ImageRegion
Repository source: ImageRegion
Description¶
This example shows how to get the image coordinates of the corners of a BorderWidget.
It currently says the pick for the lower left corner of the border widget is valid even when it is off the image.
Other languages
See (PythonicAPI)
Question
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Code¶
ImageRegion.cxx
#include <vtkAssemblyNode.h>
#include <vtkAssemblyPath.h>
#include <vtkBorderRepresentation.h>
#include <vtkBorderWidget.h>
#include <vtkCommand.h>
#include <vtkCoordinate.h>
#include <vtkImageActor.h>
#include <vtkImageMapper3D.h>
#include <vtkInteractorStyleImage.h>
#include <vtkJPEGReader.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPropPicker.h>
#include <vtkProperty2D.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
class vtkBorderCallback : public vtkCommand
{
public:
vtkBorderCallback()
{
}
static vtkBorderCallback* New()
{
return new vtkBorderCallback;
}
virtual void Execute(vtkObject* caller, unsigned long, void*)
{
vtkBorderWidget* borderWidget = reinterpret_cast<vtkBorderWidget*>(caller);
// Get the display coordinates of the two corners of the box
vtkCoordinate* lowerLeftCoordinate =
static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
->GetPositionCoordinate();
double* lowerLeft;
lowerLeft = lowerLeftCoordinate->GetComputedWorldValue(this->Renderer);
std::cout << "Lower left coordinate: " << lowerLeft[0] << ", "
<< lowerLeft[1] << std::endl;
lowerLeft[2] = 0;
vtkCoordinate* upperRightCoordinate =
static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
->GetPosition2Coordinate();
double* upperRight;
upperRight = upperRightCoordinate->GetComputedWorldValue(this->Renderer);
std::cout << "Upper right coordinate: " << upperRight[0] << ", "
<< upperRight[1] << std::endl;
upperRight[2] = 0;
// Pick at the two corners of the box.
vtkSmartPointer<vtkPropPicker> picker =
vtkSmartPointer<vtkPropPicker>::New();
// int valid1 = picker->Pick( lowerLeft[0],
picker->Pick(lowerLeft[0], lowerLeft[1], 0.0, this->Renderer);
vtkAssemblyPath* path = picker->GetPath();
vtkProp* pickedProp = NULL;
bool validPick = false;
if (path)
{
std::cout << "There are " << path->GetNumberOfItems()
<< " items in the path." << std::endl;
vtkCollectionSimpleIterator sit;
path->InitTraversal(sit);
vtkAssemblyNode* node;
for (int i = 0; i < path->GetNumberOfItems(); ++i)
{
node = path->GetNextNode(sit);
pickedProp = node->GetViewProp();
if (this->ImageActor == dynamic_cast<vtkImageActor*>(pickedProp))
{
std::cout << "Correct actor picked." << std::endl;
validPick = true;
break;
}
}
}
if (!validPick)
{
std::cout << "Off Image" << std::endl;
}
else
{
double pos1[3];
picker->GetPickPosition(pos1);
std::cout << "Lower Left Pick: " << pos1[0] << " " << pos1[1]
<< std::endl;
}
/*
if(valid1 != 0)
{
std::cout << "Valid1: " << valid1 << std::endl;
double pos1[3];
picker->GetPickPosition( pos1 );
std::cout << "Lower Left Pick: " << pos1[0] << " " << pos1[1] <<
std::endl;
}
else
{
std::cout << "Left - nothing was picked" << std::endl;
}
*/
/*
int valid2 = picker->Pick( upperRight[0],
upperRight[1], 0.0, this->Renderer );
if(valid2 != 0)
{
std::cout << "Valid2: " << valid2 << std::endl;
double pos2[3];
picker->GetPickPosition( pos2 );
std::cout << "Upper right Pick: " << pos2[0] << " " << pos2[1] <<
std::endl;
}
else
{
std::cout << "Right - nothing was picked" << std::endl;
}
*/
std::cout << std::endl;
}
void SetRenderer(vtkSmartPointer<vtkRenderer> ren)
{
this->Renderer = ren;
}
void SetImageActor(vtkSmartPointer<vtkImageActor> im)
{
this->ImageActor = im;
}
private:
vtkSmartPointer<vtkRenderer> Renderer;
vtkSmartPointer<vtkImageActor> ImageActor;
};
int main(int argc, char* argv[])
{
vtkNew<vtkNamedColors> color;
// Parse input arguments.
if (argc != 2)
{
std::cerr << "Usage: " << argv[0] << " Filename(.jpg) e.g. Gourds2.jpg"
<< std::endl;
return EXIT_FAILURE;
}
std::string InputFilename = argv[1];
// Read the image
vtkNew<vtkJPEGReader> jPEGReader;
jPEGReader->SetFileName(InputFilename.c_str());
vtkNew<vtkImageActor> actor;
actor->GetMapper()->SetInputConnection(jPEGReader->GetOutputPort());
// A renderer and render window
vtkNew<vtkRenderer> renderer;
vtkNew<vtkRenderWindow> renderWindow;
renderWindow->AddRenderer(renderer);
// An interactor
vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
renderWindowInteractor->SetRenderWindow(renderWindow);
vtkNew<vtkInteractorStyleImage> style;
renderWindowInteractor->SetInteractorStyle(style);
vtkNew<vtkBorderWidget> borderWidget;
borderWidget->SetInteractor(renderWindowInteractor);
static_cast<vtkBorderRepresentation*>(borderWidget->GetRepresentation())
->GetBorderProperty()
->SetColor(color->GetColor3d("Lime").GetData());
borderWidget->SelectableOff();
vtkNew<vtkBorderCallback> borderCallback;
borderCallback->SetRenderer(renderer);
borderCallback->SetImageActor(actor);
borderWidget->AddObserver(vtkCommand::InteractionEvent, borderCallback);
// Add the actors to the scene
renderer->AddActor(actor);
renderer->SetBackground(color->GetColor3d("DarkSlateGray").GetData());
renderWindow->SetWindowName("ImageRegion");
renderWindow->Render();
renderWindowInteractor->Initialize();
renderWindow->Render();
borderWidget->On();
renderWindowInteractor->Start();
return EXIT_SUCCESS;
}
CMakeLists.txt¶
cmake_minimum_required(VERSION 3.12 FATAL_ERROR)
project(ImageRegion)
find_package(VTK COMPONENTS
CommonColor
CommonCore
IOImage
InteractionStyle
InteractionWidgets
RenderingContextOpenGL2
RenderingCore
RenderingFreeType
RenderingGL2PSOpenGL2
RenderingOpenGL2
)
if (NOT VTK_FOUND)
message(FATAL_ERROR "ImageRegion: 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(ImageRegion MACOSX_BUNDLE ImageRegion.cxx )
target_link_libraries(ImageRegion PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
TARGETS ImageRegion
MODULES ${VTK_LIBRARIES}
)
Download and Build ImageRegion¶
Click here to download ImageRegion and its CMakeLists.txt file. Once the tarball ImageRegion.tar has been downloaded and extracted,
cd ImageRegion/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:
./ImageRegion
WINDOWS USERS
Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.