MRIntersectionPrecomputes2.h

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#pragma once
 
#include "MRVector2.h"
 
namespace MR
{
 
 
template <typename T>
void findMaxVectorDim( int& dimX, int& dimY, const Vector2<T>& dir )
{
    if( std::abs( dir.x ) >= std::abs( dir.y ) )
    {
        dimX = 1; dimY = 0;
    }
    else
    {
        dimX = 0; dimY = 1;
    }
}
 
template<typename T>
struct IntersectionPrecomputes2
{
    // {1 / dir}
    Vector2<T> invDir;
    // [0]max, [1]next, [2]next-next
    // f.e. {1,2} => {1,0}
    int maxDimIdxY = 1;
    int idxX = 0;
 
    Vector2i sign;
 
    T Sx, Sy;
    IntersectionPrecomputes2() = default;
    IntersectionPrecomputes2( const Vector2<T>& dir )
    {
        findMaxVectorDim( idxX, maxDimIdxY, dir );
 
        sign.x = dir.x >= T( 0 ) ? 1 : 0;
        sign.y = dir.y >= T( 0 ) ? 1 : 0;
 
        Sx = dir[idxX] / dir[maxDimIdxY];
        Sy = T( 1 ) / dir[maxDimIdxY];
 
        invDir.x = ( dir.x == 0 ) ? std::numeric_limits<T>::max() : T( 1 ) / dir.x;
        invDir.y = ( dir.y == 0 ) ? std::numeric_limits<T>::max() : T( 1 ) / dir.y;
    }
};
 
 
}