area.h

#ifdef _MSC_VER
#pragma once
#endif

#ifndef _SPICA_AREA_LIGHT_H_
#define _SPICA_AREA_LIGHT_H_

#include <vector>
#include <memory>

#include "core/light.h"
#include "core/shape.h"

namespace spica {

class SPICA_EXPORTS AreaLight : public Light {
public:
    AreaLight(const std::shared_ptr<Shape>& shape,
                const Transform& lightToWorld,
                const Spectrum& Lemit,
                int numSamples = 1);

    AreaLight(RenderParams &params);

    virtual ~AreaLight();

    Spectrum L(const Interaction& pLight, const Vector3d& dir) const override;

    Spectrum sampleLi(const Interaction& isect, const Point2d& rands,
                        Vector3d* dir, double* pdf,
                        VisibilityTester* vis) const override;

    double pdfLi(const Interaction& pObj, const Vector3d& dir) const override;

    Spectrum sampleLe(const Point2d& rand1, const Point2d& rand2,
                        Ray* ray, Normal3d* nLight, double* pdfPos,
                        double* pdfDir) const override;
    void pdfLe(const Ray& ray, const Normal3d& nLight, double* pdfPos,
                double* pdfDir) const override;

    Spectrum power() const override;
    Light* clone() const override;

    inline double area() const {
        return shape_->area();
    }

protected:
    std::shared_ptr<Shape> shape_;
    const Spectrum Lemit_;
};

SPICA_EXPORT_PLUGIN(AreaLight, "Area light");

}  // namespace spica

#endif  // _SPICA_AREA_LIGHT_H_