C++ u16string::substr方法代码示例

    std::vector<TextFlow::Word> TextFlow::calculateFitWord(std::u16string content, int maxPixelWidth, float scale) const
    {
        // Calculate word from content
        Word word = calculateWord(content, scale);

        // End of recursion
        if ((content.size() == 1 && word.pixelWidth > maxPixelWidth) || content.empty())
        {
            // Return empty vector as signal of failure
            return std::vector<Word>();
        }
        else if (word.pixelWidth <= maxPixelWidth)
        {
            // If word length is ok, just return it
            return std::vector<Word>(1, word);
        }
        else
        {
            // Word is too wide and content longer than 1, split it!
            int length = (int)content.size();
            int left = length / 2;
            int right = length - left;

            // Combine results from recursive call
            std::vector<Word> leftWord = calculateFitWord(content.substr(0, left), maxPixelWidth, scale);
            std::vector<Word> rightWord = calculateFitWord(content.substr(left+1, right), maxPixelWidth, scale);

            // If one or more of both are empty, forget it
            if (leftWord.empty() || rightWord.empty())
            {
                return std::vector<Word>();
            }
            else
            {
                std::vector<Word> words(leftWord);
                words.insert(words.end(), rightWord.begin(), rightWord.end());
                return words;
            }
        }
    }

bool UserDictionaryDecoder::DecodeArticle(
        IBitStream *bstr,
        std::u16string &res,
        std::u16string const& prefix,
        LenTable& ltArticles,
        std::vector<char32_t>& articleSymbols)
{
    unsigned len = bstr->read(16);
    if (len == 0xFFFF) {
        len = bstr->read(32);
    }
    res.clear();
    unsigned symIdx;
    std::vector<uint32_t> vec;
    while ((unsigned)res.length() < len) {
        ltArticles.Decode(*bstr, symIdx);
        unsigned sym = articleSymbols.at(symIdx);
        vec.push_back(sym);
        if (sym >= 0x10000) {
            if (sym >= 0x10040) {
                unsigned startIdx = bstr->read(BitLength(len));
                unsigned len = sym - 0x1003d;
                res += res.substr(startIdx, len);
                vec.push_back(startIdx);
            } else {
                unsigned startIdx = bstr->read(BitLength(prefix.length()));
                unsigned len = sym - 0xfffd;
                res += prefix.substr(startIdx, len);
                vec.push_back(startIdx);
            }
        } else {
            res += (char16_t)sym;
        }
    }
    return true;
}

    void TextFlow::specialCalculateMesh(
            std::u16string streamlinedContent,
            float lineHeight, std::vector<glm::vec3>& rVertices,
            std::vector<glm::vec2>& rTextureCoordinates)
    {
		// Reset flow width to get longest line's width of this computation
		mFlowWidth = 0;

        // OpenGL setup done in calling method

        // Get size of space character
        float pixelOfSpace = 0;

        Glyph const * pGlyph = mpFont->getGlyph(mFontSize, u' ');
        if (pGlyph == NULL)
        {
            throwWarning(
                OperationNotifier::Operation::RUNTIME,
                "TextFlow creation does not find space sign in font");
        }
        else
        {
            pixelOfSpace = mScale * pGlyph->advance.x;
        }

        // Create mark for overflow
        Word overflowMark = calculateWord(TEXT_FLOW_OVERFLOW_MARK, mScale);

        // Get pararaphs separated by \n
        std::vector<std::u16string> paragraphs;
        std::u16string paragraphDelimiter = u"\n";

        // Seperate into paragraphs
        size_t pos = 0;
        std::u16string token;
        while ((pos = streamlinedContent.find(paragraphDelimiter)) != std::u16string::npos)
        {
            token = streamlinedContent.substr(0, pos);
            paragraphs.push_back(token);
            streamlinedContent.erase(0, pos + paragraphDelimiter.length());
        }
        paragraphs.push_back(streamlinedContent); // Last paragraph (paragraphs never empty)

        // Do not generate text flow mesh when there is a failure
        bool failure = false;

        // Go over paragraphs (pens are in local pixel coordinate system with origin in lower left corner of element)
        float yPixelPen = -lineHeight; // First line should be also inside flow
        for (std::u16string& rPargraph : paragraphs)
        {
            // Get words out of paragraph
            std::vector<Word> words;
            std::u16string wordDelimiter = u" ";
            while ((pos = rPargraph.find(wordDelimiter)) != std::u16string::npos)
            {
                token = rPargraph.substr(0, pos);
                rPargraph.erase(0, pos + wordDelimiter.length());
                failure |= !insertFitWord(words, token, mWidth, mScale);
            }

            // Add last token from paragraph as well
            failure |= !insertFitWord(words, rPargraph, mWidth, mScale);

            // Failure appeared, forget it
            if (!failure)
            {
                // Prepare some values
                uint wordIndex = 0;
                bool hasNext = !words.empty();

                // Go over lines to write paragraph
                while (hasNext && abs(yPixelPen) <= mHeight)
                {
                    // Collect words in one line
                    std::vector<Word const *> line;
                    float wordsPixelWidth = 0;
                    float newWordsWithSpacesPixelWidth = 0;

                    // Still words in the paragraph and enough space? Fill into line!
                    while (hasNext && newWordsWithSpacesPixelWidth <= mWidth)
                    {
                        // First word should always fit into width because of previous checks
                        wordsPixelWidth += words[wordIndex].pixelWidth;
                        line.push_back(&words[wordIndex]);
                        wordIndex++;

                        if (wordIndex >= words.size())
                        {
                            // No words in paragraph left
                            hasNext = false;
                        }
                        else
                        {
                            // Calculate next width of line
                            newWordsWithSpacesPixelWidth = std::ceil(
                                (wordsPixelWidth + (float)words[wordIndex].pixelWidth) // Words size (old ones and new one)
                                + (((float)line.size()) - 1.0f) * pixelOfSpace); // Spaces between words
                        }
                    }

//.........这里部分代码省略.........