3 files changed, 84 insertions, 0 deletions
diff --git a/lib/core/c++/math/math.hpp b/lib/core/c++/math/math.hpp
new file mode 100644
index 0000000..3920bec
--- /dev/null
+++ b/lib/core/c++/math/math.hpp
@@ -0,0 +1,4 @@
+#pragma once
+
+#include "n_linear.hpp"
+#include "n_closest.hpp"
diff --git a/lib/core/c++/math/n_closest.hpp b/lib/core/c++/math/n_closest.hpp
new file mode 100644
index 0000000..ac0fe2f
--- /dev/null
+++ b/lib/core/c++/math/n_closest.hpp
@@ -0,0 +1,54 @@
+#pragma once
+
+#include "../common.hpp"
+#include "../iterator.hpp"
+
+namespace kel {
+namespace lbm {
+
+template<typename FieldSchema, typename Encode, typename T, uint64_t D>
+saw::data<typename FieldSchema::StoredValueSchema> n_closest_read(const saw::data<sch::Ptr<FieldSchema>,Encode>& f, const saw::data<sch::Vector<T,D>>& frac_ind){
+
+	auto shift_frac_ind = frac_ind;
+	for(uint64_t i{0u}; i < D; ++i){
+		
+		shift_frac_ind.at({{i}}) = shift_frac_ind.at({{i}})  + saw::data<T>{0.5};
+		if(shift_frac_ind.at({{i}}).get() < 0){
+			shift_frac_ind.at({{i}}) = {};
+		}
+	}
+
+	saw::data<sch::FixedArray<sch::UInt64,D>> shift_ind;
+	for(uint64_t i{0u}; i < D; ++i){
+		shift_ind.at({i}) = frac_ind.at({{i}}).template cast_to<sch::UInt64>();
+	}
+
+	return f.at(shift_ind);
+}
+
+template<typename FieldSchema, typename Encode, typename T, uint64_t D>
+void n_closest_add(const saw::data<sch::Ptr<FieldSchema>,Encode>& f, const saw::data<sch::Vector<T,D>>& frac_ind, const saw::data<typename FieldSchema::StoredValueSchema>& val){
+	auto shift_frac_ind = frac_ind;
+	for(uint64_t i{0u}; i < D; ++i){
+		
+		shift_frac_ind.at({{i}}) = shift_frac_ind.at({{i}})  + saw::data<T>{0.5};
+		if(shift_frac_ind.at({{i}}).get() < 0){
+			shift_frac_ind.at({{i}}) = {};
+		}
+	}
+
+	auto f_meta = f.meta();
+	saw::data<sch::FixedArray<sch::UInt64,D>> shift_ind;
+	for(uint64_t i{0u}; i < D; ++i){
+		shift_ind.at({i}) = frac_ind.at({{i}}).template cast_to<sch::UInt64>();
+		if(shift_ind.at({i}) < f_meta.at({i})){
+			shift_ind.at({i}) = f_meta.at({i}) - 1u;
+		}
+	}
+	auto& f_i = f.at(shift_ind);
+
+	f_i = f_i + val;
+}
+
+}
+}
diff --git a/lib/core/c++/math/round.hpp b/lib/core/c++/math/round.hpp
new file mode 100644
index 0000000..d3a2586
--- /dev/null
+++ b/lib/core/c++/math/round.hpp
@@ -0,0 +1,26 @@
+#pragma once
+
+#include "../common.hpp"
+
+namespace kel {
+namespace lbm {
+
+template<typename T, uint64_t D>
+saw::data<sch::FixedArray<sch::UInt64,D>> round_to_unsigned(const saw::data<sch::Vector<T,D>>& inp){
+	saw::data<sch::FixedArray<sch::UInt64,D>> rv;
+				
+	auto zero = static_cast<saw::native_data_type<T>::type>(0);
+	auto half = static_cast<saw::native_data_type<T>::type>(0.5);
+
+	for(uint64_t i{0u}; i < D; ++i){
+		auto val = inp.at({{i}}).get()+half;
+		val = std::max(zero,val);
+
+		rv.at({i}).set(static_cast<uint64_t>(val));
+	}
+
+	return rv;
+}
+
+}
+}