- * Basic distribution function
- * Base type
- * D
- * Q
- * Scalar factor
- * D factor
- * Q factor
- */
-using T = Float32;
-using D2Q5 = Descriptor<2,5>;
-using D2Q9 = Descriptor<2,9>;
-
-template<typename Desc>
-using DfCell = Cell<T, Desc, 0, 0, 1>;
-
-template<typename Desc>
-using CellInfo = Cell<UInt8, D2Q9, 1, 0, 0>;
-
-/**
- * Basic type for simulation
- */
-template<typename Desc>
-using CellStruct = Struct<
-	Member<DfCell<Desc>, "dfs">,
-	Member<DfCell<Desc>, "dfs_old">,
-	Member<CellInfo<Desc>, "info">
->;
-
-
-using CavityFieldD2Q9 = CellField<D2Q9, CellStruct<D2Q9>>;
-}
-
-/**
- * Calculate the macroscopic variables rho and u in Lattice Units.
- */
-template<typename Desc>
-void compute_rho_u (
-		saw::data<sch::DfCell<Desc>>& dfs,
-		typename saw::native_data_type<sch::T>::type& rho,
-		std::array<typename saw::native_data_type<sch::T>::type, 2>& vel
-	)
-{
-	using dfi = df_info<sch::T, Desc>;
-
-	rho = 0;
-	std::fill(vel.begin(), vel.end(), 0);
-
-	for(size_t i = 0; i < Desc::Q; ++i){
-		rho += dfs(i).get();
-		vel[0] += dfi::directions[i][0] * dfs(i).get();
-		vel[1] += dfi::directions[i][1] * dfs(i).get();
-	}
-
-	vel[0] /= rho;
-	vel[1] /= rho;
-}
-
-/**
- * Unsure if feasible. I would have a rho normalization on the dfs and then I would use the const rho_computation
- */
-template<typename Desc>
-void compute_const_rho_u (
-		saw::data<sch::DfCell<Desc>>& dfs,
-		const typename saw::native_data_type<sch::T>::type rho,
-		std::array<typename saw::native_data_type<sch::T>::type, 2>& vel
-	)
-{
-	using dfi = df_info<sch::T, Desc>;
-
-	saw::native_data_type<sch::T>::type real_rho = 0;
-	std::fill(vel.begin(), vel.end(), 0);
-
-	for(size_t i = 0; i < Desc::Q; ++i){
-		real_rho += dfs(i).get();
-		vel[0] += dfi::directions[i][0] * dfs(i).get();
-		vel[1] += dfi::directions[i][1] * dfs(i).get();
-	}
-	for(size_t i = 0; i < Desc::Q; ++i){
-		dfs(i).set(dfs(i).get() * (rho/real_rho));
-	}
-
-	vel[0] *= real_rho / (rho*rho);
-	vel[1] *= real_rho / (rho*rho);
-}
-
-/**
- * Calculates the equilibrium for each direction
- */
-template<typename Desc>
-std::array<typename saw::native_data_type<sch::T>::type,Desc::Q> equilibrium(
-	typename saw::native_data_type<sch::T>::type rho,
-	const std::array<typename saw::native_data_type<sch::T>::type, Desc::D>& vel
-){
-	using dfi = df_info<sch::T, Desc>;
-
-	typename std::array<saw::native_data_type<sch::T>::type,Desc::Q> eq;
-
-	for(std::size_t i = 0; i < eq.size(); ++i){
-		auto vel_c = (vel[0]*dfi::directions[i][0] + vel[1]*dfi::directions[i][1]);
-		auto vel_c_cs2 = vel_c * dfi::inv_cs2;
-		eq[i] = dfi::weights[i] * rho * (
-			1.0
-			+ vel_c_cs2
-			- dfi::inv_cs2 * 0.5 * ( vel[0] * vel[0] + vel[1] * vel[1] )
-			+ vel_c_cs2 * vel_c_cs2 * 0.5
-		);
-	}
-
-	return eq;
-}
-
-/**
- * A reason for why a component based design is really good can be seen in my LR solver example
- *
- * Add Expression Templates and you're golden.
- */
-template<typename Kind, typename Desc>
-class component;
-
-/*
-template<typename T, typename Encode>
-class df_cell_view;
-*/
-/**
- * Minor helper for the AA-Pull Pattern, so I can use only one lattice
- *
- * Am I sure I want to use AA this way?
- * Esoteric Twist technically reduces the needed memory access footprint
- */
-/*
-template<typename Desc, size_t SN, size_t DN, size_t QN, typename Encode>
-class df_cell_view<sch::Cell<sch::T, Desc, SN, DN, QN>, Encode> {
-public:
-	using Schema = sch::Cell<sch::T,Desc,SN,DN,QN>;
-private:
-		std::array<std::decay_t<typename saw::native_data_type<sch::T>::type>*, QN> view_;
-public:
-		df_cell_view(const std::array<std::decay_t<typename saw::native_data_type<sch::T>::type>*, QN>& view):
-				view_{view}
-		{}
-};
-*/
-namespace cmpt {
-struct BounceBack{};
-struct MovingWall {};
-struct BGK {};
-struct ConstRhoBGK {};
-}
-
-
-/**
- * Full-Way BounceBack. I suspect that the moving wall requires half-way bounce back.
- */
-template<typename Desc>
-class component<cmpt::BounceBack,Desc> {
-public:
-
-	void apply(saw::data<sch::DfCell<Desc>>& dfs){
-		using dfi = df_info<sch::T,Desc>;
-
-		// Technically use .copy()
-		auto df_cpy = dfs;
-
-		for(uint64_t i = 1u; i < Desc::Q; ++i){
-			dfs({i}) = df_cpy({dfi::opposite_index.at(i)});
-		}
-	}
-};
-
-/**
- * Full-Way moving wall Bounce back, something is not right here.
- * Technically it should reflect properly.
- */
-template<typename Desc>
-class component<cmpt::MovingWall, Desc> {
-public:
-	std::array<typename saw::native_data_type<sch::T>::type, Desc::D> lid_vel;
-	
-public:
-	void apply(
-		saw::data<sch::DfCell<Desc>>& dfs
-	){
-		using dfi = df_info<sch::T,Desc>;
-
-		// Technically use .copy()
-		/*
-		auto dfs_cpy = dfs;
-		
-		for(uint64_t i = 0u; i < Desc::Q; ++i){
-			dfs({dfi::opposite_index.at(i)}) = dfs_cpy({i}) - 2.0 * dfi::weights[i] * 1.0 * ( lid_vel[0] * dfi::directions[i][0] + lid_vel[1] * dfi::directions[i][1]) * dfi::inv_cs2;
-		}
-		*/
-	}
-};
-
-template<typename Desc>
-class component<cmpt::BGK, Desc> {
-public:
-	typename saw::native_data_type<sch::T>::type relaxation_;
-public:
-	void apply(saw::data<sch::DfCell<Desc>>& dfs){
-		typename saw::native_data_type<sch::T>::type rho;
-		std::array<typename saw::native_data_type<sch::T>::type, Desc::D> vel;
-		compute_rho_u<Desc>(dfs,rho,vel);
-		auto eq = equilibrium<Desc>(rho,vel);
-		
-		for(uint64_t i = 0u; i < Desc::Q; ++i){
-			dfs({i}).set(dfs({i}).get() + (1.0 / relaxation_) * (eq[i] - dfs({i}).get()));
-		}
-	}
-};
-
-template<typename Desc>
-class component<cmpt::ConstRhoBGK, Desc> {
-public:
-	typename saw::native_data_type<sch::T>::type relaxation_;
-	typename saw::native_data_type<sch::T>::type rho_;
-public:
-	void apply(saw::data<sch::DfCell<Desc>>& dfs){
-		std::array<typename saw::native_data_type<sch::T>::type, Desc::D> vel;
-		compute_const_rho_u<Desc>(dfs,rho_,vel);
-		auto eq = equilibrium<Desc>(rho_,vel);
-		
-		for(uint64_t i = 0u; i < Desc::Q; ++i){
-			dfs({i}).set(dfs({i}).get() + (1.0 / relaxation_) * (eq[i] - dfs({i}).get()));
-		}
-	}
-};
-}
-}
-
-constexpr size_t dim_size = 2;
-constexpr size_t dim_x = 128;
-constexpr size_t dim_y = 128;
-
-
-template<typename Func>
-void apply_for_cells(Func&& func, saw::data<kel::lbm::sch::CavityFieldD2Q9>& dat){
-	for(std::size_t i = 0; i < dat.meta().at({1u}).get(); ++i){
-		for(std::size_t j = 0; j < dat.meta().at({0u}).get(); ++j){
-			saw::data<saw::schema::UInt64> di{i};
-			saw::data<saw::schema::UInt64> dj{j};
-			auto& cell_v = dat({{dj,di}});
-			func(cell_v, j, i);
-		}
-	}
-}
-
-void set_geometry(saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt){
-	using namespace kel::lbm;
-	apply_for_cells([](auto& cell, std::size_t i, std::size_t j){
-		uint8_t val = 0;
-		if(j == 1){
-			val = 2u;
-		}
-		if(i == 1 || (i+2) == dim_x || (j+2) == dim_y){
-			val = 3u;
-		}
-		if(i > 1 && (i+2) < dim_x && j > 1 && (j+2) < dim_y){
-			val = 1u;
-		}
-		if(i == 0 || j == 0 || (i+1) == dim_x || (j+1) == dim_y){
-			val = 0u;
-		}
-		cell.template get<"info">()(0u).set(val);
-	}, latt);
-}
-
-void set_initial_conditions(saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt){
-	using namespace kel::lbm;
-	
-	typename saw::native_data_type<sch::T>::type rho = 1.0;
-	{
-		std::array<typename saw::native_data_type<sch::T>::type, sch::D2Q9::D> vel = {0.0, 0.0};
-		auto eq = equilibrium<sch::D2Q9>(rho, vel);
-
-		apply_for_cells([&eq](auto& cell, std::size_t i, std::size_t j){
-			(void) i;
-			(void) j;
-			auto& dfs = cell.template get<"dfs">();
-			auto& dfs_old = cell.template get<"dfs_old">();
-			auto info = cell.template get<"info">()(0u).get();
-			for(uint64_t k = 0; k < sch::D2Q9::Q; ++k){
-				dfs(k).set(eq[k]);
-				dfs_old(k).set(eq[k]);
-			}
-		}, latt);
-	}
-	
-	{
-		std::array<typename saw::native_data_type<sch::T>::type, sch::D2Q9::D> vel = {0.1, 0.0};
-		auto eq = equilibrium<sch::D2Q9>(rho, vel);
-
-		apply_for_cells([&eq](auto& cell, std::size_t i, std::size_t j){
-			(void) i;
-			(void) j;
-			auto& dfs = cell.template get<"dfs">();
-			auto& dfs_old = cell.template get<"dfs_old">();
-			auto info = cell.template get<"info">()(0u).get();
-			if(info == 2u){
-				for(uint64_t k = 0; k < sch::D2Q9::Q; ++k){
-					dfs(k).set(eq[k]);
-					dfs_old(k).set(eq[k]);
-				}
-			}
-		}, latt);
-	}
-}
-
-void lbm_step(
-	saw::data<kel::lbm::sch::CavityFieldD2Q9>& latt,
-	bool even_step
-){
-	using namespace kel::lbm;
-  using dfi = df_info<sch::T,sch::D2Q9>;
-
-	component<cmpt::BGK,sch::D2Q9> coll;
-	coll.relaxation_ = 0.5384;
-	component<cmpt::ConstRhoBGK,sch::D2Q9> rho_coll;
-	rho_coll.relaxation_ = 0.5384;
-	rho_coll.rho_ = 1.0;
-
-	component<cmpt::BounceBack,sch::D2Q9> bb;
-	component<cmpt::MovingWall,sch::D2Q9> bb_lid;
-	bb_lid.lid_vel = {0.1,0.0};
-
-	// Collide
-	apply_for_cells([&](auto& cell, std::size_t i, std::size_t j){
-		auto& df = even_step ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
-		auto& info = cell.template get<"info">();
-
-		auto info_val = info({0u}).get();
-		switch(info_val){
-		case 1u:
-			coll.apply(df);
-			break;
-		case 2u:
-			// bb.apply(df);
-			bb_lid.apply(df);
-			break;
-		case 3u:
-			bb.apply(df);
-			break;
-		}
-	}, latt);
-
-	// Stream
-	for(uint64_t i = 1; (i+1) < latt.template get_dim_size<0>().get(); ++i){
-		for(uint64_t j = 1; (j+1) < latt.template get_dim_size<1>().get(); ++j){
-			auto& cell = latt({{i,j}});
-			auto& df_new = even_step ? cell.template get<"dfs">() : cell.template get<"dfs_old">();
-			auto& info_new = cell.template get<"info">();
-
-			if(info_new({0u}).get() > 0u && info_new({0u}).get() != 2u){
-				for(uint64_t k = 0u; k < sch::D2Q9::Q; ++k){
-					auto dir = dfi::directions[dfi::opposite_index[k]];
-					auto& cell_dir_old = latt({{i+dir[0],j+dir[1]}});
-					
-					auto& df_old = even_step ? cell_dir_old.template get<"dfs_old">() : cell_dir_old.template get<"dfs">();
-					auto& info_old = cell_dir_old.template get<"info">();
-
-					if( info_old({0}).get() == 2u ){
-						auto& df_old_loc = even_step ? latt({{i,j}}).template get<"dfs_old">() : latt({{i,j}}).template get<"dfs">();
-						df_new({k}) = df_old_loc({dfi::opposite_index.at(k)}) - 2.0 * dfi::inv_cs2 * dfi::weights.at(k) * 1.0 * ( bb_lid.lid_vel[0] * dir[0] + bb_lid.lid_vel[1] * dir[1]);
-						// dfs({dfi::opposite_index.at(i)}) = dfs_cpy({i}) - 2.0 * dfi::weights[i] * 1.0 * ( lid_vel[0] * dfi::directions[i][0] + lid_vel[1] * dfi::directions[i][1]) * dfi::inv_cs2;
-					} else {
-						df_new({k}) = df_old({k});
-					}
-				}
-			}
-		}
-	}
-}
-
-int main(){
-	using namespace kel::lbm;
-
-	saw::data<sch::FixedArray<sch::UInt64,sch::D2Q9::D>> dim{{dim_x, dim_y}};
-
-	saw::data<sch::CavityFieldD2Q9, saw::encode::Native> lattice{dim};
-
-	// auto& df_field = lattices.at(0).template get<"dfs">();
-	//for(uint64_t i = 0; i < df_field.get_dim_size<0u>(); ++i){
-	//	lattices.at(i) = {dim_x, dim_y};
-	//}
-
-	/**
-	 * Set meta information describing what this cell is
-	 */
-	set_geometry(lattice);
-	/**
-	 * 
-	 */
-	set_initial_conditions(lattice);
-
-	/**
-	 * Timeloop
-	 */
-
-	/**
-	 * Print basic setup info
-	 */
-	apply_for_cells([](auto& cell, std::size_t i, std::size_t j){
-			// Not needed
-			(void) j;
-			std::cout<<(static_cast<uint32_t>(cell.template get<"info">()({0}).get()));
-			if( (i+1) < dim_x){
-				std::cout<<" ";
-			}else{
-				std::cout<<"\n";
-			}
-	}, lattice);
-	
-	uint64_t lattice_steps = 512000u;
-	bool even_step = true;
-
-	uint64_t print_every = 256u;
-	uint64_t file_no = 0u;
-
-	for(uint64_t step = 0; step < lattice_steps; ++step){
-
-		if(step % print_every == 0u){
-			std::cout<<"\n";
-			typename saw::native_data_type<sch::T>::type sum = 0.0;
-
-			apply_for_cells([&](auto& cell, std::size_t i, std::size_t j){
-				auto& dfs = cell.template get<"dfs">();
-				typename saw::native_data_type<sch::T>::type rho;
-				std::array<typename saw::native_data_type<sch::T>::type, sch::D2Q9::D> vel;
-				compute_rho_u<sch::D2Q9>(dfs,rho,vel);
-
-				if(i > 1 && (i+2) < dim_x && j > 1 && (j+2) < dim_y){
-					sum += rho;
-				}
-				auto angle = std::atan2(vel[1],vel[0]);
-			
-				auto dir_char = [&]() -> std::string_view {
-					constexpr auto pi = M_PI;
-					if((vel[1] * vel[1] + vel[0]*vel[0]) < 1e-16){
-						return "•";
-					}
-					if(angle > 7.0 / 8.0 * pi){
-						return "←";
-					}
-					if(angle > 5.0 / 8.0 * pi){
-						return "↖";
-					}
-					if(angle > 3.0 / 8.0 * pi){
-						return "↑";
-					}
-					if(angle > 1.0 / 8.0 * pi){
-						return "↗";
-					}
-					if(angle > -1.0 / 8.0 * pi){
-						return "→";
-					}
-					if(angle > -3.0 / 8.0 * pi){
-						return "↘";
-					}
-					if(angle > -5.0 / 8.0 * pi){
-						return "↓";
-					}
-					if(angle > -7.0 / 8.0 * pi){
-						return "↙";
-					}
-					return "←";
-				}();
-				std::cout<<dir_char;
-				if( (i+1) < dim_x){
-					std::cout<<" ";
-				}else{
-					std::cout<<"\n";
-				}
-			}, lattice);
-
-			std::cout<<"Average rho: "<<(sum / ((dim_x-4)*(dim_y-4)))<<std::endl;
-
-			std::ofstream vtk_file{"tmp/cavity_2d_"+std::to_string(file_no)+".vtk"};
-
-			vtk_file <<"# vtk DataFile Version 3.0\n";
-			vtk_file <<"Velocity Cavity2D example\n";
-			vtk_file <<"ASCII\n";
-			vtk_file <<"DATASET STRUCTURED_POINTS\n";
-			vtk_file <<"DIMENSIONS "<< dim_x <<" "<<dim_y<<" 1\n";
-			vtk_file <<"SPACING 1.0 1.0 1.0\n";
-			vtk_file <<"ORIGIN 0.0 0.0 0.0\n";
-			vtk_file <<"POINT_DATA "<<(dim_x*dim_y)<<"\n";
-			vtk_file <<"VECTORS Velocity float\n";
-			
-			apply_for_cells([&](auto& cell, std::size_t i, std::size_t j){
-				auto dfs = even_step ? cell.template get<"dfs_old">() : cell.template get<"dfs">();
-
-				typename saw::native_data_type<sch::T>::type rho;
-				std::array<typename saw::native_data_type<sch::T>::type, sch::D2Q9::D> vel;
-				compute_rho_u<sch::D2Q9>(dfs,rho,vel);
-
-				vtk_file << static_cast<float>(vel[0u]) << " " << static_cast<float>(vel[1u])<<" 0.0\n";
-			}, lattice);
-			
-
-			++file_no;
-		}
-		
-		lbm_step(lattice, even_step);
-
-		even_step = !even_step;
-	}
-
-	/**
-	 * Flush cout
-	 */
-	std::cout<<"\n\n";
-	std::cout.flush();
-	return 0;
-}