#include "simplecamera.h"

void SimpleCamera::setVPWindow(float xmin, float xmax, float ymin, float ymax)
{
    	Xmin = xmin;
    	Xmax = xmax;
    	Ymin = ymin;
    	Ymax = ymax;
    	Width = (Xmax-Xmin)/(float)Nx;
    	Wo2 = Width/2.0;
    	Height = (Ymax-Ymin)/(float)Ny;
    	Ho2 = Height/2.0;
}    

SimpleCamera::SimpleCamera(int nx, int ny)
/*a new camera where the view plane is mapped to nx*ny pixels*/
//defaults: VPwindow from -1.0 to 1.0 in x and y
//          zcop is at 1.0 along positive z axis
//          the direction of view is therefore down negative z-axis
{
	Nx = nx;
	Ny = ny;
	Zcop = 1.0;
    	setVPWindow(-1.0,1.0,-1.0,1.0);
}

void SimpleCamera::setResolution(int nx, int ny)
{
	Nx = nx;
	Ny = ny;
    	Width = (Xmax-Xmin)/(float)Nx;
    	Wo2 = Width/2.0;
    	Height = (Ymax-Ymin)/(float)Ny;
    	Ho2 = Height/2.0;
}

ostream& operator<<(ostream& s, SimpleCamera camera)
{
	s << "\nCamera:\n"
	  << "\nResolution: " << camera.Nx << "x" << camera.Ny
	  << "\nVP Window: [" 
	  << camera.Xmin << "," << camera.Xmax << "," << camera.Ymin << "," << camera.Ymax 
	  << "]"
	  << "\nCOP: (0,0," << camera.Zcop << ")";
	  
	return s;
}
	 		

istream& operator>>(istream& s, SimpleCamera& camera)
{
	s >> camera.Nx >> camera.Ny 
	  >> camera.Xmin >> camera.Xmax >> camera.Ymin >> camera.Ymax 
	  >> camera.Zcop;
	  
	return s;
}



Ray SimpleCamera::ray(int i, int j)
{
	/*_invisible_*/
    	Point pixel_pos(Xmin+(float)i*Width+Wo2, Ymin+(float)j*Height+Ho2, 0.0);

        Ray ray;
        Point cop(0.0,0.0,Zcop);
        //Point cop(Xmin+(float)i*Width+Wo2, Ymin+(float)j*Height+Ho2,Zcop);

        ray.origin() = cop;
        ray.direction() = pixel_pos - cop;
    
    	return ray;
	/*_invisible_*/
}