xtextext16.c

早期freebsd实现

/*
 * $XConsortium: XTextExt16.c,v 11.20 91/01/06 11:48:30 rws Exp $
 *
 * Copyright 1989 Massachusetts Institute of Technology
 */

/*
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, and that the name of M.I.T. not be used in advertising or
publicity pertaining to distribution of the software without specific,
written prior permission.  M.I.T. makes no representations about the
suitability of this software for any purpose.  It is provided "as is"
without express or implied warranty.
*/


#include "Xlibint.h"

#define min_byte2 min_char_or_byte2
#define max_byte2 max_char_or_byte2

/*
 * XTextExtents16 - compute the extents of string given as a sequence of 
 * XChar2bs.
 */
#if NeedFunctionPrototypes
XTextExtents16 (
    XFontStruct *fs,
    _Xconst XChar2b *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 */
#else
XTextExtents16 (fs, string, nchars, dir, font_ascent, font_descent, overall)
    XFontStruct *fs;
    XChar2b *string;
    int nchars;
    int *dir, *font_ascent, *font_descent;  /* RETURN font information */
    register XCharStruct *overall;	/* RETURN character information */
#endif
{
    int i;				/* iterator */
    Bool singlerow = (fs->max_byte1 == 0);  /* optimization */
    int nfound = 0;			/* number of characters found */
    XCharStruct *def;			/* info about default char */

    if (singlerow) {
	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; i < nchars; i++, string++) {
	register XCharStruct *cs;
	unsigned int r = (unsigned int) string->byte1;	/* watch for macros */
	unsigned int c = (unsigned int) string->byte2;	/* watch for macros */

	if (singlerow) {
	    unsigned int ind = ((r << 8) | c);		/* watch for macros */
	    CI_GET_CHAR_INFO_1D (fs, ind, def, cs);
	} else {
	    CI_GET_CHAR_INFO_2D (fs, r, c, 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;
}


/*
 * XTextWidth16 - compute the width of sequence of XChar2bs.  This is a 
 * subset of XTextExtents16.
 */
#if NeedFunctionPrototypes
int XTextWidth16 (
    XFontStruct *fs,
    _Xconst XChar2b *string,
    int count)
#else
int XTextWidth16 (fs, string, count)
    XFontStruct *fs;
    XChar2b *string;
    int count;
#endif
{
    int i;				/* iterator */
    Bool singlerow = (fs->max_byte1 == 0);  /* optimization */
    XCharStruct *def;			/* info about default char */
    int width = 0;			/* RETURN value */

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

    /*
     * Iterate over all character in the input string; only consider characters
     * that exist.
     */
    for (i = 0; i < count; i++, string++) {
	register XCharStruct *cs;
	unsigned int r = (unsigned int) string->byte1;	/* watch for macros */
	unsigned int c = (unsigned int) string->byte2;	/* watch for macros */

	if (singlerow) {
	    unsigned int ind = ((r << 8) | c);		/* watch for macros */
	    CI_GET_CHAR_INFO_1D (fs, ind, def, cs);
	} else {
	    CI_GET_CHAR_INFO_2D (fs, r, c, def, cs);
	}

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

    return width;
}