void AddUndoRedo(Cockpit cockpit)
        {
            HUDButton undoButton = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Disc, fDiscButtonRadius1)
            {
                Slices = 32
            },
                fCockpitRadiusButton, -6.5f, -50.0f, "icons/undo_v1");

            //UnityUtil.TranslateInFrame(undoButton.RootGameObject, -fDiscButtonRadius1*1.1f, 0, 0, CoordSpace.WorldCoords);
            undoButton.Name       = "undo";
            undoButton.OnClicked += (o, e) => { cockpit.Scene.History.InteractiveStepBack(); };
            cockpit.AddUIElement(undoButton, true);

            HUDButton redoButton = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Disc, fDiscButtonRadius1)
            {
                Slices = 32
            },
                fCockpitRadiusButton, 6.5f, -50.0f, "icons/redo_v1");

            //UnityUtil.TranslateInFrame(redoButton.RootGameObject, fDiscButtonRadius1*1.1f, 0, 0, CoordSpace.WorldCoords);
            redoButton.Name       = "redo";
            redoButton.OnClicked += (o, e) => { cockpit.Scene.History.InteractiveStepForward(); };
            cockpit.AddUIElement(redoButton, true);
        }
        // creates navigation mode toggle group
        void AddNavModeToggleGroup(Cockpit cockpit)
        {
            float h  = 25.0f;
            float dh = 13.0f;
            float v  = -50.0f;
            float dv = 13.0f;

            HUDToggleButton tumbleButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, h, v,
                "cockpit_icons/view_controls/bunny_enabled", "cockpit_icons/view_controls/bunny_disabled",
                new IconMeshGenerator()
            {
                Path      = "icon_meshes/camera",
                Scale     = 0.07f, Color = ColorUtil.make(30, 30, 30),
                Translate = new Vector3(0.04f, -0.07f, 0.04f),
                Rotate    = Quaternion.AngleAxis(30.0f, Vector3.up) * Quaternion.AngleAxis(-90.0f, Vector3.right)
            }
                );

            tumbleButton.Name = "tumbleNavMode";
            cockpit.AddUIElement(tumbleButton, true);

            HUDToggleButton flyButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, h + dh, v,
                "cockpit_icons/view_controls/sponza_enabled", "cockpit_icons/view_controls/sponza_disabled");

            flyButton.Name = "flyNavMode";
            cockpit.AddUIElement(flyButton, true);

            HUDToggleGroup group = new HUDToggleGroup();

            group.AddButton(tumbleButton);
            group.AddButton(flyButton);
            group.Selected   = 1;
            group.OnToggled += (sender, nSelected) => {
                if (nSelected == 0)
                {
                    cockpit.Context.MouseCameraController = new MayaCameraHotkeys();
                }
                else
                {
                    cockpit.Context.MouseCameraController = new RateControlledEgocentricCamera();
                }
            };

            // set initial state
            group.Selected = 0;


            HUDButton resetButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, h + 0.3f * dh, v - 0.7f * dv,
                "icons/reset_v1");

            resetButton.Name = "export";
            cockpit.AddUIElement(resetButton, true);
            resetButton.OnClicked += (s, e) => {
                cockpit.Context.ResetView(true);
            };
        }
        void AddTransformToolToggleGroup(Cockpit cockpit)
        {
            float va      = -42.0f;
            float vb      = -32.0f;
            float vbdelta = 12.0f;

            HUDToggleButton widgetButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, vb - vbdelta, va,
                "cockpit_icons/transform_modes/transformmode_widget_enabled_v1",
                "cockpit_icons/transform_modes/transformmode_widget_disabled_v1");

            widgetButton.Name = "transformWidgetToggle";
            cockpit.AddUIElement(widgetButton, true);

            HUDToggleButton snapButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, vb, va,
                "cockpit_icons/transform_modes/transformmode_snap_enabled_v1",
                "cockpit_icons/transform_modes/transformmode_snap_disabled_v1");

            snapButton.Name = "transformSnapToggle";
            cockpit.AddUIElement(snapButton, true);

            HUDToggleButton editButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, vb + vbdelta, va,
                "cockpit_icons/transform_modes/transformmode_edit_enabled_v1",
                "cockpit_icons/transform_modes/transformmode_edit_disabled_v1");

            editButton.Name = "transformEditToggle";
            cockpit.AddUIElement(editButton, true);


            HUDToggleGroup group = new HUDToggleGroup();

            group.AddButton(widgetButton);
            group.AddButton(snapButton);
            group.AddButton(editButton);
            group.Selected   = 0;
            group.OnToggled += (sender, nSelected) => {
                if (nSelected == 1)
                {
                    cockpit.Context.TransformManager.SetActiveGizmoType("snap_drag");
                }
                else if (nSelected == 2)
                {
                    cockpit.Context.TransformManager.SetActiveGizmoType("object_edit");
                }
                else
                {
                    cockpit.Context.TransformManager.SetActiveGizmoType("default");
                }
            };
            // [TODO] remember last setting? per object?
        }
        public void add_text_entry_field(Cockpit cockpit)
        {
            float fUseRadius = HUDRadius * 0.85f;
            float fAngle     = -35.0f;

            entryField            = new HUDTextEntry();
            entryField.Text       = GetDefaultFileName();
            entryField.Width      = 1.0f;
            entryField.Height     = 0.08f;
            entryField.TextHeight = 0.06f;
            entryField.Create();
            entryField.Name = "selectFileName";
            HUDUtil.PlaceInSphere(entryField, fUseRadius, 0.0f, fAngle);
            cockpit.AddUIElement(entryField, true);

            tooltipText                 = new HUDLabel();
            tooltipText.Shape           = new HUDShape(HUDShapeType.Rectangle, 1.0f, 0.04f);
            tooltipText.Text            = Tooltip;
            tooltipText.TextHeight      = 0.03f;
            tooltipText.BackgroundColor = Colorf.TransparentBlack;
            tooltipText.TextColor       = Colorf.Silver;
            tooltipText.Create();
            tooltipText.Name = "tooltip";
            HUDUtil.PlaceInSphere(tooltipText, fUseRadius, 0.0f, fAngle);
            UnityUtil.TranslateInFrame(tooltipText.RootGameObject, 0.0f, -entryField.Height, 0, CoordSpace.WorldCoords);
            cockpit.AddUIElement(tooltipText, true);


            HUDButton saveButton = HUDBuilder.CreateRectIconClickButton(
                0.2f, 0.1f, fUseRadius, 0.0f, fAngle,
                "icons/save_v1");

            UnityUtil.TranslateInFrame(saveButton.RootGameObject, 0.2f, -0.1f, 0, CoordSpace.WorldCoords);
            saveButton.Name = "save";
            cockpit.AddUIElement(saveButton, true);
            saveButton.OnClicked += (s, e) => { SaveFromEntryText(); };

            HUDButton cancelButton = HUDBuilder.CreateRectIconClickButton(
                0.2f, 0.1f, fUseRadius, 0.0f, fAngle,
                "icons/cancel_v1");

            UnityUtil.TranslateInFrame(cancelButton.RootGameObject, 0.4f, -0.1f, 0, CoordSpace.WorldCoords);
            cancelButton.Name = "cancel";
            cockpit.AddUIElement(cancelButton, true);
            cancelButton.OnClicked += (s, e) => {
                cockpit.Context.PopCockpit(true);
            };
        }
        // creates world/local frame toggle buttons, that are grouped so clicking
        // one disables the other. Connect up to TransformManager for events/etc.
        void AddFrameToggleGroup(Cockpit cockpit)
        {
            HUDToggleButton worldButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, -38.0f, -50.0f,
                "icons/frame_world_enabled", "icons/frame_world_disabled",
                new IconMeshGenerator()
            {
                Path  = "icon_meshes/axis_frame",
                Scale = 0.08f, Translate = new Vector3(0.06f, -0.06f, 0.05f), Color = ColorUtil.ForestGreen
            }
                );

            worldButton.Name = "worldFrameToggle";
            cockpit.AddUIElement(worldButton, true);

            HUDToggleButton localButton = HUDBuilder.CreateToggleButton(
                fDiscButtonRadius1, fCockpitRadiusButton, -25.0f, -50.0f, "icons/frame_local_enabled", "icons/frame_local_disabled");

            localButton.Name = "localFrameToggle";
            cockpit.AddUIElement(localButton, true);

            HUDToggleGroup group = new HUDToggleGroup();

            group.AddButton(worldButton);
            group.AddButton(localButton);
            group.Selected   = 1;
            group.OnToggled += (sender, nSelected) => {
                FrameType eSetType = (nSelected == 0) ?
                                     FrameType.WorldFrame : FrameType.LocalFrame;
                cockpit.Context.TransformManager.ActiveFrameType = eSetType;
            };
            cockpit.Context.TransformManager.OnActiveGizmoModified += (s, e) => {
                FrameType eSet = cockpit.Context.TransformManager.ActiveFrameType;
                group.Selected = (eSet == FrameType.WorldFrame) ? 0 : 1;
            };

            // set initial state
            FrameType eInitial = cockpit.Context.TransformManager.ActiveFrameType;

            group.Selected = (eInitial == FrameType.WorldFrame) ? 0 : 1;
        }
        HUDToggleGroup BuildPanels(Cockpit cockpit)
        {
            float vx = -50.0f;
            float vy = 10.0f;

            float fButtonW = fDiscButtonRadius1;


            HUDPrimitivesPanel primPanel = new HUDPrimitivesPanel();

            primPanel.Create(cockpit);
            primPanel.Name = "PrimitivesPanel";
            cockpit.AddUIElement(primPanel, true);

            HUDToolsPanel toolPanel = new HUDToolsPanel();

            toolPanel.Create(cockpit);
            toolPanel.Name = "ToolPanel";
            cockpit.AddUIElement(toolPanel, true);
            toolPanel.IsVisible = false;

            HUDMaterialsPanel matPanel = new HUDMaterialsPanel();

            matPanel.Create(cockpit);
            matPanel.Name = "MaterialPanel";
            cockpit.AddUIElement(matPanel, true);
            matPanel.IsVisible = false;

            float fIconAspect = 1.25f;

            HUDToggleButton materialsButton = HUDBuilder.CreateToggleButton(
                new HUDShape(HUDShapeType.Rectangle, fButtonW, fButtonW / fIconAspect)
            {
                UseUVSubRegion = true
            },
                fCockpitRadiusButton, vx, vy,
                "panel_tabs/materials_active_v1", "panel_tabs/materials_inactive_v1");

            UnityUtil.TranslateInFrame(materialsButton.RootGameObject, -fButtonW * 1.5f, 0, 0, CoordSpace.WorldCoords);
            materialsButton.Name = "toggleMaterials";
            cockpit.AddUIElement(materialsButton, true);

            HUDToggleButton toolsButton = HUDBuilder.CreateToggleButton(
                new HUDShape(HUDShapeType.Rectangle, fButtonW, fButtonW / fIconAspect)
            {
                UseUVSubRegion = true
            },
                fCockpitRadiusButton, vx, vy,
                "panel_tabs/tools_active_v1", "panel_tabs/tools_inactive_v1");

            UnityUtil.TranslateInFrame(toolsButton.RootGameObject, -fButtonW * 0.5f, 0, 0, CoordSpace.WorldCoords);
            toolsButton.Name = "toggleTools";
            cockpit.AddUIElement(toolsButton, true);


            HUDToggleButton shapesButton = HUDBuilder.CreateToggleButton(
                new HUDShape(HUDShapeType.Rectangle, fButtonW, fButtonW / fIconAspect)
            {
                UseUVSubRegion = true
            },
                fCockpitRadiusButton, vx, vy,
                "panel_tabs/shapes_active_v1", "panel_tabs/shapes_inactive_v1");

            UnityUtil.TranslateInFrame(shapesButton.RootGameObject, fButtonW * 0.5f, 0, 0, CoordSpace.WorldCoords);
            shapesButton.Name = "toggleShapes";
            cockpit.AddUIElement(shapesButton, true);

            HUDToggleGroup group = new HUDToggleGroup();

            group.AddButton(shapesButton);
            group.AddButton(toolsButton);
            group.AddButton(materialsButton);
            group.Selected   = 0;
            group.OnToggled += (sender, nSelected) => {
                if (nSelected == 0)
                {
                    matPanel.IsVisible  = toolPanel.IsVisible = false;
                    primPanel.IsVisible = true;
                }
                else if (nSelected == 1)
                {
                    primPanel.IsVisible = matPanel.IsVisible = false;
                    toolPanel.IsVisible = true;
                }
                else
                {
                    primPanel.IsVisible = toolPanel.IsVisible = false;
                    matPanel.IsVisible  = true;
                }
            };

            return(group);
        }
        void AddMenuButtonsGroup(Cockpit cockpit)
        {
            HUDButton importButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                //0.1f, 0.05f, 0.7f, 5.0f, -5.0f,       // for debugging
                "icons/import_v1");

            importButton.Name = "import";
            cockpit.AddUIElement(importButton, true);
            importButton.OnClicked += (s, e) => {
                var cp = new FileImportCockpit()
                {
                    InitialPath = SceneGraphConfig.LastFileOpenPath
                };
                cockpit.Context.PushCockpit(cp);
            };

            HUDButton exportButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                //0.1f, 0.05f, 0.7f, 5.0f, -5.0f,       // for debugging convenience
                "icons/export_v1");

            UnityUtil.TranslateInFrame(exportButton.RootGameObject, 0, -0.055f, 0, CoordSpace.WorldCoords);
            exportButton.Name = "export";
            cockpit.AddUIElement(exportButton, true);
            exportButton.OnClicked += (s, e) => {
                var cp = new FileExportCockpit()
                {
                    InitialPath = SceneGraphConfig.LastFileOpenPath
                };
                cockpit.Context.PushCockpit(cp);
            };


            HUDButton janusButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                //0.1f, 0.05f, 0.7f, 5.0f, -5.0f,       // for debugging convenience
                "cockpit_icons/menu_buttons/janus_v1");

            UnityUtil.TranslateInFrame(janusButton.RootGameObject, 0, 2.0f * -0.055f, 0, CoordSpace.WorldCoords);
            janusButton.Name = "export";
            cockpit.AddUIElement(janusButton, true);
            janusButton.OnClicked += (s, e) => {
                var cp = new JanusVRExportCockpit()
                {
                    InitialPath = SceneGraphConfig.LastFileOpenPath
                };
                cockpit.Context.PushCockpit(cp);
            };


            HUDButton loadButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                // 0.1f, 0.05f, 0.7f, 5.0f, -5.0f,       // for debugging convenience
                "icons/load_v1");

            UnityUtil.TranslateInFrame(loadButton.RootGameObject, 0.12f, 0, 0, CoordSpace.WorldCoords);
            loadButton.Name = "load";
            cockpit.AddUIElement(loadButton, true);
            loadButton.OnClicked += (s, e) => {
                var cp = new FileLoadSceneCockpit()
                {
                    InitialPath = SceneGraphConfig.LastFileOpenPath
                };
                cockpit.Context.PushCockpit(cp);
            };

            HUDButton saveButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                // 0.1f, 0.05f, 0.7f, 5.0f, -5.0f,       // for debugging
                "icons/save_v1");

            UnityUtil.TranslateInFrame(saveButton.RootGameObject, 0.12f, -0.055f, 0, CoordSpace.WorldCoords);
            saveButton.Name = "save";
            cockpit.AddUIElement(saveButton, true);
            saveButton.OnClicked += (s, e) => {
                var cp = new FileSaveSceneCockpit()
                {
                    InitialPath = SceneGraphConfig.LastFileOpenPath
                };
                cockpit.Context.PushCockpit(cp);
            };



            HUDButton newButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                "icons/new_v1");

            UnityUtil.TranslateInFrame(newButton.RootGameObject, 0.24f, 0, 0, CoordSpace.WorldCoords);
            newButton.Name = "new";
            cockpit.AddUIElement(newButton, true);
            newButton.OnClicked += (s, e) => {
                cockpit.Context.NewScene(true);
            };


            HUDButton quitButton = HUDBuilder.CreateRectIconClickButton(
                0.1f, 0.05f, 0.7f, 55.0f, -50.0f,
                "icons/quit_v1");

            UnityUtil.TranslateInFrame(quitButton.RootGameObject, 0.24f, -0.055f, 0, CoordSpace.WorldCoords);
            quitButton.Name = "quit";
            cockpit.AddUIElement(quitButton, true);
            quitButton.OnClicked += (s, e) => { FPlatform.QuitApplication(); };
        }
        public void Initialize(Cockpit cockpit, float fCockpitRadius)
        {
            activeCockpit = cockpit;
            activeCockpit.PositionMode = Cockpit.MovementMode.Static;
            activeCockpit.GrabFocus    = true;
            activeHUDRadius            = fCockpitRadius;

            string[] files, folders;
            try {
                files   = Source.GetFiles(FolderPath);
                folders = Source.GetFolders(FolderPath);
            } catch (Exception e) {
                Debug.Log("[CurrentFolderList.Initialize] exception! " + e.Message);
                return;
            }

            float fMinHorz = -45.0f, fMaxHorz = 45.0f;
            float fStartVert = 15.0f;
            float fTop       = HUDUtil.GetSphereFrame(fCockpitRadius, 0.0f, fStartVert).Origin.y;

            int folderi = 0, filei = 0;

            Mesh  folderMesh              = Resources.Load <Mesh>("icon_meshes/folder_v1");
            Color folderColor             = ColorUtil.make(241, 213, 146);
            Color inaccessibleFolderColor = ColorUtil.make(100, 100, 100);
            Mesh  fileMesh                = Resources.Load <Mesh>("icon_meshes/file_v1");
            Color fileColor               = ColorUtil.make(250, 250, 250);

            // [TODO] something wrong here, icons are loading backwards...??
            Quaternion meshRotation =
                Quaternion.AngleAxis(270.0f, Vector3.right) *
                Quaternion.AngleAxis(180.0f + 25.0f, Vector3.forward);
            float meshScale = IconSize * 0.9f;

            HUDCylinder hudSurf = new HUDCylinder()
            {
                Radius = fCockpitRadius, VerticalCoordIsAngle = false
            };
            float fStepH     = VRUtil.HorizontalStepAngle(fCockpitRadius, 0, IconSize + IconPadding);
            int   nStepsHorz = (int)((fMaxHorz - fMinHorz) / fStepH);

            fMinHorz = -(nStepsHorz * fStepH * 0.5f);
            fMaxHorz = (nStepsHorz * fStepH * 0.5f);
            float fStepV = IconSize + IconPadding;


            IconCollection = new HUDCollection();
            IconCollection.Create();

            bool bDone = false;
            int  yi    = 0;

            while (!bDone)
            {
                float fCurV = fTop - yi * fStepV;
                yi++;

                for (int xi = 0; xi < nStepsHorz && bDone == false; ++xi)
                {
                    float fCurH = fMinHorz + ((float)xi + 0.5f) * fStepH;

                    string name        = "x";
                    fMesh  useMesh     = null;
                    Color  useColor    = Color.white;
                    bool   bAccessible = true;
                    bool   bIsFile     = false;
                    if (folderi < folders.Length)
                    {
                        name     = folders[folderi++];
                        useMesh  = new fMesh(UnityEngine.Object.Instantiate <Mesh>(folderMesh));
                        useColor = folderColor;
                        if (Source.FilterInaccessibleFolders == false &&
                            FileSystemUtils.CanAccessFolder(Path.Combine(FolderPath, name)) == false)
                        {
                            bAccessible = false;
                            useColor    = inaccessibleFolderColor;
                        }
                    }
                    else if (filei < files.Length)
                    {
                        name     = files[filei++];
                        useMesh  = new fMesh(UnityEngine.Object.Instantiate <Mesh>(fileMesh));
                        useColor = fileColor;
                        bIsFile  = true;
                    }
                    else
                    {
                        bDone = true;
                        break;
                    }
                    //useColor.a = 0.999f;        // [RMS] can use this to force into alpha pass

                    string displayName = name;
                    if (displayName.Length > 12)
                    {
                        displayName = name.Substring(0, 12) + "...";
                    }

                    //float TextScale = 0.01f, ShiftX = -IconSize * 0.5f;
                    float TextScale = 0.005f, ShiftX = -IconSize * 0.5f;

                    HUDButton iconButton = HUDBuilder.CreateMeshClickButton(
                        useMesh, useColor, meshScale, meshRotation,
                        hudSurf, fCurH, fCurV,
                        new TextLabelGenerator()
                    {
                        Text = displayName, Scale = TextScale, Translate = new Vector3(ShiftX, 0.0f, 0.0f)
                    });
                    iconButton.Name = name;
                    //cockpit.AddUIElement(iconButton, true);
                    IconCollection.AddChild(iconButton);

                    if (bIsFile)
                    {
                        iconButton.OnClicked += (o, e) => {
                            if (this.OnFileClicked != null)
                            {
                                this.OnFileClicked(name);
                            }
                        };
                    }

                    if (bAccessible)
                    {
                        iconButton.OnDoubleClicked += IconButton_DoubleClick;
                    }
                }
            }

            cockpit.AddUIElement(IconCollection, true);
            fCurMaxScroll = Mathf.Max(0, (yi - 4) * fStepV);
        }
        public void Initialize(Cockpit cockpit)
        {
            cockpit.Name = "splashCockpit";
            cockpit.DefaultCursorDepth = 3.0f;
            cockpit.PositionMode       = Cockpit.MovementMode.Static;

            // create black sphere around camera to hide existing scene
            fGameObject blackBackground = new fGameObject(
                UnityUtil.CreateMeshGO("background_delete", "icon_meshes/inverted_sphere_tiny", 1.0f,
                                       UnityUtil.MeshAlignOption.AllAxesCentered, MaterialUtil.CreateFlatMaterial(Color.black), false));

            // add as bounds object to do mouse hit-test
            cockpit.Context.Scene.AddWorldBoundsObject(blackBackground);

            // re-parent from Scene so the sphere tracks the camera
            cockpit.FixedCameraTrackingGO.AddChild(blackBackground, false);

            HUDButton title = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 2.0f, 0.8f),
                3.0f, 0.0f, 2.5f, "simplex_startup/simplex_v2");

            title.Name    = "title";
            title.Enabled = false;
            cockpit.AddUIElement(title, true);

            HUDButton start = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.5f, 0.25f),
                3.0f, 8.0f, -10, "simplex_startup/start_v1");

            start.Name       = "start";
            start.OnClicked += (s, e) => {
                cockpit.ActiveCamera.Animator().DoActionDuringDipToBlack(() => {
                    cockpit.Context.Scene.RemoveWorldBoundsObject(blackBackground);
                    UnityEngine.GameObject.Destroy(blackBackground);
                    cockpit.Context.PushCockpit(
                        new SetupCADCockpit_V1());
                }, 1.0f);
            };
            cockpit.AddUIElement(start, true);

            HUDButton quit = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.5f, 0.25f),
                3.0f, -8.0f, -10, "simplex_startup/quit_v1");

            quit.Name       = "quit";
            quit.OnClicked += (s, e) => {
                FPlatform.QuitApplication();
            };
            cockpit.AddUIElement(quit, true);

            HUDButton logo = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.8f, 0.2f),
                3.0f, 0.0f, -25.0f, "simplex_startup/gradientspace_splash");

            logo.Name    = "logo";
            logo.Enabled = false;
            cockpit.AddUIElement(logo, true);



            HUDButton about_arrow = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.75f, 0.75f),
                3.0f, -30.0f, -10.0f, "simplex_startup/about_arrow");

            about_arrow.Name    = "about_arrow";
            about_arrow.Enabled = false;
            cockpit.AddUIElement(about_arrow, true);


            float     about_text_scale = 3.0f;
            float     angle_left       = -65.0f;
            HUDButton about_text       = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle,
                             0.8f * about_text_scale, 1.0f * about_text_scale)
            {
                UseUVSubRegion = false
            },
                3.0f, angle_left, 0.0f, "simplex_startup/about_text");

            UnityUtil.TranslateInFrame(about_text.RootGameObject, 0.0f, -0.5f, 0, CoordSpace.WorldCoords);
            about_text.Name    = "about_text";
            about_text.Enabled = false;
            cockpit.AddUIElement(about_text, true);



            HUDButton controls_arrow = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.75f, 0.75f),
                3.0f, 30.0f, -10.0f, "simplex_startup/controls_arrow");

            controls_arrow.Name    = "controls_arrow";
            controls_arrow.Enabled = false;
            cockpit.AddUIElement(controls_arrow, true);



            float     text_scale     = 3.0f;
            float     angle_right    = 65.0f;
            HUDButton controls_mouse = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.7f * text_scale, 0.7f * text_scale)
            {
                UseUVSubRegion = false
            },
                3.0f, angle_right, 0.0f, "simplex_startup/controls_mouse");

            UnityUtil.TranslateInFrame(controls_mouse.RootGameObject, 0.25f, 0.1f, 0, CoordSpace.WorldCoords);
            controls_mouse.Name    = "controls_mouse";
            controls_mouse.Enabled = false;
            cockpit.AddUIElement(controls_mouse, true);

            HUDButton controls_gamepad = HUDBuilder.CreateIconClickButton(
                new HUDShape(HUDShapeType.Rectangle, 0.7f * text_scale, 0.7f * text_scale)
            {
                UseUVSubRegion = false
            },
                3.0f, angle_right, 0.0f, "simplex_startup/controls_gamepad");

            UnityUtil.TranslateInFrame(controls_gamepad.RootGameObject, 0.25f, 0.1f, 0, CoordSpace.WorldCoords);
            controls_gamepad.Name    = "controls_gamepad";
            controls_gamepad.Enabled = false;
            cockpit.AddUIElement(controls_gamepad, true);
            controls_gamepad.RootGameObject.Hide();



            HUDToggleButton mouse_button = HUDBuilder.CreateToggleButton(
                new HUDShape(HUDShapeType.Rectangle, 1.0f, 1.0f),
                2.9f, angle_right, 0.0f, "simplex_startup/mouse", "simplex_startup/mouse_disabled");

            UnityUtil.TranslateInFrame(mouse_button.RootGameObject, -0.5f, -1.0f, 0, CoordSpace.WorldCoords);
            mouse_button.Name = "mouse_button";
            cockpit.AddUIElement(mouse_button, true);

            HUDToggleButton gamepad_button = HUDBuilder.CreateToggleButton(
                new HUDShape(HUDShapeType.Rectangle, 1.0f, 1.0f),
                2.9f, angle_right, 0.0f, "simplex_startup/gamepad_with_labels", "simplex_startup/gamepad_disabled");

            UnityUtil.TranslateInFrame(gamepad_button.RootGameObject, 0.5f, -1.0f, 0, CoordSpace.WorldCoords);
            gamepad_button.Name = "gamepad_button";
            cockpit.AddUIElement(gamepad_button, true);


            HUDToggleGroup group = new HUDToggleGroup();

            group.AddButton(mouse_button);
            group.AddButton(gamepad_button);
            group.Selected   = 0;
            group.OnToggled += (sender, nSelected) => {
                if (nSelected == 0)
                {
                    controls_gamepad.RootGameObject.Hide();
                    controls_mouse.RootGameObject.Show();
                }
                else
                {
                    controls_gamepad.RootGameObject.Show();
                    controls_mouse.RootGameObject.Hide();
                }
            };



            // setup key handlers (need to move to behavior...)
            cockpit.AddKeyHandler(new SplashScreenKeyHandler(cockpit.Context));

            cockpit.InputBehaviors.Add(new VRMouseUIBehavior(cockpit.Context)
            {
                Priority = 0
            });
            cockpit.InputBehaviors.Add(new VRGamepadUIBehavior(cockpit.Context)
            {
                Priority = 0
            });
            cockpit.InputBehaviors.Add(new VRSpatialDeviceUIBehavior(cockpit.Context)
            {
                Priority = 0
            });
        }