Method GenerateSelectionMarker

libs/drape_frontend/selection_shape_generator.cpp:135–182

static

// static
drape_ptr<RenderNode> SelectionShapeGenerator::GenerateSelectionMarker(ref_ptr<dp::GraphicsContext> context,
                                                                       ref_ptr<dp::TextureManager> mng)
{
  size_t constexpr kTriangleCount = 40;
  size_t constexpr kVertexCount = 3 * kTriangleCount;
  auto const etalonSector = static_cast<float>(2.0 * math::pi / kTriangleCount);

  dp::TextureManager::ColorRegion color;
  mng->GetColorRegion(df::GetColorConstant(df::kSelectionColor), color);
  auto const colorCoord = glsl::ToVec2(color.GetTexRect().Center());

  buffer_vector<MarkerVertex, kTriangleCount> buffer;

  glsl::vec2 const startNormal(0.0f, 1.0f);

  for (size_t i = 0; i < kTriangleCount + 1; ++i)
  {
    auto const normal = glsl::rotate(startNormal, i * etalonSector);
    auto const nextNormal = glsl::rotate(startNormal, (i + 1) * etalonSector);

    buffer.emplace_back(glsl::vec2(0.0f, 0.0f), colorCoord);
    buffer.emplace_back(normal, colorCoord);
    buffer.emplace_back(nextNormal, colorCoord);
  }

  auto state = CreateRenderState(gpu::Program::Accuracy, DepthLayer::OverlayLayer);
  state.SetColorTexture(color.GetTexture());
  state.SetDepthTestEnabled(false);

  drape_ptr<RenderNode> renderNode;
  {
    dp::Batcher batcher(kTriangleCount * dp::Batcher::IndexPerTriangle, kVertexCount);
    batcher.SetBatcherHash(static_cast<uint64_t>(BatcherBucket::Default));
    dp::SessionGuard guard(context, batcher,
                           [&renderNode](dp::RenderState const & state, drape_ptr<dp::RenderBucket> && b)
    {
      drape_ptr<dp::RenderBucket> bucket = std::move(b);
      ASSERT(bucket->GetOverlayHandlesCount() == 0, ());
      renderNode = make_unique_dp<RenderNode>(state, bucket->MoveBuffer());
    });

    dp::AttributeProvider provider(1 /* stream count */, kVertexCount);
    provider.InitStream(0 /* stream index */, GetMarkerBindingInfo(), make_ref(buffer.data()));

    batcher.InsertTriangleList(context, state, make_ref(&provider), nullptr);
  }
  return renderNode;
}

// static
drape_ptr<RenderNode> SelectionShapeGenerator::GenerateTrackSelectionMarker(ref_ptr<dp::GraphicsContext> context,