Method PrepareArrowGeometry

libs/drape_frontend/route_shape.cpp:271–378

}

void RouteShape::PrepareArrowGeometry(std::vector<m2::PointD> const & path, m2::PointD const & pivot,
                                      m2::RectF const & texRect, float depthStep, float depth,
                                      GeometryBufferData<ArrowGeometryBuffer> & geometryBufferData)
{
  ASSERT(path.size() > 1, ());

  // Construct segments.
  std::vector<LineSegment> segments;
  segments.reserve(path.size() - 1);
  ConstructLineSegments(path, std::vector<glsl::vec4>(), segments);

  auto & geometry = geometryBufferData.m_geometry;
  auto & joinsGeometry = geometryBufferData.m_joinsGeometry;

  m2::RectF tr = texRect;
  tr.setMinX(static_cast<float>(texRect.minX() * (1.0 - kArrowTailSize) + texRect.maxX() * kArrowTailSize));
  tr.setMaxX(static_cast<float>(texRect.minX() * kArrowHeadSize + texRect.maxX() * (1.0 - kArrowHeadSize)));

  // Build geometry.
  float const depthInc = depthStep / (segments.size() + 1);
  for (size_t i = 0; i < segments.size(); i++)
  {
    UpdateNormals(&segments[i], (i > 0) ? &segments[i - 1] : nullptr,
                  (i < segments.size() - 1) ? &segments[i + 1] : nullptr);

    geometryBufferData.m_boundingBox.Add(glsl::FromVec2(segments[i].m_points[StartPoint]));
    geometryBufferData.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::vec4 const startPivot = glsl::vec4(glsl::ToVec2(startPt), depth, 1.0);
    glsl::vec4 const endPivot = glsl::vec4(glsl::ToVec2(endPt), depth, 1.0);
    depth += depthInc;

    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);

    glsl::vec2 const uvCenter = rs::GetUV(tr, 0.5f, 0.5f);
    glsl::vec2 const uvLeft = rs::GetUV(tr, 0.5f, 0.0f);
    glsl::vec2 const uvRight = rs::GetUV(tr, 0.5f, 1.0f);

    geometry.emplace_back(startPivot, glsl::vec2(0, 0), uvCenter);
    geometry.emplace_back(startPivot, leftNormalStart, uvLeft);
    geometry.emplace_back(endPivot, glsl::vec2(0, 0), uvCenter);
    geometry.emplace_back(endPivot, leftNormalEnd, uvLeft);

    geometry.emplace_back(startPivot, rightNormalStart, uvRight);
    geometry.emplace_back(startPivot, glsl::vec2(0, 0), uvCenter);
    geometry.emplace_back(endPivot, rightNormalEnd, uvRight);
    geometry.emplace_back(endPivot, glsl::vec2(0, 0), uvCenter);

    // Generate joins.