GlyphPageTreeNodeMac.cpp   [plain text]

/*
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
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 *
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 *     notice, this list of conditions and the following disclaimer. 
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 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution. 
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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#include "config.h"
#include "GlyphPageTreeNode.h"

#include "Font.h"
#include "SimpleFontData.h"
#include "WebCoreSystemInterface.h"
#include <CoreText/CoreText.h>
#include <CoreText/CTFontPriv.h>

#include <wtf/UnusedParam.h>

namespace WebCore {

static bool shouldUseCoreText(UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
{
    if (fontData->platformData().widthVariant() != RegularWidth || fontData->hasVerticalGlyphs()) {
        // Ideographs don't have a vertical variant or width variants.
        for (unsigned i = 0; i < bufferLength; ++i) {
            if (!Font::isCJKIdeograph(buffer[i]))
                return true;
        }
    }

    return false;
}

bool GlyphPage::fill(unsigned offset, unsigned length, UChar* buffer, unsigned bufferLength, const SimpleFontData* fontData)
{
    bool haveGlyphs = false;

    if (!shouldUseCoreText(buffer, bufferLength, fontData)) {
        Vector<CGGlyph, 512> glyphs(bufferLength);
        // We pass in either 256 or 512  UTF-16 characters
        // 256 for U+FFFF and less
        // 512 (double character surrogates) for U+10000 and above
        // It is indeed possible to get back 512 glyphs back from the API, so the glyph buffer we pass in must be 512
        // If we get back more than 256 glyphs though we'll ignore all the ones after 256, this should not happen 
        // as the only time we pass in 512 characters is when they are surrogates.
        CGFontGetGlyphsForUnichars(fontData->platformData().cgFont(), buffer, glyphs.data(), bufferLength);
        for (unsigned i = 0; i < length; ++i) {
            if (!glyphs[i])
                setGlyphDataForIndex(offset + i, 0, 0);
            else {
                setGlyphDataForIndex(offset + i, glyphs[i], fontData);
                haveGlyphs = true;
            }
        }
    } else {
        Vector<CGGlyph, 512> glyphs(bufferLength);
        CTFontGetVerticalGlyphsForCharacters(fontData->platformData().ctFont(), buffer, glyphs.data(), bufferLength);
        for (unsigned i = 0; i < length; ++i) {
            if (!glyphs[i])
                setGlyphDataForIndex(offset + i, 0, 0);
            else {
                setGlyphDataForIndex(offset + i, glyphs[i], fontData);
                haveGlyphs = true;
            }
        }
    }

    return haveGlyphs;
}

} // namespace WebCore