/*
put your name here, just in case ****
Project 1: Ray Tracing
CS4451A, Spring 2005
*/

#include <math.h>
#include <fstream.h>
#include <iostream.h>


/* ------------ typedefs -------------- */

typedef struct {
  double r,g,b;
}
RGB;

class image {
  int xsize,ysize; // resolution
  RGB *rgb;        // pixel intensities
 public:
  image ( int m, int n );       // allocates image of specified size
  RGB &pixel ( int i, int j );  // access to a specific pixel

  friend ostream &operator<< ( ostream &ofs, image i );
  // dumps image as a ppm file
};


/* ----------- functionality of image class ---------- */

image::image ( int m, int n ) : xsize(m), ysize(n)
{
  rgb = new RGB[m*n];
}

/* ----------------------- */

RGB &image::pixel ( int i, int j )
{
  return rgb[i+xsize*j];
}

/* ----------------------- */

int clampnround ( double x )
{
  if (x>255)
    x = 255;
  if (x<0) 
    x = 0;
  return (int)floor(x+.5);
}

ostream &operator<< ( ostream &ofs, RGB c )
{
  return ofs << clampnround(255*c.r) << " " << clampnround(255*c.g) << " " << clampnround(255*c.b) << " " << endl; 
}

ostream &operator<< ( ostream &ofs, image i )
{
  int x,y;

  ofs << "P3" << endl;
  ofs << i.xsize << " " << i.ysize << endl;
  ofs << "255" << endl;
  for ( y=i.ysize-1; y>=0; y-- )
    for ( x=0; x<i.xsize; x++ )
      ofs << i.pixel(x,y);
  return ofs;
}

/* ----------------------- */

int main ( )
{
  int x,y;

  /* create a little example.... */

  image img(256,256);
  for ( x=0; x<256; x++ )
    for ( y=0; y<256; y++ )
      {
	RGB &pix = img.pixel(x,y);

	/* call your raytracer here, then assign the rgb values
	 it returns to the pixel */

	pix.r = x/255.0;
	pix.g = y/255.0;
	pix.b = (2-(x/255.0+y/255.0))/2;
      }

  /* dump the image to standard output */
  cout << img;

  return 0;
}