/*
 * tkUnixFont.c --
 *
 *	Contains the Unix implementation of the platform-independant
 *	font package interface.
 *
 * Copyright (c) 1996-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tkUnixFont.c,v 1.18.2.3 2003/10/29 01:07:46 hobbs Exp $
 */
 
#include "tkUnixInt.h"
#include "tkFont.h"
#include <netinet/in.h>		/* for htons() prototype */
#include <arpa/inet.h>		/* inet_ntoa() */

/*
 * The preferred font encodings.
 */

static CONST char *encodingList[] = {
    "iso8859-1", "jis0208", "jis0212", NULL
};

/*
 * The following structure represents a font family.  It is assumed that
 * all screen fonts constructed from the same "font family" share certain
 * properties; all screen fonts with the same "font family" point to a
 * shared instance of this structure.  The most important shared property
 * is the character existence metrics, used to determine if a screen font
 * can display a given Unicode character.
 *
 * Under Unix, there are three attributes that uniquely identify a "font
 * family": the foundry, face name, and charset.  
 */

#define FONTMAP_SHIFT		10

#define FONTMAP_PAGES	    	(1 << (sizeof(Tcl_UniChar)*8 - FONTMAP_SHIFT))
#define FONTMAP_BITSPERPAGE	(1 << FONTMAP_SHIFT)

typedef struct FontFamily {
    struct FontFamily *nextPtr;	/* Next in list of all known font families. */
    int refCount;		/* How many SubFonts are referring to this
				 * FontFamily.  When the refCount drops to
				 * zero, this FontFamily may be freed. */
    /*
     * Key.
     */

    Tk_Uid foundry;		/* Foundry key for this FontFamily. */
    Tk_Uid faceName;		/* Face name key for this FontFamily. */
    Tcl_Encoding encoding;	/* Encoding key for this FontFamily. */

    /*
     * Derived properties.
     */

    int isTwoByteFont;		/* 1 if this is a double-byte font, 0 
				 * otherwise. */
    char *fontMap[FONTMAP_PAGES];
				/* Two-level sparse table used to determine
				 * quickly if the specified character exists.
				 * As characters are encountered, more pages
				 * in this table are dynamically alloced.  The
				 * contents of each page is a bitmask
				 * consisting of FONTMAP_BITSPERPAGE bits,
				 * representing whether this font can be used
				 * to display the given character at the
				 * corresponding bit position.  The high bits
				 * of the character are used to pick which
				 * page of the table is used. */
} FontFamily;

/*
 * The following structure encapsulates an individual screen font.  A font
 * object is made up of however many SubFonts are necessary to display a
 * stream of multilingual characters.
 */

typedef struct SubFont {
    char **fontMap;		/* Pointer to font map from the FontFamily, 
				 * cached here to save a dereference. */
    XFontStruct *fontStructPtr;	/* The specific screen font that will be
				 * used when displaying/measuring chars
				 * belonging to the FontFamily. */
    FontFamily *familyPtr;	/* The FontFamily for this SubFont. */
} SubFont;

/*
 * The following structure represents Unix's implementation of a font
 * object.
 */
 
#define SUBFONT_SPACE		3
#define BASE_CHARS		256

typedef struct UnixFont {
    TkFont font;		/* Stuff used by generic font package.  Must
				 * be first in structure. */
    SubFont staticSubFonts[SUBFONT_SPACE];
				/* Builtin space for a limited number of
				 * SubFonts. */
    int numSubFonts;		/* Length of following array. */
    SubFont *subFontArray;	/* Array of SubFonts that have been loaded
				 * in order to draw/measure all the characters
				 * encountered by this font so far.  All fonts
				 * start off with one SubFont initialized by
				 * AllocFont() from the original set of font
				 * attributes.  Usually points to
				 * staticSubFonts, but may point to malloced
				 * space if there are lots of SubFonts. */
    SubFont controlSubFont;	/* Font to use to display control-character
				 * expansions. */

    Display *display;		/* Display that owns font. */
    int pixelSize;		/* Original pixel size used when font was
				 * constructed. */
    TkXLFDAttributes xa;	/* Additional attributes that specify the
				 * preferred foundry and encoding to use when
				 * constructing additional SubFonts. */
    int widths[BASE_CHARS];	/* Widths of first 256 chars in the base
				 * font, for handling common case. */
    int underlinePos;		/* Offset from baseline to origin of
				 * underline bar (used when drawing underlined
				 * font) (pixels). */
    int barHeight;		/* Height of underline or overstrike bar
				 * (used when drawing underlined or strikeout
				 * font) (pixels). */
} UnixFont;

/*
 * The following structure and definition is used to keep track of the
 * alternative names for various encodings.  Asking for an encoding that
 * matches one of the alias patterns will result in actually getting the
 * encoding by its real name.
 */
 
typedef struct EncodingAlias {
    char *realName;		/* The real name of the encoding to load if
				 * the provided name matched the pattern. */
    char *aliasPattern;		/* Pattern for encoding name, of the form
				 * that is acceptable to Tcl_StringMatch. */
} EncodingAlias;

/*
 * Just some utility structures used for passing around values in helper
 * procedures.
 */
 
typedef struct FontAttributes {
    TkFontAttributes fa;
    TkXLFDAttributes xa;
} FontAttributes;


typedef struct ThreadSpecificData {
    FontFamily *fontFamilyList; /* The list of font families that are 
				 * currently loaded.  As screen fonts
				 * are loaded, this list grows to hold 
				 * information about what characters
				 * exist in each font family. */
    FontFamily controlFamily;   /* FontFamily used to handle control 
				 * character expansions.  The encoding
				 * of this FontFamily converts UTF-8 to 
				 * backslashed escape sequences. */
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;

/*
 * The set of builtin encoding alises to convert the XLFD names for the
 * encodings into the names expected by the Tcl encoding package.
 */
 
static EncodingAlias encodingAliases[] = {
    {"gb2312-raw",	"gb2312*"},
    {"big5",		"big5*"},
    {"cns11643-1",	"cns11643*-1"},
    {"cns11643-1",	"cns11643*.1-0"},
    {"cns11643-2",	"cns11643*-2"},
    {"cns11643-2",	"cns11643*.2-0"},
    {"jis0201",		"jisx0201*"},
    {"jis0201",		"jisx0202*"},
    {"jis0208",		"jisc6226*"},
    {"jis0208",		"jisx0208*"},
    {"jis0212",		"jisx0212*"},
    {"tis620",		"tis620*"},
    {"ksc5601",		"ksc5601*"},
    {"dingbats",	"*dingbats"},
    {"ucs-2be",		"iso10646-1"},
    {NULL,		NULL}
};

/*
 * Procedures used only in this file.
 */

static void		FontPkgCleanup _ANSI_ARGS_((ClientData clientData));
static FontFamily *	AllocFontFamily _ANSI_ARGS_((Display *display,
			    XFontStruct *fontStructPtr, int base));
static SubFont *	CanUseFallback _ANSI_ARGS_((UnixFont *fontPtr,
			    CONST char *fallbackName, int ch,
			    SubFont **fixSubFontPtrPtr));
static SubFont *	CanUseFallbackWithAliases _ANSI_ARGS_((
			    UnixFont *fontPtr, char *fallbackName,
			    int ch, Tcl_DString *nameTriedPtr,
			    SubFont **fixSubFontPtrPtr));
static int		ControlUtfProc _ANSI_ARGS_((ClientData clientData,
			    CONST char *src, int srcLen, int flags,
			    Tcl_EncodingState *statePtr, char *dst,
			    int dstLen, int *srcReadPtr, int *dstWrotePtr,
			    int *dstCharsPtr));
static XFontStruct *	CreateClosestFont _ANSI_ARGS_((Tk_Window tkwin,
			    CONST TkFontAttributes *faPtr,
			    CONST TkXLFDAttributes *xaPtr));
static SubFont *	FindSubFontForChar _ANSI_ARGS_((UnixFont *fontPtr,
			    int ch, SubFont **fixSubFontPtrPtr));
static void		FontMapInsert _ANSI_ARGS_((SubFont *subFontPtr,
			    int ch));
static void		FontMapLoadPage _ANSI_ARGS_((SubFont *subFontPtr,
			    int row));
static int		FontMapLookup _ANSI_ARGS_((SubFont *subFontPtr,
			    int ch));
static void		FreeFontFamily _ANSI_ARGS_((FontFamily *afPtr));
static CONST char *	GetEncodingAlias _ANSI_ARGS_((CONST char *name));
static int		GetFontAttributes _ANSI_ARGS_((Display *display,
			    XFontStruct *fontStructPtr, FontAttributes *faPtr));
static XFontStruct *	GetScreenFont _ANSI_ARGS_((Display *display,
			    FontAttributes *wantPtr, char **nameList,
			    int bestIdx[], unsigned int bestScore[]));
static XFontStruct *	GetSystemFont _ANSI_ARGS_((Display *display));
static int		IdentifySymbolEncodings _ANSI_ARGS_((
			    FontAttributes *faPtr));
static void		InitFont _ANSI_ARGS_((Tk_Window tkwin,
			    XFontStruct *fontStructPtr, UnixFont *fontPtr));
static void		InitSubFont _ANSI_ARGS_((Display *display,
			    XFontStruct *fontStructPtr, int base,
			    SubFont *subFontPtr));
static char **		ListFonts _ANSI_ARGS_((Display *display,
			    CONST char *faceName, int *numNamesPtr));
static char **		ListFontOrAlias _ANSI_ARGS_((Display *display,
			    CONST char *faceName, int *numNamesPtr));
static unsigned int	RankAttributes _ANSI_ARGS_((FontAttributes *wantPtr,
			    FontAttributes *gotPtr));
static void		ReleaseFont _ANSI_ARGS_((UnixFont *fontPtr));
static void		ReleaseSubFont _ANSI_ARGS_((Display *display, 
			    SubFont *subFontPtr));
static int		SeenName _ANSI_ARGS_((CONST char *name,
			    Tcl_DString *dsPtr));
static int		Ucs2beToUtfProc _ANSI_ARGS_((ClientData clientData,
			    CONST char *src, int srcLen, int flags,
			    Tcl_EncodingState *statePtr, char *dst, int dstLen,
			    int *srcReadPtr, int *dstWrotePtr,
			    int *dstCharsPtr));
static int		UtfToUcs2beProc _ANSI_ARGS_((ClientData clientData,
			    CONST char *src, int srcLen, int flags,
			    Tcl_EncodingState *statePtr, char *dst, int dstLen,
			    int *srcReadPtr, int *dstWrotePtr,
			    int *dstCharsPtr));


/*
 *-------------------------------------------------------------------------
 *
 * FontPkgCleanup --
 *
 *	This procedure is called when an application is created.  It
 *	initializes all the structures that are used by the
 *	platform-dependent code on a per application basis.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Releases thread-specific resources used by font pkg.
 *
 *-------------------------------------------------------------------------
 */

static void
FontPkgCleanup(ClientData clientData)
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    
    if (tsdPtr->controlFamily.encoding != NULL) {
	FontFamily *familyPtr = &tsdPtr->controlFamily;
	int i;

	Tcl_FreeEncoding(familyPtr->encoding);
	for (i = 0; i < FONTMAP_PAGES; i++) {
	    if (familyPtr->fontMap[i] != NULL) {
		ckfree(familyPtr->fontMap[i]);
	    }
	}
	tsdPtr->controlFamily.encoding = NULL;
    }
}

/*
 *-------------------------------------------------------------------------
 *
 * TkpFontPkgInit --
 *
 *	This procedure is called when an application is created.  It
 *	initializes all the structures that are used by the
 *	platform-dependent code on a per application basis.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

void
TkpFontPkgInit(mainPtr)
    TkMainInfo *mainPtr;	/* The application being created. */
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    Tcl_EncodingType type;
    SubFont dummy;
    int i;
    
    if (tsdPtr->controlFamily.encoding == NULL) {
	type.encodingName	= "X11ControlChars";
	type.toUtfProc		= ControlUtfProc;
	type.fromUtfProc	= ControlUtfProc;
	type.freeProc		= NULL;
	type.clientData		= NULL;
	type.nullSize		= 0;
	
	tsdPtr->controlFamily.refCount = 2;
	tsdPtr->controlFamily.encoding = Tcl_CreateEncoding(&type);
	tsdPtr->controlFamily.isTwoByteFont = 0;

	dummy.familyPtr = &tsdPtr->controlFamily;
	dummy.fontMap = tsdPtr->controlFamily.fontMap;
	for (i = 0x00; i < 0x20; i++) {
	    FontMapInsert(&dummy, i);
	    FontMapInsert(&dummy, i + 0x80);
	}

	/*
	 * UCS-2BE is unicode in big-endian format.
	 * It is used in iso10646 fonts.
	 */

	type.encodingName	= "ucs-2be";
	type.toUtfProc		= Ucs2beToUtfProc;
	type.fromUtfProc	= UtfToUcs2beProc;
	type.freeProc		= NULL;
	type.clientData		= NULL;
	type.nullSize		= 2;
	Tcl_CreateEncoding(&type);
	Tcl_CreateThreadExitHandler(FontPkgCleanup, NULL);
    }
}

/*
 *-------------------------------------------------------------------------
 *
 * ControlUtfProc --
 *
 *	Convert from UTF-8 into the ASCII expansion of a control
 *	character.
 *
 * Results:
 *	Returns TCL_OK if conversion was successful.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int 
ControlUtfProc(clientData, src, srcLen, flags, statePtr, dst, dstLen,
	srcReadPtr, dstWrotePtr, dstCharsPtr)
    ClientData clientData;	/* Not used. */
    CONST char *src;		/* Source string in UTF-8. */
    int srcLen;			/* Source string length in bytes. */
    int flags;			/* Conversion control flags. */
    Tcl_EncodingState *statePtr;/* Place for conversion routine to store
				 * state information used during a piecewise
				 * conversion.  Contents of statePtr are
				 * initialized and/or reset by conversion
				 * routine under control of flags argument. */
    char *dst;			/* Output buffer in which converted string
				 * is stored. */
    int dstLen;			/* The maximum length of output buffer in
				 * bytes. */
    int *srcReadPtr;		/* Filled with the number of bytes from the
				 * source string that were converted.  This
				 * may be less than the original source length
				 * if there was a problem converting some
				 * source characters. */
    int *dstWrotePtr;		/* Filled with the number of bytes that were
				 * stored in the output buffer as a result of
				 * the conversion. */
    int *dstCharsPtr;		/* Filled with the number of characters that
				 * correspond to the bytes stored in the
				 * output buffer. */
{
    CONST char *srcStart, *srcEnd;
    char *dstStart, *dstEnd;
    Tcl_UniChar ch;
    int result;
    static char hexChars[] = "0123456789abcdef";
    static char mapChars[] = {
	0, 0, 0, 0, 0, 0, 0,
	'a', 'b', 't', 'n', 'v', 'f', 'r'
    };

    result = TCL_OK;

    srcStart = src;
    srcEnd = src + srcLen;

    dstStart = dst;
    dstEnd = dst + dstLen - 6;

    for ( ; src < srcEnd; ) {
	if (dst > dstEnd) {
	    result = TCL_CONVERT_NOSPACE;
	    break;
	}
	src += Tcl_UtfToUniChar(src, &ch);
	dst[0] = '\\';
	if ((ch < sizeof(mapChars)) && (mapChars[ch] != 0)) {
	    dst[1] = mapChars[ch];
	    dst += 2;
	} else if (ch < 256) {
	    dst[1] = 'x';
	    dst[2] = hexChars[(ch >> 4) & 0xf];
	    dst[3] = hexChars[ch & 0xf];
	    dst += 4;
	} else {
	    dst[1] = 'u';
	    dst[2] = hexChars[(ch >> 12) & 0xf];
	    dst[3] = hexChars[(ch >> 8) & 0xf];
	    dst[4] = hexChars[(ch >> 4) & 0xf];
	    dst[5] = hexChars[ch & 0xf];
	    dst += 6;
	}
    }
    *srcReadPtr = src - srcStart;
    *dstWrotePtr = dst - dstStart;
    *dstCharsPtr = dst - dstStart;
    return result;
}

/*
 *-------------------------------------------------------------------------
 *
 * Ucs2beToUtfProc --
 *
 *	Convert from UCS-2BE (big-endian 16-bit Unicode) to UTF-8.
 *
 * Results:
 *	Returns TCL_OK if conversion was successful.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int 
Ucs2beToUtfProc(clientData, src, srcLen, flags, statePtr, dst, dstLen,
	srcReadPtr, dstWrotePtr, dstCharsPtr)
    ClientData clientData;	/* Not used. */
    CONST char *src;		/* Source string in Unicode. */
    int srcLen;			/* Source string length in bytes. */
    int flags;			/* Conversion control flags. */
    Tcl_EncodingState *statePtr;/* Place for conversion routine to store
				 * state information used during a piecewise
				 * conversion.  Contents of statePtr are
				 * initialized and/or reset by conversion
				 * routine under control of flags argument. */
    char *dst;			/* Output buffer in which converted string
				 * is stored. */
    int dstLen;			/* The maximum length of output buffer in
				 * bytes. */
    int *srcReadPtr;		/* Filled with the number of bytes from the
				 * source string that were converted.  This
				 * may be less than the original source length
				 * if there was a problem converting some
				 * source characters. */
    int *dstWrotePtr;		/* Filled with the number of bytes that were
				 * stored in the output buffer as a result of
				 * the conversion. */
    int *dstCharsPtr;		/* Filled with the number of characters that
				 * correspond to the bytes stored in the
				 * output buffer. */
{
    CONST Tcl_UniChar *wSrc, *wSrcStart, *wSrcEnd;
    char *dstEnd, *dstStart;
    int result, numChars;
    
    result = TCL_OK;
    if ((srcLen % sizeof(Tcl_UniChar)) != 0) {
	result = TCL_CONVERT_MULTIBYTE;
	srcLen /= sizeof(Tcl_UniChar);
	srcLen *= sizeof(Tcl_UniChar);
    }

    wSrc = (Tcl_UniChar *) src;

    wSrcStart = (Tcl_UniChar *) src;
    wSrcEnd = (Tcl_UniChar *) (src + srcLen);

    dstStart = dst;
    dstEnd = dst + dstLen - TCL_UTF_MAX;

    for (numChars = 0; wSrc < wSrcEnd; numChars++) {
	if (dst > dstEnd) {
	    result = TCL_CONVERT_NOSPACE;
	    break;
	}
	/* 
	 * On a little-endian machine (Intel) the UCS-2BE is in the
	 * wrong byte-order in comparison to "unicode", which is
	 * in native host order.
	 */
	dst += Tcl_UniCharToUtf(htons(*wSrc), dst);
	wSrc++;
    }

    *srcReadPtr = (char *) wSrc - (char *) wSrcStart;
    *dstWrotePtr = dst - dstStart;
    *dstCharsPtr = numChars;
    return result;
}

/*
 *-------------------------------------------------------------------------
 *
 * UtfToUcs2beProc --
 *
 *	Convert from UTF-8 to UCS-2BE.
 *
 * Results:
 *	Returns TCL_OK if conversion was successful.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int 
UtfToUcs2beProc(clientData, src, srcLen, flags, statePtr, dst, dstLen,
	srcReadPtr, dstWrotePtr, dstCharsPtr)
    ClientData clientData;	/* TableEncodingData that specifies encoding. */
    CONST char *src;		/* Source string in UTF-8. */
    int srcLen;			/* Source string length in bytes. */
    int flags;			/* Conversion control flags. */
    Tcl_EncodingState *statePtr;/* Place for conversion routine to store
				 * state information used during a piecewise
				 * conversion.  Contents of statePtr are
				 * initialized and/or reset by conversion
				 * routine under control of flags argument. */
    char *dst;			/* Output buffer in which converted string
				 * is stored. */
    int dstLen;			/* The maximum length of output buffer in
				 * bytes. */
    int *srcReadPtr;		/* Filled with the number of bytes from the
				 * source string that were converted.  This
				 * may be less than the original source length
				 * if there was a problem converting some
				 * source characters. */
    int *dstWrotePtr;		/* Filled with the number of bytes that were
				 * stored in the output buffer as a result of
				 * the conversion. */
    int *dstCharsPtr;		/* Filled with the number of characters that
				 * correspond to the bytes stored in the
				 * output buffer. */
{
    CONST char *srcStart, *srcEnd, *srcClose;
    Tcl_UniChar *wDst, *wDstStart, *wDstEnd;
    int result, numChars;
    
    srcStart = src;
    srcEnd = src + srcLen;
    srcClose = srcEnd;
    if ((flags & TCL_ENCODING_END) == 0) {
	srcClose -= TCL_UTF_MAX;
    }

    wDst = (Tcl_UniChar *) dst;
    wDstStart = (Tcl_UniChar *) dst;
    wDstEnd = (Tcl_UniChar *) (dst + dstLen - sizeof(Tcl_UniChar));

    result = TCL_OK;
    for (numChars = 0; src < srcEnd; numChars++) {
	if ((src > srcClose) && (!Tcl_UtfCharComplete(src, srcEnd - src))) {
	    /*
	     * If there is more string to follow, this will ensure that the
	     * last UTF-8 character in the source buffer hasn't been cut off.
	     */

	    result = TCL_CONVERT_MULTIBYTE;
	    break;
	}
	if (wDst > wDstEnd) {
	    result = TCL_CONVERT_NOSPACE;
	    break;
        }
	src += Tcl_UtfToUniChar(src, wDst);
	/*
	 * Byte swap for little-endian machines.
	 */
	*wDst = htons(*wDst);
	wDst++;
    }
    *srcReadPtr = src - srcStart;
    *dstWrotePtr = (char *) wDst - (char *) wDstStart;
    *dstCharsPtr = numChars;
    return result;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpGetNativeFont --
 *
 *	Map a platform-specific native font name to a TkFont.
 *
 * Results:
 * 	The return value is a pointer to a TkFont that represents the
 *	native font.  If a native font by the given name could not be
 *	found, the return value is NULL.  
 *
 *	Every call to this procedure returns a new TkFont structure,
 *	even if the name has already been seen before.  The caller should
 *	call TkpDeleteFont() when the font is no longer needed.
 *
 *	The caller is responsible for initializing the memory associated
 *	with the generic TkFont when this function returns and releasing
 *	the contents of the generic TkFont before calling TkpDeleteFont().
 *
 * Side effects:
 *	Memory allocated.
 *
 *---------------------------------------------------------------------------
 */
 
TkFont *
TkpGetNativeFont(tkwin, name)
    Tk_Window tkwin;		/* For display where font will be used. */
    CONST char *name;		/* Platform-specific font name. */
{
    UnixFont *fontPtr;
    XFontStruct *fontStructPtr;
    FontAttributes fa;
    CONST char *p;
    int hasSpace, dashes, hasWild;

    /*
     * The behavior of X when given a name that isn't an XLFD is unspecified.
     * For example, Exceed 6 returns a valid font for any random string. This
     * is awkward since system names have higher priority than the other Tk
     * font syntaxes.  So, we need to perform a quick sanity check on the
     * name and fail if it looks suspicious.  We fail if the name:
     *     - contains a space immediately before a dash
     *	   - contains a space, but no '*' characters and fewer than 14 dashes
     */

    hasSpace = dashes = hasWild = 0;
    for (p = name; *p != '\0'; p++) {
	if (*p == ' ') {
	    if (p[1] == '-') {
		return NULL;
	    }
	    hasSpace = 1;
	} else if (*p == '-') {
	    dashes++;
	} else if (*p == '*') {
	    hasWild = 1;
	}
    }
    if ((dashes < 14) && !hasWild && hasSpace) {
	return NULL;
    }

    fontStructPtr = XLoadQueryFont(Tk_Display(tkwin), name);
    if (fontStructPtr == NULL) {
	/*
	 * Handle all names that look like XLFDs here.  Otherwise, when
	 * TkpGetFontFromAttributes is called from generic code, any
	 * foundry or encoding information specified in the XLFD will have
	 * been parsed out and lost.  But make sure we don't have an
	 * "-option value" string since TkFontParseXLFD would return a
	 * false success when attempting to parse it.
	 */

	if (name[0] == '-') {
	    if (name[1] != '*') {
		char *dash;
		
		dash = strchr(name + 1, '-');
		if ((dash == NULL) || (isspace(UCHAR(dash[-1])))) {
		    return NULL;
		}
	    }
	} else if (name[0] != '*') {
	    return NULL;
	}
	if (TkFontParseXLFD(name, &fa.fa, &fa.xa) != TCL_OK) {
	    return NULL;
	}
	fontStructPtr = CreateClosestFont(tkwin, &fa.fa, &fa.xa);
    }
    fontPtr = (UnixFont *) ckalloc(sizeof(UnixFont));
    InitFont(tkwin, fontStructPtr, fontPtr);

    return (TkFont *) fontPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpGetFontFromAttributes -- 
 *
 *	Given a desired set of attributes for a font, find a font with
 *	the closest matching attributes.
 *
 * Results:
 * 	The return value is a pointer to a TkFont that represents the
 *	font with the desired attributes.  If a font with the desired
 *	attributes could not be constructed, some other font will be
 *	substituted automatically.
 *
 *	Every call to this procedure returns a new TkFont structure,
 *	even if the specified attributes have already been seen before.
 *	The caller should call TkpDeleteFont() to free the platform-
 *	specific data when the font is no longer needed.  
 *
 *	The caller is responsible for initializing the memory associated
 *	with the generic TkFont when this function returns and releasing
 *	the contents of the generic TkFont before calling TkpDeleteFont().
 *
 * Side effects:
 *	Memory allocated.
 *
 *---------------------------------------------------------------------------
 */
TkFont *
TkpGetFontFromAttributes(tkFontPtr, tkwin, faPtr)
    TkFont *tkFontPtr;		/* If non-NULL, store the information in
				 * this existing TkFont structure, rather than
				 * allocating a new structure to hold the
				 * font; the existing contents of the font
				 * will be released.  If NULL, a new TkFont
				 * structure is allocated. */
    Tk_Window tkwin;		/* For display where font will be used. */
    CONST TkFontAttributes *faPtr;
				/* Set of attributes to match. */
{
    UnixFont *fontPtr;
    TkXLFDAttributes xa;
    XFontStruct *fontStructPtr;

    TkInitXLFDAttributes(&xa);
    fontStructPtr = CreateClosestFont(tkwin, faPtr, &xa);

    fontPtr = (UnixFont *) tkFontPtr;
    if (fontPtr == NULL) {
	fontPtr = (UnixFont *) ckalloc(sizeof(UnixFont));
    } else {
	ReleaseFont(fontPtr);
    }
    InitFont(tkwin, fontStructPtr, fontPtr);

    fontPtr->font.fa.underline = faPtr->underline;
    fontPtr->font.fa.overstrike = faPtr->overstrike;

    return (TkFont *) fontPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpDeleteFont --
 *
 *	Called to release a font allocated by TkpGetNativeFont() or
 *	TkpGetFontFromAttributes().  The caller should have already
 *	released the fields of the TkFont that are used exclusively by
 *	the generic TkFont code.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	TkFont is deallocated.
 *
 *---------------------------------------------------------------------------
 */

void
TkpDeleteFont(tkFontPtr)
    TkFont *tkFontPtr;		/* Token of font to be deleted. */
{
    UnixFont *fontPtr;

    fontPtr = (UnixFont *) tkFontPtr;
    ReleaseFont(fontPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpGetFontFamilies --
 *
 *	Return information about the font families that are available
 *	on the display of the given window.
 *
 * Results:
 *	Modifies interp's result object to hold a list of all the available
 *	font families.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

void
TkpGetFontFamilies(interp, tkwin)
    Tcl_Interp *interp;		/* Interp to hold result. */
    Tk_Window tkwin;		/* For display to query. */
{
    int i, new, numNames;
    char *family;
    Tcl_HashTable familyTable;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    char **nameList;
    Tcl_Obj *resultPtr, *strPtr;

    resultPtr = Tcl_GetObjResult(interp);    

    Tcl_InitHashTable(&familyTable, TCL_STRING_KEYS);
    nameList = ListFonts(Tk_Display(tkwin), "*", &numNames);
    for (i = 0; i < numNames; i++) {
	family = strchr(nameList[i] + 1, '-') + 1;
	strchr(family, '-')[0] = '\0';
	Tcl_CreateHashEntry(&familyTable, family, &new);
    }
    XFreeFontNames(nameList);

    hPtr = Tcl_FirstHashEntry(&familyTable, &search);
    while (hPtr != NULL) {
	strPtr = Tcl_NewStringObj(Tcl_GetHashKey(&familyTable, hPtr), -1); 
	Tcl_ListObjAppendElement(NULL, resultPtr, strPtr);
	hPtr = Tcl_NextHashEntry(&search);
    }

    Tcl_DeleteHashTable(&familyTable);
}

/*
 *-------------------------------------------------------------------------
 *
 * TkpGetSubFonts --
 *
 *	A function used by the testing package for querying the actual 
 *	screen fonts that make up a font object.
 *
 * Results:
 *	Modifies interp's result object to hold a list containing the 
 *	names of the screen fonts that make up the given font object.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

void
TkpGetSubFonts(interp, tkfont)
    Tcl_Interp *interp;
    Tk_Font tkfont;
{
    int i;
    Tcl_Obj *objv[3];
    Tcl_Obj *resultPtr, *listPtr;
    UnixFont *fontPtr;
    FontFamily *familyPtr;

    resultPtr = Tcl_GetObjResult(interp);    
    fontPtr = (UnixFont *) tkfont;
    for (i = 0; i < fontPtr->numSubFonts; i++) {
	familyPtr = fontPtr->subFontArray[i].familyPtr;
	objv[0] = Tcl_NewStringObj(familyPtr->faceName, -1);
	objv[1] = Tcl_NewStringObj(familyPtr->foundry, -1);
	objv[2] = Tcl_NewStringObj(Tcl_GetEncodingName(familyPtr->encoding), -1);
	listPtr = Tcl_NewListObj(3, objv);
	Tcl_ListObjAppendElement(NULL, resultPtr, listPtr);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 *  Tk_MeasureChars --
 *
 *	Determine the number of characters from the string that will fit
 *	in the given horizontal span.  The measurement is done under the
 *	assumption that Tk_DrawChars() will be used to actually display
 *	the characters.
 *
 * Results:
 *	The return value is the number of bytes from source that
 *	fit into the span that extends from 0 to maxLength.  *lengthPtr is
 *	filled with the x-coordinate of the right edge of the last
 *	character that did fit.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

int
Tk_MeasureChars(tkfont, source, numBytes, maxLength, flags, lengthPtr)
    Tk_Font tkfont;		/* Font in which characters will be drawn. */
    CONST char *source;		/* UTF-8 string to be displayed.  Need not be
				 * '\0' terminated. */
    int numBytes;		/* Maximum number of bytes to consider
				 * from source string. */
    int maxLength;		/* If >= 0, maxLength specifies the longest
				 * permissible line length in pixels; don't
				 * consider any character that would cross
				 * this x-position.  If < 0, then line length
				 * is unbounded and the flags argument is
				 * ignored. */
    int flags;			/* Various flag bits OR-ed together:
				 * TK_PARTIAL_OK means include the last char
				 * which only partially fit on this line.
				 * TK_WHOLE_WORDS means stop on a word
				 * boundary, if possible.
				 * TK_AT_LEAST_ONE means return at least one
				 * character even if no characters fit. */
    int *lengthPtr;		/* Filled with x-location just after the
				 * terminating character. */
{
    UnixFont *fontPtr;
    SubFont *lastSubFontPtr;
    int curX, curByte;

    /*
     * Unix does not use kerning or fractional character widths when
     * displaying text on the screen.  So that means we can safely measure
     * individual characters or spans of characters and add up the widths
     * w/o any "off-by-one-pixel" errors.
     */

    fontPtr = (UnixFont *) tkfont;

    lastSubFontPtr = &fontPtr->subFontArray[0];

    if (numBytes == 0) {
	curX = 0;
	curByte = 0;
    } else if (maxLength < 0) {
	CONST char *p, *end, *next;
	Tcl_UniChar ch;
	SubFont *thisSubFontPtr;
	FontFamily *familyPtr;
	Tcl_DString runString;

	/*
	 * A three step process:
	 * 1. Find a contiguous range of characters that can all be 
	 *    represented by a single screen font.
	 * 2. Convert those chars to the encoding of that font.
	 * 3. Measure converted chars.
	 */

	curX = 0;
	end = source + numBytes;
	for (p = source; p < end; ) {
	    next = p + Tcl_UtfToUniChar(p, &ch);
	    thisSubFontPtr = FindSubFontForChar(fontPtr, ch, &lastSubFontPtr);
	    if (thisSubFontPtr != lastSubFontPtr) {
		familyPtr = lastSubFontPtr->familyPtr;
		Tcl_UtfToExternalDString(familyPtr->encoding, source,
			p - source, &runString);
		if (familyPtr->isTwoByteFont) {
		    curX += XTextWidth16(lastSubFontPtr->fontStructPtr,
			    (XChar2b *) Tcl_DStringValue(&runString),
			    Tcl_DStringLength(&runString) / 2);
		} else {
		    curX += XTextWidth(lastSubFontPtr->fontStructPtr,
			    Tcl_DStringValue(&runString),
			    Tcl_DStringLength(&runString));
		}
		Tcl_DStringFree(&runString);
		lastSubFontPtr = thisSubFontPtr;
		source = p;
	    }
	    p = next;
	}
	familyPtr = lastSubFontPtr->familyPtr;
	Tcl_UtfToExternalDString(familyPtr->encoding, source,  p - source,
		&runString);
	if (familyPtr->isTwoByteFont) {
	    curX += XTextWidth16(lastSubFontPtr->fontStructPtr,
		    (XChar2b *) Tcl_DStringValue(&runString),
		    Tcl_DStringLength(&runString) >> 1);
	} else {
	    curX += XTextWidth(lastSubFontPtr->fontStructPtr,
		    Tcl_DStringValue(&runString),
		    Tcl_DStringLength(&runString));
	}
	Tcl_DStringFree(&runString);
	curByte = numBytes;
    } else {
	CONST char *p, *end, *next, *term;
	int newX, termX, sawNonSpace, dstWrote;
	Tcl_UniChar ch;
	FontFamily *familyPtr;
	char buf[16];

	/*
	 * How many chars will fit in the space allotted? 
	 * This first version may be inefficient because it measures
	 * every character individually.
	 */

	next = source + Tcl_UtfToUniChar(source, &ch);
	newX = curX = termX = 0;
	
	term = source;
	end = source + numBytes;

	sawNonSpace = (ch > 255) || !isspace(ch);
	familyPtr = lastSubFontPtr->familyPtr;
	for (p = source; ; ) {
	    if ((ch < BASE_CHARS) && (fontPtr->widths[ch] != 0)) {
		newX += fontPtr->widths[ch];
	    } else {
		lastSubFontPtr = FindSubFontForChar(fontPtr, ch, NULL);
		familyPtr = lastSubFontPtr->familyPtr;
		Tcl_UtfToExternal(NULL, familyPtr->encoding, p, next - p,
			0, NULL, buf, sizeof(buf), NULL, &dstWrote, NULL);
		if (familyPtr->isTwoByteFont) {
		    newX += XTextWidth16(lastSubFontPtr->fontStructPtr,
			    (XChar2b *) buf, dstWrote >> 1);
		} else {
		    newX += XTextWidth(lastSubFontPtr->fontStructPtr, buf,
			    dstWrote);
		}
	    }
	    if (newX > maxLength) {
		break;
	    }
	    curX = newX;
	    p = next;
	    if (p >= end) {
		term = end;
		termX = curX;
		break;
	    }

	    next += Tcl_UtfToUniChar(next, &ch);
	    if ((ch < 256) && isspace(ch)) {
		if (sawNonSpace) {
		    term = p;
		    termX = curX;
		    sawNonSpace = 0;
		}
	    } else {
		sawNonSpace = 1;
	    }
	}

	/*
	 * P points to the first character that doesn't fit in the desired
	 * span.  Use the flags to figure out what to return.
	 */

	if ((flags & TK_PARTIAL_OK) && (p < end) && (curX < maxLength)) {
	    /*
	     * Include the first character that didn't quite fit in the desired
	     * span.  The width returned will include the width of that extra
	     * character.
	     */

	    curX = newX;
	    p += Tcl_UtfToUniChar(p, &ch);
	}
	if ((flags & TK_AT_LEAST_ONE) && (term == source) && (p < end)) {
	    term = p;
	    termX = curX;
	    if (term == source) {
		term += Tcl_UtfToUniChar(term, &ch);
		termX = newX;
	    }
	} else if ((p >= end) || !(flags & TK_WHOLE_WORDS)) {
	    term = p;
	    termX = curX;
	}

	curX = termX;
	curByte = term - source;	
    }

    *lengthPtr = curX;
    return curByte;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_DrawChars --
 *
 *	Draw a string of characters on the screen.  Tk_DrawChars()
 *	expands control characters that occur in the string to 
 *	\xNN sequences.  
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information gets drawn on the screen.
 *
 *---------------------------------------------------------------------------
 */

void
Tk_DrawChars(display, drawable, gc, tkfont, source, numBytes, x, y)
    Display *display;		/* Display on which to draw. */
    Drawable drawable;		/* Window or pixmap in which to draw. */
    GC gc;			/* Graphics context for drawing characters. */
    Tk_Font tkfont;		/* Font in which characters will be drawn;
				 * must be the same as font used in GC. */
    CONST char *source;		/* UTF-8 string to be displayed.  Need not be
				 * '\0' terminated.  All Tk meta-characters
				 * (tabs, control characters, and newlines)
				 * should be stripped out of the string that
				 * is passed to this function.  If they are
				 * not stripped out, they will be displayed as
				 * regular printing characters. */
    int numBytes;		/* Number of bytes in string. */
    int x, y;			/* Coordinates at which to place origin of
				 * string when drawing. */
{
    UnixFont *fontPtr;
    SubFont *thisSubFontPtr, *lastSubFontPtr;
    Tcl_DString runString;
    CONST char *p, *end, *next;
    int xStart, needWidth, window_width, do_width;
    Tcl_UniChar ch;
    FontFamily *familyPtr;
#ifdef TK_DRAW_CHAR_XWINDOW_CHECK
    int rx, ry;
    unsigned int width, height, border_width, depth;
    Drawable root;
#endif

    fontPtr = (UnixFont *) tkfont;
    lastSubFontPtr = &fontPtr->subFontArray[0];

    xStart = x;

#ifdef TK_DRAW_CHAR_XWINDOW_CHECK
    /*
     * Get the window width so we can abort drawing outside of the window
     */
    if (XGetGeometry(display, drawable, &root, &rx, &ry, &width, &height,
	    &border_width, &depth) == False) {
	window_width = INT_MAX;
    } else {
	window_width = width;
    }
#else
    /*
     * This is used by default until we find a solution that doesn't
     * round-trip to the X server (need to get Tk cached window width).
     */
    window_width = 32768;
#endif

    end = source + numBytes;
    needWidth = fontPtr->font.fa.underline + fontPtr->font.fa.overstrike;
    for (p = source; p <= end; ) {
	if (p < end) {
	    next = p + Tcl_UtfToUniChar(p, &ch);
	    thisSubFontPtr = FindSubFontForChar(fontPtr, ch, &lastSubFontPtr);
	} else {
	    next = p + 1;
	    thisSubFontPtr = lastSubFontPtr;
	}
	if ((thisSubFontPtr != lastSubFontPtr)
		|| (p == end) || (p-source > 200)) {
	    if (p > source) {
	        do_width = (needWidth || (p != end)) ? 1 : 0;
		familyPtr = lastSubFontPtr->familyPtr;

		Tcl_UtfToExternalDString(familyPtr->encoding, source,
			p - source, &runString);
		if (familyPtr->isTwoByteFont) {
		    XDrawString16(display, drawable, gc, x, y, 
			    (XChar2b *) Tcl_DStringValue(&runString),
			    Tcl_DStringLength(&runString) / 2);
		    if (do_width) {
			x += XTextWidth16(lastSubFontPtr->fontStructPtr,
				(XChar2b *) Tcl_DStringValue(&runString),
				Tcl_DStringLength(&runString) / 2);
		    }
		} else {
		    XDrawString(display, drawable, gc, x, y,
			    Tcl_DStringValue(&runString),
			    Tcl_DStringLength(&runString));
		    if (do_width) {
			x += XTextWidth(lastSubFontPtr->fontStructPtr,
				Tcl_DStringValue(&runString),
				Tcl_DStringLength(&runString));
		    }
		}
		Tcl_DStringFree(&runString);
	    }
	    lastSubFontPtr = thisSubFontPtr;
	    source = p;
	    XSetFont(display, gc, lastSubFontPtr->fontStructPtr->fid);
	    if (x > window_width) {
	        break;
	    }
	}
	p = next;
    }

    if (lastSubFontPtr != &fontPtr->subFontArray[0]) {
	XSetFont(display, gc, fontPtr->subFontArray[0].fontStructPtr->fid);
    }

    if (fontPtr->font.fa.underline != 0) {
	XFillRectangle(display, drawable, gc, xStart,
		y + fontPtr->underlinePos,
		(unsigned) (x - xStart), (unsigned) fontPtr->barHeight);
    }
    if (fontPtr->font.fa.overstrike != 0) {
	y -= fontPtr->font.fm.descent + (fontPtr->font.fm.ascent) / 10;
	XFillRectangle(display, drawable, gc, xStart, y,
		(unsigned) (x - xStart), (unsigned) fontPtr->barHeight);
    }
}




/*
 *-------------------------------------------------------------------------
 *
 * CreateClosestFont --
 *
 *	Helper for TkpGetNativeFont() and TkpGetFontFromAttributes().
 *	Given a set of font attributes, construct a close XFontStruct.
 *	If requested face name is not available, automatically
 *	substitutes an alias for requested face name.  If encoding is
 *	not specified (or the requested one is not available),
 *	automatically chooses another encoding from the list of
 *	preferred encodings.  If the foundry is not specified (or
 *	is not available) automatically prefers "adobe" foundry.
 *	For all other attributes, if the requested value was not
 *	available, the appropriate "close" value will be used.
 *
 * Results:
 *	Return value is the XFontStruct that best matched the
 *	requested attributes.  The return value is never NULL; some
 *	font will always be returned.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static XFontStruct *
CreateClosestFont(tkwin, faPtr, xaPtr)
    Tk_Window tkwin;		/* For display where font will be used. */
    CONST TkFontAttributes *faPtr;	
				/* Set of generic attributes to match. */
    CONST TkXLFDAttributes *xaPtr;
				/* Set of X-specific attributes to match. */
{
    FontAttributes want;
    char **nameList;
    int numNames, nameIdx;
    Display *display;
    XFontStruct *fontStructPtr;
    int bestIdx[2];
    unsigned int bestScore[2];

    want.fa = *faPtr;
    want.xa = *xaPtr;

    if (want.xa.foundry == NULL) {
	want.xa.foundry = Tk_GetUid("adobe");
    }
    if (want.fa.family == NULL) {
	want.fa.family = Tk_GetUid("fixed");
    }
    want.fa.size = -TkFontGetPixels(tkwin, faPtr->size);
    if (want.xa.charset == NULL || *want.xa.charset == '\0') {
	want.xa.charset = Tk_GetUid("iso8859-1");	/* locale. */
    }

    display = Tk_Display(tkwin);

    /*
     * Algorithm to get the closest font to the name requested.
     *
     * try fontname
     * try all aliases for fontname
     * foreach fallback for fontname
     *	    try the fallback
     *	    try all aliases for the fallback
     */

    nameList = ListFontOrAlias(display, want.fa.family, &numNames);
    if (numNames == 0) {
	char ***fontFallbacks;
	int i, j;
	char *fallback;
	
	fontFallbacks = TkFontGetFallbacks();
	for (i = 0; fontFallbacks[i] != NULL; i++) {
	    for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
		if (strcasecmp(want.fa.family, fallback) == 0) {
		    break;
		}
	    }
	    if (fallback != NULL) {
		for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
		    nameList = ListFontOrAlias(display, fallback, &numNames);
		    if (numNames != 0) {
			goto found;
		    }
		}
	    }
	}
	nameList = ListFonts(display, "fixed", &numNames);
	if (numNames == 0) {
	    nameList = ListFonts(display, "*", &numNames);
	}
	if (numNames == 0) {
	    return GetSystemFont(display);
	}
    }
    found:
    bestIdx[0] = -1;
    bestIdx[1] = -1;
    bestScore[0] = (unsigned int) -1;
    bestScore[1] = (unsigned int) -1;
    for (nameIdx = 0; nameIdx < numNames; nameIdx++) {
	FontAttributes got;
	int scalable;
	unsigned int score;

	if (TkFontParseXLFD(nameList[nameIdx], &got.fa, &got.xa) != TCL_OK) {
	    continue;
	}
	IdentifySymbolEncodings(&got);
	scalable = (got.fa.size == 0);
	score = RankAttributes(&want, &got);
	if (score < bestScore[scalable]) {
	    bestIdx[scalable] = nameIdx;
	    bestScore[scalable] = score;
	}
	if (score == 0) {
	    break;
	}
    }

    fontStructPtr = GetScreenFont(display, &want, nameList, bestIdx, bestScore);
    XFreeFontNames(nameList);
    
    if (fontStructPtr == NULL) {
	return GetSystemFont(display);
    }
    return fontStructPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * InitFont --
 *
 *	Helper for TkpGetNativeFont() and TkpGetFontFromAttributes().
 *	Initializes the memory for a new UnixFont that 	wraps the
 *	platform-specific data.
 *
 *	The caller is responsible for initializing the fields of the
 *	TkFont that are used exclusively by the generic TkFont code, and
 *	for releasing those fields before calling TkpDeleteFont().
 *
 * Results:
 *	Fills the WinFont structure.
 *
 * Side effects:
 *	Memory allocated.
 *
 *---------------------------------------------------------------------------
 */ 

static void
InitFont(tkwin, fontStructPtr, fontPtr)
    Tk_Window tkwin;		/* For screen where font will be used. */
    XFontStruct *fontStructPtr;	/* X information about font. */
    UnixFont *fontPtr;		/* Filled with information constructed from
				 * the above arguments. */
{
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    unsigned long value;
    int minHi, maxHi, minLo, maxLo, fixed, width, limit, i, n;
    FontAttributes fa;
    TkFontAttributes *faPtr;
    TkFontMetrics *fmPtr;
    SubFont *controlPtr, *subFontPtr;
    char *pageMap;
    Display *display;

    /*
     * Get all font attributes and metrics.
     */
     
    display = Tk_Display(tkwin);
    GetFontAttributes(display, fontStructPtr, &fa);

    minHi = fontStructPtr->min_byte1;
    maxHi = fontStructPtr->max_byte1;
    minLo = fontStructPtr->min_char_or_byte2;
    maxLo = fontStructPtr->max_char_or_byte2;
	
    fixed = 1;
    if (fontStructPtr->per_char != NULL) {
	width = 0;
	limit = (maxHi - minHi + 1) * (maxLo - minLo + 1);
	for (i = 0; i < limit; i++) {
	    n = fontStructPtr->per_char[i].width;
	    if (n != 0) {
		if (width == 0) {
		    width = n;
		} else if (width != n) {
		    fixed = 0;
		    break;
		}
	    }
	}
    }

    fontPtr->font.fid	= fontStructPtr->fid;

    faPtr		= &fontPtr->font.fa;
    faPtr->family	= fa.fa.family;
    faPtr->size		= TkFontGetPoints(tkwin, fa.fa.size);
    faPtr->weight	= fa.fa.weight;
    faPtr->slant	= fa.fa.slant;
    faPtr->underline	= 0;
    faPtr->overstrike	= 0;

    fmPtr		= &fontPtr->font.fm;
    fmPtr->ascent	= fontStructPtr->ascent;
    fmPtr->descent	= fontStructPtr->descent;
    fmPtr->maxWidth	= fontStructPtr->max_bounds.width;
    fmPtr->fixed	= fixed;

    fontPtr->display	= display;
    fontPtr->pixelSize	= TkFontGetPixels(tkwin, fa.fa.size);
    fontPtr->xa		= fa.xa;

    fontPtr->numSubFonts	= 1;
    fontPtr->subFontArray	= fontPtr->staticSubFonts;
    InitSubFont(display, fontStructPtr, 1, &fontPtr->subFontArray[0]);

    fontPtr->controlSubFont	= fontPtr->subFontArray[0];
    subFontPtr			= FindSubFontForChar(fontPtr, '0', NULL);
    controlPtr			= &fontPtr->controlSubFont;
    controlPtr->fontStructPtr	= subFontPtr->fontStructPtr;
    controlPtr->familyPtr	= &tsdPtr->controlFamily;
    controlPtr->fontMap		= tsdPtr->controlFamily.fontMap;
    
    pageMap = fontPtr->subFontArray[0].fontMap[0];
    for (i = 0; i < 256; i++) {
	if ((minHi > 0) || (i < minLo) || (i > maxLo) ||
		(((pageMap[i >> 3] >> (i & 7)) & 1) == 0)) {
	    n = 0;
	} else if (fontStructPtr->per_char == NULL) {
	    n = fontStructPtr->max_bounds.width;
	} else {
	    n = fontStructPtr->per_char[i - minLo].width;
	}
	fontPtr->widths[i] = n;
    }
    

    if (XGetFontProperty(fontStructPtr, XA_UNDERLINE_POSITION, &value)) {
	fontPtr->underlinePos = value;
    } else {
	/*
	 * If the XA_UNDERLINE_POSITION property does not exist, the X
	 * manual recommends using the following value:
	 */

	fontPtr->underlinePos = fontStructPtr->descent / 2;
    }
    fontPtr->barHeight = 0;
    if (XGetFontProperty(fontStructPtr, XA_UNDERLINE_THICKNESS, &value)) {
	fontPtr->barHeight = value;
    }
    if (fontPtr->barHeight == 0) {
	/*
	 * If the XA_UNDERLINE_THICKNESS property does not exist, the X
	 * manual recommends using the width of the stem on a capital
	 * letter.  I don't know of a way to get the stem width of a letter,
	 * so guess and use 1/3 the width of a capital I.
	 */

	fontPtr->barHeight = fontPtr->widths['I'] / 3;
	if (fontPtr->barHeight == 0) {
	    fontPtr->barHeight = 1;
	}
    }
    if (fontPtr->underlinePos + fontPtr->barHeight > fontStructPtr->descent) {
	/*
	 * If this set of cobbled together values would cause the bottom of
	 * the underline bar to stick below the descent of the font, jack
	 * the underline up a bit higher.
	 */

	fontPtr->barHeight = fontStructPtr->descent - fontPtr->underlinePos;
	if (fontPtr->barHeight == 0) {
	    fontPtr->underlinePos--;
	    fontPtr->barHeight = 1;
	}
    }
}

/*
 *-------------------------------------------------------------------------
 *
 * ReleaseFont --
 * 
 *	Called to release the unix-specific contents of a TkFont.
 *	The caller is responsible for freeing the memory used by the
 *	font itself.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory is freed.
 *
 *---------------------------------------------------------------------------
 */
 
static void
ReleaseFont(fontPtr)
    UnixFont *fontPtr;		/* The font to delete. */
{
    int i;

    for (i = 0; i < fontPtr->numSubFonts; i++) {
	ReleaseSubFont(fontPtr->display, &fontPtr->subFontArray[i]);
    }
    if (fontPtr->subFontArray != fontPtr->staticSubFonts) {
	ckfree((char *) fontPtr->subFontArray);
    }
}

/*
 *-------------------------------------------------------------------------
 *
 * InitSubFont --
 *
 *	Wrap a screen font and load the FontFamily that represents
 *	it.  Used to prepare a SubFont so that characters can be mapped
 *	from UTF-8 to the charset of the font.
 *
 * Results:
 *	The subFontPtr is filled with information about the font.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static void
InitSubFont(display, fontStructPtr, base, subFontPtr)
    Display *display;		/* Display in which font will be used. */
    XFontStruct *fontStructPtr;	/* The screen font. */
    int base;			/* Non-zero if this SubFont is being used
				 * as the base font for a font object. */
    SubFont *subFontPtr;	/* Filled with SubFont constructed from 
    				 * above attributes. */
{
    subFontPtr->fontStructPtr = fontStructPtr;
    subFontPtr->familyPtr   = AllocFontFamily(display, fontStructPtr, base);
    subFontPtr->fontMap	    = subFontPtr->familyPtr->fontMap;
}

/*
 *-------------------------------------------------------------------------
 *
 * ReleaseSubFont --
 *
 *	Called to release the contents of a SubFont.  The caller is 
 *	responsible for freeing the memory used by the SubFont itself.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory and resources are freed.
 *
 *---------------------------------------------------------------------------
 */

static void
ReleaseSubFont(display, subFontPtr)
    Display *display;		/* Display which owns screen font. */
    SubFont *subFontPtr;	/* The SubFont to delete. */
{
    XFreeFont(display, subFontPtr->fontStructPtr);
    FreeFontFamily(subFontPtr->familyPtr);
}

/*
 *-------------------------------------------------------------------------
 *
 * AllocFontFamily --
 *
 *	Find the FontFamily structure associated with the given font
 *	name.  The information should be stored by the caller in a 
 *	SubFont and used when determining if that SubFont supports a 
 *	character.
 *
 *	Cannot use the string name used to construct the font as the 
 *	key, because the capitalization may not be canonical.  Therefore
 *	use the face name actually retrieved from the font metrics as
 *	the key.
 *
 * Results:
 *	A pointer to a FontFamily.  The reference count in the FontFamily
 *	is automatically incremented.  When the SubFont is released, the
 *	reference count is decremented.  When no SubFont is using this
 *	FontFamily, it may be deleted.
 *
 * Side effects:
 *	A new FontFamily structure will be allocated if this font family
 *	has not been seen.  TrueType character existence metrics are
 *	loaded into the FontFamily structure.
 *
 *-------------------------------------------------------------------------
 */

static FontFamily *
AllocFontFamily(display, fontStructPtr, base)
    Display *display;		/* Display in which font will be used. */
    XFontStruct *fontStructPtr;	/* Screen font whose FontFamily is to be
				 * returned. */
    int base;			/* Non-zero if this font family is to be
				 * used in the base font of a font object. */
{
    FontFamily *familyPtr;
    FontAttributes fa;
    Tcl_Encoding encoding;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    GetFontAttributes(display, fontStructPtr, &fa);
    encoding = Tcl_GetEncoding(NULL, GetEncodingAlias(fa.xa.charset));

    familyPtr = tsdPtr->fontFamilyList;
    for (; familyPtr != NULL; familyPtr = familyPtr->nextPtr) {
	if ((familyPtr->faceName == fa.fa.family)
		&& (familyPtr->foundry == fa.xa.foundry)
		&& (familyPtr->encoding == encoding)) {
	    Tcl_FreeEncoding(encoding);
	    familyPtr->refCount++;
	    return familyPtr;
	}
    }

    familyPtr = (FontFamily *) ckalloc(sizeof(FontFamily));
    memset(familyPtr, 0, sizeof(FontFamily));
    familyPtr->nextPtr = tsdPtr->fontFamilyList;
    tsdPtr->fontFamilyList = familyPtr;

    /* 
     * Set key for this FontFamily. 
     */
     
    familyPtr->foundry = fa.xa.foundry;
    familyPtr->faceName = fa.fa.family;
    familyPtr->encoding = encoding;

    /* 
     * An initial refCount of 2 means that FontFamily information will
     * persist even when the SubFont that loaded the FontFamily is released.
     * Change it to 1 to cause FontFamilies to be unloaded when not in use.
     */

    familyPtr->refCount = 2;

    /*
     * One byte/character fonts have both min_byte1 and max_byte1 0,
     * and max_char_or_byte2 <= 255.
     * Anything else specifies a two byte/character font.
     */

    familyPtr->isTwoByteFont = !(
	    (fontStructPtr->min_byte1 == 0) &&
	    (fontStructPtr->max_byte1 == 0) &&
	    (fontStructPtr->max_char_or_byte2 < 256));
    return familyPtr;
}

/*
 *-------------------------------------------------------------------------
 *
 * FreeFontFamily --
 *
 *	Called to free an FontFamily when the SubFont is finished using
 *	it. Frees the contents of the FontFamily and the memory used by
 *	the FontFamily itself.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */
 
static void
FreeFontFamily(familyPtr)
    FontFamily *familyPtr;	/* The FontFamily to delete. */
{
    FontFamily **familyPtrPtr;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));
    int i;

    if (familyPtr == NULL) {
        return;
    }
    familyPtr->refCount--;
    if (familyPtr->refCount > 0) {
    	return;
    }
    Tcl_FreeEncoding(familyPtr->encoding);
    for (i = 0; i < FONTMAP_PAGES; i++) {
        if (familyPtr->fontMap[i] != NULL) {
            ckfree(familyPtr->fontMap[i]);
        }
    }
    
    /* 
     * Delete from list. 
     */
         
    for (familyPtrPtr = &tsdPtr->fontFamilyList; ; ) {
        if (*familyPtrPtr == familyPtr) {
  	    *familyPtrPtr = familyPtr->nextPtr;
	    break;
	}
	familyPtrPtr = &(*familyPtrPtr)->nextPtr;
    }
    
    ckfree((char *) familyPtr);
}

/*
 *-------------------------------------------------------------------------
 *
 * FindSubFontForChar --
 *
 *	Determine which screen font is necessary to use to 
 *	display the given character.  If the font object does not have
 *	a screen font that can display the character, another screen font
 *	may be loaded into the font object, following a set of preferred
 *	fallback rules.
 *
 * Results:
 *	The return value is the SubFont to use to display the given 
 *	character. 
 *
 * Side effects:
 *	The contents of fontPtr are modified to cache the results
 *	of the lookup and remember any SubFonts that were dynamically 
 *	loaded.  The table of SubFonts might be extended, and if a non-NULL
 *	reference to a subfont pointer is available, it is updated if it
 *	previously pointed into the old subfont table.
 *
 *-------------------------------------------------------------------------
 */

static SubFont *
FindSubFontForChar(fontPtr, ch, fixSubFontPtrPtr)
    UnixFont *fontPtr;		/* The font object with which the character
				 * will be displayed. */
    int ch;			/* The Unicode character to be displayed. */
    SubFont **fixSubFontPtrPtr;	/* Subfont reference to fix up if we
				 * reallocate our subfont table. */
{
    int i, j, k, numNames;
    Tk_Uid faceName; 
    char *fallback;
    char **aliases, **nameList, **anyFallbacks;
    char ***fontFallbacks;
    SubFont *subFontPtr;
    Tcl_DString ds;

    if (FontMapLookup(&fontPtr->subFontArray[0], ch)) {
	return &fontPtr->subFontArray[0];
    }

    for (i = 1; i < fontPtr->numSubFonts; i++) {
	if (FontMapLookup(&fontPtr->subFontArray[i], ch)) {
	    return &fontPtr->subFontArray[i];
	}
    }

    if (FontMapLookup(&fontPtr->controlSubFont, ch)) {
	return &fontPtr->controlSubFont;
    }

    /*
     * Keep track of all face names that we check, so we don't check some
     * name multiple times if it can be reached by multiple paths.
     */
     
    Tcl_DStringInit(&ds);

    /*
     * Are there any other fonts with the same face name as the base
     * font that could display this character, e.g., if the base font
     * is adobe:fixed:iso8859-1, we could might be able to use
     * misc:fixed:iso8859-8 or sony:fixed:jisx0208.1983-0
     */
     
    faceName = fontPtr->font.fa.family;
    if (SeenName(faceName, &ds) == 0) {
	subFontPtr = CanUseFallback(fontPtr, faceName, ch, fixSubFontPtrPtr);
	if (subFontPtr != NULL) {
	    goto end;
	}
    }

    aliases = TkFontGetAliasList(faceName);

    subFontPtr = NULL;
    fontFallbacks = TkFontGetFallbacks();
    for (i = 0; fontFallbacks[i] != NULL; i++) {
	for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
	    if (strcasecmp(fallback, faceName) == 0) {
		/*
		 * If the base font has a fallback...
		 */

		goto tryfallbacks;
	    } else if (aliases != NULL) {
		/* 
		 * Or if an alias for the base font has a fallback...
		 */

		for (k = 0; aliases[k] != NULL; k++) {
		    if (strcasecmp(fallback, aliases[k]) == 0) {
			goto tryfallbacks;
		    }
		}
	    }
	}
	continue;

	tryfallbacks:

	/* 
	 * ...then see if we can use one of the fallbacks, or an
	 * alias for one of the fallbacks.
	 */

	for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
	    subFontPtr = CanUseFallbackWithAliases(fontPtr, fallback, ch, &ds,
		    fixSubFontPtrPtr);
	    if (subFontPtr != NULL) {
		goto end;
	    }
	}
    }

    /*
     * See if we can use something from the global fallback list. 
     */

    anyFallbacks = TkFontGetGlobalClass();
    for (i = 0; (fallback = anyFallbacks[i]) != NULL; i++) {
	subFontPtr = CanUseFallbackWithAliases(fontPtr, fallback, ch, &ds,
		fixSubFontPtrPtr);
	if (subFontPtr != NULL) {
	    goto end;
	}
    }

    /*
     * Try all face names available in the whole system until we
     * find one that can be used.
     */

    nameList = ListFonts(fontPtr->display, "*", &numNames);
    for (i = 0; i < numNames; i++) {
	fallback = strchr(nameList[i] + 1, '-') + 1;
	strchr(fallback, '-')[0] = '\0';
	if (SeenName(fallback, &ds) == 0) {
	    subFontPtr = CanUseFallback(fontPtr, fallback, ch,
		    fixSubFontPtrPtr);
	    if (subFontPtr != NULL) {
		XFreeFontNames(nameList);
		goto end;
	    }
	}
    }
    XFreeFontNames(nameList);

    end:
    Tcl_DStringFree(&ds);

    if (subFontPtr == NULL) {
	/*
	 * No font can display this character, so it will be displayed as a
	 * control character expansion.
	 */

	subFontPtr = &fontPtr->controlSubFont;
	FontMapInsert(subFontPtr, ch);
    }
    return subFontPtr;
}

/*
 *-------------------------------------------------------------------------
 *
 * FontMapLookup --
 *
 *	See if the screen font can display the given character.
 *
 * Results:
 *	The return value is 0 if the screen font cannot display the
 *	character, non-zero otherwise.
 *
 * Side effects:
 *	New pages are added to the font mapping cache whenever the
 *	character belongs to a page that hasn't been seen before.
 *	When a page is loaded, information about all the characters on
 *	that page is stored, not just for the single character in
 *	question.
 *
 *-------------------------------------------------------------------------
 */

static int
FontMapLookup(subFontPtr, ch)
    SubFont *subFontPtr;	/* Contains font mapping cache to be queried
				 * and possibly updated. */
    int ch;			/* Character to be tested. */
{
    int row, bitOffset;

    row = ch >> FONTMAP_SHIFT;
    if (subFontPtr->fontMap[row] == NULL) {
	FontMapLoadPage(subFontPtr, row);
    }
    bitOffset = ch & (FONTMAP_BITSPERPAGE - 1);
    return (subFontPtr->fontMap[row][bitOffset >> 3] >> (bitOffset & 7)) & 1;
}

/*
 *-------------------------------------------------------------------------
 *
 * FontMapInsert --
 *
 *	Tell the font mapping cache that the given screen font should be
 *	used to display the specified character.  This is called when no
 *	font on the system can be be found that can display that 
 *	character; we lie to the font and tell it that it can display
 *	the character, otherwise we would end up re-searching the entire
 *	fallback hierarchy every time that character was seen.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	New pages are added to the font mapping cache whenever the
 *	character belongs to a page that hasn't been seen before.
 *	When a page is loaded, information about all the characters on
 *	that page is stored, not just for the single character in
 *	question.
 *
 *-------------------------------------------------------------------------
 */

static void
FontMapInsert(subFontPtr, ch)
    SubFont *subFontPtr;	/* Contains font mapping cache to be 
				 * updated. */
    int ch;			/* Character to be added to cache. */
{
    int row, bitOffset;

    row = ch >> FONTMAP_SHIFT;
    if (subFontPtr->fontMap[row] == NULL) {
	FontMapLoadPage(subFontPtr, row);
    }
    bitOffset = ch & (FONTMAP_BITSPERPAGE - 1);
    subFontPtr->fontMap[row][bitOffset >> 3] |= 1 << (bitOffset & 7);
}

/*
 *-------------------------------------------------------------------------
 *
 * FontMapLoadPage --
 *
 *	Load information about all the characters on a given page.
 *	This information consists of one bit per character that indicates
 *	whether the associated screen font can (1) or cannot (0) display
 *	the characters on the page.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Mempry allocated.
 *
 *-------------------------------------------------------------------------
 */
static void 
FontMapLoadPage(subFontPtr, row)
    SubFont *subFontPtr;	/* Contains font mapping cache to be 
				 * updated. */
    int row;			/* Index of the page to be loaded into 
				 * the cache. */
{
    char src[TCL_UTF_MAX], buf[16];
    int minHi, maxHi, minLo, maxLo, scale, checkLo;
    int i, end, bitOffset, isTwoByteFont, n;
    Tcl_Encoding encoding;
    XFontStruct *fontStructPtr;
    XCharStruct *widths;
    ThreadSpecificData *tsdPtr = (ThreadSpecificData *) 
            Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    subFontPtr->fontMap[row] = (char *) ckalloc(FONTMAP_BITSPERPAGE / 8);
    memset(subFontPtr->fontMap[row], 0, FONTMAP_BITSPERPAGE / 8);

    if (subFontPtr->familyPtr == &tsdPtr->controlFamily) {
	return;
    }

    fontStructPtr   = subFontPtr->fontStructPtr;
    encoding	    = subFontPtr->familyPtr->encoding;
    isTwoByteFont   = subFontPtr->familyPtr->isTwoByteFont;

    widths	= fontStructPtr->per_char;
    minHi	= fontStructPtr->min_byte1;
    maxHi	= fontStructPtr->max_byte1;
    minLo	= fontStructPtr->min_char_or_byte2;
    maxLo	= fontStructPtr->max_char_or_byte2;
    scale	= maxLo - minLo + 1;
    checkLo	= minLo;

    if (! isTwoByteFont) {
	if (minLo < 32) {
	    checkLo = 32;
	}
    }

    end = (row + 1) << FONTMAP_SHIFT;
    for (i = row << FONTMAP_SHIFT; i < end; i++) {
	int hi, lo;
	
	if (Tcl_UtfToExternal(NULL, encoding, src, Tcl_UniCharToUtf(i, src),
        	TCL_ENCODING_STOPONERROR, NULL, buf, sizeof(buf), NULL, 
		NULL, NULL) != TCL_OK) {
	    continue;
	}
	if (isTwoByteFont) {
	    hi = ((unsigned char *) buf)[0];
	    lo = ((unsigned char *) buf)[1];
	} else {
	    hi = 0;
	    lo = ((unsigned char *) buf)[0];
	}
	if ((hi < minHi) || (hi > maxHi) || (lo < checkLo) || (lo > maxLo)) {
	    continue;
	}
	n = (hi - minHi) * scale + lo - minLo;
	if ((widths == NULL) || ((widths[n].width + widths[n].rbearing) != 0)) {
	    bitOffset = i & (FONTMAP_BITSPERPAGE - 1);
	    subFontPtr->fontMap[row][bitOffset >> 3] |= 1 << (bitOffset & 7);
	}
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * CanUseFallbackWithAliases --
 *
 *	Helper function for FindSubFontForChar.  Determine if the
 *	specified face name (or an alias of the specified face name)
 *	can be used to construct a screen font that can display the
 *	given character.
 *
 * Results:
 *	See CanUseFallback().
 *
 * Side effects:
 *	If the name and/or one of its aliases was rejected, the
 *	rejected string is recorded in nameTriedPtr so that it won't
 *	be tried again.  The table of SubFonts might be extended, and if
 *	a non-NULL reference to a subfont pointer is available, it is
 *	updated if it previously pointed into the old subfont table.
 *
 *---------------------------------------------------------------------------
 */

static SubFont *
CanUseFallbackWithAliases(fontPtr, faceName, ch, nameTriedPtr,
	fixSubFontPtrPtr)
    UnixFont *fontPtr;		/* The font object that will own the new
				 * screen font. */
    char *faceName;		/* Desired face name for new screen font. */
    int ch;			/* The Unicode character that the new
				 * screen font must be able to display. */
    Tcl_DString *nameTriedPtr;	/* Records face names that have already
				 * been tried.  It is possible for the same
				 * face name to be queried multiple times when
				 * trying to find a suitable screen font. */
    SubFont **fixSubFontPtrPtr;	/* Subfont reference to fix up if we
				 * reallocate our subfont table. */
{
    SubFont *subFontPtr;
    char **aliases;
    int i;
    
    if (SeenName(faceName, nameTriedPtr) == 0) {
	subFontPtr = CanUseFallback(fontPtr, faceName, ch, fixSubFontPtrPtr);
	if (subFontPtr != NULL) {
	    return subFontPtr;
	}
    }
    aliases = TkFontGetAliasList(faceName);
    if (aliases != NULL) {
	for (i = 0; aliases[i] != NULL; i++) {
	    if (SeenName(aliases[i], nameTriedPtr) == 0) {
		subFontPtr = CanUseFallback(fontPtr, aliases[i], ch,
			fixSubFontPtrPtr);
		if (subFontPtr != NULL) {
		    return subFontPtr;
		}
	    }
	}
    }
    return NULL;
}

/*
 *---------------------------------------------------------------------------
 *
 * SeenName --
 *
 *	Used to determine we have already tried and rejected the given
 *	face name when looking for a screen font that can support some
 *	Unicode character.
 *
 * Results:
 *	The return value is 0 if this face name has not already been seen,
 *	non-zero otherwise.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static int
SeenName(name, dsPtr)
    CONST char *name;		/* The name to check. */
    Tcl_DString *dsPtr;		/* Contains names that have already been
				 * seen. */
{
    CONST char *seen, *end;

    seen = Tcl_DStringValue(dsPtr);
    end = seen + Tcl_DStringLength(dsPtr);
    while (seen < end) {
	if (strcasecmp(seen, name) == 0) {
	    return 1;
	}
	seen += strlen(seen) + 1;
    }
    Tcl_DStringAppend(dsPtr, (char *) name, (int) (strlen(name) + 1));
    return 0;
}

/*
 *-------------------------------------------------------------------------
 *
 * CanUseFallback --
 *
 *	If the specified screen font has not already been loaded 
 *	into the font object, determine if the specified screen 
 *	font can display the given character.
 *
 * Results:
 *	The return value is a pointer to a newly allocated SubFont,
 *	owned by the font object.  This SubFont can be used to display
 *	the given character.  The SubFont represents the screen font
 *	with the base set of font attributes from the font object, but
 *	using the specified face name.  NULL is returned if the font
 *	object already holds a reference to the specified font or if
 *	the specified font doesn't exist or cannot display the given
 *	character.
 *
 * Side effects:				       
 *	The font object's subFontArray is updated to contain a reference
 *	to the newly allocated SubFont.  The table of SubFonts might be
 *	extended, and if a non-NULL reference to a subfont pointer is
 *	available, it is updated if it previously pointed into the old
 *	subfont table.
 *
 *-------------------------------------------------------------------------
 */

static SubFont *
CanUseFallback(fontPtr, faceName, ch, fixSubFontPtrPtr)
    UnixFont *fontPtr;		/* The font object that will own the new
				 * screen font. */
    CONST char *faceName;	/* Desired face name for new screen font. */
    int ch;			/* The Unicode character that the new
				 * screen font must be able to display. */
    SubFont **fixSubFontPtrPtr;	/* Subfont reference to fix up if we
				 * reallocate our subfont table. */
{
    int i, nameIdx, numNames, srcLen;
    Tk_Uid hateFoundry;
    int bestIdx[2];
    CONST char *charset, *hateCharset;
    unsigned int bestScore[2];
    char **nameList, **nameListOrig;
    FontAttributes want, got;
    char src[TCL_UTF_MAX];
    Display *display;
    SubFont subFont;
    XFontStruct *fontStructPtr;
    Tcl_DString dsEncodings;
    int numEncodings;
    Tcl_Encoding *encodingCachePtr;

    /*
     * Assume: the face name is times.
     * Assume: adobe:times:iso8859-1 has already been used.
     *
     * Are there any versions of times that can display this
     *    character (e.g., perhaps linotype:times:iso8859-2)?
     *	  a. Get list of all times fonts.
     *	  b1. Cross out all names whose encodings we've already used.
     *	  b2. Cross out all names whose foundry & encoding we've already seen.
     *	  c. Cross out all names whose encoding cannot handle the character.
     *	  d. Rank each name and pick the best match.
     *	  e. If that font cannot actually display the character, cross
     *	     out all names with the same foundry and encoding and go
     *	     back to (c).
     */

    display = fontPtr->display;
    nameList = ListFonts(display, faceName, &numNames);
    if (numNames == 0) {
	return NULL;
    }
    nameListOrig = nameList;

    srcLen = Tcl_UniCharToUtf(ch, src);

    want.fa = fontPtr->font.fa;
    want.xa = fontPtr->xa;

    want.fa.family = Tk_GetUid(faceName);
    want.fa.size = -fontPtr->pixelSize;

    hateFoundry = NULL;
    hateCharset = NULL;
    numEncodings = 0;
    Tcl_DStringInit(&dsEncodings);

    charset = NULL;	/* lint, since numNames must be > 0 to get here. */

    retry:
    bestIdx[0] = -1;
    bestIdx[1] = -1;
    bestScore[0] = (unsigned int) -1;
    bestScore[1] = (unsigned int) -1;
    for (nameIdx = 0; nameIdx < numNames; nameIdx++) {
	Tcl_Encoding encoding;
	char dst[16];
	int scalable, srcRead, dstWrote;
	unsigned int score;
	
	if (nameList[nameIdx] == NULL) {
	    continue;
	}
	if (TkFontParseXLFD(nameList[nameIdx], &got.fa, &got.xa) != TCL_OK) {
	    goto crossout;
	}
	IdentifySymbolEncodings(&got);
	charset = GetEncodingAlias(got.xa.charset);
	if (hateFoundry != NULL) {
	    /*
	     * E. If the font we picked cannot actually display the
	     * character, cross out all names with the same foundry and
	     * encoding. 
	     */

	    if ((hateFoundry == got.xa.foundry)
		    && (strcmp(hateCharset, charset) == 0)) {
		goto crossout;
	    }
	} else {
	    /*
	     * B. Cross out all names whose encodings we've already used.
	     */
	     
	    for (i = 0; i < fontPtr->numSubFonts; i++) {
		encoding = fontPtr->subFontArray[i].familyPtr->encoding;
		if (strcmp(charset, Tcl_GetEncodingName(encoding)) == 0) {
		    goto crossout;
		}
	    }
	}
	
	/*
	 * C. Cross out all names whose encoding cannot handle the character.
	 */
	 
	encodingCachePtr = (Tcl_Encoding *) Tcl_DStringValue(&dsEncodings);
	for (i = numEncodings; --i >= 0; encodingCachePtr++) {
	    encoding = *encodingCachePtr;
	    if (strcmp(Tcl_GetEncodingName(encoding), charset) == 0) {
		break;
	    }
	}
	if (i < 0) {
	    encoding = Tcl_GetEncoding(NULL, charset);
	    if (encoding == NULL) {
		goto crossout;
	    }

	    Tcl_DStringAppend(&dsEncodings, (char *) &encoding,
		    sizeof(encoding));
	    numEncodings++;
	}
	Tcl_UtfToExternal(NULL, encoding, src, srcLen, 
		TCL_ENCODING_STOPONERROR, NULL, dst, sizeof(dst), &srcRead, 
		&dstWrote, NULL);
	if (dstWrote == 0) {
	    goto crossout;
	}

	/*
	 * D. Rank each name and pick the best match.
	 */

	scalable = (got.fa.size == 0);
	score = RankAttributes(&want, &got);
	if (score < bestScore[scalable]) {
	    bestIdx[scalable] = nameIdx;
	    bestScore[scalable] = score;
	}
	if (score == 0) {
	    break;
	}
	continue;

	crossout:
	if (nameList == nameListOrig) {
	    /*
	     * Not allowed to change pointers to memory that X gives you,
	     * so make a copy.
	     */

	    nameList = (char **) ckalloc(numNames * sizeof(char *));
	    memcpy(nameList, nameListOrig, numNames * sizeof(char *));
	}
	nameList[nameIdx] = NULL;
    }

    fontStructPtr = GetScreenFont(display, &want, nameList, bestIdx, bestScore);

    encodingCachePtr = (Tcl_Encoding *) Tcl_DStringValue(&dsEncodings);
    for (i = numEncodings; --i >= 0; encodingCachePtr++) {
	Tcl_FreeEncoding(*encodingCachePtr);
    }
    Tcl_DStringFree(&dsEncodings);
    numEncodings = 0;

    if (fontStructPtr == NULL) {
	if (nameList != nameListOrig) {
	    ckfree((char *) nameList);
	}
	XFreeFontNames(nameListOrig);
	return NULL;
    }

    InitSubFont(display, fontStructPtr, 0, &subFont);
    if (FontMapLookup(&subFont, ch) == 0) {
	/*
	 * E. If the font we picked cannot actually display the character,
	 * cross out all names with the same foundry and encoding and pick
	 * another font.
	 */

	hateFoundry = got.xa.foundry;
	hateCharset = charset;
	ReleaseSubFont(display, &subFont);
	goto retry;
    }
    if (nameList != nameListOrig) {
	ckfree((char *) nameList);
    }
    XFreeFontNames(nameListOrig);

    if (fontPtr->numSubFonts >= SUBFONT_SPACE) {
	SubFont *newPtr;
	
	newPtr = (SubFont *) ckalloc(sizeof(SubFont) * (fontPtr->numSubFonts + 1));
	memcpy((char *) newPtr, fontPtr->subFontArray,
		fontPtr->numSubFonts * sizeof(SubFont));
	if (fixSubFontPtrPtr != NULL) {
	    register SubFont *fixSubFontPtr = *fixSubFontPtrPtr;

	    if (fixSubFontPtr != &fontPtr->controlSubFont) {
		*fixSubFontPtrPtr =
			newPtr + (fixSubFontPtr - fontPtr->subFontArray);
	    }
	}
	if (fontPtr->subFontArray != fontPtr->staticSubFonts) {
	    ckfree((char *) fontPtr->subFontArray);
	}
	fontPtr->subFontArray = newPtr;
    }
    fontPtr->subFontArray[fontPtr->numSubFonts] = subFont;
    fontPtr->numSubFonts++;
    return &fontPtr->subFontArray[fontPtr->numSubFonts - 1];
}

/*
 *---------------------------------------------------------------------------
 *
 * RankAttributes --
 *
 *	Determine how close the attributes of the font in question match
 *	the attributes that we want.
 *
 * Results:
 *	The return value is the score; lower numbers are better.
 *	*scalablePtr is set to 0 if the font was not scalable, 1 otherwise.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static unsigned int
RankAttributes(wantPtr, gotPtr)
    FontAttributes *wantPtr;	/* The desired attributes. */
    FontAttributes *gotPtr;	/* The attributes we have to live with. */
{
    unsigned int penalty;

    penalty = 0;
    if (gotPtr->xa.foundry != wantPtr->xa.foundry) {
	penalty += 4500;
    }
    if (gotPtr->fa.family != wantPtr->fa.family) {
	penalty += 9000;
    }
    if (gotPtr->fa.weight != wantPtr->fa.weight) {
	penalty += 90;
    }
    if (gotPtr->fa.slant != wantPtr->fa.slant) {
	penalty += 60;
    }
    if (gotPtr->xa.slant != wantPtr->xa.slant) {
	penalty += 10;
    }
    if (gotPtr->xa.setwidth != wantPtr->xa.setwidth) {
	penalty += 1000;
    }

    if (gotPtr->fa.size == 0) {
	/*
	 * A scalable font is almost always acceptable, but the
	 * corresponding bitmapped font would be better.
	 */

	penalty += 10;
    } else {
	int diff;

	/*
	 * It's worse to be too large than to be too small.
	 */
	 
	diff = (-gotPtr->fa.size - -wantPtr->fa.size);
	if (diff > 0) {
	    penalty += 600;
	} else if (diff < 0) {
	    penalty += 150;
	    diff = -diff;
	}
	penalty += 150 * diff;
    }
    if (gotPtr->xa.charset != wantPtr->xa.charset) {
	int i;
	CONST char *gotAlias, *wantAlias;

	penalty += 65000;
	gotAlias = GetEncodingAlias(gotPtr->xa.charset);
	wantAlias = GetEncodingAlias(wantPtr->xa.charset); 
	if (strcmp(gotAlias, wantAlias) != 0) {
	    penalty += 30000;
	    for (i = 0; encodingList[i] != NULL; i++) {
		if (strcmp(gotAlias, encodingList[i]) == 0) {
		    penalty -= 30000;
		    break;
		}
		penalty += 20000;
	    }
	}
    }
    return penalty;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetScreenFont --
 *
 *	Given the names for the best scalable and best bitmapped font,
 *	actually construct an XFontStruct based on the best XLFD.
 *	This is where all the alias and fallback substitution bottoms
 *	out.
 *
 * Results:
 *	The screen font that best corresponds to the set of attributes.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static XFontStruct *
GetScreenFont(display, wantPtr, nameList, bestIdx, bestScore)
    Display *display;		/* Display for new XFontStruct. */
    FontAttributes *wantPtr;	/* Contains desired actual pixel-size if the
				 * best font was scalable. */
    char **nameList;		/* Array of XLFDs. */
    int bestIdx[2];		/* Indices into above array for XLFD of
				 * best bitmapped and best scalable font. */
    unsigned int bestScore[2];	/* Scores of best bitmapped and best
				 * scalable font.  XLFD corresponding to
				 * lowest score will be constructed. */
{
    XFontStruct *fontStructPtr;

    if ((bestIdx[0] < 0) && (bestIdx[1] < 0)) {
	return NULL;
    }

    /*
     * Now we know which is the closest matching scalable font and the
     * closest matching bitmapped font.  If the scalable font was a
     * better match, try getting the scalable font; however, if the
     * scalable font was not actually available in the desired
     * pointsize, fall back to the closest bitmapped font.
     */

    fontStructPtr = NULL;
    if (bestScore[1] < bestScore[0]) {
	char *str, *rest;
	char buf[256];
	int i;
	
	/*
	 * Fill in the desired pixel size for this font.
	 */

	tryscale:
	str = nameList[bestIdx[1]];
	for (i = 0; i < XLFD_PIXEL_SIZE; i++) {
	    str = strchr(str + 1, '-');
	}
	rest = str;
	for (i = XLFD_PIXEL_SIZE; i < XLFD_CHARSET; i++) {
	    rest = strchr(rest + 1, '-');
	}
	*str = '\0';
	sprintf(buf, "%.200s-%d-*-*-*-*-*%s", nameList[bestIdx[1]],
		-wantPtr->fa.size, rest);
	*str = '-';
	fontStructPtr = XLoadQueryFont(display, buf);
	bestScore[1] = INT_MAX;
    }
    if (fontStructPtr == NULL) {
	fontStructPtr = XLoadQueryFont(display, nameList[bestIdx[0]]);
	if (fontStructPtr == NULL) {
	    /*
	     * This shouldn't happen because the font name is one of the
	     * names that X gave us to use, but it does anyhow.
	     */

	    if (bestScore[1] < INT_MAX) {
		goto tryscale;
	    }
	    return GetSystemFont(display);
	}
    }
    return fontStructPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetSystemFont --
 *
 *	Absolute fallback mechanism, called when we need a font and no
 *	other font can be found and/or instantiated.
 *
 * Results:
 *	A pointer to a font.  Never NULL.
 *
 * Side effects:
 *	If there are NO fonts installed on the system, this call will
 *	panic, but how did you get X running in that case?
 *
 *---------------------------------------------------------------------------
 */

static XFontStruct *
GetSystemFont(display)
    Display *display;		/* Display for new XFontStruct. */
{
    XFontStruct *fontStructPtr;

    fontStructPtr = XLoadQueryFont(display, "fixed");
    if (fontStructPtr == NULL) {
	fontStructPtr = XLoadQueryFont(display, "*");
	if (fontStructPtr == NULL) {
	    panic("TkpGetFontFromAttributes: cannot get any font");
	}
    }
    return fontStructPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetFontAttributes --
 *
 *	Given a screen font, determine its actual attributes, which are
 *	not necessarily the attributes that were used to construct it.
 *
 * Results:
 *	*faPtr is filled with the screen font's attributes.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static int
GetFontAttributes(display, fontStructPtr, faPtr)
    Display *display;		/* Display that owns the screen font. */
    XFontStruct *fontStructPtr;	/* Screen font to query. */
    FontAttributes *faPtr;	/* For storing attributes of screen font. */
{
    unsigned long value;
    char *name;
    
    if ((XGetFontProperty(fontStructPtr, XA_FONT, &value) != False) &&
	    (value != 0)) {
	name = XGetAtomName(display, (Atom) value);
	if (TkFontParseXLFD(name, &faPtr->fa, &faPtr->xa) != TCL_OK) {
	    faPtr->fa.family = Tk_GetUid(name);
	    faPtr->xa.foundry = Tk_GetUid("");
	    faPtr->xa.charset = Tk_GetUid("");
	}
	XFree(name);
    } else {
	TkInitFontAttributes(&faPtr->fa);
	TkInitXLFDAttributes(&faPtr->xa);
    }
    /*
     * Do last ditch check for family.  It seems that some X servers can
     * fail on the X font calls above, slipping through earlier checks.
     * X-Win32 5.4 is one of these.
     */
    if (faPtr->fa.family == NULL) {
	faPtr->fa.family = Tk_GetUid("");
	faPtr->xa.foundry = Tk_GetUid("");
	faPtr->xa.charset = Tk_GetUid("");
    }
    return IdentifySymbolEncodings(faPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * ListFonts --
 *
 *	Utility function to return the array of all XLFDs on the system
 *	with the specified face name.
 *
 * Results:
 *	The return value is an array of XLFDs, which should be freed with
 *	XFreeFontNames(), or NULL if no XLFDs matched the requested name.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */
 
static char **
ListFonts(display, faceName, numNamesPtr)
    Display *display;		/* Display to query. */
    CONST char *faceName;	/* Desired face name, or "*" for all. */
    int *numNamesPtr;		/* Filled with length of returned array, or
				 * 0 if no names were found. */
{
    char buf[256];

    sprintf(buf, "-*-%.80s-*-*-*-*-*-*-*-*-*-*-*-*", faceName);
    return XListFonts(display, buf, 10000, numNamesPtr);
}

static char **
ListFontOrAlias(display, faceName, numNamesPtr)
    Display *display;		/* Display to query. */
    CONST char *faceName;	/* Desired face name, or "*" for all. */
    int *numNamesPtr;		/* Filled with length of returned array, or
				 * 0 if no names were found. */
{
    char **nameList, **aliases;
    int i;
    
    nameList = ListFonts(display, faceName, numNamesPtr);
    if (nameList != NULL) {
	return nameList;
    }
    aliases = TkFontGetAliasList(faceName);
    if (aliases != NULL) {
	for (i = 0; aliases[i] != NULL; i++) {
	    nameList = ListFonts(display, aliases[i], numNamesPtr);
	    if (nameList != NULL) {
		return nameList;
	    }
	}
    }
    *numNamesPtr = 0;
    return NULL;
}

/*
 *---------------------------------------------------------------------------
 *
 * IdentifySymbolEncodings --
 *
 *	If the font attributes refer to a symbol font, update the
 *	charset field of the font attributes so that it reflects the
 *	encoding of that symbol font.  In general, the raw value for
 *	the charset field parsed from an XLFD is meaningless for symbol
 *	fonts.
 *
 *	Symbol fonts are all fonts whose name appears in the symbolClass.
 *
 * Results:
 *	The return value is non-zero if the font attributes specify a
 *	symbol font, or 0 otherwise.  If a non-zero value is returned
 *	the charset field of the font attributes will be changed to
 *	the string that represents the actual encoding for the symbol font.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static int
IdentifySymbolEncodings(faPtr)
    FontAttributes *faPtr;
{
    int i, j;
    char **aliases, **symbolClass;

    symbolClass = TkFontGetSymbolClass();
    for (i = 0; symbolClass[i] != NULL; i++) {
	if (strcasecmp(faPtr->fa.family, symbolClass[i]) == 0) {
	    faPtr->xa.charset = Tk_GetUid(GetEncodingAlias(symbolClass[i]));
	    return 1;
	}
	aliases = TkFontGetAliasList(symbolClass[i]);
	for (j = 0; (aliases != NULL) && (aliases[j] != NULL); j++) {
	    if (strcasecmp(faPtr->fa.family, aliases[j]) == 0) {
		faPtr->xa.charset = Tk_GetUid(GetEncodingAlias(aliases[j]));
		return 1;
	    }
	}
    }
    return 0;
}

/*
 *---------------------------------------------------------------------------
 *
 * GetEncodingAlias --
 *
 *	Map the name of an encoding to another name that should be used
 *	when actually loading the encoding.  For instance, the encodings
 *	"jisc6226.1978", "jisx0208.1983", "jisx0208.1990", and
 *	"jisx0208.1996" are well-known names for the same encoding and
 *	are represented by one encoding table: "jis0208".
 *
 * Results:
 *	As above.  If the name has no alias, the original name is returned.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static CONST char *
GetEncodingAlias(name)
    CONST char *name;		/* The name to look up. */
{
    EncodingAlias *aliasPtr;
    
    for (aliasPtr = encodingAliases; aliasPtr->aliasPattern != NULL; ) {
	if (Tcl_StringMatch((char *) name, aliasPtr->aliasPattern)) {
	    return aliasPtr->realName;
	}
	aliasPtr++;
    }
    return name;
}
