camera.h

#ifndef CAMERA_H
#define CAMERA_H

#include "ray.h"

struct SDim {
    int m_iX; 
    int m_iY; 
};

class Camera {
public:
    Camera() {}
    Camera(const SDim &dims, Vector3D lookFrom, Vector3D lookAt = Vector3D(0), Vector3D viewUp = Vector3D(0, 1, 0), double aperture = 0.1, double Fov = 40) : m_vOrigin(lookFrom), m_dAperture(aperture), m_vViewUp(viewUp), m_vLookAt(lookAt), m_dFov(Fov) {

        double dHalfHeight = tan(Fov*M_PI / 360);
        double dHalfWidth = (dims.m_iX / dims.m_iY) * dHalfHeight;
        double dFocusDist = (lookFrom - lookAt).Length();
        m_vW = UnitVector(lookFrom - lookAt);
        m_vU = UnitVector(viewUp.Cross(m_vW));
        m_vV = m_vW.Cross(m_vU);
        m_vLowerLeftCorner = m_vOrigin - dHalfWidth * dFocusDist * m_vU - dHalfHeight * dFocusDist * m_vV - dFocusDist * m_vW;
        m_vHorizontal = 2 * dHalfWidth*dFocusDist*m_vU;
        m_vVertical = 2 * dHalfHeight*dFocusDist*m_vV;
    }
    virtual Ray GetRay(double s, double t);

    static Vector3D RandomInUnitDisk() {
        Vector3D vP;
        do {
            vP = 2.0*Vector3D(drand48(), drand48(), 0) - Vector3D(1, 1, 0);
        } while (vP.Dot(vP) >= 1.0);
        return vP;
    }

    Vector3D m_vU; 
    Vector3D m_vV; 
    Vector3D m_vW; 
    Vector3D m_vLowerLeftCorner; 
    Vector3D m_vHorizontal; 
    Vector3D m_vVertical; 
    Vector3D m_vOrigin; 
    Vector3D m_vLookAt; 
    Vector3D m_vViewUp; 
    double m_dAperture; 
    double m_dFov; 
};

#endif // CAMERA_H