/*
    A simple RGB example (formula plot) for use with image display program.
    Copyright (C) <2013>   <Lester Vecsey>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Contact via [email protected] or mail to 700 Jane Dr, Franklin Lakes,
    NJ, 07417

*/

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

#include <sys/types.h>

int main(int argc, char *argv[]) {

  long int xres = 960, yres = 960;

  size_t img_sz = xres*yres*sizeof(u_int16_t)*3;

  u_int16_t *rgb = malloc(img_sz);

  long int n;

  double f(double x) {
    return 1.0 / (1.0 + x);
  }

  long int xpos, ypos;

  double x,y;

  for (xpos=0; xpos < xres; xpos++) {
    x = xpos-xres/2;
    x *= 6.0;
    x /= xres;
    y = f(x);
    ypos = y;
    ypos += yres/2;
    rgb[ypos*xres*3+xpos*3+0] = 65535;
    rgb[ypos*xres*3+xpos*3+1] = 65535;
    rgb[ypos*xres*3+xpos*3+2] = 65535;
  }

  write(1,rgb,img_sz);

  return 0;

}