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…
Simple Unit Test Project Let’s create a new unit test project firstly. Write our test functions in feild private Q_SLOTS for the class. tst_string.cpp: #include <QString> #include <QtTest> class String : public QObject { Q_OBJECT public: String(); private Q_SLOTS: void toUpper(); }; String::String() { } void String::toUpper() { QVERIFY2(true, “Failure”); Read more…
accumulate Interval algorithm accumulate supports custom calculate method to count elemeints in the special range. We can use it to get summary, multiple, average and etc of some elements, it’s very convenient and powerful. The syntax and usage example are in the following. Syntax: template< class InputIt, class T > Read more…
count STL algorithm count can help us to count the elements that are equal to value.Its syntax is like the following form: C++ template typename iterator_traits::difference_type count( InputIt first, InputIt last, const T &value ); Example: C++ #include #include #include using namespace std; int main(int argc, char *argv[]) { vector Read more…