libtthimage/bmp.c

/*
 *		lecture des fichiers BMP
 *		------------------------
 *
 *	ou "comment ne jamais se debarrasser de Kro$oft"
 *
 *	Mais bon, le Paintbrush des petits m'incite a perseverer
 *	sur la route du e-empire. Du moins tant que je n'ai pas
 *	fait un clone de Paintbrush pour X11. Mais ceci est un
 *	autre fantasme...
 *
 *	2 Octobre 2001: le boutisme va <EFBFBD>tre bout<EFBFBD> hors de ce module.
 */

#include  <stdio.h>
#include  <stdlib.h>
#include  "tthimage.h"

#include  "bmp.h"	/* maybe I can hardcoded bmp.h here ? */

/*::------------------------------------------------------------------::*/
static void
fatal_error(char *txt)
{
fprintf(stderr, "BMP: Fatal error: %s\n", txt);
exit(10);
}
/*::------------------------------------------------------------------::*/
int
Image_BMP_infos(char *nom, int *pw, int *ph, int *pt, int verb)
{
FILE		*fp;
BMPHEAD		head;
int		foo;

if (verb)	printf("BMP_Infos : '%s'\n", nom);

if ((fp=fopen(nom, "r")) == NULL)
	{
	fprintf(stderr, "BMP_Infos: can't open %s\n", nom);
	return FILE_NOT_FOUND;
	}

foo = fread(&head, 1, sizeof(head), fp);
fclose(fp);

if (verb)
	{
	printf("signature    %c%c           filesize %8ld\n",
		head.id[0], head.id[1], head.filesize);
	printf("headerSize   %8ld     infoSize %8ld\n",
			head.headerSize, head.infoSize);
	printf("dimensions   %ld x %ld x %d\n",
			head.width, head.height, head.bits);
	printf("colors: used %ld  important %ld\n", 
			head.clrused, head.clrimportant);
	printf("taille structure header  %d\n", sizeof(BMPHEAD));
	}
/* 
 * now, return some usefull informations.
 */

*pw = head.width;	*ph = head.height;	*pt = head.bits;

return 0;
}
/*::------------------------------------------------------------------::*/
/*
 *	Allocate memory and read a BMP file.
 */
#define PIX2BYTE(n) ((n+7)/8)

Image_Desc *
Image_BMP_alloc_load(char *nom, int reserved)
{
FILE		*fp;
BMPHEAD		head;
int		ligne, foo, larg, col, ligne2;
Image_Desc	*image;
uint8_t		*buffer;

if ((fp=fopen(nom, "r")) == NULL)
	{
	fprintf(stderr, "can't open %s\n", nom);
	return NULL;
	}

foo = fread(&head, 1, sizeof(head), fp);
#if DEBUG_LEVEL
fprintf(stderr, "BMP: on a lu %d octets pour le header.\n", foo); 
#endif

if ( head.id[0] != 'B' || head.id[1] != 'M' )
	{
	fprintf(stderr, "BMP_Alloc_Load: BAD MAGIC  %s\n", nom);
	return NULL;
	}

#if DEBUG_LEVEL
fprintf(stderr, "BMP_Alloc_Load: image depth = %d\n", head.bits);
#endif

/*
 *	first step: allocating the memory.
 */
switch (head.bits)
	{
	case 1:	case 4: case 8:
		fprintf(stderr, "bit depth %d not supported\n", head.bits);
		return NULL;
		break;

	case 24:

        	if ( (image=Image_alloc(head.width, head.height, 3))==NULL)
            		fatal_error("no memory for picture in 'alloc_load'\n");

        	if ( (buffer=(uint8_t *)malloc(4*head.width))==NULL)
            		fatal_error("no memory for buffer in 'alloc_load'\n");

		larg = head.width * 3;

		break;

	default:
		fprintf(stderr, "BMP Load: bit depth %d is unreal\n",
							head.bits);
		return NULL;
		break;
	}

/*
 *	round up to an even dword boundary	(?)
 */
if (larg & 0x00000003)
	{
	larg |= 0x00000003;
	larg++;
	}

/*
 *	second step: load all the pixels.
 *
 *	(no default case, filtered in first step)
 */
switch (head.bits)
    {
    case 24:

	for (ligne=0; ligne<head.height; ligne++)
	    {
	    foo=fread(buffer, 1, larg, fp);
	    /* printf("ligne %5d lu %d\n", ligne, foo); */
	    ligne2 = head.height - ligne - 1;
	    for (col=0; col<head.width; col++)
		{
                (image->Bpix[ligne2])[col] = buffer[  col*3 ];
                (image->Gpix[ligne2])[col] = buffer[ (col*3) + 1 ];
                (image->Rpix[ligne2])[col] = buffer[ (col*3) + 2 ];
		}
	    }

	break;

    }

return image;
}
/*::------------------------------------------------------------------::*/
/*
 *	Write a 24 bits bmp file.
 *
 *	et cette fois-ci, on va faire gaffe au boutisme :)
 */
int
Image_BMP_save_24(char *filename, Image_Desc *img, int flag)
{
FILE		*fp;
long		grand;
short		court;
int		line, foo, bytes;
uint8_t		*Rptr, *Gptr, *Bptr;
uint8_t		*buffer, *ptr;

#if DEBUG_LEVEL
fprintf(stderr, "%s : writing %p to %s, flag=%d\n", __func__,
				img, filename, flag);
#endif

if ((fp=fopen(filename, "w")) == NULL)
	{
	fprintf(stderr, "can't open %s for writing\n", filename);
	return FILE_CREATE_ERR;
	}

/*
 *	round up to an even dword boundary	(?)
 */
bytes = img->width;
fprintf(stderr, "largeur 0 = %d  (%d)\n", bytes, bytes & 3);

/* OLD CODE - DOES NOT WORK AS EXPECTED - FIXME ONE DAY...
if (bytes & 0x3)
	{
	bytes |= 0x3;
	bytes++;
	}
*/
switch (bytes & 0x3)
	{
	case 0:		/* OK */	break;
	case 1:		bytes+=3;	break;
	case 2:		bytes+=2;	break;
	case 3:		bytes+=1;	break;
	}

fprintf(stderr, "largeur 1 = %d\n", bytes);

/*
 *	writing the header
 */
fwrite("BM", 1, 2, fp);		/* signature */

/* grand = 54L + (long)bytes*(long)img->height; */	/* file size */
grand = 54L + (long)img->width*(long)img->height;	/* file size */
Image_basicIO_write_I_long(fp, grand);

grand = 0;
fwrite(&grand, 1, 2, fp);		/* reserved by micro$oft ? */
fwrite(&grand, 1, 2, fp);		/* reserved by micro$oft ? */

grand = 54L;			/* ????? */
Image_basicIO_write_I_long(fp, grand);
grand = 0x28L;			/* always this value, but why ? */
Image_basicIO_write_I_long(fp, grand);

grand = img->width;	Image_basicIO_write_I_long(fp, grand);
grand = img->height;	Image_basicIO_write_I_long(fp, grand);

court = 1;	Image_basicIO_write_I_short(fp, court);	/* biPlanes */
court = 24;	Image_basicIO_write_I_short(fp, court); /* bits */
grand = 0L;	Image_basicIO_write_I_long(fp, grand);  /* biCompression */

grand = img->width * img->height * 3;		/* biSizeImage */
/* grand = bytes * img->height * 3; */		/* biSizeImage */
Image_basicIO_write_I_long(fp, grand);

grand = 1000;					/* pixels per meter */
Image_basicIO_write_I_long(fp, grand);
Image_basicIO_write_I_long(fp, grand);

grand = 0;
Image_basicIO_write_I_long(fp, grand);		/* color-used */
Image_basicIO_write_I_long(fp, grand);		/* color-important */

fflush(fp);

/*
 *	now, we can go, and write pixels datas...
 */
if ((buffer=(uint8_t *)malloc(sizeof(uint8_t)*4*img->width)) == NULL)
    fatal_error("no memory buffer for BMP24 save operation");

for (line=img->height-1; line>=0; line--)
	{
	ptr = buffer;
        Rptr = img->Rpix[line];
        Gptr = img->Gpix[line];
        Bptr = img->Bpix[line];
        for (foo=0; foo<img->width; foo++)
            {
            *ptr++ = Bptr[foo];
            *ptr++ = Gptr[foo];
            *ptr++ = Rptr[foo];
            }
        fwrite(buffer, 3, bytes, fp);
	}

free(buffer);

fclose(fp);

return FUNC_IS_ALPHA;
}
/*::------------------------------------------------------------------::*/
/*::------------------------------------------------------------------::*/