Method resolveTextAlignment

src/layers/TextLayer.cpp:373–452

}

void TextLayer::resolveTextAlignment(const std::vector<std::shared_ptr<GlyphLine>>& glyphLines,
                                     float emptyAdvance,
                                     std::vector<std::shared_ptr<GlyphInfo>>& finalGlyphInfos,
                                     std::vector<Point>& positions) const {
  if (glyphLines.empty()) {
    return;
  }

  float xOffset = 0.0f;
  float yOffset = 0.0f;
  for (size_t i = 0; i < glyphLines.size(); ++i) {
    const auto& glyphLine = glyphLines[i];
    const auto lineGlyphCount = glyphLine->getGlyphCount();

    const auto lineWidth = glyphLine->getLineWidth();
    const auto lineHeight = getLineHeight(glyphLine);

    xOffset = 0.0f;
    yOffset += lineHeight;
    float spaceWidth = 0.0f;

    if (_width != 0.0f) {
      switch (_textAlign) {
        case TextAlign::Left:
          // do nothing
          break;
        case TextAlign::Center:
          xOffset = (_width - lineWidth) / 2.0f;
          break;
        case TextAlign::Right:
          xOffset = _width - lineWidth;
          break;
        case TextAlign::Justify: {
          // 1. Each line must have more than one character
          if (lineGlyphCount <= 1) {
            break;
          }

          // 2. If auto-wrap is disabled and the width is set very small, spaceWidth might be negative, causing characters to overlap. This needs to be avoided.
          if (_width < lineWidth) {
            break;
          }

          // 3. The last line should not be justified (align it to the left), or if auto-wrap is disabled and there is only one line of text, it should be justified.
          if (i < glyphLines.size() - 1 || (!_autoWrap && 1 == glyphLines.size())) {
            spaceWidth = (_width - lineWidth) / static_cast<float>(lineGlyphCount - 1);
          }
          break;
        }
        default:
          break;
      }
    }

    for (size_t index = 0; index < lineGlyphCount; ++index) {
      const auto& glyphInfo = glyphLine->getGlyphInfo(index);
      if (glyphInfo == nullptr) {
        continue;