#ifndef MYPGM_H
#define MYPGM_H

#include "datatypes.h"

#define PGM_MAXMAXVAL 255

/* The header of a pgm file consists of the type on the first line.
 * Optional comments with a beginning hash (#) character in next line(s).
 * The number of columns followed by the number of rows in next line.
 * The maximum value by itself on the next line (ex: 255, 4096, etc).
 * The actual pixels in raw binary or ascii format depending on type
 */

#define MAX_NUM_COMMENTS 5

/* for data, internally the image is written sequentially by row.
 * That is, first goes row 1, then row 2, and so on, until last row.
 */
typedef struct
{
  int num_comments;
  char comment[MAX_NUM_COMMENTS][512];
  int rows, cols;
  uint8 max_val;
  uint8* data;
} pgm_image;

/* functions must be called before using image */
void pgm_init(pgm_image* the_image);

/* set pixel in position row, col to given value */
void pgm_setpixel(pgm_image* the_image, int row, int col, uint8 val);

/* return value located at given row and col */
uint8 pgm_getpixel(pgm_image* the_image, int row, int col);

/* get the array for given row */
uint8* pgm_getrow(pgm_image* the_image, int row);

/* flip the image upsidedown */
void pgm_flipud(pgm_image* the_image);

/* read a pgm file from given file handle */
void pgm_readfile(pgm_image* the_image, char* filename);

/* write a pgm file to given file handle */
/* if raw is true, then image is written as raw binary (P5 type)
 * otherwise if false, then image is written as ascii (P2 type)
 */
void pgm_writefile(pgm_image* the_image, char* filename, int raw);

#endif