unsigned el_size;    char *startString;    char *startTag;    boolean maxvalPresent;    int i;    char *p;    char commentBuf[PBM_MAX_LINELEN];    assert(outFile != (FILE *)NULL);    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    /*     * Get a pointer to the data area, the size of each element, and     * the format of the header. The header may include a dummy entry     * (some of the p*m formats have a maxval entry in the header - we     * just use the maximum value we can represent).     */    switch (header->tag) {      case IMAGE_GRAY: {	rect = (void *)	    &(((((GrayImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(unsigned char);	/* This is the start of an appropriate PGM file header */	startTag = TAG_GRAY;	startString = "%d %d %d\n";	maxvalPresent = TRUE;	break;	}	          case IMAGE_FLOAT: {	rect = (void *)	    &(((((FloatImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(float);	/*	 * Not a PGM or PBM or PanythingM header - make it look strange.	 */	startTag = TAG_FLOAT;	startString = "%d %d\n";	maxvalPresent = FALSE;	break;	}	          case IMAGE_RGB: {	rect = (void *)	    &(((((RGBImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(RGB);	/* A PPM header */	startTag = TAG_RGB;	startString = "%d %d %d\n";	maxvalPresent = TRUE;	break;	}      case IMAGE_DOUBLE: {	rect = (void *)	    &(((((DoubleImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(double);	/*	 * Not a PGM or PBM or PanythingM header - make it look strange.	 */	startTag = TAG_DOUBLE;	startString = "%d %d\n";	maxvalPresent = FALSE;	break;	}	          case IMAGE_BINARY: {	rect = (void *)	    &(((((BinaryImage)im)->data)[header->ybase])[header->xbase]);	el_size = 0;	startTag = TAG_BINARY;	startString = "%d %d\n";	maxvalPresent = FALSE;	break;	}	          case IMAGE_LONG: {	rect = (void *)	    &(((((LongImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(long);	/*	 * Not a PGM or PBM or PanythingM header - make it look strange.	 */	startTag = TAG_LONG;	startString = "%d %d\n";	maxvalPresent = FALSE;	break;	}      case IMAGE_PTR: {	panic("attempt to save pointer image");	break;	}      case IMAGE_SHORT: {	rect = (void *)	    &(((((ShortImage)im)->data)[header->ybase])[header->xbase]);	el_size = sizeof(short);	/*	 * Not a PGM or PBM or PanythingM header - make it look strange.	 */	startTag = TAG_SHORT;	startString = "%d %d\n";	maxvalPresent = FALSE;	break;	}      default: {	panic("bad image tag");	}      }        /* Write out the tag, and comments if any */    if (fprintf(outFile, "%s\n", startTag) == EOF) {	return(-1);	}    if (header->comment != (char *)NULL) {	p = header->comment;	while (*p != '\0') {	    /* Copy a line into commentBuf */	    for (i = 0;		 (i < PBM_MAX_LINELEN) && (p[i] != '\n') && (p[i] != '\0');		 i++) {		commentBuf[i] = p[i];		}	    if (i == PBM_MAX_LINELEN) {		/* The line was too long - search back for whitespace */		for (i = PBM_MAX_LINELEN - 1;		     (i >= 0) && (!isspace(commentBuf[i]));		     i--) {		    }		if (i < 0) {		    /* There was no whitespace. Break it how we like it... */		    commentBuf[PBM_MAX_LINELEN - 1] = '\0';		    i = PBM_MAX_LINELEN - 1;		    }		else {		    /* Break at the whitespace */		    commentBuf[i] = '\0';		    i++;		    }		}	    else {		commentBuf[i] = '\0';		}	    /*	     * At this point, commentBuf contains i characters to be	     * printed.	     */	    if (fprintf(outFile, "#%s\n", commentBuf) == EOF) {		return(-1);		}	    /* Advance the pointer */	    p += i;	    if (*p == '\n') {		p++;		}	    }	}    /* Write out the header info */    if (maxvalPresent) {	if (fprintf(outFile, startString, header->width, header->height,		    COLRNG - 1) == EOF) {	    return(-1);	    }	}    else {	if (fprintf(outFile, startString, header->width,		    header->height) == EOF) {	    return(-1);	    }	}	    /* Write out the data block */    if (header->tag != IMAGE_BINARY) {	if (fwrite((char *)rect, el_size,		   (header->width * header->height), outFile) !=	    header->width * header->height) {	    return(-1);	    }	}    else {	/* For binary images, have to write differently */	register int i, j, c, bitsleft, height, width;		height = (int)header->height + header->ybase;	width = (int)header->width + header->xbase;	for (i = header->ybase; i < height; i++) {	    bitsleft = 8;	    c = 0;	    for (j = header->xbase; j < width; j++) {		--bitsleft;		if (imRef((BinaryImage)im, j, i)) {		    c |= 1 << bitsleft;		    }		if ((bitsleft == 0) || (j == width - 1)) {		    if (putc(c, outFile) == EOF) {			return(-1);			}		    bitsleft = 8;		    c = 0;		    }		}	    }	}    /* and successfully return */    return(0);    }void *im_Dup_(void *im, ImageHeader *header, boolean copycomment){    void *dup;    unsigned el_size;    char *oldbase;    char *newbase;    ImageHeader *newheader;    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    /* Make a copy. */    dup = imNewOffset(header->tag, header->width, header->height,		      header->xbase, header->ybase);    if (dup == (void *)NULL) {	return((void *)NULL);	}    switch(header->tag) {      case IMAGE_GRAY: {	oldbase = (void *)	    &(((GrayImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((GrayImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(unsigned char);	newheader = ((GrayImage)dup)->header;		break;	}      case IMAGE_FLOAT: {	oldbase = (void *)	    &(((FloatImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((FloatImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(float);	newheader = ((FloatImage)dup)->header;	break;	}      case IMAGE_RGB: {	oldbase = (void *)	    &(((RGBImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((RGBImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(RGB);	newheader = ((RGBImage)dup)->header; 	break;	}      case IMAGE_DOUBLE: {	oldbase = (void *)	    &(((DoubleImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((DoubleImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(double);	newheader = ((DoubleImage)dup)->header;	break;	}      case IMAGE_BINARY: {	oldbase = (void *)	    &(((BinaryImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((BinaryImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(char);	newheader = ((BinaryImage)dup)->header;	break;	}      case IMAGE_LONG: {	oldbase = (void *)	    &(((LongImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((LongImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(long);	newheader = ((LongImage)dup)->header;	break;	}      case IMAGE_PTR: {	oldbase = (void *)	    &(((PtrImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((PtrImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(void *);	newheader = ((PtrImage)dup)->header;	break;	}      case IMAGE_SHORT: {	oldbase = (void *)	    &(((ShortImage)im)->data[header->ybase][header->xbase]);	newbase = (void *)	    &(((ShortImage)dup)->data[header->ybase][header->xbase]);	el_size = sizeof(short);	newheader = ((ShortImage)dup)->header;	break;	}      default: {	panic("bad image tag");	}      }    /* Copy the comment, if any, and if we're supposed to */    if (copycomment && (header->comment != (char *)NULL)) {	newheader->comment = strdup(header->comment);	if (newheader->comment == (char *)NULL) {	    /* Failed to copy */	    im_Free_(dup, newheader);	    return((void *)NULL);	    }	}    /* Do the copy */    (void)memcpy(newbase, oldbase,		 (el_size * header->width * header->height));    return(dup);    }void *im_Promote_(void *im, ImageHeader *header, ImageType promoteto){    ImageType origtype;    void *newim;    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    origtype = header->tag;    if (!convertTable[origtype][promoteto].isPromotion) {	/* They just requested a non-promotion. Bad... */	panic("non-promotion request made to imPromote()");	}    assert(convertTable[origtype][promoteto].convertFunc !=	   (void * (*)(void *))NULL);    newim = (*convertTable[origtype][promoteto].convertFunc)(im);    return(newim);    }voidimSetPromotion(ImageType promotefrom, ImageType promoteto,	       double slope, double offset){    if (!convertTable[promotefrom][promoteto].isPromotion) {	panic("attempt made to imSetPromotion a non-promotion conversion");	}    convertTable[promotefrom][promoteto].slope = slope;    convertTable[promotefrom][promoteto].offset = offset;    }void *im_Demote_(void *im, ImageHeader *header, ImageType demoteto){    ImageType origtype;    void *newim;    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    origtype = header->tag;    if (convertTable[origtype][demoteto].isPromotion) {	/* They just requested a promotion. Bad... */	panic("promotion request made to imDemote()");	}    else if (convertTable[origtype][demoteto].convertFunc == (void * (*)(void *))NULL) {	panic("impossible request made to imDemote()");	}    newim = (*convertTable[origtype][demoteto].convertFunc)(im);    return(newim);    }void *im_Convert_(void *im, ImageHeader *header, ImageType convertto){    ImageType origtype;    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    origtype = header->tag;    if (origtype == convertto) {	/* They really just want a copy */	return(im_Dup_(im, header, FALSE));	}    else if (convertTable[origtype][convertto].isPromotion) {	/* It's a promotion */	return(im_Promote_(im, header, convertto));	}    else {	/* It's a demotion, or illegal - let imDemote handle it */	return(im_Demote_(im, header, convertto));	}    }booleanim_SetComment_(void *im, ImageHeader *header, char *newcomment){    char *newcopy;    assert(im != (void *)NULL);    assert(header != (ImageHeader *)NULL);    if (newcomment != (char *)NULL) {	newcopy = strdup(newcomment);	if (newcopy == (char *)NULL) {	    return(FALSE);	    }	}    else {	newcopy = (char *)NULL;	}    if (header->comment != (char *)NULL) {	/* Free the old comment */	free((void *)header->comment);	}    header->comment = newcopy;    return(TRUE);    }/* * Here are the actual file-reading routines. * * Each one is passed a FILE * and an ImageHeader **. It knows that the file * stream is positioned immediately after a P?M (or similar) magic number, * and implicitly what that magic number was (i.e. what form the file will * take). It then reads the file, creates an Image of the appropriate type, * and returns it as its return value, putting a pointer to its ImageHeader * into *readimHeader. */