/* Stripe pattern generator.

   ./stripes_generic <width> <height> > output.pgm

   This file implements stripe patterns by doing a coordinate
   transformation first.  It's the same spirit as stripes.c, but
   more expensive.
                                                                 */

#include<math.h>
#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#ifdef _WIN32
   #include<fcntl.h>
   #include<io.h>
#endif

#define PI  3.14159265358979323846264338327950288419716939937510

int main(int argc, char **argv)
{
   int width, height, x, y;
   double angle, scale, ratio, a, b, c, t;

   if( argc != 3 ||
       (width = atoi(argv[1])) <= 0 ||
       (height = atoi(argv[2])) <= 0 )
   {
      return printf("%s <width> <height>\n", *argv);
   }
   if( width >= 0x8000 || height >= 0x8000 )
      return !puts("Output size too large.");

   #ifdef _WIN32
      setmode(STDOUT_FILENO, O_BINARY);
   #endif

   srand(time(NULL));

   /* Generate transformation. */
   angle = (double)rand() / RAND_MAX * 2.0 * PI;
   scale = (double)rand() / RAND_MAX * 0.09 + 0.01;
   a = cos(angle) * scale;
   b = sin(angle) * scale;
   c = (double)rand() / RAND_MAX;
   ratio = (double)rand() / RAND_MAX * 0.6 + 0.2;

   printf("P5\n%d %d\n255\n", width, height);
   for(y = 0; y < height; y++)
   {
      for(x = 0; x < width; x++)
      {
         t = a * x + b * y + c;
         fputc(t - floor(t) > ratio ? 255 : 0, stdout);
      }
   }
   return 0;
}