libgd/src/wbmp.c

/* WBMP
 * ----
 * WBMP Level 0: B/W, Uncompressed
 * This implements the WBMP format as specified in WAPSpec 1.1 and 1.2.
 * It does not support ExtHeaders as defined in the spec. The spec states
 * that a WAP client does not need to implement ExtHeaders.
 *
 * (c) 2000 Johan Van den Brande <johan@vandenbrande.com>
 */

#ifdef HAVE_CONFIG_H
#	include "config.h"
#endif

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>

#include "wbmp.h"
#include "gd.h"
#include "gdhelpers.h"

#ifdef NOTDEF
#	define __TEST	/* Compile with main function */
#	define __DEBUG	/* Extra verbose when with __TEST */
#	define __WRITE	/* readwbmp and writewbmp(stdout) */
#	define __VIEW	/* view the wbmp on stdout */
#endif

/* getmbi
 * ------
 * Get a multibyte integer from a generic getin function
 * 'getin' can be getc, with in = NULL
 * you can find getin as a function just above the main function
 * This way you gain a lot of flexibility about how this package
 * reads a wbmp file.
 */
int getmbi(int (*getin) (void *in), void *in)
{
	unsigned int mbi = 0;
	int i;

	do {
		i = getin(in);
		if(i < 0) {
			return (-1);
		}
		mbi = (mbi << 7) | (i & 0x7f);
	} while(i & 0x80);

	return mbi;
}

/* putmbi
 * ------
 * Put a multibyte intgerer in some kind of output stream
 * I work here with a function pointer, to make it as generic
 * as possible. Look at this function as an iterator on the
 * mbi integers it spits out.
 *
 */
void putmbi(int i, void (*putout)(int c, void *out), void *out)
{
	int cnt, l, accu;

	/* Get number of septets */
	accu = cnt = 0;
	while(accu != i) {
		accu += i & 0x7f << 7 * cnt++;
	}

	/* Produce the multibyte output */
	for(l = cnt - 1; l > 0; l--) {
		putout(0x80 | (i & 0x7f << 7 * l) >> 7 * l, out);
	}

	putout(i & 0x7f, out);
}

/* skipheader
 * ----------
 * Skips the ExtHeader. Not needed for the moment
 */
int skipheader(int (*getin)(void *in), void *in)
{
	int i;

	do {
		i = getin(in);
		if(i < 0) {
			return (-1);
		}
	} while(i & 0x80);

	return 0;
}

/* create wbmp
 * -----------
 * create an empty wbmp
 */
Wbmp *createwbmp(int width, int height, int color)
{
	int i;
	Wbmp *wbmp;

	if((wbmp = (Wbmp *)gdMalloc(sizeof (Wbmp))) == NULL) {
		return (NULL);
	}

	if(overflow2(sizeof(int), width)) {
		gdFree(wbmp);
		return NULL;
	}

	if(overflow2(sizeof(int) * width, height)) {
		gdFree(wbmp);
		return NULL;
	}

	if((wbmp->bitmap = (int *)gdMalloc(sizeof(int) * width * height)) == NULL) {
		gdFree(wbmp);
		return NULL;
	}

	wbmp->width = width;
	wbmp->height = height;

	for(i = 0; i < width * height; wbmp->bitmap[i++] = color);

	return wbmp;
}

/* readwbmp
 * -------
 * Actually reads the WBMP format from an open file descriptor
 * It goes along by returning a pointer to a WBMP struct.
 */
int readwbmp(int (*getin) (void *in), void *in, Wbmp **return_wbmp)
{
	int row, col, byte, pel, pos;
	Wbmp *wbmp;

	if((wbmp = (Wbmp *)gdMalloc(sizeof(Wbmp))) == NULL) {
		return -1;
	}

	wbmp->type = getin(in);
	if(wbmp->type != 0) {
		gdFree(wbmp);
		return -1;
	}

	if(skipheader(getin, in)) {
		gdFree(wbmp);
		return -1;
	}

	wbmp->width = getmbi(getin, in);
	if(wbmp->width == -1) {
		gdFree(wbmp);
		return -1;
	}

	wbmp->height = getmbi(getin, in);
	if(wbmp->height == -1) {
		gdFree(wbmp);
		return -1;
	}

#ifdef __DEBUG
	printf("W: %d, H: %d\n", wbmp->width, wbmp->height);
#endif

	if(	overflow2(sizeof(int), wbmp->width) ||
		overflow2(sizeof(int) * wbmp->width, wbmp->height)) {
		gdFree(wbmp);
		return -1;
	}

	if((wbmp->bitmap = (int *)gdMalloc(sizeof(int) * wbmp->width * wbmp->height)) == NULL) {
		gdFree(wbmp);
		return -1;
	}

#ifdef __DEBUG
	printf("DATA CONSTRUCTED\n");
#endif

	pos = 0;
	for(row = 0; row < wbmp->height; row++) {
		for(col = 0; col < wbmp->width;) {
			byte = getin(in);

			for(pel = 7; pel >= 0; pel--) {
				if(col++ < wbmp->width) {
					if(byte & 1 << pel) {
						wbmp->bitmap[pos] = WBMP_WHITE;
					} else {
						wbmp->bitmap[pos] = WBMP_BLACK;
					}
					pos++;
				}
			}
		}
	}

	*return_wbmp = wbmp;

	return 0;
}

/* writewbmp
 * ---------
 * Write a wbmp to a file descriptor
 *
 * Why not just giving a filedescriptor to this function?
 * Well, the incentive to write this function was the complete
 * integration in gd library from www.libgd.org. They use
 * their own io functions, so the passing of a function seemed to be
 * a logic(?) decision ...
 */
int writewbmp(Wbmp *wbmp, void (*putout)(int c, void *out), void *out)
{
	int row, col;
	int bitpos, octet;

	/* Generate the header */
	putout(0, out); /* WBMP Type 0: B/W, Uncompressed bitmap */
	putout(0, out); /* FixHeaderField */

	/* Size of the image */
	putmbi(wbmp->width, putout, out);	/* width */
	putmbi(wbmp->height, putout, out);	/* height */


	/* Image data */
	for(row = 0; row < wbmp->height; row++) {
		bitpos = 8;
		octet = 0;

		for(col = 0; col < wbmp->width; col++) {
			octet |= ((wbmp->bitmap[row * wbmp->width + col] == 1) ? WBMP_WHITE : WBMP_BLACK) << --bitpos;
			if(bitpos == 0) {
				bitpos = 8;
				putout(octet, out);
				octet = 0;
			}
		}

		if(bitpos != 8) {
			putout(octet, out);
		}
	}

	return 0;
}

/* freewbmp
 * --------
 * gdFrees up memory occupied by a WBMP structure
 */
void freewbmp(Wbmp *wbmp)
{
	gdFree(wbmp->bitmap);
	gdFree(wbmp);
}

/* printwbmp
 * ---------
 * print a WBMP to stdout for visualisation
 */
void printwbmp(Wbmp *wbmp)
{
	int row, col;

	for(row = 0; row < wbmp->height; row++) {
		for(col = 0; col < wbmp->width; col++) {
			if(wbmp->bitmap[wbmp->width * row + col] == WBMP_BLACK) {
				putchar('#');
			} else {
				putchar(' ');
			}
		}
		putchar('\n');
	}
}

#ifdef __TEST

/* putout to file descriptor
 * -------------------------
 */
int putout(int c, void *out)
{
	return (putc(c, (FILE *)out));
}

/* getin from file descriptor
 * --------------------------
 */
int getin(void *in)
{
	return (getc((FILE *)in));
}

/* Main function
 * -------------
 */
int main(int argc, char *argv[])
{
	FILE *wbmp_file;
	Wbmp *wbmp;

	wbmp_file = fopen(argv[1], "rb");
	if(wbmp_file) {
		readwbmp(&getin, wbmp_file, &wbmp);
#ifdef __VIEW
#ifdef __DEBUG
		printf("\nVIEWING IMAGE\n");
#endif
		printwbmp(wbmp);
#endif
#ifdef __WRITE
#ifdef __DEBUG
		printf("\nDUMPING WBMP to STDOUT\n");
#endif
		writewbmp(wbmp, &putout, stdout);
#endif
		freewbmp(wbmp);
		fclose(wbmp_file);
	}
}
#endif