GlyphPageMac.cpp   [plain text]

/*
 * Copyright (C) 2006, 2007 Apple Inc. All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer. 
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 *     notice, this list of conditions and the following disclaimer in the
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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
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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#include "config.h"
#include "GlyphPage.h"

#include "CoreGraphicsSPI.h"
#include "CoreTextSPI.h"
#include "Font.h"
#include "FontCascade.h"
#include "WebCoreSystemInterface.h"
#if !PLATFORM(IOS)
#include <ApplicationServices/ApplicationServices.h>
#endif

namespace WebCore {

static bool shouldUseCoreText(const UChar* buffer, unsigned bufferLength, const Font* fontData)
{
    if (fontData->platformData().isCompositeFontReference() || fontData->isSystemFont())
        return true;
    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 (!FontCascade::isCJKIdeograph(buffer[i]))
                return true;
        }
    }

    return false;
}

bool GlyphPage::mayUseMixedFontsWhenFilling(const UChar* buffer, unsigned bufferLength, const Font* fontData)
{
#if USE(APPKIT)
    // FIXME: This is only really needed for composite font references.
    return shouldUseCoreText(buffer, bufferLength, fontData);
#else
    UNUSED_PARAM(buffer);
    UNUSED_PARAM(bufferLength);
    UNUSED_PARAM(fontData);
    return false;
#endif
}

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

    Vector<CGGlyph, 512> glyphs(bufferLength);
    if (!shouldUseCoreText(buffer, bufferLength, fontData)) {
        // 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 if (!fontData->platformData().isCompositeFontReference() && ((fontData->platformData().widthVariant() == RegularWidth)
        ? CTFontGetVerticalGlyphsForCharacters(fontData->platformData().ctFont(), buffer, glyphs.data(), bufferLength)
        : CTFontGetGlyphsForCharacters(fontData->platformData().ctFont(), buffer, glyphs.data(), bufferLength))) {
        // When buffer consists of surrogate pairs, CTFontGetVerticalGlyphsForCharacters and CTFontGetGlyphsForCharacters
        // place the glyphs at indices corresponding to the first character of each pair.
        ASSERT(!(bufferLength % length) && (bufferLength / length == 1 || bufferLength / length == 2));
        unsigned glyphStep = bufferLength / length;
        for (unsigned i = 0; i < length; ++i) {
            if (!glyphs[i * glyphStep])
                setGlyphDataForIndex(offset + i, 0, 0);
            else {
                setGlyphDataForIndex(offset + i, glyphs[i * glyphStep], fontData);
                haveGlyphs = true;
            }
        }
    } else {
        // We ask CoreText for possible vertical variant glyphs
        RetainPtr<CFStringRef> string = adoptCF(CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault, buffer, bufferLength, kCFAllocatorNull));
        RetainPtr<CFAttributedStringRef> attributedString = adoptCF(CFAttributedStringCreate(kCFAllocatorDefault, string.get(), fontData->getCFStringAttributes(0, fontData->hasVerticalGlyphs() ? Vertical : Horizontal)));
        RetainPtr<CTLineRef> line = adoptCF(CTLineCreateWithAttributedString(attributedString.get()));

        CFArrayRef runArray = CTLineGetGlyphRuns(line.get());
        CFIndex runCount = CFArrayGetCount(runArray);

        // Initialize glyph entries
        for (unsigned index = 0; index < length; ++index)
            setGlyphDataForIndex(offset + index, 0, 0);

        Vector<CGGlyph, 512> glyphVector;
        Vector<CFIndex, 512> indexVector;
        bool done = false;

        RetainPtr<CFTypeRef> fontEqualityObject = fontData->platformData().objectForEqualityCheck();

        for (CFIndex r = 0; r < runCount && !done ; ++r) {
            // CTLine could map characters over multiple fonts using its own font fallback list.
            // We need to pick runs that use the exact font we need, i.e., fontData->platformData().ctFont().
            CTRunRef ctRun = static_cast<CTRunRef>(CFArrayGetValueAtIndex(runArray, r));
            ASSERT(CFGetTypeID(ctRun) == CTRunGetTypeID());

            CFDictionaryRef attributes = CTRunGetAttributes(ctRun);
            CTFontRef runFont = static_cast<CTFontRef>(CFDictionaryGetValue(attributes, kCTFontAttributeName));
            bool gotBaseFont = CFEqual(fontEqualityObject.get(), FontPlatformData::objectForEqualityCheck(runFont).get());
            if (gotBaseFont || fontData->platformData().isCompositeFontReference()) {
                // This run uses the font we want. Extract glyphs.
                CFIndex glyphCount = CTRunGetGlyphCount(ctRun);
                const CGGlyph* glyphs = CTRunGetGlyphsPtr(ctRun);
                if (!glyphs) {
                    glyphVector.resize(glyphCount);
                    CTRunGetGlyphs(ctRun, CFRangeMake(0, 0), glyphVector.data());
                    glyphs = glyphVector.data();
                }
                const CFIndex* stringIndices = CTRunGetStringIndicesPtr(ctRun);
                if (!stringIndices) {
                    indexVector.resize(glyphCount);
                    CTRunGetStringIndices(ctRun, CFRangeMake(0, 0), indexVector.data());
                    stringIndices = indexVector.data();
                }

                // When buffer consists of surrogate pairs, CTRunGetStringIndicesPtr and CTRunGetStringIndices
                // place the glyphs at indices corresponding to the first character of each pair.
                ASSERT(!(bufferLength % length) && (bufferLength / length == 1 || bufferLength / length == 2));
                unsigned glyphStep = bufferLength / length;
                if (gotBaseFont) {
                    for (CFIndex i = 0; i < glyphCount; ++i) {
                        if (stringIndices[i] >= static_cast<CFIndex>(bufferLength)) {
                            done = true;
                            break;
                        }
                        if (glyphs[i]) {
                            setGlyphDataForIndex(offset + (stringIndices[i] / glyphStep), glyphs[i], fontData);
                            haveGlyphs = true;
                        }
                    }
#if USE(APPKIT)
                } else {
                    const Font* runSimple = fontData->compositeFontReferenceFont((NSFont *)runFont);
                    if (runSimple) {
                        for (CFIndex i = 0; i < glyphCount; ++i) {
                            if (stringIndices[i] >= static_cast<CFIndex>(bufferLength)) {
                                done = true;
                                break;
                            }
                            if (glyphs[i]) {
                                setGlyphDataForIndex(offset + (stringIndices[i] / glyphStep), glyphs[i], runSimple);
                                haveGlyphs = true;
                            }
                        }
                    }
#endif
                }
            }
        }
    }

    return haveGlyphs;
}

} // namespace WebCore