FontGlyphs.cpp   [plain text]

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

#include "Font.h"
#include "FontCache.h"
#include "SegmentedFontData.h"
#include <wtf/unicode/Unicode.h>

namespace WebCore {


FontGlyphs::FontGlyphs(PassRefPtr<FontSelector> fontSelector)
    : m_pageZero(0)
    , m_cachedPrimarySimpleFontData(0)
    , m_fontSelector(fontSelector)
    , m_fontSelectorVersion(m_fontSelector ? m_fontSelector->version() : 0)
    , m_familyIndex(0)
    , m_generation(fontCache()->generation())
    , m_pitch(UnknownPitch)
    , m_loadingCustomFonts(false)
    , m_isForPlatformFont(false)
{
}

FontGlyphs::FontGlyphs(const FontPlatformData& platformData)
    : m_pageZero(0)
    , m_cachedPrimarySimpleFontData(0)
    , m_fontSelector(0)
    , m_fontSelectorVersion(0)
    , m_familyIndex(cAllFamiliesScanned)
    , m_generation(fontCache()->generation())
    , m_pitch(UnknownPitch)
    , m_loadingCustomFonts(false)
    , m_isForPlatformFont(true)
{
    RefPtr<FontData> fontData = fontCache()->getCachedFontData(&platformData);
    m_realizedFontData.append(fontData.release());
}

void FontGlyphs::releaseFontData()
{
    unsigned numFonts = m_realizedFontData.size();
    for (unsigned i = 0; i < numFonts; ++i) {
        if (m_realizedFontData[i]->isCustomFont())
            continue;
        ASSERT(!m_realizedFontData[i]->isSegmented());
        fontCache()->releaseFontData(static_cast<const SimpleFontData*>(m_realizedFontData[i].get()));
    }
}

void FontGlyphs::determinePitch(const FontDescription& description) const
{
    const FontData* fontData = primaryFontData(description);
    if (!fontData->isSegmented())
        m_pitch = static_cast<const SimpleFontData*>(fontData)->pitch();
    else {
        const SegmentedFontData* segmentedFontData = static_cast<const SegmentedFontData*>(fontData);
        unsigned numRanges = segmentedFontData->numRanges();
        if (numRanges == 1)
            m_pitch = segmentedFontData->rangeAt(0).fontData()->pitch();
        else
            m_pitch = VariablePitch;
    }
}

const FontData* FontGlyphs::realizeFontDataAt(const FontDescription& description, unsigned realizedFontIndex) const
{
    if (realizedFontIndex < m_realizedFontData.size())
        return m_realizedFontData[realizedFontIndex].get(); // This fallback font is already in our list.

    // Make sure we're not passing in some crazy value here.
    ASSERT(realizedFontIndex == m_realizedFontData.size());

    if (m_familyIndex == cAllFamiliesScanned)
        return 0;

    // Ask the font cache for the font data.
    // We are obtaining this font for the first time. We keep track of the families we've looked at before
    // in |m_familyIndex|, so that we never scan the same spot in the list twice. getFontData will adjust our
    // |m_familyIndex| as it scans for the right font to make.
    ASSERT(fontCache()->generation() == m_generation);
    RefPtr<FontData> result = fontCache()->getFontData(description, m_familyIndex, m_fontSelector.get());
    if (result) {
        m_realizedFontData.append(result);
        if (result->isLoading())
            m_loadingCustomFonts = true;
    }
    return result.get();
}

static inline bool isInRange(UChar32 character, UChar32 lowerBound, UChar32 upperBound)
{
    return character >= lowerBound && character <= upperBound;
}

static bool shouldIgnoreRotation(UChar32 character)
{
    if (character == 0x000A7 || character == 0x000A9 || character == 0x000AE)
        return true;

    if (character == 0x000B6 || character == 0x000BC || character == 0x000BD || character == 0x000BE)
        return true;

    if (isInRange(character, 0x002E5, 0x002EB))
        return true;
    
    if (isInRange(character, 0x01100, 0x011FF) || isInRange(character, 0x01401, 0x0167F) || isInRange(character, 0x01800, 0x018FF))
        return true;

    if (character == 0x02016 || character == 0x02018 || character == 0x02019 || character == 0x02020 || character == 0x02021
        || character == 0x2030 || character == 0x02031)
        return true;

    if (isInRange(character, 0x0203B, 0x0203D) || character == 0x02042 || character == 0x02044 || character == 0x02047
        || character == 0x02048 || character == 0x02049 || character == 0x2051)
        return true;

    if (isInRange(character, 0x02065, 0x02069) || isInRange(character, 0x020DD, 0x020E0)
        || isInRange(character, 0x020E2, 0x020E4) || isInRange(character, 0x02100, 0x02117)
        || isInRange(character, 0x02119, 0x02131) || isInRange(character, 0x02133, 0x0213F))
        return true;

    if (isInRange(character, 0x02145, 0x0214A) || character == 0x0214C || character == 0x0214D
        || isInRange(character, 0x0214F, 0x0218F))
        return true;

    if (isInRange(character, 0x02300, 0x02307) || isInRange(character, 0x0230C, 0x0231F)
        || isInRange(character, 0x02322, 0x0232B) || isInRange(character, 0x0237D, 0x0239A)
        || isInRange(character, 0x023B4, 0x023B6) || isInRange(character, 0x023BA, 0x023CF)
        || isInRange(character, 0x023D1, 0x023DB) || isInRange(character, 0x023E2, 0x024FF))
        return true;

    if (isInRange(character, 0x025A0, 0x02619) || isInRange(character, 0x02620, 0x02767)
        || isInRange(character, 0x02776, 0x02793) || isInRange(character, 0x02B12, 0x02B2F)
        || isInRange(character, 0x02B4D, 0x02BFF) || isInRange(character, 0x02E80, 0x03007))
        return true;

    if (character == 0x03012 || character == 0x03013 || isInRange(character, 0x03020, 0x0302F)
        || isInRange(character, 0x03031, 0x0309F) || isInRange(character, 0x030A1, 0x030FB)
        || isInRange(character, 0x030FD, 0x0A4CF))
        return true;

    if (isInRange(character, 0x0A840, 0x0A87F) || isInRange(character, 0x0A960, 0x0A97F)
        || isInRange(character, 0x0AC00, 0x0D7FF) || isInRange(character, 0x0E000, 0x0FAFF))
        return true;

    if (isInRange(character, 0x0FE10, 0x0FE1F) || isInRange(character, 0x0FE30, 0x0FE48)
        || isInRange(character, 0x0FE50, 0x0FE57) || isInRange(character, 0x0FE5F, 0x0FE62)
        || isInRange(character, 0x0FE67, 0x0FE6F))
        return true;

    if (isInRange(character, 0x0FF01, 0x0FF07) || isInRange(character, 0x0FF0A, 0x0FF0C)
        || isInRange(character, 0x0FF0E, 0x0FF19) || character == 0x0FF1B || isInRange(character, 0x0FF1F, 0x0FF3A))
        return true;

    if (character == 0x0FF3C || character == 0x0FF3E)
        return true;

    if (isInRange(character, 0x0FF40, 0x0FF5A) || isInRange(character, 0x0FFE0, 0x0FFE2)
        || isInRange(character, 0x0FFE4, 0x0FFE7) || isInRange(character, 0x0FFF0, 0x0FFF8)
        || character == 0x0FFFD)
        return true;

    if (isInRange(character, 0x13000, 0x1342F) || isInRange(character, 0x1B000, 0x1B0FF)
        || isInRange(character, 0x1D000, 0x1D1FF) || isInRange(character, 0x1D300, 0x1D37F)
        || isInRange(character, 0x1F000, 0x1F64F) || isInRange(character, 0x1F680, 0x1F77F))
        return true;
    
    if (isInRange(character, 0x20000, 0x2FFFD) || isInRange(character, 0x30000, 0x3FFFD))
        return true;

    return false;
}

static inline std::pair<GlyphData, GlyphPage*> glyphDataAndPageForCJKCharacterWithoutSyntheticItalic(UChar32 character, GlyphData& data, GlyphPage* page, unsigned pageNumber)
{
    RefPtr<SimpleFontData> nonItalicFontData = data.fontData->nonSyntheticItalicFontData();
    GlyphPageTreeNode* nonItalicNode = GlyphPageTreeNode::getRootChild(nonItalicFontData.get(), pageNumber);
    GlyphPage* nonItalicPage = nonItalicNode->page();
    if (nonItalicPage) {
        GlyphData nonItalicData = nonItalicPage->glyphDataForCharacter(character);
        if (nonItalicData.fontData)
            return std::make_pair(nonItalicData, nonItalicPage);
    }
    return std::make_pair(data, page);
}
    
static inline std::pair<GlyphData, GlyphPage*> glyphDataAndPageForNonCJKCharacterWithGlyphOrientation(UChar32 character, NonCJKGlyphOrientation orientation, GlyphData& data, GlyphPage* page, unsigned pageNumber)
{
    if (orientation == NonCJKGlyphOrientationUpright || shouldIgnoreRotation(character)) {
        RefPtr<SimpleFontData> uprightFontData = data.fontData->uprightOrientationFontData();
        GlyphPageTreeNode* uprightNode = GlyphPageTreeNode::getRootChild(uprightFontData.get(), pageNumber);
        GlyphPage* uprightPage = uprightNode->page();
        if (uprightPage) {
            GlyphData uprightData = uprightPage->glyphDataForCharacter(character);
            // If the glyphs are the same, then we know we can just use the horizontal glyph rotated vertically to be upright.
            if (data.glyph == uprightData.glyph)
                return std::make_pair(data, page);
            // The glyphs are distinct, meaning that the font has a vertical-right glyph baked into it. We can't use that
            // glyph, so we fall back to the upright data and use the horizontal glyph.
            if (uprightData.fontData)
                return std::make_pair(uprightData, uprightPage);
        }
    } else if (orientation == NonCJKGlyphOrientationVerticalRight) {
        RefPtr<SimpleFontData> verticalRightFontData = data.fontData->verticalRightOrientationFontData();
        GlyphPageTreeNode* verticalRightNode = GlyphPageTreeNode::getRootChild(verticalRightFontData.get(), pageNumber);
        GlyphPage* verticalRightPage = verticalRightNode->page();
        if (verticalRightPage) {
            GlyphData verticalRightData = verticalRightPage->glyphDataForCharacter(character);
            // If the glyphs are distinct, we will make the assumption that the font has a vertical-right glyph baked
            // into it.
            if (data.glyph != verticalRightData.glyph)
                return std::make_pair(data, page);
            // The glyphs are identical, meaning that we should just use the horizontal glyph.
            if (verticalRightData.fontData)
                return std::make_pair(verticalRightData, verticalRightPage);
        }
    }
    return std::make_pair(data, page);
}

std::pair<GlyphData, GlyphPage*> FontGlyphs::glyphDataAndPageForCharacter(const FontDescription& description, UChar32 c, bool mirror, FontDataVariant variant) const
{
    ASSERT(isMainThread());

    if (variant == AutoVariant) {
        if (description.smallCaps() && !primarySimpleFontData(description)->isSVGFont()) {
            UChar32 upperC = WTF::Unicode::toUpper(c);
            if (upperC != c) {
                c = upperC;
                variant = SmallCapsVariant;
            } else
                variant = NormalVariant;
        } else
            variant = NormalVariant;
    }

    if (mirror)
        c = WTF::Unicode::mirroredChar(c);

    unsigned pageNumber = (c / GlyphPage::size);

    GlyphPageTreeNode* node = pageNumber ? m_pages.get(pageNumber) : m_pageZero;
    if (!node) {
        node = GlyphPageTreeNode::getRootChild(realizeFontDataAt(description, 0), pageNumber);
        if (pageNumber)
            m_pages.set(pageNumber, node);
        else
            m_pageZero = node;
    }

    GlyphPage* page = 0;
    if (variant == NormalVariant) {
        // Fastest loop, for the common case (normal variant).
        while (true) {
            page = node->page();
            if (page) {
                GlyphData data = page->glyphDataForCharacter(c);
                if (data.fontData && (data.fontData->platformData().orientation() == Horizontal || data.fontData->isTextOrientationFallback()))
                    return std::make_pair(data, page);

                if (data.fontData) {
                    if (Font::isCJKIdeographOrSymbol(c)) {
                        if (!data.fontData->hasVerticalGlyphs()) {
                            // Use the broken ideograph font data. The broken ideograph font will use the horizontal width of glyphs
                            // to make sure you get a square (even for broken glyphs like symbols used for punctuation).
                            variant = BrokenIdeographVariant;
                            break;
                        }
#if PLATFORM(MAC)
                        else if (data.fontData->platformData().syntheticOblique())
                            return glyphDataAndPageForCJKCharacterWithoutSyntheticItalic(c, data, page, pageNumber);
#endif
                    } else
                        return glyphDataAndPageForNonCJKCharacterWithGlyphOrientation(c, description.nonCJKGlyphOrientation(), data, page, pageNumber);

                    return std::make_pair(data, page);
                }

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

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


}