LoadPGM

LoadPGM

unsigned short LoadPGM(FILE * inFile, Image * inImg) {
	
	/********************************************************************************************/

	// parse binary pgn file to validate format, extract width, height, and greyvalue data array. 

	// read file bytewise
	int position = 1;
	int c; 
	// parse first line. Expecting P5, abort if not. P is 80, 5 is 53, linebreak is 10
	while ((c = fgetc(inFile)) != LINEBREAK) {

	if( position == 1 && !(c == CHAR_P) ) {
		printf("argument is not binary PGM file> fail\n"); 
		return 1;
	}

	if( position == 2 && !(c == CHAR_5) ) {
		printf("argument is not binary PGM file> fail\n"); 
		return 1; 
	}
	inImg->pgmType[position-1] = c;
	position ++; 
	}

	/********************************************************************************************/
	// skip the next comment lines
	
	// if char is #, then skip the line 
	printf("c is: %u\n", c); 
	
	if ((c = fgetc(inFile)) == CHAR_COMMENT) {
		do 
		{
			while ((c = fgetc(inFile)) != LINEBREAK){} 
		}
	 	while ((c = fgetc(inFile)) == CHAR_COMMENT);
	} 
	/********************************************************************************************/

	// now we're at the width. 32 is space, so read till 32 for width, and then till newline(=10) for height. 
 	// construct the byte array that is the width byte by byte. 
	position=0; 
	// dirty fix> have to figure out how to determine the size of the bytearray sometime. this will only work if i know the values in advance... 
	char soonAnInt[STRINGBUF];
	memset(&soonAnInt[0], 0, sizeof(soonAnInt));
	do {
		soonAnInt[position] = c; 
		position++;
		if(position > STRINGBUF) {
				//freak out
		}
	}	while ((c = fgetc(inFile)) != SPACE);
	
	inImg->width = atoi(soonAnInt);

	/********************************************************************************************/
	// now the height
	// reset position and char array helpers
	position=0; 
	memset(&soonAnInt[0], 0, sizeof(soonAnInt));
	// and again, only here till line break 
	while ((c = fgetc(inFile)) != LINEBREAK){
		soonAnInt[position] = c; 
		position++;
	}
	inImg->height = atoi(soonAnInt);

	/********************************************************************************************/
	// now we're getting the depth info, 255 / ignore till next newline 
	position=0; 
	memset(&soonAnInt[0], 0, sizeof(soonAnInt));
	while ((c = fgetc(inFile)) != LINEBREAK){
		soonAnInt[position] = c; 
		position++;
	}
	inImg->depth = atoi(soonAnInt);
	/********************************************************************************************/

	/********************************************************************************************/
	// allocate memory for inImg bytes
	int i=0,j=0;
	// Allocation
	inImg->data = (byte **) malloc(inImg->height*sizeof(byte*));
	for(i=0;i<inImg->height;i++){
	  	inImg->data[i]=(byte *) malloc(inImg->width*sizeof(byte));
	}
	/********************************************************************************************/
	// fill data with values
	
	for(i=0;i<inImg->height;i++) {
		//runs once for every line
		for(j=0;j<inImg->width;j++) {
			//runs once for every pixel inside that line, for each line.
			if ((c = fgetc(inFile)) != EOF) {
				inImg->data[i][j] = c;
			} else {
				inImg->data[i][j] = 0;
			}
		}
	}
	return 0; 
}