path: root/src/ports/SkFontHost_win.cpp

/*
 ** Copyright 2006, The Android Open Source Project
 **
 ** Licensed under the Apache License, Version 2.0 (the "License");
 ** you may not use this file except in compliance with the License.
 ** You may obtain a copy of the License at
 **
 **     http://www.apache.org/licenses/LICENSE-2.0
 **
 ** Unless required by applicable law or agreed to in writing, software
 ** distributed under the License is distributed on an "AS IS" BASIS,
 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 ** See the License for the specific language governing permissions and
 ** limitations under the License.
 */

#include "SkString.h"
//#include "SkStream.h"

#include "SkFontHost.h"
#include "SkDescriptor.h"
#include "SkAdvancedTypefaceMetrics.h"
#include "SkStream.h"
#include "SkThread.h"
#include "SkUtils.h"

#ifdef WIN32
#include "windows.h"
#include "tchar.h"
#include "Usp10.h"

// Export this for callers that already have a LOGFONT created
/**
 *  Return a new typeface that best fits the specified LOGFONT. The typeface
 *  should be treated as "new" in that the caller is now an owner (since
 *  typeface is reference counted), though the actual typeface may be part of
 *  an internal cache, so that subsequent requests may return the same ptr.
 */
extern SkTypeface* SkCreateTypefaceFromLOGFONT(const LOGFONT& lf);

// client3d has to undefine this for now
#define CAN_USE_LOGFONT_NAME

using namespace skia_advanced_typeface_metrics_utils;

static SkMutex gFTMutex;

static const uint16_t BUFFERSIZE = (16384 - 32);
static uint8_t glyphbuf[BUFFERSIZE];

// Give 1MB font cache budget
#define FONT_CACHE_MEMORY_BUDGET    (1024 * 1024)

static inline FIXED SkFixedToFIXED(SkFixed x) {
    return *(FIXED*)(&x);
}

static inline FIXED SkScalarToFIXED(SkScalar x) {
    return SkFixedToFIXED(SkScalarToFixed(x));
}

static SkTypeface::Style GetFontStyle(const LOGFONT& lf) {
    int style = SkTypeface::kNormal;
    if (lf.lfWeight == FW_SEMIBOLD || lf.lfWeight == FW_DEMIBOLD || lf.lfWeight == FW_BOLD)
        style |= SkTypeface::kBold;
    if (lf.lfItalic)
        style |= SkTypeface::kItalic;

    return (SkTypeface::Style)style;
}

// have to do this because SkTypeface::SkTypeface() is protected
class LogFontTypeface : public SkTypeface {
private:
    static SkMutex                  gMutex;
    static LogFontTypeface*         gHead;
    static int32_t                  gCurrId;

    LogFontTypeface*                fNext;
    LOGFONT                         fLogFont;

public:

    LogFontTypeface(Style style, const LOGFONT& logFont) :
      SkTypeface(style, sk_atomic_inc(&gCurrId)+1), // 0 id is reserved so add 1
      fLogFont(logFont)
    {
        SkAutoMutexAcquire am(gMutex);
        fNext = gHead;
        gHead = this;
    }

    const LOGFONT& logFont() const { return fLogFont; }

    virtual ~LogFontTypeface() {
        SkAutoMutexAcquire am(gMutex);
        if (gHead == this) {
            gHead = fNext;
            return;
        }

        LogFontTypeface* prev = gHead;
        SkASSERT(prev);
        while (prev->fNext != this) {
            prev = prev->fNext;
            SkASSERT(prev);
        }
        prev->fNext = fNext;
    }

    static LogFontTypeface* FindById(uint32_t id){
        SkASSERT(gHead);
        LogFontTypeface* curr = gHead;
        while (curr->uniqueID() != id) {
            curr = curr->fNext;
            SkASSERT(curr);
        }
        return curr;
    }

    static LogFontTypeface* FindByLogFont(const LOGFONT& lf)
    {
        LogFontTypeface* curr = gHead;
        while (curr && memcmp(&curr->fLogFont, &lf, sizeof(LOGFONT))) {
            curr = curr->fNext;
        }
        return curr;
    }
};

LogFontTypeface* LogFontTypeface::gHead;
int32_t LogFontTypeface::gCurrId;
SkMutex LogFontTypeface::gMutex;

static const LOGFONT& get_default_font() {
    static LOGFONT gDefaultFont;
    // don't hardcode on Windows, Win2000, XP, Vista, and international all have different default
    // and the user could change too


//  lfMessageFont is garbage on my XP, so skip for now
#if 0
    if (gDefaultFont.lfFaceName[0] != 0) {
        return gDefaultFont;
    }

    NONCLIENTMETRICS ncm;
    ncm.cbSize = sizeof(NONCLIENTMETRICS);
    SystemParametersInfo(SPI_GETNONCLIENTMETRICS, sizeof(ncm), &ncm, 0);

    //memcpy(&gDefaultFont, &(ncm.lfMessageFont), sizeof(LOGFONT));
#endif

    return gDefaultFont;
}

SkTypeface* SkCreateTypefaceFromLOGFONT(const LOGFONT& lf) {

    LogFontTypeface* ptypeface = LogFontTypeface::FindByLogFont(lf);

    if (NULL == ptypeface) {
        SkTypeface::Style style = GetFontStyle(lf);
        ptypeface = new LogFontTypeface(style, lf);
    } else {
        ptypeface->ref();
    }
    return ptypeface;
}

uint32_t SkFontHost::NextLogicalFont(uint32_t fontID) {
  // Zero means that we don't have any fallback fonts for this fontID.
  // This function is implemented on Android, but doesn't have much
  // meaning here.
  return 0;
}

class SkScalerContext_Windows : public SkScalerContext {
public:
    SkScalerContext_Windows(const SkDescriptor* desc);
    virtual ~SkScalerContext_Windows();

protected:
    virtual unsigned generateGlyphCount() const;
    virtual uint16_t generateCharToGlyph(SkUnichar uni);
    virtual void generateAdvance(SkGlyph* glyph);
    virtual void generateMetrics(SkGlyph* glyph);
    virtual void generateImage(const SkGlyph& glyph);
    virtual void generatePath(const SkGlyph& glyph, SkPath* path);
    virtual void generateLineHeight(SkPoint* ascent, SkPoint* descent);
    virtual void generateFontMetrics(SkPaint::FontMetrics* mX, SkPaint::FontMetrics* mY);
    //virtual SkDeviceContext getDC() {return ddc;}
private:
    LOGFONT      lf;
    MAT2         mat22;
    HDC          ddc;
    HFONT        savefont;
    HFONT        font;
    SCRIPT_CACHE sc;
};

SkScalerContext_Windows::SkScalerContext_Windows(const SkDescriptor* desc)
        : SkScalerContext(desc), ddc(0), font(0), savefont(0), sc(0) {
    SkAutoMutexAcquire  ac(gFTMutex);

    lf = LogFontTypeface::FindById(fRec.fFontID)->logFont();

    mat22.eM11 = SkScalarToFIXED(fRec.fPost2x2[0][0]);
    mat22.eM12 = SkScalarToFIXED(-fRec.fPost2x2[0][1]);
    mat22.eM21 = SkScalarToFIXED(fRec.fPost2x2[1][0]);
    mat22.eM22 = SkScalarToFIXED(-fRec.fPost2x2[1][1]);

    ddc = ::CreateCompatibleDC(NULL);
    SetBkMode(ddc, TRANSPARENT);

    // Scaling by the DPI is inconsistent with how Skia draws elsewhere
    //SkScalar height = -(fRec.fTextSize * GetDeviceCaps(ddc, LOGPIXELSY) / 72);
    SkScalar height = -fRec.fTextSize;
    lf.lfHeight = SkScalarRound(height);
    font = CreateFontIndirect(&lf);
    savefont = (HFONT)SelectObject(ddc, font);
}

SkScalerContext_Windows::~SkScalerContext_Windows() {
    if (ddc) {
        ::SelectObject(ddc, savefont);
        ::DeleteDC(ddc);
        ddc = NULL;
    }
    if (font) {
        ::DeleteObject(font);
    }
    if (sc) {
        ::ScriptFreeCache(&sc);
    }
}

unsigned SkScalerContext_Windows::generateGlyphCount() const {
    return 0xFFFF;
    //    return fFace->num_glyphs;
}

uint16_t SkScalerContext_Windows::generateCharToGlyph(SkUnichar uni) {
    uint16_t index = 0;
    WCHAR c[2];
    // TODO(ctguil): Support characters that generate more than one glyph.
    if (SkUTF16_FromUnichar(uni, (uint16_t*)c) == 1) {
        // Type1 fonts fail with uniscribe API. Use GetGlyphIndices for plane 0.
        SkAssertResult(GetGlyphIndicesW(ddc, c, 1, &index, 0));
    } else {
        // Use uniscribe to detemine glyph index for non-BMP characters.
        // Need to add extra item to SCRIPT_ITEM to work around a bug in older
        // windows versions. https://bugzilla.mozilla.org/show_bug.cgi?id=366643
        SCRIPT_ITEM si[2 + 1];
        int items;
        SkAssertResult(
            SUCCEEDED(ScriptItemize(c, 2, 2, NULL, NULL, si, &items)));

        WORD log[2];
        SCRIPT_VISATTR vsa;
        int glyphs;
        SkAssertResult(SUCCEEDED(ScriptShape(
            ddc, &sc, c, 2, 1, &si[0].a, &index, log, &vsa, &glyphs)));
    }
    return index;
}

void SkScalerContext_Windows::generateAdvance(SkGlyph* glyph) {
    this->generateMetrics(glyph);
}

void SkScalerContext_Windows::generateMetrics(SkGlyph* glyph) {

    SkASSERT(ddc);

    GLYPHMETRICS gm;
    memset(&gm, 0, sizeof(gm));

    glyph->fRsbDelta = 0;
    glyph->fLsbDelta = 0;

    // Note: need to use GGO_GRAY8_BITMAP instead of GGO_METRICS because GGO_METRICS returns a smaller
    // BlackBlox; we need the bigger one in case we need the image.  fAdvance is the same.
    uint32_t ret = GetGlyphOutlineW(ddc, glyph->getGlyphID(0), GGO_GRAY8_BITMAP | GGO_GLYPH_INDEX, &gm, 0, NULL, &mat22);

    if (GDI_ERROR != ret) {
        if (ret == 0) {
            // for white space, ret is zero and gmBlackBoxX, gmBlackBoxY are 1 incorrectly!
            gm.gmBlackBoxX = gm.gmBlackBoxY = 0;
        }
        glyph->fWidth   = gm.gmBlackBoxX;
        glyph->fHeight  = gm.gmBlackBoxY;
        glyph->fTop     = SkToS16(gm.gmptGlyphOrigin.y - gm.gmBlackBoxY);
        glyph->fLeft    = SkToS16(gm.gmptGlyphOrigin.x);
        glyph->fAdvanceX = SkIntToFixed(gm.gmCellIncX);
        glyph->fAdvanceY = -SkIntToFixed(gm.gmCellIncY);
    } else {
        glyph->fWidth = 0;
    }

#if 0
    char buf[1024];
    sprintf(buf, "generateMetrics: id:%d, w=%d, h=%d, font:%s, fh:%d\n", glyph->fID, glyph->fWidth, glyph->fHeight, lf.lfFaceName, lf.lfHeight);
    OutputDebugString(buf);
#endif
}

void SkScalerContext_Windows::generateFontMetrics(SkPaint::FontMetrics* mx, SkPaint::FontMetrics* my) {
// Note: This code was borrowed from generateLineHeight, which has a note
// stating that it may be incorrect.
    if (!(mx || my))
      return;

    SkASSERT(ddc);

    OUTLINETEXTMETRIC otm;

    uint32_t ret = GetOutlineTextMetrics(ddc, sizeof(otm), &otm);
    if (sizeof(otm) != ret) {
      return;
    }

    if (mx) {
      mx->fTop = -SkIntToScalar(otm.otmTextMetrics.tmAscent);  // Actually a long.
      mx->fAscent = -SkIntToScalar(otm.otmAscent);
      mx->fDescent = -SkIntToScalar(otm.otmDescent);
      mx->fBottom = SkIntToScalar(otm.otmTextMetrics.tmDescent);  // Long
      mx->fLeading = SkIntToScalar(otm.otmTextMetrics.tmInternalLeading
          + otm.otmTextMetrics.tmExternalLeading);  // Long
    }

    if (my) {
      my->fTop = -SkIntToScalar(otm.otmTextMetrics.tmAscent);  // Actually a long.
      my->fAscent = -SkIntToScalar(otm.otmAscent);
      my->fDescent = -SkIntToScalar(otm.otmDescent);
      my->fBottom = SkIntToScalar(otm.otmTextMetrics.tmDescent);  // Long
      my->fLeading = SkIntToScalar(otm.otmTextMetrics.tmInternalLeading
          + otm.otmTextMetrics.tmExternalLeading);  // Long
    }
}

void SkScalerContext_Windows::generateImage(const SkGlyph& glyph) {

    SkAutoMutexAcquire  ac(gFTMutex);

    SkASSERT(ddc);

    GLYPHMETRICS gm;
    memset(&gm, 0, sizeof(gm));

#if 0
    char buf[1024];
    sprintf(buf, "generateImage: id:%d, w=%d, h=%d, font:%s,fh:%d\n", glyph.fID, glyph.fWidth, glyph.fHeight, lf.lfFaceName, lf.lfHeight);
    OutputDebugString(buf);
#endif

    uint32_t bytecount = 0;
    uint32_t total_size = GetGlyphOutlineW(ddc, glyph.fID, GGO_GRAY8_BITMAP | GGO_GLYPH_INDEX, &gm, 0, NULL, &mat22);
    if (GDI_ERROR != total_size && total_size > 0) {
        uint8_t *pBuff = new uint8_t[total_size];
        if (NULL != pBuff) {
            total_size = GetGlyphOutlineW(ddc, glyph.fID, GGO_GRAY8_BITMAP | GGO_GLYPH_INDEX, &gm, total_size, pBuff, &mat22);

            SkASSERT(total_size != GDI_ERROR);

            SkASSERT(glyph.fWidth == gm.gmBlackBoxX);
            SkASSERT(glyph.fHeight == gm.gmBlackBoxY);

            uint8_t* dst = (uint8_t*)glyph.fImage;
            uint32_t pitch = (gm.gmBlackBoxX + 3) & ~0x3;
            if (pitch != glyph.rowBytes()) {
                SkASSERT(false); // glyph.fImage has different rowsize!?
            }

            for (int32_t y = gm.gmBlackBoxY - 1; y >= 0; y--) {
                uint8_t* src = pBuff + pitch * y;

                for (uint32_t x = 0; x < gm.gmBlackBoxX; x++) {
                    if (*src > 63) {
                        *dst = 0xFF;
                    }
                    else {
                        *dst = *src << 2; // scale to 0-255
                    }
                    dst++;
                    src++;
                    bytecount++;
                }
                memset(dst, 0, glyph.rowBytes() - glyph.fWidth);
                dst += glyph.rowBytes() - glyph.fWidth;
            }

            delete[] pBuff;
        }
    }

    SkASSERT(GDI_ERROR != total_size && total_size >= 0);

}

void SkScalerContext_Windows::generatePath(const SkGlyph& glyph, SkPath* path) {

    SkAutoMutexAcquire  ac(gFTMutex);

    SkASSERT(&glyph && path);
    SkASSERT(ddc);

    path->reset();

#if 0
    char buf[1024];
    sprintf(buf, "generatePath: id:%d, w=%d, h=%d, font:%s,fh:%d\n", glyph.fID, glyph.fWidth, glyph.fHeight, lf.lfFaceName, lf.lfHeight);
    OutputDebugString(buf);
#endif

    GLYPHMETRICS gm;
    uint32_t total_size = GetGlyphOutlineW(ddc, glyph.fID, GGO_NATIVE | GGO_GLYPH_INDEX, &gm, BUFFERSIZE, glyphbuf, &mat22);

    if (GDI_ERROR != total_size) {

        const uint8_t* cur_glyph = glyphbuf;
        const uint8_t* end_glyph = glyphbuf + total_size;

        while(cur_glyph < end_glyph) {
            const TTPOLYGONHEADER* th = (TTPOLYGONHEADER*)cur_glyph;

            const uint8_t* end_poly = cur_glyph + th->cb;
            const uint8_t* cur_poly = cur_glyph + sizeof(TTPOLYGONHEADER);

            path->moveTo(SkFixedToScalar(*(SkFixed*)(&th->pfxStart.x)), SkFixedToScalar(*(SkFixed*)(&th->pfxStart.y)));

            while(cur_poly < end_poly) {
                const TTPOLYCURVE* pc = (const TTPOLYCURVE*)cur_poly;

                if (pc->wType == TT_PRIM_LINE) {
                    for (uint16_t i = 0; i < pc->cpfx; i++) {
                        path->lineTo(SkFixedToScalar(*(SkFixed*)(&pc->apfx[i].x)), SkFixedToScalar(*(SkFixed*)(&pc->apfx[i].y)));
                    }
                }

                if (pc->wType == TT_PRIM_QSPLINE) {
                    for (uint16_t u = 0; u < pc->cpfx - 1; u++) { // Walk through points in spline
                        POINTFX pnt_b = pc->apfx[u];    // B is always the current point
                        POINTFX pnt_c = pc->apfx[u+1];

                        if (u < pc->cpfx - 2) {          // If not on last spline, compute C
                            pnt_c.x = SkFixedToFIXED(SkFixedAve(*(SkFixed*)(&pnt_b.x), *(SkFixed*)(&pnt_c.x)));
                            pnt_c.y = SkFixedToFIXED(SkFixedAve(*(SkFixed*)(&pnt_b.y), *(SkFixed*)(&pnt_c.y)));
                        }

                        path->quadTo(SkFixedToScalar(*(SkFixed*)(&pnt_b.x)), SkFixedToScalar(*(SkFixed*)(&pnt_b.y)), SkFixedToScalar(*(SkFixed*)(&pnt_c.x)), SkFixedToScalar(*(SkFixed*)(&pnt_c.y)));
                    }
                }
                cur_poly += sizeof(uint16_t) * 2 + sizeof(POINTFX) * pc->cpfx;
            }
            cur_glyph += th->cb;
            path->close();
        }
    }
    else {
        SkASSERT(false);
    }
    //char buf[1024];
    //sprintf(buf, "generatePath: count:%d\n", count);
    //OutputDebugString(buf);
}


// Note:  not sure this is the correct implementation
void SkScalerContext_Windows::generateLineHeight(SkPoint* ascent, SkPoint* descent) {

    SkASSERT(ddc);

    OUTLINETEXTMETRIC otm;

    uint32_t ret = GetOutlineTextMetrics(ddc, sizeof(otm), &otm);

    if (sizeof(otm) == ret) {
        if (ascent)
            ascent->iset(0, otm.otmAscent);
        if (descent)
            descent->iset(0, otm.otmDescent);
    }

    return;
}

void SkFontHost::Serialize(const SkTypeface* face, SkWStream* stream) {
    SkASSERT(!"SkFontHost::Serialize unimplemented");
}

SkTypeface* SkFontHost::Deserialize(SkStream* stream) {
    SkASSERT(!"SkFontHost::Deserialize unimplemented");
    return NULL;
}

static bool getWidthAdvance(HDC hdc, int gId, int16_t* advance) {
    // Initialize the MAT2 structure to the identify transformation matrix.
    static const MAT2 mat2 = {SkScalarToFIXED(1), SkScalarToFIXED(0),
                        SkScalarToFIXED(0), SkScalarToFIXED(1)};
    int flags = GGO_METRICS | GGO_GLYPH_INDEX;
    GLYPHMETRICS gm;
    if (GDI_ERROR == GetGlyphOutline(hdc, gId, flags, &gm, 0, NULL, &mat2)) {
        return false;
    }
    SkASSERT(advance);
    *advance = gm.gmCellIncX;
    return true;
}

// static
SkAdvancedTypefaceMetrics* SkFontHost::GetAdvancedTypefaceMetrics(
        uint32_t fontID, bool perGlyphInfo) {
    SkAutoMutexAcquire ac(gFTMutex);
    LogFontTypeface* rec = LogFontTypeface::FindById(fontID);
    LOGFONT lf = rec->logFont();
    SkAdvancedTypefaceMetrics* info = NULL;

    HDC hdc = CreateCompatibleDC(NULL);
    HFONT font = CreateFontIndirect(&lf);
    HFONT savefont = (HFONT)SelectObject(hdc, font);
    HFONT designFont = NULL;

    // To request design units, create a logical font whose height is specified
    // as unitsPerEm.
    OUTLINETEXTMETRIC otm;
    if (!GetOutlineTextMetrics(hdc, sizeof(otm), &otm) ||
        !GetTextFace(hdc, LF_FACESIZE, lf.lfFaceName)) {
        goto Error;
    }
    lf.lfHeight = -SkToS32(otm.otmEMSquare);
    designFont = CreateFontIndirect(&lf);
    SelectObject(hdc, designFont);
    if (!GetOutlineTextMetrics(hdc, sizeof(otm), &otm)) {
        goto Error;
    }

    info = new SkAdvancedTypefaceMetrics;
#ifdef UNICODE
    // Get the buffer size needed first.
    size_t str_len = WideCharToMultiByte(CP_UTF8, 0, lf.lfFaceName, -1, NULL,
                                         0, NULL, NULL);
    // Allocate a buffer (str_len already has terminating null accounted for).
    char *familyName = new char[str_len];
    // Now actually convert the string.
    WideCharToMultiByte(CP_UTF8, 0, lf.lfFaceName, -1, familyName, str_len,
                          NULL, NULL);
    info->fFontName.set(familyName);
    delete [] familyName;
#else
    info->fFontName.set(lf.lfFaceName);
#endif

    if (otm.otmTextMetrics.tmPitchAndFamily & TMPF_TRUETYPE) {
        info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font;
    } else {
        info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
    }
    info->fEmSize = otm.otmEMSquare;
    info->fMultiMaster = false;
    info->fLastGlyphID = 0;

    info->fStyle = 0;
    // If this bit is clear the font is a fixed pitch font.
    if (!(otm.otmTextMetrics.tmPitchAndFamily & TMPF_FIXED_PITCH)) {
        info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style;
    }
    if (otm.otmTextMetrics.tmItalic) {
        info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style;
    }
    // Setting symbolic style by default for now.
    info->fStyle |= SkAdvancedTypefaceMetrics::kSymbolic_Style;
    if (otm.otmTextMetrics.tmPitchAndFamily & FF_ROMAN) {
        info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style;
    } else if (otm.otmTextMetrics.tmPitchAndFamily & FF_SCRIPT) {
            info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style;
    }

    // The main italic angle of the font, in tenths of a degree counterclockwise
    // from vertical.
    info->fItalicAngle = otm.otmItalicAngle / 10;
    info->fAscent = SkToS16(otm.otmTextMetrics.tmAscent);
    info->fDescent = SkToS16(-otm.otmTextMetrics.tmDescent);
    // TODO(ctguil): Use alternate cap height calculation.
    // MSDN says otmsCapEmHeight is not support but it is returning a value on
    // my Win7 box.
    info->fCapHeight = otm.otmsCapEmHeight;
    info->fBBox =
        SkIRect::MakeLTRB(otm.otmrcFontBox.left, otm.otmrcFontBox.top,
                          otm.otmrcFontBox.right, otm.otmrcFontBox.bottom);

    // Figure out a good guess for StemV - Min width of i, I, !, 1.
    // This probably isn't very good with an italic font.
    int16_t min_width = SHRT_MAX;
    info->fStemV = 0;
    char stem_chars[] = {'i', 'I', '!', '1'};
    for (size_t i = 0; i < SK_ARRAY_COUNT(stem_chars); i++) {
        ABC abcWidths;
        if (GetCharABCWidths(hdc, stem_chars[i], stem_chars[i], &abcWidths)) {
            int16_t width = abcWidths.abcB;
            if (width > 0 && width < min_width) {
                min_width = width;
                info->fStemV = min_width;
            }
        }
    }

    // If bit 1 is set, the font may not be embedded in a document.
    // If bit 1 is clear, the font can be embedded.
    // If bit 2 is set, the embedding is read-only.
    if (otm.otmfsType & 0x1) {
        info->fType = SkAdvancedTypefaceMetrics::kNotEmbeddable_Font;
    } else if (perGlyphInfo) {
        info->fGlyphWidths.reset(
            getAdvanceData(hdc, SHRT_MAX, &getWidthAdvance));

        // Obtain the last glyph index.
        SkAdvancedTypefaceMetrics::WidthRange* last = info->fGlyphWidths.get();
        if (last) {
            while (last->fNext.get()) {
                last = last->fNext.get();
            }
            info->fLastGlyphID = last->fEndId;
        }
    }

Error:
    SelectObject(hdc, savefont);
    DeleteObject(designFont);
    DeleteObject(font);
    DeleteDC(hdc);

    return info;
}

SkTypeface* SkFontHost::CreateTypefaceFromStream(SkStream* stream) {

    //Should not be used on Windows, keep linker happy
    SkASSERT(false);
    return SkCreateTypefaceFromLOGFONT(get_default_font());
}

SkStream* SkFontHost::OpenStream(SkFontID uniqueID) {
    SkAutoMutexAcquire ac(gFTMutex);
    LogFontTypeface* rec = LogFontTypeface::FindById(uniqueID);

    HDC hdc = ::CreateCompatibleDC(NULL);
    HFONT font = CreateFontIndirect(&rec->logFont());
    HFONT savefont = (HFONT)SelectObject(hdc, font);

    size_t bufferSize = GetFontData(hdc, 0, 0, NULL, 0);
    SkMemoryStream* stream = new SkMemoryStream(bufferSize);
    if (!GetFontData(hdc, 0, 0, (void*)stream->getMemoryBase(), bufferSize)) {
        delete stream;
        stream = NULL;
    }

    SelectObject(hdc, savefont);
    DeleteObject(font);
    DeleteDC(hdc);

    return stream;
}

SkScalerContext* SkFontHost::CreateScalerContext(const SkDescriptor* desc) {
    return SkNEW_ARGS(SkScalerContext_Windows, (desc));
}

/** Return the closest matching typeface given either an existing family
 (specified by a typeface in that family) or by a familyName, and a
 requested style.
 1) If familyFace is null, use famillyName.
 2) If famillyName is null, use familyFace.
 3) If both are null, return the default font that best matches style
 This MUST not return NULL.
 */

SkTypeface* SkFontHost::CreateTypeface(const SkTypeface* familyFace,
                                       const char familyName[],
                                       const void* data, size_t bytelength,
                                       SkTypeface::Style style) {

    static SkTypeface* gDefaultTypeface;
    SkAutoMutexAcquire  ac(gFTMutex);

#ifndef CAN_USE_LOGFONT_NAME
    familyName = NULL;
    familyFace = NULL;
#endif

    // clip to legal style bits
    style = (SkTypeface::Style)(style & SkTypeface::kBoldItalic);

    SkTypeface* tf = NULL;
    if (NULL == familyFace && NULL == familyName) {
        LOGFONT lf = get_default_font();
        lf.lfWeight = (style & SkTypeface::kBold) != 0 ? FW_BOLD : FW_NORMAL ;
        lf.lfItalic = ((style & SkTypeface::kItalic) != 0);
        // hack until we figure out if SkTypeface should cache this itself
        if (style == SkTypeface::kNormal) {
            if (NULL == gDefaultTypeface) {
                gDefaultTypeface = SkCreateTypefaceFromLOGFONT(lf);
            }
            tf = gDefaultTypeface;
            tf->ref();
        } else {
            tf = SkCreateTypefaceFromLOGFONT(lf);
        }
    } else {
#ifdef CAN_USE_LOGFONT_NAME
        LOGFONT lf;
        if (NULL != familyFace) {
            uint32_t id = familyFace->uniqueID();
            LogFontTypeface* rec = LogFontTypeface::FindById(id);
            if (!rec) {
                SkASSERT(false);
                lf = get_default_font();
            }
            else {
                lf = rec->logFont();
            }
        }
        else {
            memset(&lf, 0, sizeof(LOGFONT));

            lf.lfHeight = -11; // default
            lf.lfQuality = PROOF_QUALITY;
            lf.lfCharSet = DEFAULT_CHARSET;

#ifdef UNICODE
            // Get the buffer size needed first.
            size_t str_len = ::MultiByteToWideChar(CP_UTF8, 0, familyName,
                                                   -1, NULL, 0);
            // Allocate a buffer (str_len already has terminating null
            // accounted for).
            wchar_t *wideFamilyName = new wchar_t[str_len];
            // Now actually convert the string.
            ::MultiByteToWideChar(CP_UTF8, 0, familyName, -1,
                                  wideFamilyName, str_len);
            ::wcsncpy(lf.lfFaceName, wideFamilyName, LF_FACESIZE);
            delete [] wideFamilyName;
#else
            ::strncpy(lf.lfFaceName, familyName, LF_FACESIZE);
#endif
            lf.lfFaceName[LF_FACESIZE-1] = '\0';
        }

        // use the style desired
        lf.lfWeight = (style & SkTypeface::kBold) != 0 ? FW_BOLD : FW_NORMAL ;
        lf.lfItalic = ((style & SkTypeface::kItalic) != 0);
        tf = SkCreateTypefaceFromLOGFONT(lf);
#endif
    }

    if (NULL == tf) {
        tf = SkCreateTypefaceFromLOGFONT(get_default_font());
    }
    return tf;
}

size_t SkFontHost::ShouldPurgeFontCache(size_t sizeAllocatedSoFar) {
    if (sizeAllocatedSoFar > FONT_CACHE_MEMORY_BUDGET)
        return sizeAllocatedSoFar - FONT_CACHE_MEMORY_BUDGET;
    else
        return 0;   // nothing to do
}

int SkFontHost::ComputeGammaFlag(const SkPaint& paint) {
    return 0;
}

void SkFontHost::GetGammaTables(const uint8_t* tables[2]) {
    tables[0] = NULL;   // black gamma (e.g. exp=1.4)
    tables[1] = NULL;   // white gamma (e.g. exp= 1/1.4)
}

SkTypeface* SkFontHost::CreateTypefaceFromFile(const char path[]) {
    printf("SkFontHost::CreateTypefaceFromFile unimplemented");
    return NULL;
}

void SkFontHost::FilterRec(SkScalerContext::Rec* rec) {
    // We don't control the hinting nor ClearType settings here
    rec->setHinting(SkPaint::kNormal_Hinting);
    if (SkMask::FormatIsLCD((SkMask::Format)rec->fMaskFormat)) {
        rec->fMaskFormat = SkMask::kA8_Format;
    }
}

#endif // WIN32