Method EmitPath

src/pdf/PDFUtils.cpp:277–349

}  // namespace

void PDFUtils::EmitPath(const Path& path, bool doConsumeDegerates,
                        const std::shared_ptr<MemoryWriteStream>& content) {
  if (path.isEmpty()) {
    PDFUtils::AppendRectangle({0, 0, 0, 0}, content);
    return;
  }
  // Filling a path with no area results in a drawing in PDF renderers but
  // Chrome expects to be able to draw some such entities with no visible
  // result, so we detect those cases and discard the drawing for them.
  // Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y).

  auto rect = Rect::MakeEmpty();
  bool isClosed = true;  // Both closure and direction need to be checked.
  bool isReversed = false;
  if (path.isRect(&rect, &isClosed, &isReversed) && isClosed &&
      (!isReversed || PathFillType::EvenOdd == path.getFillType())) {
    PDFUtils::AppendRectangle(rect, content);
    return;
  }

  enum class SkipFillState {
    Empty,
    SingleLine,
    NonSingleLine,
  };

  auto fillState = SkipFillState::Empty;
  auto lastMovePt = Point::Make(0, 0);
  auto currentSegment = MemoryWriteStream::Make();

  auto pathIterator = [&](PathVerb verb, const Point points[4], void* /*info*/) -> void {
    switch (verb) {
      case PathVerb::Move:
        MoveTo(points[0].x, points[0].y, currentSegment);
        lastMovePt = points[0];
        fillState = SkipFillState::Empty;
        break;
      case PathVerb::Line:
        if (!doConsumeDegerates || !AllPointsEqual(points, 2)) {
          AppendLine(points[1].x, points[1].y, currentSegment);
          if ((fillState == SkipFillState::Empty) && (points[0] != lastMovePt)) {
            fillState = SkipFillState::SingleLine;
            break;
          }
          fillState = SkipFillState::NonSingleLine;
        }
        break;
      case PathVerb::Quad:
        if (!doConsumeDegerates || !AllPointsEqual(points, 3)) {
          AppendQuad(points, currentSegment);
          fillState = SkipFillState::NonSingleLine;
        }
        break;
      case PathVerb::Cubic:
        if (!doConsumeDegerates || !AllPointsEqual(points, 4)) {
          AppendCubic(points[1].x, points[1].y, points[2].x, points[2].y, points[3].x, points[3].y,
                      currentSegment);
          fillState = SkipFillState::NonSingleLine;