hashes.hpp

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#pragma once
 
#include <unordered_map>
#include <glm/vec3.hpp>
#include <glm/vec2.hpp>
 
namespace std
{
    template<>
    struct hash<glm::ivec3>
    {
        std::size_t operator()(const glm::ivec3 & v) const
        {
            static const unsigned int m = 0x5bd1e995U;
 
            unsigned int hash = 0;
            unsigned int k = v.x;
 
            //first vector element
            k *= m;
            k ^= k >> 24;
            k *= m;
            hash *= m;
            hash ^= k;
            //second vector element
            k = v.y;
            k *= m;
            k ^= k >> 24;
            k *= m;
            hash *= m;
            hash ^= k;
            //third vector element
            k = v.z;
            k *= m;
            k ^= k >> 24;
            k *= m;
            hash *= m;
            hash ^= k;
 
            hash ^= hash >> 13;
            hash *= m;
            hash ^= hash >> 15;
            return hash;
        }
    };
 
    template<>
    struct hash<glm::ivec2>
    {
        std::size_t operator()(const glm::ivec2 & v) const
        {
            static const unsigned int m = 0x5bd1e995U;
 
            unsigned int hash = 0;
            unsigned int k = v.x;
 
            //first vector element
            k *= m;
            k ^= k >> 24;
            k *= m;
            hash *= m;
            hash ^= k;
            //second vector element
            k = v.y;
            k *= m;
            k ^= k >> 24;
            k *= m;
            hash *= m;
            hash ^= k;
 
            hash ^= hash >> 13;
            hash *= m;
            hash ^= hash >> 15;
            return hash;
        }
    };
}