1 files changed, 107 insertions, 7 deletions

diff --git a/c++/ico.hpp b/c++/ico.hpp
index 0ac1a91..257f12d 100644
--- a/c++/ico.hpp
+++ b/c++/ico.hpp
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <array>
+#include <cassert>
 #include <cstdint>
 
 namespace kel {
@@ -11,7 +12,7 @@ struct ico_surface_helper {
 	 * triangle. The orientation of the triangle is determined by the horizontal line
 	 * (on the 2D foldout of the icosahedron) which is the down direction.  
 	 */
-	static constexpr std::array<std::array<uint8_t,3u>, 20u> neighbour_map {
+	static constexpr std::array<std::array<uint8_t,3u>, 20u> neighbour_map {{
 		{1,4,5},//0
 		{2,0,6},//1
 		{3,1,7},//2
@@ -32,26 +33,112 @@ struct ico_surface_helper {
 		{16,18,12},//17
 		{17,19,13},//18
 		{18,15,14} //19
-	};
+	}};
 };
 }
 
 template<uint64_t SubD>
 class ico_addr {
 private:
-	std::array<uint8_t, SubD+1u> vals_;
+	std::array<uint8_t, SubD> vals_;
 public:
-	template<uint64_t Div = 1u>
-	ico_addr<Div> slice() const {
-		return {};
+	uint8_t& at(uint64_t i){
+		return vals_[i];
+	}
+
+	const uint8_t& at(uint64_t i) const {
+		return vals_[i];
+	}
+
+	constexpr uint64_t size() const {
+		return SubD;
+	}
+
+	bool is_equal(const ico_addr<SubD>& rhs) const {
+		bool eq = true;
+
+		for(uint64_t i = 0u; i < size(); ++i){
+			eq &= (at(i) == rhs.at(i));
+		}
+
+		return eq;
+	}
+
+	bool has_zero() const {
+		uint64_t z_ctr = 0u;
+		for(uint64_t i = 1u; i < size(); ++i){
+			z_ctr += (at(i) == 0u ? 1u : 0u);
+		}
+		return (z_ctr > 0u);
+	}
+
+	std::array<uint64_t,4u> count_groups() const {
+		std::array<uint64_t,4u> grps{0,0,0,0};
+
+		for(uint64_t i = 1u; i < size(); ++i){
+			auto& addr_i = vals_[i];
+			assert(addr_i < 4);
+
+			++grps[addr_i];
+		}
+
+		return grps;
+	}
+
+	uint64_t count_non_zero_groups() const {
+		auto ctr = count_groups();
+
+		uint64_t grp_ctr = 0u;
+		for(uint64_t i = 1u; i < ctr.size(); ++i){
+			grp_ctr += (ctr[i] > 0u ? 1u : 0u);
+		}
+		return grp_ctr;
+	}
+
+	bool has_all_non_zero_groups() const {
+		auto ctr = count_non_zero_groups();
+		return (ctr == 3u);
+	}
+
+	ico_addr<SubD> go_to(uint8_t dir_i){
+		ico_addr<SubD> cpy_addr;
+		cpy_addr.vals_ = vals_;
+
+		if(at(size() - 1u) == 0u){
+			cpy_addr.at(size() - 1u) = dir_i + 1u;
+		}
+		if(at(size() - 1u) == (dir_i + 1u)){
+			cpy_addr.at(size() - 1u) = 0u;
+		}
+
+		return cpy_addr;
+	}
+
+	bool borders_root() const {
+		return not (has_all_non_zero_groups() or has_zero());
 	}
 };
 
 template<typename T, uint64_t D>
 class ico_triangle {
 private:
-	std::array<ico_triangle<T,D-1u>> subdivs_;
+	std::array<ico_triangle<T,D-1u>,4u> subdivs_;
 public:
+
+	ico_triangle<T,D-1u>& at(uint8_t i){
+		return subdivs_[i];
+	}
+
+	template<uint64_t AddrOrigLen>
+	ico_triangle<T,0u> at(const ico_addr<AddrOrigLen>& addr, uint64_t next_i){
+		auto& addr_i = addr[next_i];
+
+		auto& sub_triangle = subdivs_[addr_i];
+		if constexpr ( D == 1u){
+			return sub_triangle;
+		}
+		return sub_triangle.at(addr,next_i+1u);
+	}
 };
 
 template<typename T>
@@ -61,10 +148,23 @@ private:
 public:
 };
 
+namespace impl {
+}
+
 template<typename T, uint64_t SubD>
 class icosahedron final {
 private:
 	std::array<ico_triangle<T,SubD>,20u> surfaces_;
 public:
+
+	template<uint64_t AddrD>
+	ico_triangle<T,SubD+1u-AddrD> at(const ico_addr<AddrD>& addr){
+		static_assert(AddrD <= (SubD+1u), "Addr length to large.");
+		static_assert(AddrD > 0u, "Addr length to small.");
+
+		auto& root_addr = addr[0u];
+		auto& root_triangle = surfaces_[root_addr];
+		return root_triangle.at(addr, 1u);
+	}
 };
 }