Method PrepareGeometry

libs/drape_frontend/route_shape.cpp:151–269

}

void RouteShape::PrepareGeometry(std::vector<m2::PointD> const & path, m2::PointD const & pivot,
                                 std::vector<glsl::vec4> const & segmentsColors, float baseDepth,
                                 std::vector<GeometryBufferData<GeometryBuffer>> & geometryBufferData)
{
  ASSERT(path.size() > 1, ());

  // Construct segments.
  std::vector<LineSegment> segments;
  segments.reserve(path.size() - 1);
  ConstructLineSegments(path, segmentsColors, segments);

  if (segments.empty())
    return;

  // Build geometry.
  float length = 0.0f;
  for (auto const & segment : segments)
    length += glsl::length(segment.m_points[EndPoint] - segment.m_points[StartPoint]);

  geometryBufferData.push_back({});

  uint32_t constexpr kMinVertices = 5000;
  double constexpr kMinExtent = mercator::Bounds::kRangeX / (1 << 10);

  float depth = baseDepth;
  float const depthStep = rs::kRouteDepth / (1 + segments.size());
  int const lastIndex = static_cast<int>(segments.size() - 1);
  for (int i = lastIndex; i >= 0; i--)
  {
    auto & geomBufferData = geometryBufferData.back();
    auto & geometry = geomBufferData.m_geometry;
    auto & joinsGeometry = geomBufferData.m_joinsGeometry;

    UpdateNormals(&segments[i], (i > 0) ? &segments[i - 1] : nullptr, i < lastIndex ? &segments[i + 1] : nullptr);

    geomBufferData.m_boundingBox.Add(glsl::FromVec2(segments[i].m_points[StartPoint]));
    geomBufferData.m_boundingBox.Add(glsl::FromVec2(segments[i].m_points[EndPoint]));

    // Generate main geometry.
    m2::PointD const startPt =
        MapShape::ConvertToLocal(glsl::FromVec2(segments[i].m_points[StartPoint]), pivot, kShapeCoordScalar);
    m2::PointD const endPt =
        MapShape::ConvertToLocal(glsl::FromVec2(segments[i].m_points[EndPoint]), pivot, kShapeCoordScalar);

    glsl::vec3 const startPivot = glsl::vec3(glsl::ToVec2(startPt), depth);
    glsl::vec3 const endPivot = glsl::vec3(glsl::ToVec2(endPt), depth);
    depth += depthStep;

    float const startLength = length - glsl::length(segments[i].m_points[EndPoint] - segments[i].m_points[StartPoint]);

    glsl::vec2 const leftNormalStart = GetNormal(segments[i], true /* isLeft */, StartNormal);
    glsl::vec2 const rightNormalStart = GetNormal(segments[i], false /* isLeft */, StartNormal);
    glsl::vec2 const leftNormalEnd = GetNormal(segments[i], true /* isLeft */, EndNormal);
    glsl::vec2 const rightNormalEnd = GetNormal(segments[i], false /* isLeft */, EndNormal);

    float const projLeftStart = -segments[i].m_leftWidthScalar[StartPoint].y;
    float const projLeftEnd = segments[i].m_leftWidthScalar[EndPoint].y;
    float const projRightStart = -segments[i].m_rightWidthScalar[StartPoint].y;