#ifndef INC_PGM
#define INC_PGM
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#define HI(num) (((num) & 0x0000FF00) >> 8)
#define LO(num) ((num) & 0x000000FF)
//PODATKOVNE STRUKTURE
//Podatkovna struktura, ki hrani podatke o sliki
typedef struct {
int height; //viöina slike
int width; //öirina slike
int max_gray; //maksimalna vrednost sivin
int *image; //polje pikslov na hostu
} PGMData;
//--------------------------------------------------------//
//FUNKCIJE
//Funkcija prebere sliko z imenom filename in jo zapiöe v podatkovno strukturo tipa PGMData
PGMData* readPGM(const char *filename, PGMData *data);
//Funkcija zapiöe sliko, ki se nahaja v podatkovni stukturi tipa PGMData v datoteko z imenom filename
void writePGM(const char *filename, const PGMData *data);
//--------------------------------------------------------//
void SkipComments(FILE *fp)
{
int ch;
char line[100];
while ((ch = fgetc(fp)) != EOF && isspace(ch))
;
if (ch == '#') {
fgets(line, sizeof(line), fp);
SkipComments(fp);
} else
fseek(fp, -1, SEEK_CUR);
}
PGMData* readPGM(const char *filename, PGMData *data)
{
FILE *pgmFile;
char version[3];
int i, j;
int lo, hi;
pgmFile = fopen(filename, "rb");
if (pgmFile == NULL) {
perror("Cannot open file to read");
exit(EXIT_FAILURE);
}
fgets(version, sizeof(version), pgmFile);
if (strcmp(version, "P5")) {
fprintf(stderr, "Wrong file type!\n");
exit(EXIT_FAILURE);
}
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->width);
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->height);
SkipComments(pgmFile);
fscanf(pgmFile, "%d", &data->max_gray);
fgetc(pgmFile);
data->image = (int *)malloc(data->height*data->width*sizeof(int));
if (data->max_gray > 255)
for (i = 0; i < data->height; ++i)
for (j = 0; j < data->width; ++j) {
hi = fgetc(pgmFile);
lo = fgetc(pgmFile);
data->image[i*data->width+j] = (hi << 8) + lo;
}
else
for (i = 0; i < data->height; ++i)
for (j = 0; j < data->width; ++j) {
lo = fgetc(pgmFile);
data->image[i*data->width+j] = lo;
}
fclose(pgmFile);
return data;
}
void writePGM(const char *filename, const PGMData *data)
{
FILE *pgmFile;
int i, j;
int hi, lo;
int width=(data->width)-1;
pgmFile = fopen(filename, "wb");
if (pgmFile == NULL) {
perror("Cannot open file to write");
exit(EXIT_FAILURE);
}
fprintf(pgmFile, "P5 ");
fprintf(pgmFile, "%d %d ", data->width, data->height);
fprintf(pgmFile, "%d ", data->max_gray);
if (data->max_gray > 255) {
for (i = 0; i < data->height; ++i) {
for (j = 0; j < data->width; ++j) {
hi = HI(data->image[i*data->width+j]);
lo = LO(data->image[i*data->width+j]);
fputc(hi, pgmFile);
fputc(lo, pgmFile);
}
}
} else {
for (i = 0; i < data->height; ++i)
for (j = 0; j < data->width; ++j) {
lo = LO(data->image[i*data->width+j]);
fputc(lo, pgmFile);
}
}
fclose(pgmFile);
free(data->image);
}
#endif
