xref: /xsrc/external/mit/libX11/dist/src/TextExt.c

/* $Xorg: TextExt.c,v 1.4 2001/02/09 02:03:37 xorgcvs Exp $ */
/*

Copyright 1989, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/
/* $XFree86: xc/lib/X11/TextExt.c,v 1.4 2001/12/14 19:54:07 dawes Exp $ */
/*
 * Copyright 1995 by FUJITSU LIMITED
 * This is source code modified by FUJITSU LIMITED under the Joint
 * Development Agreement for the CDE/Motif PST.
 */


#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "Xlibint.h"

#define min_byte2 min_char_or_byte2
#define max_byte2 max_char_or_byte2


/*
 * CI_GET_ROWZERO_CHAR_INFO_2D - do the same thing as CI_GET_CHAR_INFO_1D,
 * except that the font has more than one row.  This is special case of more
 * general version used in XTextExt16.c since row == 0.  This is used when
 * max_byte2 is not zero.  A further optimization would do the check for
 * min_byte1 being zero ahead of time.
 */

#define CI_GET_ROWZERO_CHAR_INFO_2D(fs,col,def,cs) \
{ \
    cs = def; \
    if (fs->min_byte1 == 0 && \
	col >= fs->min_byte2 && col <= fs->max_byte2) { \
	if (fs->per_char == NULL) { \
	    cs = &fs->min_bounds; \
	} else { \
	    cs = &fs->per_char[(col - fs->min_byte2)]; \
	    if (CI_NONEXISTCHAR(cs)) cs = def; \
	} \
    } \
}


/*
 * XTextExtents - compute the extents of string given as a sequences of eight
 * bit bytes.  Since we know that the input characters will always be from the
 * first row of the font (i.e. byte1 == 0), we can do some optimizations beyond
 * what is done in XTextExtents16.
 */
int
XTextExtents (
    XFontStruct *fs,
    _Xconst char *string,
    int nchars,
    int *dir,           /* RETURN font information */
    int *font_ascent,   /* RETURN font information */
    int *font_descent,  /* RETURN font information */
    register XCharStruct *overall)	/* RETURN character information */
{
    int i;				/* iterator */
    Bool singlerow = (fs->max_byte1 == 0);  /* optimization */
    int nfound = 0;			/* number of characters found */
    XCharStruct *def;			/* info about default char */
    unsigned char *us;  		/* be 8bit clean */

    if (singlerow) {			/* optimization */
	CI_GET_DEFAULT_INFO_1D (fs, def);
    } else {
	CI_GET_DEFAULT_INFO_2D (fs, def);
    }

    *dir = fs->direction;
    *font_ascent = fs->ascent;
    *font_descent = fs->descent;

    /*
     * Iterate over the input string getting the appropriate * char struct.
     * The default (which may be null if there is no def_char) will be returned
     * if the character doesn't exist.  On the first time * through the loop,
     * assign the values to overall; otherwise, compute * the new values.
     */

    for (i = 0, us = (unsigned char *) string; i < nchars; i++, us++) {
	register unsigned uc = (unsigned) *us;	/* since about to do macro */
	register XCharStruct *cs;

	if (singlerow) {		/* optimization */
	    CI_GET_CHAR_INFO_1D (fs, uc, def, cs);
	} else {
	    CI_GET_ROWZERO_CHAR_INFO_2D (fs, uc, def, cs);
	}

	if (cs) {
	    if (nfound++ == 0) {
		*overall = *cs;
	    } else {
		overall->ascent = max (overall->ascent, cs->ascent);
		overall->descent = max (overall->descent, cs->descent);
		overall->lbearing = min (overall->lbearing,
					 overall->width + cs->lbearing);
		overall->rbearing = max (overall->rbearing,
					 overall->width + cs->rbearing);
		overall->width += cs->width;
	    }
	}
    }

    /*
     * if there were no characters, then set everything to 0
     */
    if (nfound == 0) {
	overall->width = overall->ascent = overall->descent =
	  overall->lbearing = overall->rbearing = 0;
    }

    return 0;
}


/*
 * XTextWidth - compute the width of a string of eightbit bytes.  This is a
 * subset of XTextExtents.
 */
int
XTextWidth (
    XFontStruct *fs,
    _Xconst char *string,
    int count)
{
    int i;				/* iterator */
    Bool singlerow = (fs->max_byte1 == 0);  /* optimization */
    XCharStruct *def;			/* info about default char */
    unsigned char *us;  		/* be 8bit clean */
    int width = 0;			/* RETURN value */

    if (singlerow) {			/* optimization */
	CI_GET_DEFAULT_INFO_1D (fs, def);
    } else {
	CI_GET_DEFAULT_INFO_2D (fs, def);
    }

    if (def && fs->min_bounds.width == fs->max_bounds.width)
	return (fs->min_bounds.width * count);

    /*
     * Iterate over all character in the input string; only consider characters
     * that exist.
     */
    for (i = 0, us = (unsigned char *) string; i < count; i++, us++) {
	register unsigned uc = (unsigned) *us;	/* since about to do macro */
	register XCharStruct *cs;

	if (singlerow) {		/* optimization */
	    CI_GET_CHAR_INFO_1D (fs, uc, def, cs);
	} else {
	    CI_GET_ROWZERO_CHAR_INFO_2D (fs, uc, def, cs);
	}

	if (cs) width += cs->width;
    }

    return width;
}



/*
 * _XTextHeight - compute the height of a string of eightbit bytes.
 */
int
_XTextHeight (
    XFontStruct *fs,
    _Xconst char *string,
    int count)
{
    int i;				/* iterator */
    Bool singlerow = (fs->max_byte1 == 0);  /* optimization */
    XCharStruct *def;			/* info about default char */
    unsigned char *us;  		/* be 8bit clean */
    int height = 0;			/* RETURN value */

    if (singlerow) {			/* optimization */
	CI_GET_DEFAULT_INFO_1D (fs, def);
    } else {
	CI_GET_DEFAULT_INFO_2D (fs, def);
    }

    if (def && (fs->min_bounds.ascent == fs->max_bounds.ascent)
	    && (fs->min_bounds.descent == fs->max_bounds.descent))
	return ((fs->min_bounds.ascent + fs->min_bounds.descent) * count);

    /*
     * Iterate over all character in the input string; only consider characters
     * that exist.
     */
    for (i = 0, us = (unsigned char *) string; i < count; i++, us++) {
	register unsigned uc = (unsigned) *us;	/* since about to do macro */
	register XCharStruct *cs;

	if (singlerow) {		/* optimization */
	    CI_GET_CHAR_INFO_1D (fs, uc, def, cs);
	} else {
	    CI_GET_ROWZERO_CHAR_INFO_2D (fs, uc, def, cs);
	}

	if (cs) height += (cs->ascent + cs->descent);
    }

    return height;
}