Method CreateTriangleLineIndexBuffer

Rendering/OpenGL2/vtkOpenGLIndexBufferObject.cxx:332–344

used to create an IBO for primitives as lines. This method treats each line segment as independent. So for a triangle mesh you would get 6 verts per triangle 3 edges * 2 verts each. With a line loop you only get 3 verts so half the storage. but... line loops are slower than line segments.

// 3 edges * 2 verts each.  With a line loop you only get 3 verts so half the storage.
// but... line loops are slower than line segments.
size_t vtkOpenGLIndexBufferObject::CreateTriangleLineIndexBuffer(vtkCellArray* cells)
{
  if (!cells->GetNumberOfCells())
  {
    this->IndexCount = 0;
    return 0;
  }
  std::vector<unsigned int> indexArray;
  AppendTriangleLineIndexBuffer(indexArray, cells, 0);
  this->Upload(indexArray, vtkOpenGLIndexBufferObject::ElementArrayBuffer);
  this->IndexCount = indexArray.size();
  return indexArray.size();
}

// used to create an IBO for primitives as lines.  This method treats each
// line segment as independent.  So for a line strip you would get multiple