Source/WebCore/platform/graphics/win/SimpleFontDataCGWin.cpp

/*
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#include "config.h"
#include "Font.h"

#if USE(CG)

#include "FloatRect.h"
#include "FontCache.h"
#include "FontCascade.h"
#include "FontDescription.h"
#include "GlyphPage.h"
#include "HWndDC.h"
#include "OpenTypeCG.h"
#include <mlang.h>
#include <pal/spi/win/CoreTextSPIWin.h>
#include <unicode/uchar.h>
#include <unicode/unorm.h>
#include <winsock2.h>
#include <wtf/MathExtras.h>
#include <wtf/RetainPtr.h>
#include <wtf/text/WTFString.h>

namespace WebCore {

void Font::platformInit()
{
    m_syntheticBoldOffset = m_platformData.syntheticBold() ? 1.0f : 0.f;
    m_scriptCache = 0;
    m_scriptFontProperties = 0;

    if (m_platformData.useGDI())
        return initGDIFont();

    CGFontRef font = m_platformData.cgFont();
    int iAscent = CGFontGetAscent(font);
    int iDescent = CGFontGetDescent(font);
    int iLineGap = CGFontGetLeading(font);
    int iCapHeight = CGFontGetCapHeight(font);

    // The Open Font Format describes the OS/2 USE_TYPO_METRICS flag as follows:
    // "If set, it is strongly recommended to use OS/2.sTypoAscender - OS/2.sTypoDescender+ OS/2.sTypoLineGap as a value for default line spacing for this font."
    short typoAscent, typoDescent, typoLineGap;
    if (OpenType::tryGetTypoMetrics(adoptCF(CTFontCreateWithGraphicsFont(m_platformData.cgFont(), m_platformData.size(), nullptr, nullptr)).get(), typoAscent, typoDescent, typoLineGap)) {
        iAscent = typoAscent;
        iDescent = typoDescent;
        iLineGap = typoLineGap;
    }

    unsigned unitsPerEm = CGFontGetUnitsPerEm(font);
    float pointSize = m_platformData.size();
    float fAscent = scaleEmToUnits(iAscent, unitsPerEm) * pointSize;
    float fDescent = -scaleEmToUnits(iDescent, unitsPerEm) * pointSize;
    float fCapHeight = scaleEmToUnits(iCapHeight, unitsPerEm) * pointSize;
    float fLineGap = scaleEmToUnits(iLineGap, unitsPerEm) * pointSize;

    if (origin() == Origin::Local) {
        HWndDC dc(0);
        HGDIOBJ oldFont = SelectObject(dc, m_platformData.hfont());
        int faceLength = GetTextFace(dc, 0, 0);
        Vector<WCHAR> faceName(faceLength);
        GetTextFace(dc, faceLength, faceName.data());
        SelectObject(dc, oldFont);

        fAscent = ascentConsideringMacAscentHack(faceName.data(), fAscent, fDescent);
    }

    m_fontMetrics.setAscent(fAscent);
    m_fontMetrics.setDescent(fDescent);
    m_fontMetrics.setCapHeight(fCapHeight);
    m_fontMetrics.setLineGap(fLineGap);
    m_fontMetrics.setLineSpacing(lroundf(fAscent) + lroundf(fDescent) + lroundf(fLineGap));

    Glyph xGlyph = glyphDataForCharacter('x').glyph;
    if (xGlyph) {
        // Measure the actual character "x", since it's possible for it to extend below the baseline, and we need the
        // reported x-height to only include the portion of the glyph that is above the baseline.
        CGRect xBox;
        CGFontGetGlyphBBoxes(font, &xGlyph, 1, &xBox);
        m_fontMetrics.setXHeight(scaleEmToUnits(CGRectGetMaxY(xBox), unitsPerEm) * pointSize);
    } else {
        int iXHeight = CGFontGetXHeight(font);
        m_fontMetrics.setXHeight(scaleEmToUnits(iXHeight, unitsPerEm) * pointSize);
    }

    m_fontMetrics.setUnitsPerEm(unitsPerEm);
}

FloatRect Font::platformBoundsForGlyph(Glyph glyph) const
{
    if (!platformData().size())
        return FloatRect();

    if (m_platformData.useGDI())
        return boundsForGDIGlyph(glyph);

    CGRect box;
    CGFontGetGlyphBBoxes(m_platformData.cgFont(), &glyph, 1, &box);
    float pointSize = m_platformData.size();
    CGFloat scale = pointSize / fontMetrics().unitsPerEm();
    FloatRect boundingBox = CGRectApplyAffineTransform(box, CGAffineTransformMakeScale(scale, -scale));
    if (m_syntheticBoldOffset)
        boundingBox.setWidth(boundingBox.width() + m_syntheticBoldOffset);

    return boundingBox;
}

float Font::platformWidthForGlyph(Glyph glyph) const
{
    if (!platformData().size())
        return 0;

    if (m_platformData.useGDI())
        return widthForGDIGlyph(glyph);

    CGFontRef font = m_platformData.cgFont();
    float pointSize = m_platformData.size();
    CGSize advance;
    CGAffineTransform m = CGAffineTransformMakeScale(pointSize, pointSize);
 
    bool isPrinterFont = false;
    FontCascade::getPlatformGlyphAdvances(font, m, m_platformData.isSystemFont(), isPrinterFont, glyph, advance);

    return advance.width + m_syntheticBoldOffset;
}

Path Font::platformPathForGlyph(Glyph glyph) const
{
    auto ctFont = adoptCF(CTFontCreateWithGraphicsFont(platformData().cgFont(), platformData().size(), nullptr, nullptr));
    auto result = adoptCF(CTFontCreatePathForGlyph(ctFont.get(), glyph, nullptr));
    auto syntheticBoldOffset = this->syntheticBoldOffset();
    if (syntheticBoldOffset) {
        auto newPath = adoptCF(CGPathCreateMutable());
        CGPathAddPath(newPath.get(), nullptr, result.get());
        auto translation = CGAffineTransformMakeTranslation(syntheticBoldOffset, 0);
        CGPathAddPath(newPath.get(), &translation, result.get());
        return newPath;
    }
    return adoptCF(CGPathCreateMutableCopy(result.get()));
}

}

#endif