IHeadPoseEstimator.h

#pragma once

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

#include <cmath>

namespace fsdk {

#ifndef DOXYGEN_SHOULD_SKIP_THIS
    DECLARE_SMARTPTR(IHeadPoseEstimator);
#endif

    struct HeadPoseEstimation {
        float pitch;    
        float yaw;      
        float roll;     

        enum FrontalFaceType {
            FrontalFace0 = 0,   
            FrontalFace1,       
            FrontalFace2        
        };

        inline FrontalFaceType getFrontalFaceType() const;
    };

    struct IHeadPoseEstimator : IRefCounted {
        virtual Result<FSDKError> estimate(
            const Landmarks68 &landmarks,
            HeadPoseEstimation& out) const noexcept = 0;
        virtual Result<FSDKError>
        estimate(
            const fsdk::Image& image,
            const fsdk::Detection& detection,
            HeadPoseEstimation& out) const noexcept = 0;
        virtual Result<FSDKError>
        estimate(
            const fsdk::Image images[],
            const fsdk::Detection detections[],
            const uint32_t batchSize,
            HeadPoseEstimation out[]) const noexcept = 0;
    };

    /*
        Implementation details.
    */
    HeadPoseEstimation::FrontalFaceType
    HeadPoseEstimation::getFrontalFaceType() const {
        if(std::abs(roll) <= 8 && std::abs(pitch) <= 5 && std::abs(yaw) <= 5)
            return HeadPoseEstimation::FrontalFace2;
        if(std::abs(roll) <= 30 && std::abs(pitch) <= 40 && std::abs(yaw) <= 40)
            return HeadPoseEstimation::FrontalFace1;
        return HeadPoseEstimation::FrontalFace0;
    }

} // namespace fsdk