BorderWidget
vtk-examples/Cxx/Widgets/BorderWidget
Description¶
This example draws a border around a region selected with the mouse. Note that the default border color is white - so if you have a white background you will not see anything!
Also see the BorderWidgetQt example.
Question
If you have a question about this example, please use the VTK Discourse Forum
Code¶
BorderWidget.cxx
#include <vtkActor.h>
#include <vtkBorderRepresentation.h>
#include <vtkBorderWidget.h>
#include <vtkCommand.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkObjectFactory.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>
#include <vtkWidgetCallbackMapper.h>
#include <vtkWidgetEvent.h>
namespace {
class vtkCustomBorderWidget : public vtkBorderWidget
{
public:
static vtkCustomBorderWidget* New();
vtkTypeMacro(vtkCustomBorderWidget, vtkBorderWidget);
static void EndSelectAction(vtkAbstractWidget* w);
vtkCustomBorderWidget();
};
vtkStandardNewMacro(vtkCustomBorderWidget);
} // namespace
int main(int, char*[])
{
vtkNew<vtkNamedColors> colors;
// Sphere
vtkNew<vtkSphereSource> sphereSource;
sphereSource->SetRadius(4.0);
sphereSource->Update();
vtkNew<vtkPolyDataMapper> mapper;
mapper->SetInputConnection(sphereSource->GetOutputPort());
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
actor->GetProperty()->SetColor(
colors->GetColor3d("DarkOliveGreen").GetData());
// A renderer and render window
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
renderWindow->SetWindowName("BorderWidget");
// An interactor
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);
vtkNew<vtkCustomBorderWidget> borderWidget;
borderWidget->SetInteractor(renderWindowInteractor);
borderWidget->CreateDefaultRepresentation();
borderWidget->SelectableOff();
// Add the actors to the scene
renderer->AddActor(actor);
renderer->SetBackground(colors->GetColor3d("SteelBlue").GetData());
// Render an image (lights and cameras are created automatically)
renderWindowInteractor->Initialize();
renderWindow->Render();
borderWidget->On();
// Begin mouse interaction
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
namespace {
vtkCustomBorderWidget::vtkCustomBorderWidget()
{
this->CallbackMapper->SetCallbackMethod(
vtkCommand::MiddleButtonReleaseEvent, vtkWidgetEvent::EndSelect, this,
vtkCustomBorderWidget::EndSelectAction);
}
void vtkCustomBorderWidget::EndSelectAction(vtkAbstractWidget* w)
{
vtkBorderWidget* borderWidget = dynamic_cast<vtkBorderWidget*>(w);
// Get the actual box coordinates/planes
// vtkNew<vtkPolyData> polydata;
// Get the bottom left corner
auto lowerLeft =
static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
->GetPosition();
std::cout << "Lower left: " << lowerLeft[0] << " " << lowerLeft[1]
<< std::endl;
auto upperRight =
static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
->GetPosition2();
std::cout << "Upper right: " << upperRight[0] << " " << upperRight[1]
<< std::endl;
vtkBorderWidget::EndSelectAction(w);
}
} // namespace```
###CMakeLists.txt
```cmake
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(BorderWidget)
find_package(VTK COMPONENTS
vtkCommonColor
vtkCommonCore
vtkCommonDataModel
vtkFiltersSources
vtkInteractionStyle
vtkInteractionWidgets
vtkRenderingContextOpenGL2
vtkRenderingCore
vtkRenderingFreeType
vtkRenderingGL2PSOpenGL2
vtkRenderingOpenGL2
QUIET
)
if (NOT VTK_FOUND)
message("Skipping BorderWidget: ${VTK_NOT_FOUND_MESSAGE}")
return()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
# old system
include(${VTK_USE_FILE})
add_executable(BorderWidget MACOSX_BUNDLE BorderWidget.cxx )
target_link_libraries(BorderWidget PRIVATE ${VTK_LIBRARIES})
else()
# 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(BorderWidget MACOSX_BUNDLE BorderWidget.cxx )
target_link_libraries(BorderWidget PRIVATE ${VTK_LIBRARIES})
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS BorderWidget
MODULES ${VTK_LIBRARIES}
)
endif()
Download and Build BorderWidget¶
Click here to download BorderWidget and its CMakeLists.txt file. Once the tarball BorderWidget.tar has been downloaded and extracted,
cd BorderWidget/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:
./BorderWidget
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.