diff --git a/doc/tutorials/viz/images/window_demo.png b/doc/tutorials/viz/images/window_demo.png new file mode 100644 index 000000000..b853fe29d Binary files /dev/null and b/doc/tutorials/viz/images/window_demo.png differ diff --git a/doc/tutorials/viz/viz.rst b/doc/tutorials/viz/viz.rst new file mode 100644 index 000000000..ceceaf197 --- /dev/null +++ b/doc/tutorials/viz/viz.rst @@ -0,0 +1,118 @@ +.. _viz: + +Launching Viz +************* + +Goal +==== + +In this tutorial you will learn how to + +.. container:: enumeratevisibleitemswithsquare + + * Open a visualization window. + * Access a window by its name. + * Start event loop. + * Start event loop for a given amount of time. + +Code +==== + +You can download the code from `here <../../../../samples/cpp/tutorial_code/viz/launching_viz.cpp>`_. + +.. code-block:: cpp + + #include + #include + + using namespace cv; + using namespace std; + + /** + * @function main + */ + int main() + { + /// Create a window + viz::Viz3d myWindow("Viz Demo"); + + /// Start event loop + myWindow.spin(); + + /// Event loop is over when pressed q, Q, e, E + cout << "First event loop is over" << endl; + + /// Access window via its name + viz::Viz3d sameWindow = viz::get("Viz Demo"); + + /// Start event loop + sameWindow.spin(); + + /// Event loop is over when pressed q, Q, e, E + cout << "Second event loop is over" << endl; + + /// Event loop is over when pressed q, Q, e, E + /// Start event loop once for 1 millisecond + sameWindow.spinOnce(1, true); + while(!sameWindow.wasStopped()) + { + /// Interact with window + + /// Event loop for 1 millisecond + sameWindow.spinOnce(1, true); + } + + /// Once more event loop is stopped + cout << "Last event loop is over" << endl; + return 0; + } + +Explanation +=========== + +Here is the general structure of the program: + +* Create a window. + +.. code-block:: cpp + + /// Create a window + viz::Viz3d myWindow("Viz Demo"); + +* Start event loop. This event loop will run until user terminates it by pressing **e**, **E**, **q**, **Q**. + +.. code-block:: cpp + + /// Start event loop + myWindow.spin(); + +* Access same window via its name. Since windows are implicitly shared, **sameWindow** is exactly the same with **myWindow**. If the name does not exist, a new window is created. + +.. code-block:: cpp + + /// Access window via its name + viz::Viz3d sameWindow = viz::get("Viz Demo"); + +* Start a controlled event loop. Once it starts, **wasStopped** is set to false. Inside the while loop, in each iteration, **spinOnce** is called to prevent event loop from completely stopping. Inside the while loop, user can execute other statements including those which interact with the window. + +.. code-block:: cpp + + /// Event loop is over when pressed q, Q, e, E + /// Start event loop once for 1 millisecond + sameWindow.spinOnce(1, true); + while(!sameWindow.wasStopped()) + { + /// Interact with window + + /// Event loop for 1 millisecond + sameWindow.spinOnce(1, true); + } + +Results +======= + +Here is the result of the program. + +.. image:: images/window_demo.png + :alt: Launching Viz + :align: center diff --git a/samples/cpp/tutorial_code/viz/launching_viz.cpp b/samples/cpp/tutorial_code/viz/launching_viz.cpp new file mode 100644 index 000000000..1827b33ea --- /dev/null +++ b/samples/cpp/tutorial_code/viz/launching_viz.cpp @@ -0,0 +1,53 @@ +#include +#include + +using namespace cv; +using namespace std; + +void help() +{ + cout + << "--------------------------------------------------------------------------" << endl + << "This program shows how to launch a 3D visualization window. You can stop event loop to continue executing. " + << "You can access the same window via its name. You can run event loop for a given period of time. " << endl + << "Usage:" << endl + << "./window_demo" << endl + << endl; +} + +int main() +{ + help(); + /// Create a window + viz::Viz3d myWindow("Viz Demo"); + + /// Start event loop + myWindow.spin(); + + /// Event loop is over when pressed q, Q, e, E + cout << "First event loop is over" << endl; + + /// Access window via its name + viz::Viz3d sameWindow = viz::get("Viz Demo"); + + /// Start event loop + sameWindow.spin(); + + /// Event loop is over when pressed q, Q, e, E + cout << "Second event loop is over" << endl; + + /// Event loop is over when pressed q, Q, e, E + /// Start event loop once for 1 millisecond + sameWindow.spinOnce(1, true); + while(!sameWindow.wasStopped()) + { + /// Interact with window + + /// Event loop for 1 millisecond + sameWindow.spinOnce(1, true); + } + + /// Once more event loop is stopped + cout << "Last event loop is over" << endl; + return 0; +}