Function lineBreak

snap_drawing/src/snap_drawing/cpp/Text/TextLayoutBuilder.cpp:88–145

};

static LineBreakResult lineBreak(const ShapedGlyph* begin,
                                 const ShapedGlyph* end,
                                 LineBreakStrategy strategy,
                                 Scalar containerWidth,
                                 Scalar accumulatedWidth) {
    const auto* it = begin;
    // The last iterator that we can safely break on
    const auto* lastSafeBreakIt = it;
    auto prevWasWhitespace = false;

    while (it < end) {
        if (Unicode::isNewline(it->character())) {
            return LineBreakResult(it, it + 1, true, true);
        }

        accumulatedWidth += it->advanceX;

        auto isWhitespace = Unicode::isBreakingWhitespace(it->character());

        switch (strategy) {
            case LineBreakStrategy::ByWord:
                if (isWhitespace && !prevWasWhitespace) {
                    lastSafeBreakIt = it;
                }
                break;
            case LineBreakStrategy::ByCharacter:
                if (!it->unsafeToBreak() && !prevWasWhitespace) {
                    lastSafeBreakIt = it;
                }
                break;
        }

        if (accumulatedWidth > containerWidth) {
            // Reached the end of our container

            if (!isWhitespace) {
                // If we are not in a whitespace, we move back the iterator
                // down to our first safe breaking point in order to consume
                // all the breaking whitespaces that might be there.
                // This is to set our next iterator on the first word instead
                // of having leading whitespaces.
                it = lastSafeBreakIt;
            }

            // Eat up all the trailing whitespaces
            while (it < end && Unicode::isBreakingWhitespace(it->character())) {
                it++;
            }

            return LineBreakResult(lastSafeBreakIt, it, true, false);
        }

        prevWasWhitespace = isWhitespace;
        it++;
    }

    return LineBreakResult(it, it, false, false);
}