C++ GlyphPage::fontDataForCharacter方法代码示例

bool Font::primaryFontHasGlyphForCharacter(UChar32 character) const
{
    unsigned pageNumber = (character / GlyphPage::size);

    GlyphPageTreeNode* node = GlyphPageTreeNode::getRootChild(primaryFont(), pageNumber);
    GlyphPage* page = node->page();

    return page && page->fontDataForCharacter(character);
}

//.........这里部分代码省略.........
        while (true) {
            page = node->page();
            if (page) {
                GlyphData data = page->glyphDataForCharacter(c);
                if (data.fontData) {
                    // The variantFontData function should not normally return 0.
                    // But if it does, we will just render the capital letter big.
                    RefPtr<SimpleFontData> variantFontData = data.fontData->variantFontData(description, variant);
                    if (!variantFontData)
                        return std::make_pair(data, page);

                    GlyphPageTreeNode* variantNode = GlyphPageTreeNode::getRootChild(variantFontData.get(), pageNumber);
                    GlyphPage* variantPage = variantNode->page();
                    if (variantPage) {
                        GlyphData data = variantPage->glyphDataForCharacter(c);
                        if (data.fontData)
                            return std::make_pair(data, variantPage);
                    }

                    // Do not attempt system fallback off the variantFontData. This is the very unlikely case that
                    // a font has the lowercase character but the small caps font does not have its uppercase version.
                    return std::make_pair(variantFontData->missingGlyphData(), page);
                }

                if (node->isSystemFallback())
                    break;
            }

            node = node->getChild(realizeFontDataAt(description, node->level()), pageNumber);
            if (pageNumber)
                m_pages.set(pageNumber, node);
            else
                m_pageZero = node;
        }
    }

    ASSERT(page);
    ASSERT(node->isSystemFallback());

    // System fallback is character-dependent. When we get here, we
    // know that the character in question isn't in the system fallback
    // font's glyph page. Try to lazily create it here.
    UChar codeUnits[2];
    int codeUnitsLength;
    if (c <= 0xFFFF) {
        codeUnits[0] = Font::normalizeSpaces(c);
        codeUnitsLength = 1;
    } else {
        codeUnits[0] = U16_LEAD(c);
        codeUnits[1] = U16_TRAIL(c);
        codeUnitsLength = 2;
    }
    const SimpleFontData* originalFontData = primaryFontData(description)->fontDataForCharacter(c);
    RefPtr<SimpleFontData> characterFontData = fontCache().systemFallbackForCharacters(description, originalFontData, m_isForPlatformFont, codeUnits, codeUnitsLength);
    if (characterFontData) {
        if (characterFontData->platformData().orientation() == Vertical && !characterFontData->hasVerticalGlyphs() && Font::isCJKIdeographOrSymbol(c))
            variant = BrokenIdeographVariant;
        if (variant != NormalVariant)
            characterFontData = characterFontData->variantFontData(description, variant);
    }
    if (characterFontData) {
        // Got the fallback glyph and font.
        GlyphPage* fallbackPage = GlyphPageTreeNode::getRootChild(characterFontData.get(), pageNumber)->page();
        GlyphData data = fallbackPage && fallbackPage->fontDataForCharacter(c) ? fallbackPage->glyphDataForCharacter(c) : characterFontData->missingGlyphData();
        // Cache it so we don't have to do system fallback again next time.
        if (variant == NormalVariant) {
#if OS(WINCE)
            // missingGlyphData returns a null character, which is not suitable for GDI to display.
            // Also, sometimes we cannot map a font for the character on WINCE, but GDI can still
            // display the character, probably because the font package is not installed correctly.
            // So we just always set the glyph to be same as the character, and let GDI solve it.
            page->setGlyphDataForCharacter(c, c, characterFontData.get());
            characterFontData->setMaxGlyphPageTreeLevel(std::max(characterFontData->maxGlyphPageTreeLevel(), node->level()));
            return std::make_pair(page->glyphDataForCharacter(c), page);
#else
            page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
            data.fontData->setMaxGlyphPageTreeLevel(std::max(data.fontData->maxGlyphPageTreeLevel(), node->level()));
            if (!Font::isCJKIdeographOrSymbol(c) && data.fontData->platformData().orientation() != Horizontal && !data.fontData->isTextOrientationFallback())
                return glyphDataAndPageForNonCJKCharacterWithGlyphOrientation(c, description.nonCJKGlyphOrientation(), data, fallbackPage, pageNumber);
#endif
        }
        return std::make_pair(data, page);
    }

    // Even system fallback can fail; use the missing glyph in that case.
    // FIXME: It would be nicer to use the missing glyph from the last resort font instead.
    GlyphData data = primarySimpleFontData(description)->missingGlyphData();
    if (variant == NormalVariant) {
#if OS(WINCE)
        // See comment about WINCE GDI handling near setGlyphDataForCharacter above.
        page->setGlyphDataForCharacter(c, c, data.fontData);
        data.fontData->setMaxGlyphPageTreeLevel(std::max(data.fontData->maxGlyphPageTreeLevel(), node->level()));
        return std::make_pair(page->glyphDataForCharacter(c), page);
#else
        page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
        data.fontData->setMaxGlyphPageTreeLevel(std::max(data.fontData->maxGlyphPageTreeLevel(), node->level()));
#endif
    }
    return std::make_pair(data, page);
}

//.........这里部分代码省略.........
                    } else {
                        return glyphDataAndPageForNonCJKCharacterWithGlyphOrientation(c, m_fontDescription.nonCJKGlyphOrientation(), data, page, pageNumber);
                    }

                    return make_pair(data, page);
                }

                if (node->isSystemFallback())
                    break;
            }

            // Proceed with the fallback list.
            node = node->getChild(fontDataAt(node->level()), pageNumber);
            if (pageNumber)
                m_fontFallbackList->m_pages.set(pageNumber, node);
            else
                m_fontFallbackList->m_pageZero = node;
        }
    }
    if (variant != NormalVariant) {
        while (true) {
            page = node->page();
            if (page) {
                GlyphData data = page->glyphDataForCharacter(c);
                if (data.fontData) {
                    // The variantFontData function should not normally return 0.
                    // But if it does, we will just render the capital letter big.
                    RefPtr<SimpleFontData> variantFontData = data.fontData->variantFontData(m_fontDescription, variant);
                    if (!variantFontData)
                        return make_pair(data, page);

                    GlyphPageTreeNode* variantNode = GlyphPageTreeNode::getRootChild(variantFontData.get(), pageNumber);
                    GlyphPage* variantPage = variantNode->page();
                    if (variantPage) {
                        GlyphData data = variantPage->glyphDataForCharacter(c);
                        if (data.fontData)
                            return make_pair(data, variantPage);
                    }

                    // Do not attempt system fallback off the variantFontData. This is the very unlikely case that
                    // a font has the lowercase character but the small caps font does not have its uppercase version.
                    return make_pair(variantFontData->missingGlyphData(), page);
                }

                if (node->isSystemFallback())
                    break;
            }

            // Proceed with the fallback list.
            node = node->getChild(fontDataAt(node->level()), pageNumber);
            if (pageNumber)
                m_fontFallbackList->m_pages.set(pageNumber, node);
            else
                m_fontFallbackList->m_pageZero = node;
        }
    }

    ASSERT(page);
    ASSERT(node->isSystemFallback());

    // System fallback is character-dependent. When we get here, we
    // know that the character in question isn't in the system fallback
    // font's glyph page. Try to lazily create it here.

    // FIXME: Unclear if this should normalizeSpaces above 0xFFFF.
    // Doing so changes fast/text/international/plane2-diffs.html
    UChar32 characterToRender = c;
    if (characterToRender <=  0xFFFF)
        characterToRender = Character::normalizeSpaces(characterToRender);
    const SimpleFontData* fontDataToSubstitute = fontDataAt(0)->fontDataForCharacter(characterToRender);
    RefPtr<SimpleFontData> characterFontData = FontCache::fontCache()->platformFallbackForCharacter(m_fontDescription, characterToRender, fontDataToSubstitute);
    if (characterFontData) {
        if (characterFontData->platformData().orientation() == Vertical && !characterFontData->hasVerticalGlyphs() && Character::isCJKIdeographOrSymbol(c))
            variant = BrokenIdeographVariant;
        if (variant != NormalVariant)
            characterFontData = characterFontData->variantFontData(m_fontDescription, variant);
    }
    if (characterFontData) {
        // Got the fallback glyph and font.
        GlyphPage* fallbackPage = GlyphPageTreeNode::getRootChild(characterFontData.get(), pageNumber)->page();
        GlyphData data = fallbackPage && fallbackPage->fontDataForCharacter(c) ? fallbackPage->glyphDataForCharacter(c) : characterFontData->missingGlyphData();
        // Cache it so we don't have to do system fallback again next time.
        if (variant == NormalVariant) {
            page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
            data.fontData->setMaxGlyphPageTreeLevel(max(data.fontData->maxGlyphPageTreeLevel(), node->level()));
            if (!Character::isCJKIdeographOrSymbol(c) && data.fontData->platformData().orientation() != Horizontal && !data.fontData->isTextOrientationFallback())
                return glyphDataAndPageForNonCJKCharacterWithGlyphOrientation(c, m_fontDescription.nonCJKGlyphOrientation(), data, fallbackPage, pageNumber);
        }
        return make_pair(data, page);
    }

    // Even system fallback can fail; use the missing glyph in that case.
    // FIXME: It would be nicer to use the missing glyph from the last resort font instead.
    GlyphData data = primaryFont()->missingGlyphData();
    if (variant == NormalVariant) {
        page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
        data.fontData->setMaxGlyphPageTreeLevel(max(data.fontData->maxGlyphPageTreeLevel(), node->level()));
    }
    return make_pair(data, page);
}

//.........这里部分代码省略.........
            }

            // Proceed with the fallback list.
            node = node->getChild(fontDataAt(node->level()), pageNumber);
            if (pageNumber)
                m_fontList->m_pages.set(pageNumber, node);
            else
                m_fontList->m_pageZero = node;
        }
    } else {
        while (true) {
            page = node->page();
            if (page) {
                GlyphData data = page->glyphDataForCharacter(c);
                if (data.fontData) {
                    // The smallCapsFontData function should not normally return 0.
                    // But if it does, we will just render the capital letter big.
                    const SimpleFontData* smallCapsFontData = data.fontData->smallCapsFontData(m_fontDescription);
                    if (!smallCapsFontData)
                        return data;

                    GlyphPageTreeNode* smallCapsNode = GlyphPageTreeNode::getRootChild(smallCapsFontData, pageNumber);
                    const GlyphPage* smallCapsPage = smallCapsNode->page();
                    if (smallCapsPage) {
                        GlyphData data = smallCapsPage->glyphDataForCharacter(c);
                        if (data.fontData)
                            return data;
                    }

                    // Do not attempt system fallback off the smallCapsFontData. This is the very unlikely case that
                    // a font has the lowercase character but the small caps font does not have its uppercase version.
                    return smallCapsFontData->missingGlyphData();
                }

                if (node->isSystemFallback())
                    break;
            }

            // Proceed with the fallback list.
            node = node->getChild(fontDataAt(node->level()), pageNumber);
            if (pageNumber)
                m_fontList->m_pages.set(pageNumber, node);
            else
                m_fontList->m_pageZero = node;
        }
    }

    ASSERT(page);
    ASSERT(node->isSystemFallback());

    // System fallback is character-dependent. When we get here, we
    // know that the character in question isn't in the system fallback
    // font's glyph page. Try to lazily create it here.
    UChar codeUnits[2];
    int codeUnitsLength;
    if (c <= 0xFFFF) {
        codeUnits[0] = Font::normalizeSpaces(c);
        codeUnitsLength = 1;
    } else {
        codeUnits[0] = U16_LEAD(c);
        codeUnits[1] = U16_TRAIL(c);
        codeUnitsLength = 2;
    }
    const SimpleFontData* characterFontData = fontCache()->getFontDataForCharacters(*this, codeUnits, codeUnitsLength);
    if (useSmallCapsFont && characterFontData)
        characterFontData = characterFontData->smallCapsFontData(m_fontDescription);
    if (characterFontData) {
        // Got the fallback glyph and font.
        GlyphPage* fallbackPage = GlyphPageTreeNode::getRootChild(characterFontData, pageNumber)->page();
        GlyphData data = fallbackPage && fallbackPage->fontDataForCharacter(c) ? fallbackPage->glyphDataForCharacter(c) : characterFontData->missingGlyphData();
        // Cache it so we don't have to do system fallback again next time.
        if (!useSmallCapsFont) {
#if OS(WINCE)
            // missingGlyphData returns a null character, which is not suitable for GDI to display.
            // Also, sometimes we cannot map a font for the character on WINCE, but GDI can still
            // display the character, probably because the font package is not installed correctly.
            // So we just always set the glyph to be same as the character, and let GDI solve it.
            page->setGlyphDataForCharacter(c, c, characterFontData);
            return page->glyphDataForCharacter(c);
#else
            page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
#endif
        }
        return data;
    }

    // Even system fallback can fail; use the missing glyph in that case.
    // FIXME: It would be nicer to use the missing glyph from the last resort font instead.
    GlyphData data = primaryFont()->missingGlyphData();
    if (!useSmallCapsFont) {
#if OS(WINCE)
        // See comment about WINCE GDI handling near setGlyphDataForCharacter above.
        page->setGlyphDataForCharacter(c, c, data.fontData);
        return page->glyphDataForCharacter(c);
#else
        page->setGlyphDataForCharacter(c, data.glyph, data.fontData);
#endif
    }
    return data;
}