Skip to content

Slider2D

Repository source: Slider2D

Description

This example demonstrates how to use a slider that is drawn in window coordinates - so if you move the scene the slider is not affected. Contrast this with the 3D slider widget that remains at a fixed location in the world coordinates.

If the callback is connected to InteractionEvent, the scene will update immediately. This is not ideal if the re-rendering takes significant time as it will make the interaction very choppy. If you want to move the slider and have the scene update when the mouse button is released, connect the callback to EndInteractionEvent instead.

Note

This original source code for this example is here.

Other languages

See (PythonicAPI)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

Slider2D.cxx

#include <vtkActor.h>
#include <vtkCallbackCommand.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkProperty2D.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSliderRepresentation2D.h>
#include <vtkSliderWidget.h>
#include <vtkSphereSource.h>
#include <vtkTextProperty.h>

namespace {
/**
 * @brief The Slider2DProperties struct.
 *
 * These are the default properties.
 * Instantiate the struct and modify as appropriate.
 *
 * @return The properties.
 */
struct Slider2DProperties
{
  struct _Colors
  {
    // The color of the text indicating what the slider controls.
    std::string titleColor{"White"};
    // The color of the text displaying the value.
    std::string labelColor{"White"};
    // The color of the knob that slides.
    std::string sliderColor{"White"};
    // The color of the bar.
    std::string barColor{"White"};
    // The color of the ends of the bar.
    std::string barEndsColor{"White"};
    // The color of the knob when the mouse is held on it.
    std::string selectedColor{"HotPink"};
  };

  struct _Dimensions
  {
    double tubeWidth{0.008};
    double sliderLength{0.01};
    double sliderWidth{0.02};
    double endCapLength{0.005};
    double endCapWidth{0.05};
    double titleHeight{0.03};
    double labelHeight{0.025};
  };

  struct _Position
  {
    int coordinateSystem = VTK_NORMALIZED_VIEWPORT;
    std::array<double, 2> point1{0.1, 0.1};
    std::array<double, 2> point2{0.9, 0.1};
  };

  struct _Range
  {
    double minimumValue{0.0};
    double maximumValue{1.0};
    double value{0.0};
  };

  struct _Text
  {
    // Font families are: Ariel, Courier and Times
    std::string title{};
    std::string titleFontFamily{"Arial"};
    bool titleBold{true};
    bool titleItalic{false};
    bool titleShadow{true};
    std::string labelFontFamily{"Arial"};
    bool labelBold{true};
    bool labelItalic{false};
    bool labelShadow{true};
  };

  struct _Colors Colors;
  struct _Dimensions Dimensions;
  struct _Position Position;
  struct _Range Range;
  struct _Text Text;
};

/**
 * @brief MakeSlider2DProperties
 *
 * This applies more specific values to the default Slider2DProperties.
 *
 * @return The slider 2D properties.
 */
Slider2DProperties MakeSlider2DProperties();

/**
 * @brief Make2DSliderWidget
 *
 * Make a 2D slider widget.
 *
 * @param properties The 2D slider properties.
 * @param iren The vtkInteractor.
 * @return The slider widget.
 */
vtkNew<vtkSliderWidget> Make2DSliderWidget(Slider2DProperties const& properties,
                                           vtkRenderWindowInteractor* iren);

// This does the actual work.
// Callback for the interaction.
class vtkSliderCallback : public vtkCommand
{
public:
  static vtkSliderCallback* New()
  {
    return new vtkSliderCallback;
  }
  virtual void Execute(vtkObject* caller, unsigned long, void*)
  {
    vtkSliderWidget* sliderWidget = reinterpret_cast<vtkSliderWidget*>(caller);
    auto level = static_cast<int>(vtkMath::Round(
        static_cast<vtkSliderRepresentation*>(sliderWidget->GetRepresentation())
            ->GetValue()));
    this->SphereSource->SetPhiResolution(level);
    this->SphereSource->SetThetaResolution(level);
    sliderWidget->GetSliderRepresentation()->SetValue(level);
  }
  vtkSliderCallback() : SphereSource(0)
  {
  }
  vtkSphereSource* SphereSource;
};
} // namespace

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

  // A sphere.
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(4.0);

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetInterpolationToFlat();
  actor->GetProperty()->SetColor(colors->GetColor3d("MistyRose").GetData());
  actor->GetProperty()->SetEdgeColor(colors->GetColor3d("Tomato").GetData());
  actor->GetProperty()->EdgeVisibilityOn();

  // A renderer and render window.
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("Slider2D");
  renderWindow->SetSize(640, 480);

  // An interactor
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  // Add the actors to the scene.
  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("SlateGray").GetData());

  // Render an image (lights and cameras are created automatically).
  renderWindow->Render();

  auto sp = MakeSlider2DProperties();
  sp.Range.minimumValue = 3;
  sp.Range.maximumValue = 20;
  sp.Range.value = 5;
  sp.Text.title = "Sphere Resolution";

  auto sliderWidget = Make2DSliderWidget(sp, renderWindowInteractor);
  vtkNew<vtkSliderCallback> callback;
  callback->SphereSource = sphereSource;

  sliderWidget->AddObserver(vtkCommand::InteractionEvent, callback);

  renderWindowInteractor->Initialize();
  renderWindow->Render();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

namespace {

Slider2DProperties MakeSlider2DProperties()
{
  auto sp = Slider2DProperties();

  // Set color properties:
  // Change the color of the knob that slides.
  sp.Colors.sliderColor = "Green";
  // Change the color of the text indicating what the slider controls.
  sp.Colors.titleColor = "AliceBlue";
  // Change the color of the text displaying the value.
  sp.Colors.labelColor = "AliceBlue";
  // Change the color of the knob when the mouse is held on it.
  sp.Colors.selectedColor = "DeepPink";
  // Change the color of the bar.
  sp.Colors.barColor = "MistyRose";
  // Change the color of the ends of the bar.
  sp.Colors.barEndsColor = "Yellow";
  sp.Dimensions.sliderLength = 0.05;
  sp.Dimensions.sliderWidth = 0.025;
  sp.Dimensions.endCapLength = 0.02;
  sp.Dimensions.titleHeight = 0.045;
  sp.Dimensions.labelHeight = 0.035;
  sp.Position.point1 = std::array<double, 2>{0.3, 0.1};
  sp.Position.point2 = std::array<double, 2>{0.7, 0.1};

  return sp;
}

vtkNew<vtkSliderWidget> Make2DSliderWidget(Slider2DProperties const& properties,
                                           vtkRenderWindowInteractor* iren)
{
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkSliderRepresentation2D> sliderRep;

  sliderRep->SetMinimumValue(properties.Range.minimumValue);
  sliderRep->SetMaximumValue(properties.Range.maximumValue);
  sliderRep->SetValue(properties.Range.value);
  sliderRep->SetTitleText(properties.Text.title.c_str());
  sliderRep->SetTubeWidth(properties.Dimensions.tubeWidth);
  sliderRep->SetSliderLength(properties.Dimensions.sliderLength);
  sliderRep->SetSliderWidth(properties.Dimensions.sliderWidth);
  sliderRep->SetEndCapLength(properties.Dimensions.endCapLength);
  sliderRep->SetEndCapWidth(properties.Dimensions.endCapWidth);
  sliderRep->SetTitleHeight(properties.Dimensions.titleHeight);
  sliderRep->SetLabelHeight(properties.Dimensions.labelHeight);

  // Set the color properties.
  sliderRep->GetTitleProperty()->SetColor(
      colors->GetColor3d(properties.Colors.titleColor).GetData());
  sliderRep->GetLabelProperty()->SetColor(
      colors->GetColor3d(properties.Colors.labelColor).GetData());
  sliderRep->GetTubeProperty()->SetColor(
      colors->GetColor3d(properties.Colors.barColor).GetData());
  sliderRep->GetCapProperty()->SetColor(
      colors->GetColor3d(properties.Colors.barEndsColor).GetData());
  sliderRep->GetSliderProperty()->SetColor(
      colors->GetColor3d(properties.Colors.sliderColor).GetData());
  sliderRep->GetSelectedProperty()->SetColor(
      colors->GetColor3d(properties.Colors.selectedColor).GetData());

  // Set the position.
  sliderRep->GetPoint1Coordinate()->SetCoordinateSystem(
      properties.Position.coordinateSystem);
  sliderRep->GetPoint1Coordinate()->SetValue(properties.Position.point1.data());
  sliderRep->GetPoint2Coordinate()->SetCoordinateSystem(
      properties.Position.coordinateSystem);
  sliderRep->GetPoint2Coordinate()->SetValue(properties.Position.point2.data());

  std::string titleFontFamily = properties.Text.titleFontFamily;
  if (titleFontFamily == "Courier")
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToCourier();
  }
  else if (titleFontFamily == "Times")
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToTimes();
  }
  else
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToArial();
  }
  sliderRep->GetTitleProperty()->SetBold(properties.Text.titleBold);
  sliderRep->GetTitleProperty()->SetItalic(properties.Text.titleItalic);
  sliderRep->GetTitleProperty()->SetShadow(properties.Text.titleShadow);
  std::string labelFontFamily = properties.Text.labelFontFamily;
  if (labelFontFamily == "Courier")
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToCourier();
  }
  else if (labelFontFamily == "Times")
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToTimes();
  }
  else
  {
    sliderRep->GetLabelProperty()->SetFontFamilyToArial();
  }
  sliderRep->GetLabelProperty()->SetBold(properties.Text.labelBold);
  sliderRep->GetLabelProperty()->SetItalic(properties.Text.labelItalic);
  sliderRep->GetLabelProperty()->SetShadow(properties.Text.labelShadow);

  vtkNew<vtkSliderWidget> widget;
  widget->SetInteractor(iren);
  widget->SetRepresentation(sliderRep);
  widget->EnabledOn();
  widget->SetAnimationModeToAnimate();

  return widget;
}

} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(Slider2D)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  FiltersSources
  InteractionStyle
  InteractionWidgets
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "Slider2D: 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(Slider2D MACOSX_BUNDLE Slider2D.cxx )
  target_link_libraries(Slider2D PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS Slider2D
  MODULES ${VTK_LIBRARIES}
)

Download and Build Slider2D

Click here to download Slider2D and its CMakeLists.txt file. Once the tarball Slider2D.tar has been downloaded and extracted,

cd Slider2D/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

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

Build the project:

make

and run it:

./Slider2D

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.