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#ifndef Distance_h
#define Distance_h

namespace WebCore {

// Distance models are defined according to the OpenAL specification:
// http://connect.creativelabs.com/openal/Documentation/OpenAL%201.1%20Specification.htm.

enum class DistanceModelType {
    Linear,
    Inverse,
    Exponential
};

class DistanceEffect final {
    WTF_MAKE_FAST_ALLOCATED;
public:
    DistanceEffect();

    // Returns scalar gain for the given distance the current distance model is used
    double gain(double distance) const;

    DistanceModelType model() const { return m_model; }

    void setModel(DistanceModelType model, bool clamped)
    {
        m_model = model;
        m_isClamped = clamped;
    }

    // Distance params
    void setRefDistance(double refDistance) { m_refDistance = refDistance; }
    void setMaxDistance(double maxDistance) { m_maxDistance = maxDistance; }
    void setRolloffFactor(double rolloffFactor) { m_rolloffFactor = rolloffFactor; }

    double refDistance() const { return m_refDistance; }
    double maxDistance() const { return m_maxDistance; }
    double rolloffFactor() const { return m_rolloffFactor; }

protected:
    double linearGain(double distance) const;
    double inverseGain(double distance) const;
    double exponentialGain(double distance) const;

    DistanceModelType m_model { DistanceModelType::Inverse };
    bool m_isClamped { true };
    double m_refDistance { 1 };
    double m_maxDistance { 10000 };
    double m_rolloffFactor { 1 };
};

} // namespace WebCore

#endif // Distance_h