Driven class of unary_function can be used to check a single element based on special condition.Programmer can regard it as some algorithms’ parameter, such as count_if, find_if, and find_if_not.The following code shows how to write a customized unray class and use it. C++ struct Widget { int GetSpeed() const { return speed; } Widget( const Read more…
We need not sort all elements sometimes. Here are a few simple examples of STL algorithms partial_sort, nth_element, and partition. partial_sort For example, find the 5 biggest ones in 10 random numbers. #include <iostream> #include <vector> #include <cstdlib> #include <ctime> #include <algorithm> using namespace std; int main() { vector<int> values; Read more…
We need a flexible compare way for our objects in some situations, so it’s necessary to write our own compare class. The article has an example which puts all widgets in a multiset container, the widgets should be sort by its data member Speed. The widgets are created with random Read more…
vtkReverseSense can help us to reverse the direction of point normals and cell normals. The following code shows a simple example which display vertexes’ normals by cones in a sphere. Here is its original geometric states. #include <iostream> #include <vtkSmartPointer.h> #include <vtkSphereSource.h> #include <vtkActor.h> #include <vtkConeSource.h> #include <vtkRenderer.h> #include <vtkRenderWindow.h> Read more…
Borderless window: setWindowFlags( Qt::FramelessWindowHint ); Set background color: QPalette pal = mainWin->Getui().qvtkWidget->palette(); pal.setColor( QPalette::Background, Qt::black ); setAutoFillBackground( true ); this->setPalette( pal ); Make window stay on the top level: setWindowFlags(Qt::WindowStaysOnTopHint) Remove maximize button in widget： setWindowFlags( this->windowFlags() & ~Qt::WindowMaximizeButtonHint ); Definite buttons on title bar: setWindowFlags( Qt::CustomizeWindowHint | Qt::WindowMaximizeButtonHint); //Only Read more…
The interfaces can imitate users’ operations. QTest::keyClick QTest::keyPress QTest::mouseClick QSignalSpy listens for signal emission, it is a list of QVariant lists. It will not shield off signal to make slot invalid. QCheckBox *box = …; QSignalSpy spy(box, SIGNAL(clicked(bool))); //… QList arguments = spy.takeFirst(); // take the first signal QVERIFY(arguments.at(0).toBool() == Read more…
Development environment: VTK-8.1.1 macOS 10.14.4 Qt 5.11.2 Clang 8.1.0 package for vtk program use otool command tool to find all depent library files for executable. otool -L exe Then we can redirect all output logs into a local file and make it as a shell script file. Rewrite it and Read more…
The article shows how to use vtkViewUpdater to update different views when the selections changed. Relevant development environment: VTK-8.1.1; Qt 5.11.2 (x86_64-little_endian-lp64 shared (dynamic) release build; Clang 8.1.0 (clang-802.0.42) (Apple)) on “cocoa”; macOS 10.14 [darwin version 18.5.0]; #include <QApplication> #include <qsurfaceformat.h> #include <QVTKOpenGLWidget.h> #include <vtkRandomGraphSource.h> #include <vtkDataObjectToTable.h> #include <vtkQtTableView.h> #include Read more…
The algorithm copy_if is useful, it can help us to get all elements that meet special conditions. C++ template OutputIt copy_if( InputIt first, InputIt last, OutputIt d_first, UnaryPredicate pred ); Possible implement: C++ template OutputIt copy_if(InputIt first, InputIt last, OutputIt d_first, UnaryPredicate pred) { while (first != last) { if Read more…