//
//  ParticleSystemGradients.h
//  cocos2d_libs
//
//  Created by 徐俊杰 on 2020/4/24.
//

#ifndef ParticleSystemGradients_h
#define ParticleSystemGradients_h

#include "rparticle/Macros/RParticleMacros.h"

#include "rparticle/Math/Gradient.h"

NS_RRP_BEGIN

enum MinMaxGradientEvalMode
{
    kGEMGradient,
    kGEMGradientMinMax,
    kGEMSlow,
};

enum MinMaxGradientState
{
    kMMGColor = 0,
    kMMGGradient = 1,
    kMMGRandomBetweenTwoColors = 2,
    kMMGRandomBetweenTwoGradients = 3
};

struct OptimizedMinMaxGradient
{
    OptimizedGradient max;
    OptimizedGradient min;
};

inline ColorRGBA32 EvaluateGradient (const OptimizedMinMaxGradient& g, float t)
{
    return g.max.Evaluate(t);
}

inline ColorRGBA32 EvaluateRandomGradient (const OptimizedMinMaxGradient& g, float t, UInt32 factor)
{
    return Lerp (g.min.Evaluate(t), g.max.Evaluate(t), factor);
}

struct MinMaxGradient
{
    GradientNEW maxGradient;
    GradientNEW minGradient;
    ColorRGBA32 minColor;    // we have the colors separate to prevent destroying the gradients
    ColorRGBA32 maxColor;
    short minMaxState;        // see enum State
    
    MinMaxGradient();
    
    //TODO: Serialize
//    DEFINE_GET_TYPESTRING (MinMaxGradient)
    
    void InitializeOptimized(OptimizedMinMaxGradient& g);
    
    template<class TransferFunction>
    void Transfer (TransferFunction& transfer);
};

inline ColorRGBA32 EvaluateColor (const MinMaxGradient& gradient)
{
    return gradient.maxColor;
}

inline ColorRGBA32 EvaluateGradient (const MinMaxGradient& gradient, float t)
{
    return gradient.maxGradient.Evaluate(t);
}

inline ColorRGBA32 EvaluateRandomColor (const MinMaxGradient& gradient, UInt32 factor)
{
    return Lerp (gradient.minColor, gradient.maxColor, factor);
}

inline ColorRGBA32 EvaluateRandomGradient (const MinMaxGradient& gradient, float t, UInt32 factor)
{
    return Lerp (gradient.minGradient.Evaluate(t), gradient.maxGradient.Evaluate(t), factor);
}

inline ColorRGBA32 Evaluate (const MinMaxGradient& gradient, float t, UInt32 factor = 0xff)
{
    if (gradient.minMaxState == kMMGColor)
        return EvaluateColor(gradient);
    else if (gradient.minMaxState == kMMGGradient)
        return EvaluateGradient(gradient, t);
    else if (gradient.minMaxState == kMMGRandomBetweenTwoColors)
        return EvaluateRandomColor(gradient, factor);
    else // gradient.minMaxState == kMMGRandomBetweenTwoGradients
        return EvaluateRandomGradient(gradient, t, factor);
}

NS_RRP_END

#endif /* ParticleSystemGradients_h */