Method drawTo

src/roo_display/composition/streamable_stack.cpp:761–788

}  // namespace

void StreamableStack::drawTo(const Surface& s) const {
  Box bounds = Box::Intersect(s.clip_box(), extents_.translate(s.dx(), s.dy()));
  if (bounds.empty()) return;
  std::vector<internal::BufferingStream> streams;
  std::vector<BlendingMode> blending_modes;
  Composition composition(bounds);
  for (const auto& input : inputs_) {
    Box extents =
        Box::Intersect(input.extents(), bounds.translate(-s.dx(), -s.dy()));
    if (composition.Add(extents.translate(s.dx(), s.dy()),
                        input.blending_mode())) {
      streams.emplace_back(input.createStream(extents), extents.area());
    } else {
      streams.emplace_back(nullptr, 0);
    }
    blending_modes.push_back(input.blending_mode());
  }

  Program prg;
  composition.Compile(&prg);
  Engine engine(&prg);
  if (s.fill_mode() == FillMode::kExtents) {
    WriteRect(&engine, bounds, &*streams.begin(), &*blending_modes.begin(), s);
  } else {
    WriteVisible(&engine, bounds, &*streams.begin(), &*blending_modes.begin(),
                 s);
  }
}

std::unique_ptr<PixelStream> StreamableStack::createStream() const {
  Box bounds = extents();