ColorEdges

#include <vtkCamera.h>
#include <vtkDataSetAttributes.h>
#include <vtkGraphLayoutView.h>
#include <vtkIntArray.h>
#include <vtkLookupTable.h>
#include <vtkMutableDirectedGraph.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkViewTheme.h>

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkMutableDirectedGraph> graph;

  // Create a graph.
  vtkIdType v1 = graph->AddVertex();
  vtkIdType v2 = graph->AddVertex();
  vtkIdType v3 = graph->AddVertex();
  graph->AddEdge(v1, v2);
  graph->AddEdge(v2, v3);

  // Create the color array.
  vtkNew<vtkIntArray> edgeColors;
  edgeColors->SetNumberOfComponents(1);
  edgeColors->SetName("Color");

  vtkNew<vtkLookupTable> lookupTable;
  lookupTable->SetNumberOfTableValues(2);
  lookupTable->SetTableValue(0, colors->GetColor4d("Red").GetData());
  lookupTable->SetTableValue(1, colors->GetColor4d("Lime").GetData());
  lookupTable->Build();

  edgeColors->InsertNextValue(0);
  edgeColors->InsertNextValue(1);

  // Add the color array to the graph.
  graph->GetEdgeData()->AddArray(edgeColors);

  vtkNew<vtkGraphLayoutView> graphLayoutView;
  graphLayoutView->AddRepresentationFromInput(graph);
  // Needs VTK::InfovisBoostGraphAlgorithms.
  // graphLayoutView->SetLayoutStrategyToTree();
  graphLayoutView->SetLayoutStrategy("Simple 2D");

  graphLayoutView->SetEdgeColorArrayName("Color");
  graphLayoutView->ColorEdgesOn();

  vtkNew<vtkViewTheme> theme;
  theme->SetCellLookupTable(lookupTable);

  graphLayoutView->ApplyViewTheme(theme);
  graphLayoutView->ResetCamera();
  // graphLayoutView->GetRenderer()->SetBackground(
  //    colors->GetColor3d("Navy").GetData());
  // graphLayoutView->GetRenderer()->SetBackground2(
  //    colors->GetColor3d("MidnightBlue").GetData());
  graphLayoutView->GetRenderer()->GetActiveCamera()->Zoom(0.8);
  graphLayoutView->GetRenderWindow()->SetWindowName("ColorEdges");
  graphLayoutView->GetInteractor()->Initialize();
  graphLayoutView->GetInteractor()->Start();

  return EXIT_SUCCESS;
}

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(ColorEdges)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonDataModel
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
  ViewsCore
  ViewsInfovis
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "ColorEdges: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(ColorEdges MACOSX_BUNDLE ColorEdges.cxx )
  target_link_libraries(ColorEdges PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS ColorEdges
  MODULES ${VTK_LIBRARIES}
)

cd ColorEdges/build

cmake ..

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

make

./ColorEdges