/*
 * $XConsortium: RdBitF.c,v 1.6 89/12/12 18:43:10 jim Exp $
 *
 * Copyright 1988 Massachusetts Institute of Technology
 *
 * This file contains miscellaneous utility routines and is not part of the
 * Xlib standard.
 *
 * Public entry points:
 *
 *     XmuReadBitmapData		read data from FILE descriptor
 *     XmuReadBitmapDataFromFile	read X10 or X11 format bitmap files
 *					and return data
 *
 * Note that this file and ../X/XRdBitF.c look very similar....  Keep them
 * that way (but don't use common source code so that people can have one 
 * without the other).
 */

#ifndef vax11c
#include <X11/copyright.h>
#endif /* !vax11c */

/*
 * Based on an optimized version provided by Jim Becker, Auguest 5, 1988.
 */

#ifdef vax11c
#include <decw$include/Xos.h>
#include <decw$include/Xlib.h>
#include <decw$include/Xutil.h>
#else
#include <X11/Xos.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#endif /* vax11c */
#include <stdio.h>
#include <ctype.h>


#define MAX_SIZE 255

/* shared data for the image read/parse logic */
static short hexTable[256];		/* conversion value */
static Bool initialized = False;	/* easier to fill in at run time */


/*
 *	Table index for the hex values. Initialized once, first time.
 *	Used for translation value or delimiter significance lookup.
 */
static void initHexTable()
{
    /*
     * We build the table at run time for several reasons:
     *
     *     1.  portable to non-ASCII machines.
     *     2.  still reentrant since we set the init flag after setting table.
     *     3.  easier to extend.
     *     4.  less prone to bugs.
     */
    hexTable['0'] = 0;	hexTable['1'] = 1;
    hexTable['2'] = 2;	hexTable['3'] = 3;
    hexTable['4'] = 4;	hexTable['5'] = 5;
    hexTable['6'] = 6;	hexTable['7'] = 7;
    hexTable['8'] = 8;	hexTable['9'] = 9;
    hexTable['A'] = 10;	hexTable['B'] = 11;
    hexTable['C'] = 12;	hexTable['D'] = 13;
    hexTable['E'] = 14;	hexTable['F'] = 15;
    hexTable['a'] = 10;	hexTable['b'] = 11;
    hexTable['c'] = 12;	hexTable['d'] = 13;
    hexTable['e'] = 14;	hexTable['f'] = 15;

    /* delimiters of significance are flagged w/ negative value */
    hexTable[' '] = -1;	hexTable[','] = -1;
    hexTable['}'] = -1;	hexTable['\n'] = -1;
    hexTable['\t'] = -1;
	
    initialized = True;
}

/*
 *	read next hex value in the input stream, return -1 if EOF
 */
static NextInt (fstream)
    FILE *fstream;
{
    int	ch;
    int	value = 0;
    int gotone = 0;
    int done = 0;
    
    /* loop, accumulate hex value until find delimiter  */
    /* skip any initial delimiters found in read stream */

    while (!done) {
	ch = getc(fstream);
	if (ch == EOF) {
	    value	= -1;
	    done++;
	} else {
	    /* trim high bits, check type and accumulate */
	    ch &= 0xff;
	    if (isascii(ch) && isxdigit(ch)) {
		value = (value << 4) + hexTable[ch];
		gotone++;
	    } else if ((hexTable[ch]) < 0 && gotone)
	      done++;
	}
    }
    return value;
}


/*
 * The data returned by the following routine is always in left-most byte
 * first and left-most bit first.  If it doesn't return BitmapSuccess then
 * its arguments won't have been touched.  This routine should look as much
 * like the Xlib routine XReadBitmapfile as possible.
 */
int XmuReadBitmapData (fstream, width, height, datap, x_hot, y_hot)
    FILE *fstream;			/* handle on file  */
    unsigned int *width, *height;	/* RETURNED */
    unsigned char **datap;		/* RETURNED */
    int *x_hot, *y_hot;			/* RETURNED */
{
    unsigned char *data = NULL;		/* working variable */
    char line[MAX_SIZE];		/* input line from file */
    int size;				/* number of bytes of data */
    char name_and_type[MAX_SIZE];	/* an input line */
    char *type;				/* for parsing */
    int value;				/* from an input line */
    int version10p;			/* boolean, old format */
    int padding;			/* to handle alignment */
    int bytes_per_line;			/* per scanline of data */
    unsigned int ww = 0;		/* width */
    unsigned int hh = 0;		/* height */
    int hx = -1;			/* x hotspot */
    int hy = -1;			/* y hotspot */

#define Xmalloc(size) malloc(size)

    /* first time initialization */
    if (initialized == False) initHexTable();

    /* error cleanup and return macro	*/
#define	RETURN(code) { if (data) free (data); return code; }

    while (fgets(line, MAX_SIZE, fstream)) {
	if (strlen(line) == MAX_SIZE-1) {
	    RETURN (BitmapFileInvalid);
	}
	if (sscanf(line,"#define %s %d",name_and_type,&value) == 2) {
	    if (!(type = rindex(name_and_type, '_')))
	      type = name_and_type;
	    else
	      type++;

	    if (!strcmp("width", type))
	      ww = (unsigned int) value;
	    if (!strcmp("height", type))
	      hh = (unsigned int) value;
	    if (!strcmp("hot", type)) {
		if (type-- == name_and_type || type-- == name_and_type)
		  continue;
		if (!strcmp("x_hot", type))
		  hx = value;
		if (!strcmp("y_hot", type))
		  hy = value;
	    }
	    continue;
	}
    
	if (sscanf(line, "static short %s = {", name_and_type) == 1)
	  version10p = 1;
	else if (sscanf(line,"static unsigned char %s = {",name_and_type) == 1)
	  version10p = 0;
	else if (sscanf(line, "static char %s = {", name_and_type) == 1)
	  version10p = 0;
	else
	  continue;

	if (!(type = rindex(name_and_type, '_')))
	  type = name_and_type;
	else
	  type++;

	if (strcmp("bits[]", type))
	  continue;
    
	if (!ww || !hh)
	  RETURN (BitmapFileInvalid);

	if ((ww % 16) && ((ww % 16) < 9) && version10p)
	  padding = 1;
	else
	  padding = 0;

	bytes_per_line = (ww+7)/8 + padding;

	size = bytes_per_line * hh;
	data = (unsigned char *) Xmalloc ((unsigned int) size);
	if (!data) 
	  RETURN (BitmapNoMemory);

	if (version10p) {
	    unsigned char *ptr;
	    int bytes;

	    for (bytes=0, ptr=data; bytes<size; (bytes += 2)) {
		if ((value = NextInt(fstream)) < 0)
		  RETURN (BitmapFileInvalid);
		*(ptr++) = value;
		if (!padding || ((bytes+2) % bytes_per_line))
		  *(ptr++) = value >> 8;
	    }
	} else {
	    unsigned char *ptr;
	    int bytes;

	    for (bytes=0, ptr=data; bytes<size; bytes++, ptr++) {
		if ((value = NextInt(fstream)) < 0) 
		  RETURN (BitmapFileInvalid);
		*ptr=value;
	    }
	}
    }					/* end while */

    if (data == NULL) {
	RETURN (BitmapFileInvalid);
    }

    *datap = data;
    data = NULL;
    *width = ww;
    *height = hh;
    if (x_hot) *x_hot = hx;
    if (y_hot) *y_hot = hy;

    RETURN (BitmapSuccess);
}


int XmuReadBitmapDataFromFile (filename, width, height, datap, x_hot, y_hot)
    char *filename;
    unsigned int *width, *height;	/* RETURNED */
    unsigned char **datap;		/* RETURNED */
    int *x_hot, *y_hot;			/* RETURNED */
{
    FILE *fstream;
    int status;

    if ((fstream = fopen (filename, "r")) == NULL) {
	return BitmapOpenFailed;
    }
    status = XmuReadBitmapData (fstream, width, height, datap, x_hot, y_hot);
    fclose (fstream);
    return status;
}
