//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: a class for performing cube-mapped spherical sample lookups.
//
// $Workfile:     $
// $Date:         $
// $NoKeywords: $
//===========================================================================//

#ifndef CUBEMAP_H
#define CUBEMAP_H

#ifdef _WIN32
#pragma once
#endif

#include "mathlib/mathlib.h"
#include "tier0/platform.h"
#include "tier1/utlmemory.h"

template <class T, int RES>
struct CCubeMap {
    T m_Samples[6][RES][RES];

   public:
    FORCEINLINE void GetCoords(Vector const &vecNormalizedDirection, int &nX,
                               int &nY, int &nFace) {
        // find largest magnitude component
        int nLargest = 0;
        int nAxis0 = 1;
        int nAxis1 = 2;
        if (fabs(vecNormalizedDirection[1]) > fabs(vecNormalizedDirection[0])) {
            nLargest = 1;
            nAxis0 = 0;
            nAxis1 = 2;
        }
        if (fabs(vecNormalizedDirection[2]) >
            fabs(vecNormalizedDirection[nLargest])) {
            nLargest = 2;
            nAxis0 = 0;
            nAxis1 = 1;
        }
        float flZ = vecNormalizedDirection[nLargest];
        if (flZ < 0) {
            flZ = -flZ;
            nLargest += 3;
        }
        nFace = nLargest;
        flZ = 1.0 / flZ;
        nX = RemapValClamped(vecNormalizedDirection[nAxis0] * flZ, -1, 1, 0,
                             RES - 1);
        nY = RemapValClamped(vecNormalizedDirection[nAxis1] * flZ, -1, 1, 0,
                             RES - 1);
    }

    FORCEINLINE T &GetSample(Vector const &vecNormalizedDirection) {
        int nX, nY, nFace;
        GetCoords(vecNormalizedDirection, nX, nY, nFace);
        return m_Samples[nFace][nX][nY];
    }
};

#endif  // CUBEMAP_H