IEmotionsEstimator.h

#pragma once

#include <fsdk/IObject.h>
#include <fsdk/FSDKError.h>
#include <fsdk/Optional.h>
#include <fsdk/Types.h>

#include <algorithm>

namespace fsdk {

#ifndef DOXYGEN_SHOULD_SKIP_THIS
    DECLARE_SMARTPTR(IEmotionsEstimator);
#endif

    struct EmotionsEstimation {
        float anger;    
        float disgust;  
        float fear;     
        float happiness;
        float sadness;  
        float surprise; 
        float neutral;  

        enum Emotions {
            Anger = 0,
            Disgust,
            Fear,
            Happiness,
            Sadness,
            Surprise,
            Neutral,
            Count
        };

        inline Emotions getPredominantEmotion() const;

        inline float getEmotionScore(Emotions emotion) const;
    };

    struct IEmotionsEstimator : IRefCounted {
        virtual Result<FSDKError>
        estimate(
            const Image& warp,
            EmotionsEstimation& estimation) const noexcept = 0;

        virtual Result<FSDKError>
        estimate(
            Span<const Image> warps,
            Span<EmotionsEstimation> emotionEstimations) const noexcept = 0;

        virtual Result<FSDKError>
        validate(
            Span<const Image> warps,
            Span<Result<FSDKError>> errors) const noexcept = 0;
    };

    /*
        Implementation details.
    */
    EmotionsEstimation::Emotions
    EmotionsEstimation::getPredominantEmotion() const {
        const float* arr = &this->anger;
        return static_cast<EmotionsEstimation::Emotions>(
            std::distance(arr, std::max_element(arr, arr+EmotionsEstimation::Count))
        );
    }

    /*
        Implementation details.
    */
    float EmotionsEstimation::getEmotionScore(Emotions emotion) const {
        return *(&this->anger + static_cast<uint32_t>(emotion));
    }

} // namespace fsdk