/*
 * 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 1.18.2.2 2003/07/19 01:45:42 hobbs Exp $
 */
#include "tkUnixInt.h"
#include "tkFont.h"
#ifndef USE_XFT_FONTS
#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", "ksc5601", "big5", "ucs-2be", 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.
 * FIXME: the existance assumption above does _NOT_ hold for UNICODE fonts
 * e.g. -misc-fixed-*-*-*-*-*-*-*-*-*-*-iso10646-1 has smaller repertoire
 * in bold/italic than in regular forms
 */
#if TCL_UTF_MAX <= 3
#define FONTMAP_SHIFT           8
#else
#define FONTMAP_SHIFT           10
#endif
#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. */
    char *name;                 /* Name used (malloc-ed) */
    int   trigger;              /* Character which caused us to load 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[], int *indexPtr));
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, int ch, const char *name));
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));
    SubFont dummy;
    int i;
    if (tsdPtr->controlFamily.encoding == NULL) {
        tsdPtr->controlFamily.refCount = 2;
        tsdPtr->controlFamily.encoding = Lang_CreateEncoding(
            "X11ControlChars",   /* encodingName */
            ControlUtfProc,      /* toUtfProc */
            ControlUtfProc,      /* fromUtfProc */
            NULL,                /* freeProc */
            NULL,                /* clientData */
            0                    /* nullSize */
            );
        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.
         */
#ifndef _LANG
        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);
#else
        Lang_CreateEncoding(
        "ucs-2be",
        Ucs2beToUtfProc,
        UtfToUcs2beProc,
        NULL,
        NULL,
        2);
#endif
    }
}
/*
 *-------------------------------------------------------------------------
 *
 * 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[4];
    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);
        objv[3] = Tcl_NewIntObj(fontPtr->subFontArray[i].trigger);
        listPtr = Tcl_NewListObj(4, objv);
        if (fontPtr->subFontArray[i].name) {
            Tcl_ListObjAppendElement(interp, listPtr,
                  Tcl_NewStringObj(fontPtr->subFontArray[i].name, -1));
        }
        Tcl_ListObjAppendElement(interp, 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, ' ', nameList[nameIdx]);
        if (score < bestScore[scalable]) {
            bestIdx[scalable] = nameIdx;
            bestScore[scalable] = score;
        }
        if (score == 0) {
            break;
        }
    }
    fontStructPtr = GetScreenFont(display, &want, nameList, bestIdx, bestScore, &nameIdx);
    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;
#if 0
    faPtr->size              = TkFontGetPoints(tkwin, fa.fa.size);
#else
    /* Actuals are in pixels - says NI-S */
    faPtr->size              = -TkFontGetPixels(tkwin, fa.fa.size);
#endif
    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;
    subFontPtr->name        = NULL;
    subFontPtr->trigger     = -1;
}
/*
 *-------------------------------------------------------------------------
 *
 * 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);
    if (subFontPtr->name) {
        ckfree(subFontPtr->name);
    }
}
/*
 *-------------------------------------------------------------------------
 *
 * 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.
     */
#ifndef _LANG
    familyPtr->refCount = 2;
#else
    familyPtr->refCount = 1;
#endif
    /*
     * 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.
     */
    /* Why not use a hash table ! */
    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));
    int unicode = 0;
    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;
        }
    }
    else {
        unicode = strstr(Tcl_GetEncodingName(encoding),"ucs-2") ? 1 : 0;
    }
    end = (row + 1) << FONTMAP_SHIFT;
    for (i = row << FONTMAP_SHIFT; i < end; i++) {
        int hi, lo;
        if (unicode) {
             buf[0] = (i >> 8);
             buf[1] = (i & 0xFF);
        }
        else 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];
        }
        n = (hi - minHi) * scale + lo - minLo;
        if ((hi < minHi) || (hi > maxHi) || (lo < checkLo) || (lo > maxLo)) {
            continue;
        }
        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)) {
                /* not clear this is correct for Unicode
                   foundry may not always use same subset
                   on the other hand if it isn't in foundary's
                   -iso10646-1 font it probably isn't in their
                   -iso8859-* fonts either.
                   It is less clear with oriental and symbol fonts
                   that other encodings might not handle
                */
                if (1 || strcmp(hateCharset, "ucs-2be") != 0)
                goto crossout;
            }
        } else {
            /*
             * B. Cross out all names whose encodings we've already used.
             */
            if (strcmp(charset,"ucs-2be") == 0) {
                if ((unsigned int) ch <= 0xffff)
                    goto do_ranking;
                goto crossout;
            }
            for (i = 0; i < fontPtr->numSubFonts; i++) {
                encoding = fontPtr->subFontArray[i].familyPtr->encoding;
                if (strcmp(charset, Tcl_GetEncodingName(encoding)) == 0) {
                    goto crossout;
                }
            }
        }
         
   do_ranking:
        /*
         * 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, ch, nameList[nameIdx]);
        if (score < bestScore[scalable]) {
            bestIdx[scalable] = nameIdx;
            bestScore[scalable] = score;
        }
        if (score == 0) {
            break;
        }
        /* Allow ranking to have a veto */
        else if (score == (unsigned int) -1) {
            hateFoundry = got.xa.foundry;
            hateCharset = charset;
            goto crossout;
        }
        else if (score == (unsigned int) -2) {
            goto crossout;
        }
        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;
    }
    /* There may be merit in a version of this which just does XQueryFont()
       rather than load it server-side until we know it is of use
     */
    fontStructPtr = GetScreenFont(display, &want, nameList, bestIdx, bestScore, &nameIdx);
    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;
    }
#ifdef _LANG
    TkFontParseXLFD(nameList[nameIdx], &got.fa, &got.xa);
    IdentifySymbolEncodings(&got);
#endif
    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 = GetEncodingAlias(got.xa.charset);
        ReleaseSubFont(display, &subFont);
#ifdef _LANG
        LangFontRank((unsigned int ) -1, ch, nameList[nameIdx],
                     want.xa.foundry, &want.fa, want.xa.charset,
                     got.xa.foundry, &got.fa, got.xa.charset);
#endif
        goto retry;
    }
#ifdef _LANG
    LangFontRank(0, ch, nameList[nameIdx],
                 want.xa.foundry, &want.fa, want.xa.charset,
                 got.xa.foundry, &got.fa, got.xa.charset);
#endif
    subFont.name = ckalloc(strlen(nameList[nameIdx])+1);
    subFont.trigger = ch;
    if (subFont.name) {
        strcpy(subFont.name,nameList[nameIdx]);
    }
    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, ch, name)
    FontAttributes *wantPtr;    /* The desired attributes. */
    FontAttributes *gotPtr;     /* The attributes we have to live with. */
    int ch;                     /* character we want */
    const char *name;           /* Font we are trying */
{
    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 increases as we go down prefered list */
                penalty += 20000;
            }
        }
    }
#ifdef _LANG
    penalty = LangFontRank(penalty, ch, name,
                           wantPtr->xa.foundry,&wantPtr->fa, wantPtr->xa.charset,
                           gotPtr->xa.foundry,&gotPtr->fa, gotPtr->xa.charset);
#endif
    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, indexPtr)
    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. */
    int *indexPtr;              /* Return index of name we used */                              
{
    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] && bestScore[1] < (unsigned int) -2) {
        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);
        if (fontStructPtr != NULL) {
            *indexPtr = bestIdx[1];
        }
        bestScore[1] = (unsigned int) -1;
    }
    if (fontStructPtr == NULL && bestScore[0] < (unsigned int) -2) {
        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] < (unsigned int) -2) {
                goto tryscale;
            }
            return GetSystemFont(display);
        }
        else {
            *indexPtr = bestIdx[0];
        }
    }
    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);
        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;
}
#endif /* USE_XFT_FONTS */