Pangolin: 3 - Use UI

# Targets - Add button - Print some texts when click Button # Modules ## Add UI panel ```cpp const int UI_WIDTH = 180; // Add named OpenGL viewport to window and provide 3D Handler pangolin::View& d_cam = pangolin::CreateDisplay() .SetBounds(0.0, 1.0, pangolin::Attach::Pix(UI_WIDTH), 1.0, -float(w) / float(h)) .SetHandler(new pangolin::Handler3D(s_cam)); // Add named Panel and bind to variables beginning 'ui' // A Panel is just a View with a default layout and input handling pangolin::CreatePanel("ui") .SetBounds(0.0, 1.0, 0.0, pangolin::Attach::Pix(UI_WIDTH)); ``` ## Add button ```cpp pangolin::CreatePanel("ui").SetBounds(0.0, 1.0, 0.0, pangolin::Attach::Pix(UI_WIDTH)); pangolin::Var a_button("ui.Button", false, false); if (pangolin::Pushed(a_button)) std::cout << "You Pushed a button!" << std::endl; ``` Result:  Clic the button: ```sh You Pushed a button! ``` ## Add callback function to deal with keyboard event and mouse click event ```cpp pangolin::Var> reset("ui.Reset", SampleMethod); pangolin::RegisterKeyPressCallback(pangolin::PANGO_CTRL + 'r', SampleMethod); void SampleMethod() { std::cout << "You typed ctrl-r or pushed reset" << std::endl; } ``` Result: Click "Reset" or press "C-r" to reset sth.  ## Save window and cube ```cpp pangolin::Var save_window("ui.Save_Window", false, false); pangolin::Var save_cube("ui.Save_Cube", false, false); if (pangolin::Pushed(save_window)) { std::cout<<"Save window"< record_cube("ui.Record_Cube",false,false); if (pangolin::Pushed(record_cube)) pangolin::DisplayBase().RecordOnRender("ffmpeg:[fps=50,bps=8388608,unique_filename]//screencap.avi"); ```