Question

I am developing a simulator. I have chosen QT for the GUI. My project involves a lot of manipulation of data and I use QT just to plot my results.

My code structure is such that my main function contains a global object of my data, an object of the QT GUI and other objects for manipulating this data. I need to modify this data at every 30 ms. I have also attached a simplified version of my main file.

My problem is that I cannot call functions of my other objects (other than the GUI) before exiting the QT object. I have implemented timers in QT in isolation which plots the new data and works fine. All I want to do is call my ai and phySim object at a particular time interval independant of the QT object. I want these three objects to be completely independent.

world* _world;
int main(int argc, char *args[])

{
_world = new world();


gui *GUI; ///QT object

ai *AI;//object to manipulate data

phySim *sim;//object to manipulate data

/////////////////////////////////// this gets executed only when i close the QT gui
    AI = new ai(_world); 
AI->doSomething();

sim = new phySim(_world);
sim->updateWorld();
//////////////////////////////////////////////////////////////////////////////

QApplication app(argc,args);
GUI = new gui(_world);  
GUI->show();


return app.exec();  
} 

Answer 1

Maybe you should try not not run the app.exec(), but instead create a custom (almost) infinite loop, call processEvents() within that loop and your updateWorld() plus a wait of 30ms (or a little less, due to the function execution will take some ms). Drawing is then part of Qt (you should pass the instance of your simulator and add a render method (maybe best in pure OpenGL, as this can be passed through the Qt layer via a QGLWidget). Call that method within paint() or respectivly paintGL() for QGLWidget I hope this helps (a little), you should read QGLWidget doc

Note: You will have to write some wrappers in form of signals, calling your simulationObj methods, otherwise no UI interaction will be possible within Qt.