Method UpdateLineSpans

src/window.cpp:417–652

This is the most expensive part of window update; applying line span generation for wrapped text and unicode character sizes which may vary in byte count and physical pixel width It can take about a millisecond to do during editing on release buildj; but this is fast enough for now. There are several ways in which this function can be optimized: - Only regenerate spans which have changed, since on

// - Have a no-wrap text mode and save a lot of the wrapping work.
// - Do some threading
void ZepWindow::UpdateLineSpans()
{
    TIME_SCOPE(UpdateLineSpans);

    m_maxDisplayLines = (long)std::max(0.0f, std::floor(m_textRegion->rect.Height() / m_defaultLineSize));

    const auto& textBuffer = m_pBuffer->GetWorkingBuffer();

    long bufferLine = 0;
    long spanLine = 0;
    float bufferPosYPx = 0.0f;
    float xOffset = m_xPad;

    bool isMarkdown = m_pBuffer->GetFileExtension() == ".md";

    // Nuke the existing spans
    // In future we can in-place modify for speed
    std::for_each(m_windowLines.begin(), m_windowLines.end(), [](SpanInfo* pInfo) { delete pInfo; });
    m_windowLines.clear();

    //auto& display = GetEditor().GetDisplay();

    auto widgetMarkers = m_pBuffer->GetRangeMarkers(RangeMarkerType::Widget);
    auto itrWidgetMarkers = widgetMarkers.begin();

    // Process every buffer line
    for (;;)
    {
        // We haven't processed this line yet, so we can't display anything
        // else
        if (m_pBuffer->GetLineCount() <= bufferLine)
            break;

        ByteRange lineByteRange;
        if (!m_pBuffer->GetLineOffsets(bufferLine, lineByteRange))
            break;

        // Padding at the top of the line
        NVec2f topPadding = NVec2f(DPI_Y((float)GetEditor().GetConfig().lineMargins.x), DPI_Y((float)GetEditor().GetConfig().lineMargins.y));

        auto markersOnLine = m_pBuffer->GetRangeMarkersOnLine(RangeMarkerType::All, bufferLine);
        auto lineWidgetHeight = ArrangeLineMarkers(markersOnLine);

        // Move the line down by the height of the widget
        bufferPosYPx += lineWidgetHeight.x;

        // TODO: Find a clean way to do this extra work during layout for extensions that need it
        ZepTextType type = ZepTextType::Text;
        if (isMarkdown)
        {
            uint32_t headerCount = 0;
            // Markdown experiment
            for (auto ch = lineByteRange.first; ch < lineByteRange.second; ch += utf8_codepoint_length(textBuffer[ch]))
            {
                if (textBuffer[ch] != '#')
                    break;
                headerCount++;
            }