src/rcrt/lights/PointLight.cpp

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#include "PointLight.h"

namespace rcrt
{

PointLight::PointLight(RGBColor p, Point3D pos):Light(p,1),position(pos)
{
}

PointLight::~PointLight()
{
}

const Point3D& PointLight::getPosition() const
{
        return position;
}

LightSample PointLight::illuminate(const Point3D& p, const Vec3D& no) const
{
        Vec3D dir(position-p);
        float dist = dir.norm();
        dir.normalize();
        
        float A0 = 1;
        float A1 = 0.25;
        float A2 = 0.001;
        
        float att = 1.0f / (A0 + A1 * (dist) + A2 * dist * dist); // linear attenuation
//      float att = 1.0f / dist; // linear attenuation
                
        return LightSample(1, dir, dist, power*att);
        
}

void PointLight::illuminate(const Point3D& p, const Vec3D& no, std::vector<LightSample>& samples,
                        const int& noSamples, Scene* s) const
{
        samples.push_back(illuminate(p,no));
}

RGBColor PointLight::getEmitted(const Vec3D& dir, const Point3D& pos) const
{
        return power;
}

void PointLight::emitPhoton(Photon* photon) const
{
        photon->setPos(position);
        photon->setPower(power);
        float xi1 = float(rand()) / float(RAND_MAX);
        float xi2 = float(rand()) / float(RAND_MAX);
        float r = sqrt(1.0f - xi1*xi1);
        float a = 2.0f*M_PI * xi2;
        float xi3 = float(rand()) / float(RAND_MAX);
        photon->setDir(Vec3D(r * cos(a), r * sin(a), (xi3 > 0.5 ? -1 : 1)* xi1));
}

}

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