path: root/win/tkWinFont.c

/*
 * tkWinFont.c --
 *
 *	Contains the Windows implementation of the platform-independant font
 *	package interface.
 *
 * Copyright (c) 1994 Software Research Associates, Inc.
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 * Copyright (c) 1998-1999 by Scriptics Corporation.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 */

#include "tkWinInt.h"
#include "tkFont.h"

/*
 * 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 Windows, a "font family" is uniquely identified by its face name.
 */

#define FONTMAP_SHIFT	    10

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

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

    Tk_Uid faceName;		/* Face name key for this FontFamily. */

    /*
     * Derived properties.
     */

    Tcl_Encoding encoding;	/* Encoding for this font family. */
    int isSymbolFont;		/* Non-zero if this is a symbol font. */
    int isWideFont;		/* 1 if this is a double-byte font, 0
				 * otherwise. */
    BOOL (WINAPI *textOutProc)(HDC hdc, int x, int y, TCHAR *str, int len);
				/* The procedure to use to draw text after it
				 * has been converted from UTF-8 to the
				 * encoding of this font. */
    BOOL (WINAPI *getTextExtentPoint32Proc)(HDC, TCHAR *, int, LPSIZE);
				/* The procedure to use to measure text after
				 * it has been converted from UTF-8 to the
				 * encoding of this font. */

    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 added. 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. */

    /*
     * Cached Truetype font info.
     */

    int segCount;		/* The length of the following arrays. */
    USHORT *startCount;		/* Truetype information about the font, */
    USHORT *endCount;		/* indicating which characters this font can
				 * display (malloced). The format of this
				 * information is (relatively) compact, but
				 * would take longer to search than indexing
				 * into the fontMap[][] table. */
} 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. */
    HFONT hFont0;		/* The specific screen font that will be used
				 * when displaying/measuring chars belonging
				 * to the FontFamily. */
    FontFamily *familyPtr;	/* The FontFamily for this SubFont. */
    HFONT hFontAngled;
    double angle;
} SubFont;

/*
 * The following structure represents Windows' implementation of a font
 * object.
 */

#define SUBFONT_SPACE		3
#define BASE_CHARS		128

typedef struct WinFont {
    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. */
    HWND hwnd;			/* Toplevel window of application that owns
				 * this font, used for getting HDC for
				 * offscreen measurements. */
    int pixelSize;		/* Original pixel size used when font was
				 * constructed. */
    int widths[BASE_CHARS];	/* Widths of first 128 chars in the base font,
				 * for handling common case. The base font is
				 * always used to draw characters between
				 * 0x0000 and 0x007f. */
} WinFont;

/*
 * The following structure is passed as the LPARAM when calling the font
 * enumeration procedure to determine if a font can support the given
 * character.
 */

typedef struct CanUse {
    HDC hdc;
    WinFont *fontPtr;
    Tcl_DString *nameTriedPtr;
    int ch;
    SubFont *subFontPtr;
    SubFont **subFontPtrPtr;
} CanUse;

/*
 * The following structure is used to map between the Tcl strings that
 * represent the system fonts and the numbers used by Windows.
 */

static const TkStateMap systemMap[] = {
    {ANSI_FIXED_FONT,	    "ansifixed"},
    {ANSI_FIXED_FONT,	    "fixed"},
    {ANSI_VAR_FONT,	    "ansi"},
    {DEVICE_DEFAULT_FONT,   "device"},
    {DEFAULT_GUI_FONT,	    "defaultgui"},
    {OEM_FIXED_FONT,	    "oemfixed"},
    {SYSTEM_FIXED_FONT,	    "systemfixed"},
    {SYSTEM_FONT,	    "system"},
    {-1,		    NULL}
};

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. */
    Tcl_HashTable uidTable;
} ThreadSpecificData;
static Tcl_ThreadDataKey dataKey;

/*
 * Information cached about the system at startup time.
 */

static Tcl_Encoding systemEncoding;

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

static FontFamily *	AllocFontFamily(HDC hdc, HFONT hFont, int base);
static SubFont *	CanUseFallback(HDC hdc, WinFont *fontPtr,
			    const char *fallbackName, int ch,
			    SubFont **subFontPtrPtr);
static SubFont *	CanUseFallbackWithAliases(HDC hdc, WinFont *fontPtr,
			    const char *faceName, int ch,
			    Tcl_DString *nameTriedPtr,
			    SubFont **subFontPtrPtr);
static int		FamilyExists(HDC hdc, const char *faceName);
static const char *	FamilyOrAliasExists(HDC hdc, const char *faceName);
static SubFont *	FindSubFontForChar(WinFont *fontPtr, int ch,
			    SubFont **subFontPtrPtr);
static void		FontMapInsert(SubFont *subFontPtr, int ch);
static void		FontMapLoadPage(SubFont *subFontPtr, int row);
static int		FontMapLookup(SubFont *subFontPtr, int ch);
static void		FreeFontFamily(FontFamily *familyPtr);
static HFONT		GetScreenFont(const TkFontAttributes *faPtr,
			    const char *faceName, int pixelSize,
			    double angle);
static void		InitFont(Tk_Window tkwin, HFONT hFont,
			    int overstrike, WinFont *tkFontPtr);
static inline void	InitSubFont(HDC hdc, HFONT hFont, int base,
			    SubFont *subFontPtr);
static int		CreateNamedSystemLogFont(Tcl_Interp *interp,
			    Tk_Window tkwin, const char* name,
			    LOGFONT* logFontPtr);
static int		CreateNamedSystemFont(Tcl_Interp *interp,
			    Tk_Window tkwin, const char* name, HFONT hFont);
static int		LoadFontRanges(HDC hdc, HFONT hFont,
			    USHORT **startCount, USHORT **endCount,
			    int *symbolPtr);
static void		MultiFontTextOut(HDC hdc, WinFont *fontPtr,
			    const char *source, int numBytes, int x, int y,
			    double angle);
static void		ReleaseFont(WinFont *fontPtr);
static inline void	ReleaseSubFont(SubFont *subFontPtr);
static int		SeenName(const char *name, Tcl_DString *dsPtr);
static inline HFONT	SelectFont(HDC hdc, WinFont *fontPtr,
			    SubFont *subFontPtr, double angle);
static inline void	SwapLong(PULONG p);
static inline void	SwapShort(USHORT *p);
static int CALLBACK	WinFontCanUseProc(ENUMLOGFONT *lfPtr,
			    NEWTEXTMETRIC *tmPtr, int fontType,
			    LPARAM lParam);
static int CALLBACK	WinFontExistProc(ENUMLOGFONT *lfPtr,
			    NEWTEXTMETRIC *tmPtr, int fontType,
			    LPARAM lParam);
static int CALLBACK	WinFontFamilyEnumProc(ENUMLOGFONT *lfPtr,
			    NEWTEXTMETRIC *tmPtr, int fontType,
			    LPARAM lParam);

/*
 *-------------------------------------------------------------------------
 *
 * 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(
    TkMainInfo *mainPtr)	/* The application being created. */
{
    systemEncoding = TkWinGetUnicodeEncoding();
    TkWinSetupSystemFonts(mainPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * 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(
    Tk_Window tkwin,		/* For display where font will be used. */
    const char *name)		/* Platform-specific font name. */
{
    int object;
    WinFont *fontPtr;

    object = TkFindStateNum(NULL, NULL, systemMap, name);
    if (object < 0) {
	return NULL;
    }

    tkwin = (Tk_Window) ((TkWindow *) tkwin)->mainPtr->winPtr;
    fontPtr = ckalloc(sizeof(WinFont));
    InitFont(tkwin, GetStockObject(object), 0, fontPtr);

    return (TkFont *) fontPtr;
}

/*
 *---------------------------------------------------------------------------
 *
 * CreateNamedSystemFont --
 *
 *	This function registers a Windows logical font description with the Tk
 *	named font mechanism.
 *
 * Side effects:
 *	A new named font is added to the Tk font registry.
 *
 *---------------------------------------------------------------------------
 */

static int
CreateNamedSystemLogFont(
    Tcl_Interp *interp,
    Tk_Window tkwin,
    const char* name,
    LOGFONT* logFontPtr)
{
    HFONT hFont;
    int r;

    hFont = CreateFontIndirect(logFontPtr);
    r = CreateNamedSystemFont(interp, tkwin, name, hFont);
    DeleteObject((HGDIOBJ)hFont);
    return r;
}

/*
 *---------------------------------------------------------------------------
 *
 * CreateNamedSystemFont --
 *
 *	This function registers a Windows font with the Tk named font
 *	mechanism.
 *
 * Side effects:
 *	A new named font is added to the Tk font registry.
 *
 *---------------------------------------------------------------------------
 */

static int
CreateNamedSystemFont(
    Tcl_Interp *interp,
    Tk_Window tkwin,
    const char* name,
    HFONT hFont)
{
    WinFont winfont;
    int r;

    TkDeleteNamedFont(NULL, tkwin, name);
    InitFont(tkwin, hFont, 0, &winfont);
    r = TkCreateNamedFont(interp, tkwin, name, &winfont.font.fa);
    TkpDeleteFont((TkFont *)&winfont);
    return r;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkWinSystemFonts --
 *
 *	Create some platform specific named fonts that to give access to the
 *	system fonts. These are all defined for the Windows desktop
 *	parameters.
 *
 *---------------------------------------------------------------------------
 */

void
TkWinSetupSystemFonts(
    TkMainInfo *mainPtr)
{
    Tcl_Interp *interp;
    Tk_Window tkwin;
    const TkStateMap *mapPtr;
    NONCLIENTMETRICS ncMetrics;
    ICONMETRICS iconMetrics;
    HFONT hFont;

    interp = (Tcl_Interp *) mainPtr->interp;
    tkwin = (Tk_Window) mainPtr->winPtr;

    /* force this for now */
    if (((TkWindow *) tkwin)->mainPtr == NULL) {
	((TkWindow *) tkwin)->mainPtr = mainPtr;
    }

    /*
     * If this API call fails then we will fallback to setting these named
     * fonts from script in ttk/fonts.tcl. So far I've only seen it fail when
     * WINVER has been defined for a higher platform than we are running on.
     * (i.e. WINVER=0x0600 and running on XP).
     */

    ZeroMemory(&ncMetrics, sizeof(ncMetrics));
    ncMetrics.cbSize = sizeof(ncMetrics);
    if (SystemParametersInfo(SPI_GETNONCLIENTMETRICS,
	    sizeof(ncMetrics), &ncMetrics, 0)) {
	CreateNamedSystemLogFont(interp, tkwin, "TkDefaultFont",
		&ncMetrics.lfMessageFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkHeadingFont",
		&ncMetrics.lfMessageFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkTextFont",
		&ncMetrics.lfMessageFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkMenuFont",
		&ncMetrics.lfMenuFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkTooltipFont",
		&ncMetrics.lfStatusFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkCaptionFont",
		&ncMetrics.lfCaptionFont);
	CreateNamedSystemLogFont(interp, tkwin, "TkSmallCaptionFont",
		&ncMetrics.lfSmCaptionFont);
    }

    iconMetrics.cbSize = sizeof(iconMetrics);
    if (SystemParametersInfo(SPI_GETICONMETRICS, sizeof(iconMetrics),
	    &iconMetrics, 0)) {
	CreateNamedSystemLogFont(interp, tkwin, "TkIconFont",
		&iconMetrics.lfFont);
    }

    /*
     * Identify an available fixed font. Equivalent to ANSI_FIXED_FONT but
     * more reliable on Russian Windows.
     */

    {
	LOGFONT lfFixed = {
	    0, 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, DEFAULT_CHARSET,
	    0, 0, DEFAULT_QUALITY, FIXED_PITCH | FF_MODERN, TEXT("")
	};
	long pointSize, dpi;
	HDC hdc = GetDC(NULL);
	dpi = GetDeviceCaps(hdc, LOGPIXELSY);
	pointSize = -MulDiv(ncMetrics.lfMessageFont.lfHeight, 72, dpi);
	lfFixed.lfHeight = -MulDiv(pointSize+1, dpi, 72);
	ReleaseDC(NULL, hdc);
	CreateNamedSystemLogFont(interp, tkwin, "TkFixedFont", &lfFixed);
    }

    /*
     * Setup the remaining standard Tk font names as named fonts.
     */

    for (mapPtr = systemMap; mapPtr->strKey != NULL; mapPtr++) {
	hFont = (HFONT) GetStockObject(mapPtr->numKey);
	CreateNamedSystemFont(interp, tkwin, mapPtr->strKey, hFont);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * 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. NULL is never returned.
 *
 *	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(
    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. */
{
    int i, j;
    HDC hdc;
    HWND hwnd;
    HFONT hFont;
    Window window;
    WinFont *fontPtr;
    const char *const *const *fontFallbacks;
    Tk_Uid faceName, fallback, actualName;

    tkwin = (Tk_Window) ((TkWindow *) tkwin)->mainPtr->winPtr;
    window = Tk_WindowId(tkwin);
    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
    hdc = GetDC(hwnd);

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

    faceName = faPtr->family;
    if (faceName != NULL) {
	actualName = FamilyOrAliasExists(hdc, faceName);
	if (actualName != NULL) {
	    faceName = actualName;
	    goto found;
	}
	fontFallbacks = TkFontGetFallbacks();
	for (i = 0; fontFallbacks[i] != NULL; i++) {
	    for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
		if (strcasecmp(faceName, fallback) == 0) {
		    break;
		}
	    }
	    if (fallback != NULL) {
		for (j = 0; (fallback = fontFallbacks[i][j]) != NULL; j++) {
		    actualName = FamilyOrAliasExists(hdc, fallback);
		    if (actualName != NULL) {
			faceName = actualName;
			goto found;
		    }
		}
	    }
	}
    }

  found:
    ReleaseDC(hwnd, hdc);

    hFont = GetScreenFont(faPtr, faceName,
	    TkFontGetPixels(tkwin, faPtr->size), 0.0);
    if (tkFontPtr == NULL) {
	fontPtr = ckalloc(sizeof(WinFont));
    } else {
	fontPtr = (WinFont *) tkFontPtr;
	ReleaseFont(fontPtr);
    }
    InitFont(tkwin, hFont, faPtr->overstrike, fontPtr);

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

    fontPtr = (WinFont *) tkFontPtr;
    ReleaseFont(fontPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpGetFontFamilies, WinFontFamilyEnumProc --
 *
 *	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(
    Tcl_Interp *interp,		/* Interp to hold result. */
    Tk_Window tkwin)		/* For display to query. */
{
    HDC hdc;
    HWND hwnd;
    Window window;
    Tcl_Obj *resultObj;

    window = Tk_WindowId(tkwin);
    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
    hdc = GetDC(hwnd);
    resultObj = Tcl_NewObj();

    /*
     * On any version NT, there may fonts with international names. Use the
     * NT-only Unicode version of EnumFontFamilies to get the font names. If
     * we used the ANSI version on a non-internationalized version of NT, we
     * would get font names with '?' replacing all the international
     * characters.
     *
     * On a non-internationalized verson of 95, fonts with international names
     * are not allowed, so the ANSI version of EnumFontFamilies will work. On
     * an internationalized version of 95, there may be fonts with
     * international names; the ANSI version will work, fetching the name in
     * the system code page. Can't use the Unicode version of EnumFontFamilies
     * because it only exists under NT.
     */

    EnumFontFamilies(hdc, NULL, (FONTENUMPROC) WinFontFamilyEnumProc,
	    (LPARAM) resultObj);
    ReleaseDC(hwnd, hdc);
    Tcl_SetObjResult(interp, resultObj);
}

static int CALLBACK
WinFontFamilyEnumProc(
    ENUMLOGFONT *lfPtr,		/* Logical-font data. */
    NEWTEXTMETRIC *tmPtr,	/* Physical-font data (not used). */
    int fontType,		/* Type of font (not used). */
    LPARAM lParam)		/* Result object to hold result. */
{
    char *faceName = (char *) lfPtr->elfLogFont.lfFaceName;
    Tcl_Obj *resultObj = (Tcl_Obj *) lParam;
    Tcl_DString faceString;

    Tcl_ExternalToUtfDString(systemEncoding, faceName, -1, &faceString);
    Tcl_ListObjAppendElement(NULL, resultObj, Tcl_NewStringObj(
	    Tcl_DStringValue(&faceString), Tcl_DStringLength(&faceString)));
    Tcl_DStringFree(&faceString);
    return 1;
}

/*
 *-------------------------------------------------------------------------
 *
 * 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(
    Tcl_Interp *interp,		/* Interp to hold result. */
    Tk_Font tkfont)		/* Font object to query. */
{
    int i;
    WinFont *fontPtr;
    FontFamily *familyPtr;
    Tcl_Obj *resultPtr, *strPtr;

    resultPtr = Tcl_NewObj();
    fontPtr = (WinFont *) tkfont;
    for (i = 0; i < fontPtr->numSubFonts; i++) {
	familyPtr = fontPtr->subFontArray[i].familyPtr;
	strPtr = Tcl_NewStringObj(familyPtr->faceName, -1);
	Tcl_ListObjAppendElement(NULL, resultPtr, strPtr);
    }
    Tcl_SetObjResult(interp, resultPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TkpGetFontAttrsForChar --
 *
 *	Retrieve the font attributes of the actual font used to render a given
 *	character.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The font attributes are stored in *faPtr.
 *
 *----------------------------------------------------------------------
 */

void
TkpGetFontAttrsForChar(
    Tk_Window tkwin,		/* Window on the font's display */
    Tk_Font tkfont,		/* Font to query */
    int c,         		/* Character of interest */
    TkFontAttributes *faPtr)	/* Output: Font attributes */
{
    WinFont *fontPtr = (WinFont *) tkfont;
				/* Structure describing the logical font */
    HDC hdc = GetDC(fontPtr->hwnd);
				/* GDI device context */
    SubFont *lastSubFontPtr = &fontPtr->subFontArray[0];
				/* Pointer to subfont array in case
				 * FindSubFontForChar needs to fix up the
				 * memory allocation */
    SubFont *thisSubFontPtr =
	    FindSubFontForChar(fontPtr, c, &lastSubFontPtr);
				/* Pointer to the subfont to use for the given
				 * character */
    FontFamily *familyPtr = thisSubFontPtr->familyPtr;
    HFONT oldfont;		/* Saved font from the device context */
    TEXTMETRIC tm;		/* Font metrics of the selected subfont */

    /*
     * Get the font attributes.
     */

    oldfont = SelectObject(hdc, thisSubFontPtr->hFont0);
    GetTextMetrics(hdc, &tm);
    SelectObject(hdc, oldfont);
    ReleaseDC(fontPtr->hwnd, hdc);
    faPtr->family = familyPtr->faceName;
    faPtr->size = TkFontGetPoints(tkwin,
	    tm.tmInternalLeading - tm.tmHeight);
    faPtr->weight = (tm.tmWeight > FW_MEDIUM) ? TK_FW_BOLD : TK_FW_NORMAL;
    faPtr->slant = tm.tmItalic ? TK_FS_ITALIC : TK_FS_ROMAN;
    faPtr->underline = (tm.tmUnderlined != 0);
    faPtr->overstrike = fontPtr->font.fa.overstrike;
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_MeasureChars --
 *
 *	Determine the number of bytes 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(
    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 fits on this line.
				 * TK_WHOLE_WORDS means stop on a word
				 * boundary, if possible. TK_AT_LEAST_ONE
				 * means return at least one character (or at
				 * least the first partial word in case
				 * TK_WHOLE_WORDS is also set) even if no
				 * characters (words) fit. */
    int *lengthPtr)		/* Filled with x-location just after the
				 * terminating character. */
{
    HDC hdc;
    HFONT oldFont;
    WinFont *fontPtr;
    int curX, moretomeasure;
    int ch;
    SIZE size;
    FontFamily *familyPtr;
    Tcl_DString runString;
    SubFont *thisSubFontPtr, *lastSubFontPtr;
    const char *p, *end, *next = NULL, *start;

    if (numBytes == 0) {
	*lengthPtr = 0;
	return 0;
    }

    fontPtr = (WinFont *) tkfont;

    hdc = GetDC(fontPtr->hwnd);
    lastSubFontPtr = &fontPtr->subFontArray[0];
    oldFont = SelectObject(hdc, lastSubFontPtr->hFont0);

    /*
     * 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.
     */

    moretomeasure = 0;
    curX = 0;
    start = source;
    end = start + numBytes;
    for (p = start; p < end; ) {
	next = p + TkUtfToUniChar(p, &ch);
	thisSubFontPtr = FindSubFontForChar(fontPtr, ch, &lastSubFontPtr);
	if (thisSubFontPtr != lastSubFontPtr) {
	    familyPtr = lastSubFontPtr->familyPtr;
	    Tcl_UtfToExternalDString(familyPtr->encoding, start,
		    (int) (p - start), &runString);
	    size.cx = 0;
	    familyPtr->getTextExtentPoint32Proc(hdc,
		    (TCHAR *)Tcl_DStringValue(&runString),
		    Tcl_DStringLength(&runString) >> familyPtr->isWideFont,
		    &size);
	    Tcl_DStringFree(&runString);
	    if (maxLength >= 0 && (curX+size.cx) > maxLength) {
		moretomeasure = 1;
		break;
	    }
	    curX += size.cx;
	    lastSubFontPtr = thisSubFontPtr;
	    start = p;

	    SelectObject(hdc, lastSubFontPtr->hFont0);
	}
	p = next;
    }

    if (!moretomeasure) {
	/*
	 * We get here if the previous loop was just finished normally,
	 * without a break. Just measure the last run and that's it.
	 */

	familyPtr = lastSubFontPtr->familyPtr;
	Tcl_UtfToExternalDString(familyPtr->encoding, start,
		(int) (p - start), &runString);
	size.cx = 0;
	familyPtr->getTextExtentPoint32Proc(hdc, (TCHAR *) Tcl_DStringValue(&runString),
		Tcl_DStringLength(&runString) >> familyPtr->isWideFont,
		&size);
	Tcl_DStringFree(&runString);
	if (maxLength >= 0 && (curX+size.cx) > maxLength) {
	    moretomeasure = 1;
	} else {
	    curX += size.cx;
	    p = end;
	}
    }

    if (moretomeasure) {
	/*
	 * We get here if the measurement of the last run was over the
	 * maxLength limit. We need to restart this run and do it char by
	 * char, but always in context with the previous text to account for
	 * kerning (especially italics).
	 */

	char buf[16];
	int dstWrote;
	int lastSize = 0;

	familyPtr = lastSubFontPtr->familyPtr;
	Tcl_DStringInit(&runString);
	for (p = start; p < end; ) {
	    next = p + TkUtfToUniChar(p, &ch);
	    Tcl_UtfToExternal(NULL, familyPtr->encoding, p,
		    (int) (next - p), 0, NULL, buf, sizeof(buf), NULL,
		    &dstWrote, NULL);
	    Tcl_DStringAppend(&runString,buf,dstWrote);
	    size.cx = 0;
	    familyPtr->getTextExtentPoint32Proc(hdc,
		    (TCHAR *) Tcl_DStringValue(&runString),
		    Tcl_DStringLength(&runString) >> familyPtr->isWideFont,
		    &size);
	    if ((curX+size.cx) > maxLength) {
		break;
	    }
	    lastSize = size.cx;
	    p = next;
	}
	Tcl_DStringFree(&runString);

	/*
	 * "p" points to the first character that doesn't fit in the desired
	 * span. Look at the flags to figure out whether to include this next
	 * character.
	 */

	if ((p < end) && (((flags & TK_PARTIAL_OK) && (curX != maxLength))
		|| ((p==source) && (flags&TK_AT_LEAST_ONE) && (curX==0)))) {
	    /*
	     * Include the first character that didn't quite fit in the
	     * desired span. The width returned will include the width of that
	     * extra character.
	     */

	    p = next;
	    curX += size.cx;
	} else {
	    curX += lastSize;
	}
    }

    SelectObject(hdc, oldFont);
    ReleaseDC(fontPtr->hwnd, hdc);

    if ((flags & TK_WHOLE_WORDS) && (p < end)) {
	/*
	 * Scan the string for the last word break and than repeat the whole
	 * procedure without the maxLength limit or any flags.
	 */

	const char *lastWordBreak = NULL;
	int ch2;

	end = p;
	p = source;
	ch = ' ';
	while (p < end) {
	    next = p + TkUtfToUniChar(p, &ch2);
	    if ((ch != ' ') && (ch2 == ' ')) {
		lastWordBreak = p;
	    }
	    p = next;
	    ch = ch2;
	}

	if (lastWordBreak != NULL) {
	    return Tk_MeasureChars(tkfont, source, lastWordBreak-source,
		    -1, 0, lengthPtr);
	}
	if (flags & TK_AT_LEAST_ONE) {
	    p = end;
	} else {
	    p = source;
	    curX = 0;
	}
    }

    *lengthPtr = curX;
    return p - source;
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpMeasureCharsInContext --
 *
 *	Determine the number of bytes from the string that will fit in the
 *	given horizontal span. The measurement is done under the assumption
 *	that TkpDrawCharsInContext() will be used to actually display the
 *	characters.
 *
 *	This one is almost the same as Tk_MeasureChars(), but with access to
 *	all the characters on the line for context. On Windows this context
 *	isn't consulted, so we just call Tk_MeasureChars().
 *
 * 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
TkpMeasureCharsInContext(
    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 in all. */
    int rangeStart,		/* Index of first byte to measure. */
    int rangeLength,		/* Length of range to measure in bytes. */
    int maxLength,		/* If >= 0, maxLength specifies the longest
				 * permissible line length; 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. TK_ISOLATE_END means
				 * that the last character should not be
				 * considered in context with the rest of the
				 * string (used for breaking lines). */
    int *lengthPtr)		/* Filled with x-location just after the
				 * terminating character. */
{
    (void) numBytes; /*unused*/
    return Tk_MeasureChars(tkfont, source + rangeStart, rangeLength,
	    maxLength, flags, lengthPtr);
}

/*
 *---------------------------------------------------------------------------
 *
 * Tk_DrawChars --
 *
 *	Draw a string of characters on the screen.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information gets drawn on the screen.
 *
 *---------------------------------------------------------------------------
 */

void
Tk_DrawChars(
    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, int y)		/* Coordinates at which to place origin of
				 * string when drawing. */
{
    HDC dc;
    WinFont *fontPtr;
    TkWinDCState state;

    fontPtr = (WinFont *) gc->font;
    display->request++;

    if (drawable == None) {
	return;
    }

    dc = TkWinGetDrawableDC(display, drawable, &state);

    SetROP2(dc, tkpWinRopModes[gc->function]);

    if ((gc->clip_mask != None) &&
	    ((TkpClipMask *) gc->clip_mask)->type == TKP_CLIP_REGION) {
	SelectClipRgn(dc, (HRGN)((TkpClipMask *)gc->clip_mask)->value.region);
    }

    if ((gc->fill_style == FillStippled
	    || gc->fill_style == FillOpaqueStippled)
	    && gc->stipple != None) {
	TkWinDrawable *twdPtr = (TkWinDrawable *) gc->stipple;
	HBRUSH oldBrush, stipple;
	HBITMAP oldBitmap, bitmap;
	HDC dcMem;
	TEXTMETRIC tm;
	SIZE size;

	if (twdPtr->type != TWD_BITMAP) {
	    Tcl_Panic("unexpected drawable type in stipple");
	}

	/*
	 * Select stipple pattern into destination dc.
	 */

	dcMem = CreateCompatibleDC(dc);

	stipple = CreatePatternBrush(twdPtr->bitmap.handle);
	SetBrushOrgEx(dc, gc->ts_x_origin, gc->ts_y_origin, NULL);
	oldBrush = SelectObject(dc, stipple);

	SetTextAlign(dcMem, TA_LEFT | TA_BASELINE);
	SetTextColor(dcMem, gc->foreground);
	SetBkMode(dcMem, TRANSPARENT);
	SetBkColor(dcMem, RGB(0, 0, 0));

	/*
	 * Compute the bounding box and create a compatible bitmap.
	 */

	GetTextExtentPointA(dcMem, source, numBytes, &size);
	GetTextMetrics(dcMem, &tm);
	size.cx -= tm.tmOverhang;
	bitmap = CreateCompatibleBitmap(dc, size.cx, size.cy);
	oldBitmap = SelectObject(dcMem, bitmap);

	/*
	 * The following code is tricky because fonts are rendered in multiple
	 * colors. First we draw onto a black background and copy the white
	 * bits. Then we draw onto a white background and copy the black bits.
	 * Both the foreground and background bits of the font are ANDed with
	 * the stipple pattern as they are copied.
	 */

	PatBlt(dcMem, 0, 0, size.cx, size.cy, BLACKNESS);
	MultiFontTextOut(dc, fontPtr, source, numBytes, x, y, 0.0);
	BitBlt(dc, x, y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0xEA02E9);
	PatBlt(dcMem, 0, 0, size.cx, size.cy, WHITENESS);
	MultiFontTextOut(dc, fontPtr, source, numBytes, x, y, 0.0);
	BitBlt(dc, x, y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0x8A0E06);

	/*
	 * Destroy the temporary bitmap and restore the device context.
	 */

	SelectObject(dcMem, oldBitmap);
	DeleteObject(bitmap);
	DeleteDC(dcMem);
	SelectObject(dc, oldBrush);
	DeleteObject(stipple);
    } else if (gc->function == GXcopy) {
	SetTextAlign(dc, TA_LEFT | TA_BASELINE);
	SetTextColor(dc, gc->foreground);
	SetBkMode(dc, TRANSPARENT);
	MultiFontTextOut(dc, fontPtr, source, numBytes, x, y, 0.0);
    } else {
	HBITMAP oldBitmap, bitmap;
	HDC dcMem;
	TEXTMETRIC tm;
	SIZE size;

	dcMem = CreateCompatibleDC(dc);

	SetTextAlign(dcMem, TA_LEFT | TA_BASELINE);
	SetTextColor(dcMem, gc->foreground);
	SetBkMode(dcMem, TRANSPARENT);
	SetBkColor(dcMem, RGB(0, 0, 0));

	/*
	 * Compute the bounding box and create a compatible bitmap.
	 */

	GetTextExtentPointA(dcMem, source, numBytes, &size);
	GetTextMetrics(dcMem, &tm);
	size.cx -= tm.tmOverhang;
	bitmap = CreateCompatibleBitmap(dc, size.cx, size.cy);
	oldBitmap = SelectObject(dcMem, bitmap);

	MultiFontTextOut(dcMem, fontPtr, source, numBytes, 0, tm.tmAscent,
		0.0);
	BitBlt(dc, x, y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, (DWORD) tkpWinBltModes[gc->function]);

	/*
	 * Destroy the temporary bitmap and restore the device context.
	 */

	SelectObject(dcMem, oldBitmap);
	DeleteObject(bitmap);
	DeleteDC(dcMem);
    }
    TkWinReleaseDrawableDC(drawable, dc, &state);
}

void
TkDrawAngledChars(
    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. */
    double x, double y,		/* Coordinates at which to place origin of
				 * string when drawing. */
    double angle)
{
    HDC dc;
    WinFont *fontPtr;
    TkWinDCState state;

    fontPtr = (WinFont *) gc->font;
    display->request++;

    if (drawable == None) {
	return;
    }

    dc = TkWinGetDrawableDC(display, drawable, &state);

    SetROP2(dc, tkpWinRopModes[gc->function]);

    if ((gc->clip_mask != None) &&
	    ((TkpClipMask *) gc->clip_mask)->type == TKP_CLIP_REGION) {
	SelectClipRgn(dc, (HRGN)((TkpClipMask *)gc->clip_mask)->value.region);
    }

    if ((gc->fill_style == FillStippled
	    || gc->fill_style == FillOpaqueStippled)
	    && gc->stipple != None) {
	TkWinDrawable *twdPtr = (TkWinDrawable *)gc->stipple;
	HBRUSH oldBrush, stipple;
	HBITMAP oldBitmap, bitmap;
	HDC dcMem;
	TEXTMETRIC tm;
	SIZE size;

	if (twdPtr->type != TWD_BITMAP) {
	    Tcl_Panic("unexpected drawable type in stipple");
	}

	/*
	 * Select stipple pattern into destination dc.
	 */

	dcMem = CreateCompatibleDC(dc);

	stipple = CreatePatternBrush(twdPtr->bitmap.handle);
	SetBrushOrgEx(dc, gc->ts_x_origin, gc->ts_y_origin, NULL);
	oldBrush = SelectObject(dc, stipple);

	SetTextAlign(dcMem, TA_LEFT | TA_BASELINE);
	SetTextColor(dcMem, gc->foreground);
	SetBkMode(dcMem, TRANSPARENT);
	SetBkColor(dcMem, RGB(0, 0, 0));

	/*
	 * Compute the bounding box and create a compatible bitmap.
	 */

	GetTextExtentPointA(dcMem, source, numBytes, &size);
	GetTextMetrics(dcMem, &tm);
	size.cx -= tm.tmOverhang;
	bitmap = CreateCompatibleBitmap(dc, size.cx, size.cy);
	oldBitmap = SelectObject(dcMem, bitmap);

	/*
	 * The following code is tricky because fonts are rendered in multiple
	 * colors. First we draw onto a black background and copy the white
	 * bits. Then we draw onto a white background and copy the black bits.
	 * Both the foreground and background bits of the font are ANDed with
	 * the stipple pattern as they are copied.
	 */

	PatBlt(dcMem, 0, 0, size.cx, size.cy, BLACKNESS);
	MultiFontTextOut(dc, fontPtr, source, numBytes, (int)x, (int)y, angle);
	BitBlt(dc, (int)x, (int)y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0xEA02E9);
	PatBlt(dcMem, 0, 0, size.cx, size.cy, WHITENESS);
	MultiFontTextOut(dc, fontPtr, source, numBytes, (int)x, (int)y, angle);
	BitBlt(dc, (int)x, (int)y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, 0x8A0E06);

	/*
	 * Destroy the temporary bitmap and restore the device context.
	 */

	SelectObject(dcMem, oldBitmap);
	DeleteObject(bitmap);
	DeleteDC(dcMem);
	SelectObject(dc, oldBrush);
	DeleteObject(stipple);
    } else if (gc->function == GXcopy) {
	SetTextAlign(dc, TA_LEFT | TA_BASELINE);
	SetTextColor(dc, gc->foreground);
	SetBkMode(dc, TRANSPARENT);
	MultiFontTextOut(dc, fontPtr, source, numBytes, (int)x, (int)y, angle);
    } else {
	HBITMAP oldBitmap, bitmap;
	HDC dcMem;
	TEXTMETRIC tm;
	SIZE size;

	dcMem = CreateCompatibleDC(dc);

	SetTextAlign(dcMem, TA_LEFT | TA_BASELINE);
	SetTextColor(dcMem, gc->foreground);
	SetBkMode(dcMem, TRANSPARENT);
	SetBkColor(dcMem, RGB(0, 0, 0));

	/*
	 * Compute the bounding box and create a compatible bitmap.
	 */

	GetTextExtentPointA(dcMem, source, numBytes, &size);
	GetTextMetrics(dcMem, &tm);
	size.cx -= tm.tmOverhang;
	bitmap = CreateCompatibleBitmap(dc, size.cx, size.cy);
	oldBitmap = SelectObject(dcMem, bitmap);

	MultiFontTextOut(dcMem, fontPtr, source, numBytes, 0, tm.tmAscent,
		angle);
	BitBlt(dc, (int)x, (int)y - tm.tmAscent, size.cx, size.cy, dcMem,
		0, 0, (DWORD) tkpWinBltModes[gc->function]);

	/*
	 * Destroy the temporary bitmap and restore the device context.
	 */

	SelectObject(dcMem, oldBitmap);
	DeleteObject(bitmap);
	DeleteDC(dcMem);
    }
    TkWinReleaseDrawableDC(drawable, dc, &state);
}

/*
 *---------------------------------------------------------------------------
 *
 * TkpDrawCharsInContext --
 *
 *	Draw a string of characters on the screen like Tk_DrawChars(), but
 *	with access to all the characters on the line for context. On Windows
 *	this context isn't consulted, so we just call Tk_DrawChars().
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information gets drawn on the screen.
 *
 *---------------------------------------------------------------------------
 */

void
TkpDrawCharsInContext(
    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 rangeStart,		/* Index of first byte to draw. */
    int rangeLength,		/* Length of range to draw in bytes. */
    int x, int y)		/* Coordinates at which to place origin of the
				 * whole (not just the range) string when
				 * drawing. */
{
    int widthUntilStart;

    (void) numBytes; /*unused*/

    Tk_MeasureChars(tkfont, source, rangeStart, -1, 0, &widthUntilStart);
    Tk_DrawChars(display, drawable, gc, tkfont, source + rangeStart,
	    rangeLength, x+widthUntilStart, y);
}

/*
 *-------------------------------------------------------------------------
 *
 * MultiFontTextOut --
 *
 *	Helper function for Tk_DrawChars. Draws characters, using the various
 *	screen fonts in fontPtr to draw multilingual characters. Note: No
 *	bidirectional support.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Information gets drawn on the screen. Contents of fontPtr may be
 *	modified if more subfonts were loaded in order to draw all the
 *	multilingual characters in the given string.
 *
 *-------------------------------------------------------------------------
 */

static void
MultiFontTextOut(
    HDC hdc,			/* HDC to draw into. */
    WinFont *fontPtr,		/* Contains set of fonts to use when drawing
				 * following string. */
    const char *source,		/* Potentially multilingual UTF-8 string. */
    int numBytes,		/* Length of string in bytes. */
    int x, int y,		/* Coordinates at which to place origin of
				 * string when drawing. */
    double angle)
{
    int ch;
    SIZE size;
    HFONT oldFont;
    FontFamily *familyPtr;
    Tcl_DString runString;
    const char *p, *end, *next;
    SubFont *lastSubFontPtr, *thisSubFontPtr;
    TEXTMETRIC tm;

    lastSubFontPtr = &fontPtr->subFontArray[0];
    oldFont = SelectFont(hdc, fontPtr, lastSubFontPtr, angle);
    GetTextMetrics(hdc, &tm);

    end = source + numBytes;
    for (p = source; p < end; ) {
	next = p + TkUtfToUniChar(p, &ch);
	thisSubFontPtr = FindSubFontForChar(fontPtr, ch, &lastSubFontPtr);

	/*
	 * The drawing API has a limit of 32767 pixels in one go.
	 * To avoid spending time on a rare case we do not measure each char,
	 * instead we limit to drawing chunks of 200 bytes since that works
	 * well in practice.
	 */

	if ((thisSubFontPtr != lastSubFontPtr) || (p-source > 200)) {
	    if (p > source) {
		familyPtr = lastSubFontPtr->familyPtr;
 		Tcl_UtfToExternalDString(familyPtr->encoding, source,
			(int) (p - source), &runString);
		familyPtr->textOutProc(hdc, x-(tm.tmOverhang/2), y,
			(TCHAR *)Tcl_DStringValue(&runString),
			Tcl_DStringLength(&runString)>>familyPtr->isWideFont);
		familyPtr->getTextExtentPoint32Proc(hdc,
			(TCHAR *)Tcl_DStringValue(&runString),
			Tcl_DStringLength(&runString) >> familyPtr->isWideFont,
			&size);
		x += size.cx;
		Tcl_DStringFree(&runString);
	    }
	    lastSubFontPtr = thisSubFontPtr;
	    source = p;
	    SelectFont(hdc, fontPtr, lastSubFontPtr, angle);
	    GetTextMetrics(hdc, &tm);
	}
	p = next;
    }
    if (p > source) {
	familyPtr = lastSubFontPtr->familyPtr;
 	Tcl_UtfToExternalDString(familyPtr->encoding, source,
		(int) (p - source), &runString);
	familyPtr->textOutProc(hdc, x-(tm.tmOverhang/2), y,
		(TCHAR *)Tcl_DStringValue(&runString),
		Tcl_DStringLength(&runString) >> familyPtr->isWideFont);
	Tcl_DStringFree(&runString);
    }
    SelectObject(hdc, oldFont);
}

static inline HFONT
SelectFont(
    HDC hdc,
    WinFont *fontPtr,
    SubFont *subFontPtr,
    double angle)
{
    if (angle == 0.0) {
	return SelectObject(hdc, subFontPtr->hFont0);
    } else if (angle == subFontPtr->angle) {
	return SelectObject(hdc, subFontPtr->hFontAngled);
    } else {
	if (subFontPtr->hFontAngled) {
	    DeleteObject(subFontPtr->hFontAngled);
	}
	subFontPtr->hFontAngled = GetScreenFont(&fontPtr->font.fa,
		subFontPtr->familyPtr->faceName, fontPtr->pixelSize, angle);
	if (subFontPtr->hFontAngled == NULL) {
	    return SelectObject(hdc, subFontPtr->hFont0);
	}
	subFontPtr->angle = angle;
	return SelectObject(hdc, subFontPtr->hFontAngled);
    }
}

/*
 *---------------------------------------------------------------------------
 *
 * InitFont --
 *
 *	Helper for TkpGetNativeFont() and TkpGetFontFromAttributes().
 *	Initializes the memory for a new WinFont that wraps the
 *	platform-specific data.
 *
 *	The caller is responsible for initializing the fields of the WinFont
 *	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(
    Tk_Window tkwin,		/* Main window of interp in which font will be
				 * used, for getting HDC. */
    HFONT hFont,		/* Windows token for font. */
    int overstrike,		/* The overstrike attribute of logfont used to
				 * allocate this font. For some reason, the
				 * TEXTMETRICs may contain incorrect info in
				 * the tmStruckOut field. */
    WinFont *fontPtr)		/* Filled with information constructed from
				 * the above arguments. */
{
    HDC hdc;
    HWND hwnd;
    HFONT oldFont;
    TEXTMETRIC tm;
    Window window;
    TkFontMetrics *fmPtr;
    Tcl_Encoding encoding;
    Tcl_DString faceString;
    TkFontAttributes *faPtr;
    TCHAR buf[LF_FACESIZE];

    window = Tk_WindowId(tkwin);
    hwnd = (window == None) ? NULL : TkWinGetHWND(window);
    hdc = GetDC(hwnd);
    oldFont = SelectObject(hdc, hFont);

    GetTextMetrics(hdc, &tm);

    /*
     * On any version NT, there may fonts with international names. Use the
     * NT-only Unicode version of GetTextFace to get the font's name. If we
     * used the ANSI version on a non-internationalized version of NT, we
     * would get a font name with '?' replacing all the international
     * characters.
     *
     * On a non-internationalized verson of 95, fonts with international names
     * are not allowed, so the ANSI version of GetTextFace will work. On an
     * internationalized version of 95, there may be fonts with international
     * names; the ANSI version will work, fetching the name in the
     * international system code page. Can't use the Unicode version of
     * GetTextFace because it only exists under NT.
     */

    GetTextFace(hdc, LF_FACESIZE, buf);
    Tcl_ExternalToUtfDString(systemEncoding, (char *) buf, -1, &faceString);

    fontPtr->font.fid	= (Font) fontPtr;
    fontPtr->hwnd	= hwnd;
    fontPtr->pixelSize	= tm.tmHeight - tm.tmInternalLeading;

    faPtr		= &fontPtr->font.fa;
    faPtr->family	= Tk_GetUid(Tcl_DStringValue(&faceString));

    faPtr->size =
	TkFontGetPoints(tkwin,  -(fontPtr->pixelSize));
    faPtr->weight =
	    (tm.tmWeight > FW_MEDIUM) ? TK_FW_BOLD : TK_FW_NORMAL;
    faPtr->slant	= (tm.tmItalic != 0) ? TK_FS_ITALIC : TK_FS_ROMAN;
    faPtr->underline	= (tm.tmUnderlined != 0) ? 1 : 0;
    faPtr->overstrike	= overstrike;

    fmPtr		= &fontPtr->font.fm;
    fmPtr->ascent	= tm.tmAscent;
    fmPtr->descent	= tm.tmDescent;
    fmPtr->maxWidth	= tm.tmMaxCharWidth;
    fmPtr->fixed	= !(tm.tmPitchAndFamily & TMPF_FIXED_PITCH);

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

    encoding = fontPtr->subFontArray[0].familyPtr->encoding;
    if (encoding == TkWinGetUnicodeEncoding()) {
	GetCharWidth(hdc, 0, BASE_CHARS - 1, fontPtr->widths);
    } else {
	GetCharWidthA(hdc, 0, BASE_CHARS - 1, fontPtr->widths);
    }
    Tcl_DStringFree(&faceString);

    SelectObject(hdc, oldFont);
    ReleaseDC(hwnd, hdc);
}

/*
 *-------------------------------------------------------------------------
 *
 * ReleaseFont --
 *
 *	Called to release the windows-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(
    WinFont *fontPtr)		/* The font to delete. */
{
    int i;

    for (i = 0; i < fontPtr->numSubFonts; i++) {
	ReleaseSubFont(&fontPtr->subFontArray[i]);
    }
    if (fontPtr->subFontArray != fontPtr->staticSubFonts) {
	ckfree(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 inline void
InitSubFont(
    HDC hdc,			/* HDC in which font can be selected. */
    HFONT hFont,		/* 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->hFont0	    = hFont;
    subFontPtr->familyPtr   = AllocFontFamily(hdc, hFont, base);
    subFontPtr->fontMap	    = subFontPtr->familyPtr->fontMap;
    subFontPtr->hFontAngled = NULL;
    subFontPtr->angle	    = 0.0;
}

/*
 *-------------------------------------------------------------------------
 *
 * 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 inline void
ReleaseSubFont(
    SubFont *subFontPtr)	/* The SubFont to delete. */
{
    DeleteObject(subFontPtr->hFont0);
    if (subFontPtr->hFontAngled) {
	DeleteObject(subFontPtr->hFontAngled);
    }
    FreeFontFamily(subFontPtr->familyPtr);
}

/*
 *-------------------------------------------------------------------------
 *
 * AllocFontFamily --
 *
 *	Find the FontFamily structure associated with the given font name. The
 *	information should be stored by the caller in a SubFont and used when
 *	determining if that SubFont supports a character.
 *
 *	Cannot use the string name used to construct the font as the key,
 *	because the capitalization may not be canonical. Therefore use the
 *	face name actually retrieved from the font metrics as the key.
 *
 * Results:
 *	A pointer to a FontFamily. The reference count in the FontFamily is
 *	automatically incremented. When the SubFont is released, the reference
 *	count is decremented. When no SubFont is using this FontFamily, it may
 *	be deleted.
 *
 * Side effects:
 *	A new FontFamily structure will be allocated if this font family has
 *	not been seen. TrueType character existence metrics are loaded into
 *	the FontFamily structure.
 *
 *-------------------------------------------------------------------------
 */

static FontFamily *
AllocFontFamily(
    HDC hdc,			/* HDC in which font can be selected. */
    HFONT hFont,		/* 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. */
{
    Tk_Uid faceName;
    FontFamily *familyPtr;
    Tcl_DString faceString;
    Tcl_Encoding encoding;
    TCHAR buf[LF_FACESIZE];
    ThreadSpecificData *tsdPtr =
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    hFont = SelectObject(hdc, hFont);
    GetTextFace(hdc, LF_FACESIZE, buf);
    Tcl_ExternalToUtfDString(systemEncoding, (char *) buf, -1, &faceString);
    faceName = Tk_GetUid(Tcl_DStringValue(&faceString));
    Tcl_DStringFree(&faceString);
    hFont = SelectObject(hdc, hFont);

    familyPtr = tsdPtr->fontFamilyList;
    for ( ; familyPtr != NULL; familyPtr = familyPtr->nextPtr) {
	if (familyPtr->faceName == faceName) {
	    familyPtr->refCount++;
	    return familyPtr;
	}
    }

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

    /*
     * Set key for this FontFamily.
     */

    familyPtr->faceName = faceName;

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

    familyPtr->refCount = 2;

    familyPtr->segCount = LoadFontRanges(hdc, hFont, &familyPtr->startCount,
	    &familyPtr->endCount, &familyPtr->isSymbolFont);

    encoding = NULL;
    if (familyPtr->isSymbolFont != 0) {
	/*
	 * Symbol fonts are handled specially. For instance, Unicode 0393
	 * (GREEK CAPITAL GAMMA) must be mapped to Symbol character 0047
	 * (GREEK CAPITAL GAMMA), because the Symbol font doesn't have a GREEK
	 * CAPITAL GAMMA at location 0393. If Tk interpreted the Symbol font
	 * using the Unicode encoding, it would decide that the Symbol font
	 * has no GREEK CAPITAL GAMMA, because the Symbol encoding (of course)
	 * reports that character 0393 doesn't exist.
	 *
	 * With non-symbol Windows fonts, such as Times New Roman, if the font
	 * has a GREEK CAPITAL GAMMA, it will be found in the correct Unicode
	 * location (0393); the GREEK CAPITAL GAMMA will not be off hiding at
	 * some other location.
	 */

	encoding = Tcl_GetEncoding(NULL, faceName);
    }

    if (encoding == NULL) {
	encoding = Tcl_GetEncoding(NULL, "unicode");
	familyPtr->textOutProc =
	    (BOOL (WINAPI *)(HDC, int, int, TCHAR *, int)) TextOutW;
	familyPtr->getTextExtentPoint32Proc =
	    (BOOL (WINAPI *)(HDC, TCHAR *, int, LPSIZE)) GetTextExtentPoint32W;
	familyPtr->isWideFont = 1;
    } else {
	familyPtr->textOutProc =
	    (BOOL (WINAPI *)(HDC, int, int, TCHAR *, int)) TextOutA;
	familyPtr->getTextExtentPoint32Proc =
	    (BOOL (WINAPI *)(HDC, TCHAR *, int, LPSIZE)) GetTextExtentPoint32A;
	familyPtr->isWideFont = 0;
    }

    familyPtr->encoding = encoding;

    return familyPtr;
}

/*
 *-------------------------------------------------------------------------
 *
 * FreeFontFamily --
 *
 *	Called to free a 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(
    FontFamily *familyPtr)	/* The FontFamily to delete. */
{
    int i;
    FontFamily **familyPtrPtr;
    ThreadSpecificData *tsdPtr =
	    Tcl_GetThreadData(&dataKey, sizeof(ThreadSpecificData));

    if (familyPtr == NULL) {
	return;
    }
    if (familyPtr->refCount-- > 1) {
    	return;
    }
    for (i = 0; i < FONTMAP_PAGES; i++) {
	if (familyPtr->fontMap[i] != NULL) {
	    ckfree(familyPtr->fontMap[i]);
	}
    }
    if (familyPtr->startCount != NULL) {
	ckfree(familyPtr->startCount);
    }
    if (familyPtr->endCount != NULL) {
	ckfree(familyPtr->endCount);
    }
    if (familyPtr->encoding != TkWinGetUnicodeEncoding()) {
	Tcl_FreeEncoding(familyPtr->encoding);
    }

    /*
     * Delete from list.
     */

    for (familyPtrPtr = &tsdPtr->fontFamilyList; ; ) {
	if (*familyPtrPtr == familyPtr) {
	    *familyPtrPtr = familyPtr->nextPtr;
	    break;
	}
	familyPtrPtr = &(*familyPtrPtr)->nextPtr;
    }

    ckfree(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.
 *
 *-------------------------------------------------------------------------
 */

static SubFont *
FindSubFontForChar(
    WinFont *fontPtr,		/* The font object with which the character
				 * will be displayed. */
    int ch,			/* The Unicode character to be displayed. */
    SubFont **subFontPtrPtr)	/* Pointer to var to be fixed up if we
				 * reallocate the subfont table. */
{
    HDC hdc;
    int i, j, k;
    CanUse canUse;
    const char *const *aliases;
    const char *const *anyFallbacks;
    const char *const *const *fontFallbacks;
    const char *fallbackName;
    SubFont *subFontPtr;
    Tcl_DString ds;


    if ((ch < BASE_CHARS) || (ch >= 0x10000)) {
	return &fontPtr->subFontArray[0];
    }

    for (i = 0; i < fontPtr->numSubFonts; i++) {
	if (FontMapLookup(&fontPtr->subFontArray[i], ch)) {
	    return &fontPtr->subFontArray[i];
	}
    }

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

    Tcl_DStringInit(&ds);
    hdc = GetDC(fontPtr->hwnd);

    aliases = TkFontGetAliasList(fontPtr->font.fa.family);

    fontFallbacks = TkFontGetFallbacks();
    for (i = 0; fontFallbacks[i] != NULL; i++) {
	for (j = 0; fontFallbacks[i][j] != NULL; j++) {
	    fallbackName = fontFallbacks[i][j];
	    if (strcasecmp(fallbackName, fontPtr->font.fa.family) == 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(aliases[k], fallbackName) == 0) {
			goto tryfallbacks;
		    }
		}
	    }
	}
	continue;

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

    tryfallbacks:
	for (j = 0; fontFallbacks[i][j] != NULL; j++) {
	    fallbackName = fontFallbacks[i][j];
	    subFontPtr = CanUseFallbackWithAliases(hdc, fontPtr, fallbackName,
		    ch, &ds, subFontPtrPtr);
	    if (subFontPtr != NULL) {
		goto end;
	    }
	}
    }

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

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

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

    canUse.hdc = hdc;
    canUse.fontPtr = fontPtr;
    canUse.nameTriedPtr = &ds;
    canUse.ch = ch;
    canUse.subFontPtr = NULL;
    canUse.subFontPtrPtr = subFontPtrPtr;
    EnumFontFamilies(hdc, NULL, (FONTENUMPROC) WinFontCanUseProc,
	    (LPARAM) &canUse);
    subFontPtr = canUse.subFontPtr;

  end:
    Tcl_DStringFree(&ds);

    if (subFontPtr == NULL) {
	/*
	 * No font can display this character. We will use the base font and
	 * have it display the "unknown" character.
	 */

	subFontPtr = &fontPtr->subFontArray[0];
	FontMapInsert(subFontPtr, ch);
    }
    ReleaseDC(fontPtr->hwnd, hdc);
    return subFontPtr;
}

static int CALLBACK
WinFontCanUseProc(
    ENUMLOGFONT *lfPtr,		/* Logical-font data. */
    NEWTEXTMETRIC *tmPtr,	/* Physical-font data (not used). */
    int fontType,		/* Type of font (not used). */
    LPARAM lParam)		/* Result object to hold result. */
{
    int ch;
    HDC hdc;
    WinFont *fontPtr;
    CanUse *canUsePtr;
    char *fallbackName;
    SubFont *subFontPtr;
    Tcl_DString faceString;
    Tcl_DString *nameTriedPtr;

    canUsePtr	    = (CanUse *) lParam;
    ch		    = canUsePtr->ch;
    hdc		    = canUsePtr->hdc;
    fontPtr	    = canUsePtr->fontPtr;
    nameTriedPtr    = canUsePtr->nameTriedPtr;

    fallbackName = (char *) lfPtr->elfLogFont.lfFaceName;
    Tcl_ExternalToUtfDString(systemEncoding, fallbackName, -1, &faceString);
    fallbackName = Tcl_DStringValue(&faceString);

    if (SeenName(fallbackName, nameTriedPtr) == 0) {
	subFontPtr = CanUseFallback(hdc, fontPtr, fallbackName, ch,
		canUsePtr->subFontPtrPtr);
	if (subFontPtr != NULL) {
	    canUsePtr->subFontPtr = subFontPtr;
	    Tcl_DStringFree(&faceString);
	    return 0;
	}
    }
    Tcl_DStringFree(&faceString);
    return 1;
}

/*
 *-------------------------------------------------------------------------
 *
 * 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(
    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(
    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 HFONT can (1) or cannot (0) display the characters on
 *	the page.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Mempry allocated.
 *
 *-------------------------------------------------------------------------
 */

static void
FontMapLoadPage(
    SubFont *subFontPtr,	/* Contains font mapping cache to be
				 * updated. */
    int row)			/* Index of the page to be loaded into the
				 * cache. */
{
    FontFamily *familyPtr;
    Tcl_Encoding encoding;
    char src[XMaxTransChars], buf[16];
    USHORT *startCount, *endCount;
    int i, j, bitOffset, end, segCount;

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

    familyPtr = subFontPtr->familyPtr;
    encoding = familyPtr->encoding;

    if (familyPtr->encoding == TkWinGetUnicodeEncoding()) {
	/*
	 * Font is Unicode. Few fonts are going to have all characters, so
	 * examine the TrueType character existence metrics to determine what
	 * characters actually exist in this font.
	 */

	segCount    = familyPtr->segCount;
	startCount  = familyPtr->startCount;
	endCount    = familyPtr->endCount;

	j = 0;
	end = (row + 1) << FONTMAP_SHIFT;
	for (i = row << FONTMAP_SHIFT; i < end; i++) {
	    for ( ; j < segCount; j++) {
		if (endCount[j] >= i) {
		    if (startCount[j] <= i) {
			bitOffset = i & (FONTMAP_BITSPERPAGE - 1);
			subFontPtr->fontMap[row][bitOffset >> 3] |=
				1 << (bitOffset & 7);
		    }
		    break;
		}
	    }
	}
    } else if (familyPtr->isSymbolFont) {
	/*
	 * Assume that a symbol font with a known encoding has all the
	 * characters that its encoding claims it supports.
	 *
	 * The test for "encoding == unicodeEncoding" must occur before this
	 * case, to catch all symbol fonts (such as {Comic Sans MS} or
	 * Wingdings) for which we don't have encoding information; those
	 * symbol fonts are treated as if they were in the Unicode encoding
	 * and their symbolic character existence metrics are treated as if
	 * they were Unicode character existence metrics. This way, although
	 * we don't know the proper Unicode -> symbol font mapping, we can
	 * install the symbol font as the base font and access its glyphs.
	 */

	end = (row + 1) << FONTMAP_SHIFT;
	for (i = row << FONTMAP_SHIFT; i < end; i++) {
	    if (Tcl_UtfToExternal(NULL, encoding, src,
		    Tcl_UniCharToUtf(i, src), TCL_ENCODING_STOPONERROR, NULL,
		    buf, sizeof(buf), NULL, NULL, NULL) != TCL_OK) {
		continue;
	    }
	    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.
 *
 *---------------------------------------------------------------------------
 */

static SubFont *
CanUseFallbackWithAliases(
    HDC hdc,			/* HDC in which font can be selected. */
    WinFont *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. */
    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 **subFontPtrPtr)	/* Variable to fixup if we reallocate the
				 * array of subfonts. */
{
    int i;
    const char *const *aliases;
    SubFont *subFontPtr;

    if (SeenName(faceName, nameTriedPtr) == 0) {
	subFontPtr = CanUseFallback(hdc, fontPtr, faceName, ch, subFontPtrPtr);
	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(hdc, fontPtr, aliases[i], ch,
			subFontPtrPtr);
		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(
    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, name, (int) (strlen(name) + 1));
    return 0;
}

/*
 *-------------------------------------------------------------------------
 *
 * CanUseFallback --
 *
 *	If the specified screen font has not already been loaded into the font
 *	object, determine if it 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 font
 *	name. NULL is returned if the font object already holds a reference to
 *	the specified physical font or if the specified physical font cannot
 *	display the given character.
 *
 * Side effects:
 *	The font object's subFontArray is updated to contain a reference to
 *	the newly allocated SubFont.
 *
 *-------------------------------------------------------------------------
 */

static SubFont *
CanUseFallback(
    HDC hdc,			/* HDC in which font can be selected. */
    WinFont *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 **subFontPtrPtr)	/* Variable to fix-up if we realloc the array
				 * of subfonts. */
{
    int i;
    HFONT hFont;
    SubFont subFont;

    if (FamilyExists(hdc, faceName) == 0) {
	return NULL;
    }

    /*
     * Skip all fonts we've already used.
     */

    for (i = 0; i < fontPtr->numSubFonts; i++) {
	if (faceName == fontPtr->subFontArray[i].familyPtr->faceName) {
	    return NULL;
	}
    }

    /*
     * Load this font and see if it has the desired character.
     */

    hFont = GetScreenFont(&fontPtr->font.fa, faceName, fontPtr->pixelSize,
	    0.0);
    InitSubFont(hdc, hFont, 0, &subFont);
    if (((ch < 256) && (subFont.familyPtr->isSymbolFont))
	    || (FontMapLookup(&subFont, ch) == 0)) {
	/*
	 * Don't use a symbol font as a fallback font for characters below
	 * 256.
	 */

	ReleaseSubFont(&subFont);
	return NULL;
    }

    if (fontPtr->numSubFonts >= SUBFONT_SPACE) {
	SubFont *newPtr;

    	newPtr = ckalloc(sizeof(SubFont) * (fontPtr->numSubFonts + 1));
	memcpy(newPtr, fontPtr->subFontArray,
		fontPtr->numSubFonts * sizeof(SubFont));
	if (fontPtr->subFontArray != fontPtr->staticSubFonts) {
	    ckfree(fontPtr->subFontArray);
	}

	/*
	 * Fix up the variable pointed to by subFontPtrPtr so it still points
	 * into the live array. [Bug 618872]
	 */

	*subFontPtrPtr = newPtr + (*subFontPtrPtr - fontPtr->subFontArray);
	fontPtr->subFontArray = newPtr;
    }
    fontPtr->subFontArray[fontPtr->numSubFonts] = subFont;
    fontPtr->numSubFonts++;
    return &fontPtr->subFontArray[fontPtr->numSubFonts - 1];
}

/*
 *---------------------------------------------------------------------------
 *
 * GetScreenFont --
 *
 *	Given the name and other attributes, construct an HFONT. This is where
 *	all the alias and fallback substitution bottoms out.
 *
 * Results:
 *	The screen font that corresponds to the attributes.
 *
 * Side effects:
 *	None.
 *
 *---------------------------------------------------------------------------
 */

static HFONT
GetScreenFont(
    const TkFontAttributes *faPtr,
				/* Desired font attributes for new HFONT. */
    const char *faceName,	/* Overrides font family specified in font
				 * attributes. */
    int pixelSize,		/* Overrides size specified in font
				 * attributes. */
    double angle)		/* What is the desired orientation of the
				 * font. */
{
    Tcl_DString ds;
    HFONT hFont;
    LOGFONT lf;

    memset(&lf, 0, sizeof(lf));
    lf.lfHeight		= -pixelSize;
    lf.lfWidth		= 0;
    lf.lfEscapement	= ROUND16(angle * 10);
    lf.lfOrientation	= ROUND16(angle * 10);
    lf.lfWeight = (faPtr->weight == TK_FW_NORMAL) ? FW_NORMAL : FW_BOLD;
    lf.lfItalic		= faPtr->slant;
    lf.lfUnderline	= faPtr->underline;
    lf.lfStrikeOut	= faPtr->overstrike;
    lf.lfCharSet	= DEFAULT_CHARSET;
    lf.lfOutPrecision	= OUT_TT_PRECIS;
    lf.lfClipPrecision	= CLIP_DEFAULT_PRECIS;
    lf.lfQuality	= DEFAULT_QUALITY;
    lf.lfPitchAndFamily = DEFAULT_PITCH | FF_DONTCARE;

    Tcl_UtfToExternalDString(systemEncoding, faceName, -1, &ds);
    _tcsncpy(lf.lfFaceName, (TCHAR *)Tcl_DStringValue(&ds), LF_FACESIZE-1);
    Tcl_DStringFree(&ds);
    lf.lfFaceName[LF_FACESIZE-1] = 0;
    hFont = CreateFontIndirect(&lf);
    return hFont;
}

/*
 *-------------------------------------------------------------------------
 *
 * FamilyExists, FamilyOrAliasExists, WinFontExistsProc --
 *
 *	Determines if any physical screen font exists on the system with the
 *	given family name. If the family exists, then it should be possible to
 *	construct some physical screen font with that family name.
 *
 * Results:
 *	The return value is 0 if the specified font family does not exist,
 *	non-zero otherwise.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int
FamilyExists(
    HDC hdc,			/* HDC in which font family will be used. */
    const char *faceName)	/* Font family to query. */
{
    int result;
    Tcl_DString faceString;

    /*
     * Just immediately rule out the following fonts, because they look so
     * ugly on windows. The caller's fallback mechanism will cause the
     * corresponding appropriate TrueType fonts to be selected.
     */

    if (strcasecmp(faceName, "Courier") == 0) {
	return 0;
    }
    if (strcasecmp(faceName, "Times") == 0) {
	return 0;
    }
    if (strcasecmp(faceName, "Helvetica") == 0) {
	return 0;
    }

    Tcl_UtfToExternalDString(systemEncoding, faceName, -1, &faceString);

    /*
     * If the family exists, WinFontExistProc() will be called and
     * EnumFontFamilies() will return whatever WinFontExistProc() returns. If
     * the family doesn't exist, EnumFontFamilies() will just return a
     * non-zero value.
     */

    result = EnumFontFamilies(hdc, (TCHAR*) Tcl_DStringValue(&faceString),
	    (FONTENUMPROC) WinFontExistProc, 0);
    Tcl_DStringFree(&faceString);
    return (result == 0);
}

static const char *
FamilyOrAliasExists(
    HDC hdc,
    const char *faceName)
{
    const char *const *aliases;
    int i;

    if (FamilyExists(hdc, faceName) != 0) {
	return faceName;
    }
    aliases = TkFontGetAliasList(faceName);
    if (aliases != NULL) {
	for (i = 0; aliases[i] != NULL; i++) {
	    if (FamilyExists(hdc, aliases[i]) != 0) {
		return aliases[i];
	    }
	}
    }
    return NULL;
}

static int CALLBACK
WinFontExistProc(
    ENUMLOGFONT *lfPtr,		/* Logical-font data. */
    NEWTEXTMETRIC *tmPtr,	/* Physical-font data (not used). */
    int fontType,		/* Type of font (not used). */
    LPARAM lParam)		/* EnumFontData to hold result. */
{
    return 0;
}

/*
 * The following data structures are used when querying a TrueType font file
 * to determine which characters the font supports.
 */

#pragma pack(1)			/* Structures are byte aligned in file. */

#define CMAPHEX 0x636d6170	/* Key for character map resource. */

typedef struct CMAPTABLE {
    USHORT version;		/* Table version number (0). */
    USHORT numTables;		/* Number of encoding tables following. */
} CMAPTABLE;

typedef struct ENCODINGTABLE {
    USHORT platform;		/* Platform for which data is targeted. 3
				 * means data is for Windows. */
    USHORT encoding;		/* How characters in font are encoded. 1 means
				 * that the following subtable is keyed based
				 * on Unicode. */
    ULONG offset;		/* Byte offset from beginning of CMAPTABLE to
				 * the subtable for this encoding. */
} ENCODINGTABLE;

typedef struct ANYTABLE {
    USHORT format;		/* Format number. */
    USHORT length;		/* The actual length in bytes of this
				 * subtable. */
    USHORT version;		/* Version number (starts at 0). */
} ANYTABLE;

typedef struct BYTETABLE {
    USHORT format;		/* Format number is set to 0. */
    USHORT length;		/* The actual length in bytes of this
				 * subtable. */
    USHORT version;		/* Version number (starts at 0). */
    BYTE glyphIdArray[256];	/* Array that maps up to 256 single-byte char
				 * codes to glyph indices. */
} BYTETABLE;

typedef struct SUBHEADER {
    USHORT firstCode;		/* First valid low byte for subHeader. */
    USHORT entryCount;		/* Number valid low bytes for subHeader. */
    SHORT idDelta;		/* Constant adder to get base glyph index. */
    USHORT idRangeOffset;	/* Byte offset from here to appropriate
				 * glyphIndexArray. */
} SUBHEADER;

typedef struct HIBYTETABLE {
    USHORT format;		/* Format number is set to 2. */
    USHORT length;		/* The actual length in bytes of this
				 * subtable. */
    USHORT version;		/* Version number (starts at 0). */
    USHORT subHeaderKeys[256];	/* Maps high bytes to subHeaders: value is
				 * subHeader index * 8. */
#if 0
    SUBHEADER subHeaders[];	/* Variable-length array of SUBHEADERs. */
    USHORT glyphIndexArray[];	/* Variable-length array containing subarrays
				 * used for mapping the low byte of 2-byte
				 * characters. */
#endif
} HIBYTETABLE;

typedef struct SEGMENTTABLE {
    USHORT format;		/* Format number is set to 4. */
    USHORT length;		/* The actual length in bytes of this
				 * subtable. */
    USHORT version;		/* Version number (starts at 0). */
    USHORT segCountX2;		/* 2 x segCount. */
    USHORT searchRange;		/* 2 x (2**floor(log2(segCount))). */
    USHORT entrySelector;	/* log2(searchRange/2). */
    USHORT rangeShift;		/* 2 x segCount - searchRange. */
#if 0
    USHORT endCount[segCount]	/* End characterCode for each segment. */
    USHORT reservedPad;		/* Set to 0. */
    USHORT startCount[segCount];/* Start character code for each segment. */
    USHORT idDelta[segCount];	/* Delta for all character in segment. */
    USHORT idRangeOffset[segCount]; /* Offsets into glyphIdArray or 0. */
    USHORT glyphIdArray[]	/* Glyph index array. */
#endif
} SEGMENTTABLE;

typedef struct TRIMMEDTABLE {
    USHORT format;		/* Format number is set to 6. */
    USHORT length;		/* The actual length in bytes of this
				 * subtable. */
    USHORT version;		/* Version number (starts at 0). */
    USHORT firstCode;		/* First character code of subrange. */
    USHORT entryCount;		/* Number of character codes in subrange. */
#if 0
    USHORT glyphIdArray[];	/* Array of glyph index values for
				 * character codes in the range. */
#endif
} TRIMMEDTABLE;

typedef union SUBTABLE {
    ANYTABLE any;
    BYTETABLE byte;
    HIBYTETABLE hiByte;
    SEGMENTTABLE segment;
    TRIMMEDTABLE trimmed;
} SUBTABLE;

#pragma pack()

/*
 *-------------------------------------------------------------------------
 *
 * LoadFontRanges --
 *
 *	Given an HFONT, get the information about the characters that this
 *	font can display.
 *
 * Results:
 *	If the font has no Unicode character information, the return value is
 *	0 and *startCountPtr and *endCountPtr are filled with NULL. Otherwise,
 *	*startCountPtr and *endCountPtr are set to pointers to arrays of
 *	TrueType character existence information and the return value is the
 *	length of the arrays (the two arrays are always the same length as
 *	each other).
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static int
LoadFontRanges(
    HDC hdc,			/* HDC into which font can be selected. */
    HFONT hFont,		/* HFONT to query. */
    USHORT **startCountPtr,	/* Filled with malloced pointer to character
				 * range information. */
    USHORT **endCountPtr,	/* Filled with malloced pointer to character
				 * range information. */
    int *symbolPtr)
 {
    int n, i, swapped, offset, cbData, segCount;
    DWORD cmapKey;
    USHORT *startCount, *endCount;
    CMAPTABLE cmapTable;
    ENCODINGTABLE encTable;
    SUBTABLE subTable;
    char *s;

    segCount = 0;
    startCount = NULL;
    endCount = NULL;
    *symbolPtr = 0;

    hFont = SelectObject(hdc, hFont);

    i = 0;
    s = (char *) &i;
    *s = '\1';
    swapped = 0;

    if (i == 1) {
	swapped = 1;
    }

    cmapKey = CMAPHEX;
    if (swapped) {
	SwapLong(&cmapKey);
    }

    n = GetFontData(hdc, cmapKey, 0, &cmapTable, sizeof(cmapTable));
    if (n != (int) GDI_ERROR) {
	if (swapped) {
	    SwapShort(&cmapTable.numTables);
	}
	for (i = 0; i < cmapTable.numTables; i++) {
	    offset = sizeof(cmapTable) + i * sizeof(encTable);
	    GetFontData(hdc, cmapKey, (DWORD) offset, &encTable,
		    sizeof(encTable));
	    if (swapped) {
		SwapShort(&encTable.platform);
		SwapShort(&encTable.encoding);
		SwapLong(&encTable.offset);
	    }
	    if (encTable.platform != 3) {
		/*
		 * Not Microsoft encoding.
		 */

		continue;
	    }
	    if (encTable.encoding == 0) {
		*symbolPtr = 1;
	    } else if (encTable.encoding != 1) {
		continue;
	    }

	    GetFontData(hdc, cmapKey, (DWORD) encTable.offset, &subTable,
		    sizeof(subTable));
	    if (swapped) {
		SwapShort(&subTable.any.format);
	    }
	    if (subTable.any.format == 4) {
		if (swapped) {
		    SwapShort(&subTable.segment.segCountX2);
		}
		segCount = subTable.segment.segCountX2 / 2;
		cbData = segCount * sizeof(USHORT);

		startCount = ckalloc(cbData);
		endCount = ckalloc(cbData);

		offset = encTable.offset + sizeof(subTable.segment);
		GetFontData(hdc, cmapKey, (DWORD) offset, endCount, cbData);
		offset += cbData + sizeof(USHORT);
		GetFontData(hdc, cmapKey, (DWORD) offset, startCount, cbData);
		if (swapped) {
		    for (i = 0; i < segCount; i++) {
			SwapShort(&endCount[i]);
			SwapShort(&startCount[i]);
		    }
		}
		if (*symbolPtr != 0) {
		    /*
		     * Empirically determined: When a symbol font is loaded,
		     * the character existence metrics obtained from the
		     * system are mildly wrong. If the real range of the
		     * symbol font is from 0020 to 00FE, then the metrics are
		     * reported as F020 to F0FE. When we load a symbol font,
		     * we must fix the character existence metrics.
		     *
		     * Symbol fonts should only use the symbol encoding for
		     * 8-bit characters [note Bug: 2406]
		     */

		    for (i = 0; i < segCount; i++) {
			if (((startCount[i] & 0xff00) == 0xf000)
				&& ((endCount[i] & 0xff00) == 0xf000)) {
			    startCount[i] &= 0xff;
			    endCount[i] &= 0xff;
			}
		    }
		}
	    }
	}
    } else if (GetTextCharset(hdc) == ANSI_CHARSET) {
	/*
	 * Bitmap font. We should also support ranges for the other *_CHARSET
	 * values.
	 */

	segCount = 1;
	cbData = segCount * sizeof(USHORT);
	startCount = ckalloc(cbData);
	endCount = ckalloc(cbData);
	startCount[0] = 0x0000;
	endCount[0] = 0x00ff;
    }
    SelectObject(hdc, hFont);

    *startCountPtr = startCount;
    *endCountPtr = endCount;
    return segCount;
}

/*
 *-------------------------------------------------------------------------
 *
 * SwapShort, SwapLong --
 *
 *	Helper functions to convert the data loaded from TrueType font files
 *	to Intel byte ordering.
 *
 * Results:
 *	Bytes of input value are swapped and stored back in argument.
 *
 * Side effects:
 *	None.
 *
 *-------------------------------------------------------------------------
 */

static inline void
SwapShort(
    PUSHORT p)
{
    *p = (SHORT)(HIBYTE(*p) + (LOBYTE(*p) << 8));
}

static inline void
SwapLong(
    PULONG p)
{
    ULONG temp;

    temp = (LONG) ((BYTE) *p);
    temp <<= 8;
    *p >>=8;

    temp += (LONG) ((BYTE) *p);
    temp <<= 8;
    *p >>=8;

    temp += (LONG) ((BYTE) *p);
    temp <<= 8;
    *p >>=8;

    temp += (LONG) ((BYTE) *p);
    *p = temp;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */