// magnify PPM image 
//
#include <stdio.h>
#include <stdlib.h>
 
#include "ppm.h"
 
#define MAG 100 // default magnification factor
 
void scale( unsigned char **b, unsigned char **a, int brows, int bcols, int mag)
{
  for( int i = 0; i < brows; ++i)
    for( int j = 0; j < bcols; ++j)
      b[i][j] = a[i/mag][j/mag];
}
 
ppm magnify( ppm a, int mag)
{
  ppm b = ppm_new( a.rows*mag, a.cols*mag);
 
  scale( b.r, a.r, b.rows, b.cols, mag);
  scale( b.g, a.g, b.rows, b.cols, mag);
  scale( b.b, a.b, b.rows, b.cols, mag);
 
  return b;
}
 
int main( int argc, char *argv[])
{
  int mag = MAG;
 
  if( argc > 1)
  {
    int t = atoi( argv[1]);
    if( t > 0) mag = t;
  }
 
  ppm a = ppm_read();
 
  ppm b = magnify( a, mag);
 
  ppm_write( b);
 
  return 0;
}