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NAME

       SoQtViewer - The SoQtViewer class is the top level base viewer class.

       This is an abstract class, which adds the following features to it’s
       SoQtRenderArea superclass: convenient methods for camera handling, an
       automatic headlight configuration.

SYNOPSIS

       #include <Inventor/Qt/viewers/SoQtViewer.h>

       Inherits SoQtRenderArea.

       Inherited by SoQtFullViewer.

   Public Types
       enum Type { BROWSER, EDITOR }
       enum DrawStyle { VIEW_AS_IS, VIEW_HIDDEN_LINE, VIEW_NO_TEXTURE,
           VIEW_LOW_COMPLEXITY, VIEW_LINE, VIEW_POINT, VIEW_BBOX,
           VIEW_LOW_RES_LINE, VIEW_LOW_RES_POINT, VIEW_SAME_AS_STILL,
           VIEW_WIREFRAME_OVERLAY }
       enum DrawType { STILL =  0, INTERACTIVE }
       enum BufferType { BUFFER_SINGLE, BUFFER_DOUBLE, BUFFER_INTERACTIVE }
       enum AutoClippingStrategy { VARIABLE_NEAR_PLANE, CONSTANT_NEAR_PLANE }
       enum StereoType { STEREO_NONE, STEREO_ANAGLYPH, STEREO_QUADBUFFER,
           STEREO_INTERLEAVED_ROWS, STEREO_INTERLEAVED_COLUMNS }

   Public Member Functions
       virtual void setCamera (SoCamera *camera)
       SoCamera * getCamera (void) const
       virtual void setCameraType (SoType type)
       SoType getCameraType (void) const
       virtual void toggleCameraType (void)
       virtual void viewAll (void)
       virtual void saveHomePosition (void)
       virtual void resetToHomePosition (void)
       virtual void setHeadlight (SbBool enable)
       SbBool isHeadlight (void) const
       SoDirectionalLight * getHeadlight (void) const
       virtual void setDrawStyle (SoQtViewer::DrawType type,
           SoQtViewer::DrawStyle style)
       SoQtViewer::DrawStyle getDrawStyle (const SoQtViewer::DrawType type)
           const
       virtual void setBufferingType (SoQtViewer::BufferType type)
       SoQtViewer::BufferType getBufferingType (void) const
       virtual void setViewing (SbBool enable)
       SbBool isViewing (void) const
       virtual void setCursorEnabled (SbBool enable)
       SbBool isCursorEnabled (void) const
       void setAutoClipping (SbBool enable)
       SbBool isAutoClipping (void) const
       void setAutoClippingStrategy (const AutoClippingStrategy strategy,
           const float value=0.6f, SoQtAutoClippingCB *cb=NULL, void
           *cbuserdata=NULL)
       virtual void setStereoViewing (SbBool enable)
       SbBool isStereoViewing (void) const
       virtual void setStereoOffset (const float dist)
       float getStereoOffset (void) const
       SbBool setStereoType (SoQtViewer::StereoType s)
       SoQtViewer::StereoType getStereoType (void) const
       void setAnaglyphStereoColorMasks (const SbBool left[3], const SbBool
           right[3])
       void getAnaglyphStereoColorMasks (SbBool left[3], SbBool right[3])
       void setDetailSeek (const SbBool enable)
       SbBool isDetailSeek (void) const
       void setSeekTime (const float seconds)
       float getSeekTime (void) const
       void addStartCallback (SoQtViewerCB *func, void *data=NULL)
       void addFinishCallback (SoQtViewerCB *func, void *data=NULL)
       void removeStartCallback (SoQtViewerCB *func, void *data=NULL)
       void removeFinishCallback (SoQtViewerCB *func, void *data=NULL)
       void setWireframeOverlayColor (const SbColor &color)
       const SbColor & getWireframeOverlayColor (void) const
       virtual void setDoubleBuffer (const SbBool enable)
       virtual void setSceneGraph (SoNode *root)
       virtual SoNode * getSceneGraph (void)

   Protected Member Functions
       SoQtViewer (QWidget *parent, const char *name, SbBool embed, Type type,
           SbBool build)
       ~SoQtViewer ()
       virtual void sizeChanged (const SbVec2s &size)
       virtual void setSeekMode (SbBool enable)
       SbBool isSeekMode (void) const
       SbBool seekToPoint (const SbVec2s screenpos)
       void seekToPoint (const SbVec3f &scenepos)
       virtual void computeSeekFinalOrientation (void)
       virtual void actualRedraw (void)
       virtual SbBool processSoEvent (const SoEvent *const event)
       void interactiveCountInc (void)
       void interactiveCountDec (void)
       int getInteractiveCount (void) const
       void setSeekDistance (const float distance)
       float getSeekDistance (void) const
       void setSeekValueAsPercentage (const SbBool on)
       SbBool isSeekValuePercentage (void) const
       virtual void changeCameraValues (SoCamera *camera)
       void addSuperimposition (SoNode *scene)
       void removeSuperimposition (SoNode *scene)
       void setSuperimpositionEnabled (SoNode *scene, const SbBool enable)
       SbBool getSuperimpositionEnabled (SoNode *scene) const

   Friends
       class SoQtViewerP
       class SoQtPlaneViewer

Detailed Description

       The SoQtViewer class is the top level base viewer class.

       This is an abstract class, which adds the following features to it’s
       SoQtRenderArea superclass: convenient methods for camera handling, an
       automatic headlight configuration.

       As for the camera handling: when setting a new scenegraph for the
       viewer, the scenegraph will automatically be scanned for a node derived
       from SoCamera. If not found, the viewer will itself set up a camera for
       the scene. The camera can then be conveniently controlled by the
       application programmers in many aspects:

       · camera type: toggle between using an orthographic camera and a
         perspective camera with SoQtViewer::toggleCameraType()

       · zoom out to exactly encompass all scene geometry within the view by
         using SoQtViewer::viewAll()

       · tag a specific position and orientation for the camera as the ’home’
         position with SoQtViewer::saveHomePosition(), which one can then
         return to by using SoQtViewer::resetToHomePosition()

       · automatically fit the near and far clipping planes of the camera
         around the scene’s geometry by using SoQtViewer::setAutoClipping()

       · control stereo viewing parameters

       Note that there is no dragger or manipulator attached to the scene
       camera. The camera transform manipulation is calculated in a more
       direct manner in the non-abstract viewer classes inheriting SoQtViewer
       by reading mouse and keyboard events and interpreting how these should
       influence the camera. The calculations results in new values for
       SoCamera::position, SoCamera::orientation, and the other SoCamera field
       values for the camera designated to be the viewer viewpoint camera.
       These values are then inserted directly into the viewer’s SoCamera
       node.
       See e.g. the source code for SoQtExaminerViewer::processSoEvent() for
       the details.
       The SoQtViewer class automatically adds a headlight to the scene, which
       will always point in the approximate same direction as the current
       viewer camera, thereby securing that the scene geometry is always
       lighted and visible. (If you don’t want the constant headlight, but
       rather want to light the scene on your own, this behavior can be turned
       off with SoQtViewer::setHeadlight()).
       SoQtViewer-derived viewers all inherit the following keyboard controls
       from this class (but only when the viewer is in ’examine mode’, ie
       SoQtViewer::isViewing() returns TRUE):
       ·

       ·

       · arrow keys: moves camera slightly left, right, up or down

       ·

Member Enumeration Documentation

   enum SoQtViewer::Type
       Hints about what context the viewer will be used in. Usually not very
       interesting for the application programmer, it doesn’t matter much
       which value is used for the viewer type. This ’feature’ of the viewer
       is included just to be compatible with the old SGI Inventor API.
       Enumerator:
       BROWSER
              If a user-supplied scenegraph passed into the setSceneGraph()
              function does not contain a camera, setting the viewer type to
              BROWSER will make the viewer in that case automatically set up a
              camera outside the scene, as part of the viewer’s private and
              hidden ’supergraph’.
       EDITOR If a user-supplied scenegraph passed into the setSceneGraph)
              function does not contain a camera, setting the viewer type to
              EDITOR will make the viewer in that case automatically set up a
              camera in the user-supplied scene.
       So if you want to avoid having the SoQtViewer class muck about with
       your supplied scenegraph, set the type-flag to SoQtViewer::BROWSER
       instead.
   enum SoQtViewer::DrawStyle
       Decides drawstyle for a scene with either a still camera or an
       animating camera.
       See also:
           SoQtViewer::setDrawStyle(), SoQtViewer::DrawType

       Enumerator:
       VIEW_AS_IS
              Normal rendering, draws all scene geometry in it’s original
              style.
       VIEW_HIDDEN_LINE
              Draw scene in ’hidden line’ mode: that is, as wireframe with no
              ’see-through’.
       Note that this is actually an expensive way to render, as the scene
       must be rendered twice to achieve the effect of hiding lines behind the
       invisible geometry.
       VIEW_NO_TEXTURE
              Render scene without textures.
       VIEW_LOW_COMPLEXITY
              Render all ’complex’ shape types with low complexity to improve
              rendering performance.
       VIEW_LINE
              View all polygon geometry in wireframe mode.
       VIEW_POINT
              Render only the vertex positions of the geometry.
       VIEW_BBOX
              View the scene’s bounding boxes, instead of rendering the full
              geometry.
       A very efficient way of optimizing rendering performance for scenes
       with high primitive counts while moving the camera about is to set this
       mode for the SoQtViewer::INTERACTIVE DrawType.
       VIEW_LOW_RES_LINE
              Render as wireframe and don’t bother with getting them rendered
              correctly in depth.
       VIEW_LOW_RES_POINT
              Render as vertex points and don’t bother with getting them
              rendered correctly in depth.
       VIEW_SAME_AS_STILL
              Always render a scene with an animating camera (ie
              SoQtViewer::INTERACTIVE DrawType) in the same manner as scene
              with a still camera.
       VIEW_WIREFRAME_OVERLAY
              Render the scene as normal, but overlay a set of lines showing
              the contours of all polygons.
   enum SoQtViewer::DrawType
       Contains valid values for the first argument to the
       SoQtViewer::setDrawStyle() call. Decides the effect of the second
       argument.
       See also:
           SoQtViewer::setDrawStyle(), SoQtViewer::DrawStyle

       Enumerator:
       STILL  If this value is passed as the first argument of
              SoQtViewer::setDrawStyle(), the second argument decides which
              draw style to use when the viewer camera is standing still in
              the same position with the same orientation -- i.e. when the end
              user is not interacting with the scene camera.
       INTERACTIVE
              If this value is passed as the first argument of
              SoQtViewer::setDrawStyle(), the second argument decides which
              draw style to use when the end user is interacting with the
              scene camera, causing continuous animation redraws.
   enum SoQtViewer::BufferType
       Set of valid values for SoQtViewer::setBufferingType().
       Enumerator:
       BUFFER_SINGLE
              Change underlying OpenGL canvas to be single-buffered.
       BUFFER_DOUBLE
              Change underlying OpenGL canvas to be double-buffered.
       BUFFER_INTERACTIVE
              Set up so animation rendering is done in a double-buffered
              OpenGL canvas, but ordinary rendering happens directly in the
              front-buffer.
       This mode can be useful with absurdly large scenes, as the rendering
       will visibly progress, and one will avoid having the end user wonder
       why nothing is happening while the scene is rendered to the back buffer
       in the default SoQtViewer::BUFFER_DOUBLE mode.
   enum SoQtViewer::AutoClippingStrategy
       Enum for auto clipping strategy.
       See also:
           setAutoClippingStrategy()

       Enumerator:
       VARIABLE_NEAR_PLANE
              Variable near plane auto clipping strategy. Explained in detail
              in the documentation for the
              SoQtViewer::setAutoClippingStrategy() method.
       CONSTANT_NEAR_PLANE
              Constant near plane auto clipping strategy. Explained in detail
              in the documentation for the
              SoQtViewer::setAutoClippingStrategy() method.
   enum SoQtViewer::StereoType
       Contains list of supported stereo rendering techniques.
       See also:
           SoQtViewer::setStereoType()

       Enumerator:
       STEREO_NONE
              Use monoscopic rendering.
       STEREO_ANAGLYPH
              Render stereo by superimposing two images of the same scene, but
              with different color filters over the left and right view (or
              ’eye’).
       This is a way of rendering stereo which works on any display, using
       color-filter glasses. Such glasses are usually cheap and easy to come
       by.
       See also:
           setAnaglyphStereoColorMasks()

       STEREO_QUADBUFFER
              Render stereo by using OpenGL quad-buffers. This is the most
              common interface for stereo rendering for more expensive
              hardware devices, such as shutter glasses and polarized glasses.
       The well known Crystal Eyes glasses are commonly used with this type of
       stereo display.
       STEREO_INTERLEAVED_ROWS
              Interleaving / interlacing rows from the left and right eye is
              another stereo rendering method requiring special hardware. One
              example of a provider of shutter glasses working with
              interleaved glasses is VRex:
       http://www.vrex.com/
       STEREO_INTERLEAVED_COLUMNS
              Same basic technique as SoQtViewer::STEREO_INTERLEAVED_ROWS,
              only it is vertical lines that are interleaved / interlaced,
              instead of horizontal lines.

Constructor & Destructor Documentation

   SoQtViewer::SoQtViewer (QWidget * parent, const char * name, SbBool embed,
       SoQtViewer::Type t, SbBool build) [protected]
       Constructor. parent, name and embed are passed on to SoQtRenderArea, so
       see the documentation for our parent constructor for for more
       information on those.
       The t type setting hints about what context the viewer will be used in.
       Usually not very interesting for the application programmer, but if you
       want to make sure the SoQtViewer class doesn’t muck about with your
       supplied scenegraph, set the type-flag to SoQtViewer::BROWSER. (This
       ’feature’ of the viewer is included just to be compatible with the old
       SGI Inventor API.)
       The build flag decides whether or not to delay building the widgets /
       window which is going to make up the components of the viewer.
       References addFinishCallback(), addStartCallback(), BUFFER_DOUBLE,
       BUFFER_SINGLE, SoQtRenderArea::buildWidget(),
       SoQtObject::getClassTypeId(), SoQtComponent::getParentWidget(),
       INTERACTIVE, SoQtGLWidget::isDoubleBuffer(),
       SoQtComponent::setBaseWidget(), SoQtComponent::setClassName(), STILL,
       VIEW_AS_IS, and VIEW_SAME_AS_STILL.
   SoQtViewer::~SoQtViewer () [protected]
       Destructor.
       References removeSuperimposition(), and setSceneGraph().

Member Function Documentation

   void SoQtViewer::setCamera (SoCamera * cam) [virtual]
       Set the camera we want the viewer to manipulate when interacting with
       the viewer controls.
       The camera passed in as an argument to this method must already be part
       of the viewer’s scenegraph. You do not inject viewpoint cameras to the
       viewer with this method.
       You should rather insert a camera into the scene graph first (if
       necessary, often one will be present already), then register it as the
       camera used by the viewer controls with this method.
       If the application code doesn’t explicitly set up a camera through this
       method, the viewer will automatically scan through the scenegraph to
       find a camera to use. If no camera is available in the scenegraph at
       all, it will set up it’s own camera.
       See also:
           getCamera()

       Reimplemented in SoQtPlaneViewer, SoQtExaminerViewer,
       SoQtConstrainedViewer, and SoQtFlyViewer.
       References saveHomePosition().
       Referenced by setCameraType(), and setSceneGraph().
   SoCamera * SoQtViewer::getCamera (void) const
       Returns the camera currently used by the viewer for the user’s main
       viewpoint.
       It is possible that this function returns NULL, for instance if there’s
       no scenegraph present in the viewer. (This is mostly meant as a note
       for developers extending the SoQt library, as application programmers
       usually controls if and when a viewer contains a scenegraph, and
       therefore know in advance if this method will return a valid camera
       pointer.)
       See also:
           setCamera()

       Referenced by actualRedraw(), SoQtFlyViewer::actualRedraw(),
       SoQtPlaneViewer::bottomWheelMotion(), changeCameraValues(),
       SoQtConstrainedViewer::checkForCameraUpConstrain(),
       SoQtPlaneViewer::leftWheelMotion(), SoQtPlaneViewer::processSoEvent(),
       SoQtExaminerViewer::processSoEvent(),
       SoQtPlaneViewer::rightWheelMotion(),
       SoQtExaminerViewer::rightWheelMotion(), setSceneGraph(),
       SoQtConstrainedViewer::setUpDirection(), and
       SoQtConstrainedViewer::tiltCamera().
   void SoQtViewer::setCameraType (SoType t) [virtual]
       When the viewer has to make its own camera as a result of the graph
       passed to setSceneGraph() not containing any camera nodes, this call
       can be made in advance to decide which type the camera will be of.
       Default is to use an SoPerspectiveCamera.
       If this method is called when there is a scene graph and a camera
       already set up, it will delete the old camera and set up a camera with
       the new type if the t type is different from that of the current
       camera.
       See also:
           getCameraType()

       Reimplemented in SoQtFlyViewer.
       References SoQtObject::getClassTypeId(), and setCamera().
       Referenced by toggleCameraType().
   SoType SoQtViewer::getCameraType (void) const
       Returns camera type which will be used when the viewer has to make its
       own camera.
       Note that this call does not return the current cameratype, as one
       might expect. Use getCamera() and SoType::getTypeId() for that inquiry.
       See also:
           setCameraType()

       Referenced by SoQtPlaneViewer::createViewerButtons(), and
       SoQtExaminerViewer::createViewerButtons().
   void SoQtViewer::toggleCameraType (void) [virtual]
       If the current camera is of perspective type, switch to orthographic,
       and vice versa.
       Automatically calls SoQtViewer::setCameraType() so the change will
       immediately take place.
       References SoQtObject::getClassTypeId(), and setCameraType().
   void SoQtViewer::viewAll (void) [virtual]
       Reposition the current camera so we can see the complete scene.
       Reimplemented in SoQtFlyViewer.
       References SoQtRenderArea::getViewportRegion().
   void SoQtViewer::saveHomePosition (void) [virtual]
       Store the current camera settings for later retrieval with
       resetToHomePosition().
       See also:
           resetToHomePosition()

       Reimplemented in SoQtConstrainedViewer.
       Referenced by setCamera().
   void SoQtViewer::resetToHomePosition (void) [virtual]
       Restore the saved camera settings.
       See also:
           saveHomePosition()

       Reimplemented in SoQtConstrainedViewer, and SoQtFlyViewer.
       Referenced by processSoEvent().
   void SoQtViewer::setHeadlight (SbBool on) [virtual]
       Turn the camera headlight on or off.
       Default is to have a headlight turned on.
       See also:
           isHeadlight(), getHeadlight()

   SbBool SoQtViewer::isHeadlight (void) const
       Returns status of the viewer headlight, whether it is on or off.
       See also:
           setHeadlight(), getHeadlight()

   SoDirectionalLight * SoQtViewer::getHeadlight (void) const
       Returns the a pointer to the directional light node which is the viewer
       headlight.
       The fields of the node is available for user editing.
       See also:
           isHeadlight(), setHeadlight()

   void SoQtViewer::setDrawStyle (SoQtViewer::DrawType type,
       SoQtViewer::DrawStyle style) [virtual]
       Set up a drawing style. The type argument specifies if the given style
       should be interpreted as the drawstyle during animation or when the
       camera is static.
       Default values for the drawing style is to render the scene ’as is’ in
       both still mode and while the camera is moving.
       See the documentation for the DrawType and DrawStyle for more
       information.
       See also:
           getDrawStyle()

       References getDrawStyle(), INTERACTIVE, and STILL.
   SoQtViewer::DrawStyle SoQtViewer::getDrawStyle (const SoQtViewer::DrawType
       type) const
       Return current drawstyles for the given type (STILL or INTERACTIVE).
       See also:
           setDrawStyle()

       References INTERACTIVE, and STILL.
       Referenced by setDrawStyle().
   void SoQtViewer::setBufferingType (SoQtViewer::BufferType type) [virtual]
       Set the viewer’s buffer type. Available types are
       SoQtViewer::BUFFER_SINGLE, SoQtViewer::BUFFER_DOUBLE and
       SoQtViewer::BUFFER_INTERACTIVE.
       (With a buffer type of SoQtViewer::BUFFER_INTERACTIVE, the viewer will
       render with doublebuffering during user interaction and with single
       buffering otherwise.)
       Default is SoQtViewer::BUFFER_DOUBLE.
       See also:
           getBufferingType()

       References BUFFER_DOUBLE, BUFFER_INTERACTIVE, BUFFER_SINGLE, and
       setDoubleBuffer().
   SoQtViewer::BufferType SoQtViewer::getBufferingType (void) const
       Return the viewer’s buffer type.
       See also:
           setBufferingType()

   void SoQtViewer::setViewing (SbBool enable) [virtual]
       Set view mode.
       If the view mode is on, user events will be caught and used to
       influence the camera position / orientation. If view mode is off, all
       events in the viewer canvas (like for instance keypresses or
       mouseclicks and -movements) will be passed along to the scene graph.
       Default is to have the view mode active.
       See also:
           isViewing()

       Reimplemented in SoQtFullViewer, SoQtPlaneViewer, SoQtExaminerViewer,
       and SoQtFlyViewer.
       References SoQtRenderArea::getGLRenderAction().
       Referenced by processSoEvent().
   SbBool SoQtViewer::isViewing (void) const
       Return state of view mode.
       TRUE means that the mode of the viewer is set such that user
       interaction with the mouse is used to modify the position and
       orientation of the camera.
       See also:
           setViewing()

       Referenced by SoQtFlyViewer::actualRedraw(),
       SoQtFullViewer::createViewerButtons(), processSoEvent(),
       SoQtPlaneViewer::processSoEvent(), SoQtFullViewer::processSoEvent(),
       SoQtFlyViewer::processSoEvent(), SoQtExaminerViewer::processSoEvent(),
       SoQtExaminerViewer::setFeedbackSize(),
       SoQtExaminerViewer::setFeedbackVisibility(), setSeekMode(),
       SoQtPlaneViewer::setSeekMode(), SoQtExaminerViewer::setSeekMode(),
       SoQtPlaneViewer::setViewing(), SoQtFlyViewer::setViewing(),
       SoQtExaminerViewer::setViewing(), SoQtFullViewer::setViewing(), and
       SoQtExaminerViewer::stopAnimating().
   void SoQtViewer::setCursorEnabled (SbBool on) [virtual]
       Set whether or not the mouse cursor representation should be visible in
       the viewer canvas.
       Default value is on.
       See also:
           isCursorEnabled()

       Reimplemented in SoQtPlaneViewer, SoQtExaminerViewer, and
       SoQtFlyViewer.
   SbBool SoQtViewer::isCursorEnabled (void) const
       Returns visibility status of mouse cursor.
       See also:
           setCursorEnabled()

   void SoQtViewer::setAutoClipping (SbBool enable)
       Turn on or off continuous automatic adjustments of the near and far
       clipping planes.
       If on, the distance from the camera position to the near and far planes
       will be calculated to be a ’best fit’ around the geometry in the scene,
       to maximize the ’stretch’ of values for the visible geometry in the z-
       buffer. This is important, as z-buffer resolution is usually limited
       enough that one will quickly see flickering in the rasterization of
       close polygons upon lousy utilization of the z-buffer.
       Automatic calculations of near and far clip planes are on as default.
       For better control over what happens in boundary conditions (for
       instance when the distance between near and far planes get very far, or
       if geometry gets very close to the camera position), it is possible to
       use the SoQtViewer::setAutoClippingStrategy() method to fine-tune the
       near/far clipping plane settings.
       On a major note, be aware that turning auto-updating of near and far
       clip planes off have a potentially serious detrimental effect on
       performance, due to an important side effect: updating the near and far
       clip planes triggers an SoGetBoundingBoxAction to traverse the scene
       graph, which causes bounding boxes to be calculated and stored in
       caches. The bounding box caches are then used by the SoGLRenderAction
       traversal for view frustum culling operations. With no bounding box
       caches, the rendering will not do culling, which can cause much worse
       performance. Systems in Motion are working on correcting this problem
       properly from within the Coin library.
       On a minor note, be aware that notifications will be temporarily turned
       off for the scene’s SoCamera when changing the near and far clipping
       planes (which is done right before each redraw). This is done to avoid
       notifications being sent through the scene graph right before
       rendering, as that causes some latency. It is mentioned here in case
       you have any client code which for some reason needs to sense all
       changes to the scene camera. This is however unlikely, so you can very
       probably ignore this.
       See also:
           getAutoClipping()

       References SoQtRenderArea::scheduleRedraw().
   SbBool SoQtViewer::isAutoClipping (void) const
       Return value of the automatic near/far clipplane adjustment indicator.
       See also:
           setAutoClipping()

   void SoQtViewer::setAutoClippingStrategy (const AutoClippingStrategy
       strategy, const float value = 0.6f, SoQtAutoClippingCB * cb = NULL,
       void * cbuserdata = NULL)
       Set the strategy used for automatic updates of the distances to the
       near and far clipping planes.
       When auto clipping is enabled, the near plane distance is calculated so
       that it is just in front of the scene bounding box. If this near plane
       is behind or very close to the projection point, one of the following
       strategies will be used to calculate the new clipping plane.
       The VARIABLE_NEAR_PLANE strategy considers the number of z buffer bits
       available for the current OpenGL context, and uses value to calculate
       the number of bits that is lost because of the far/near ratio. value
       should be in the range [0.0, 1.0]. A higher value will increase the z-
       buffer precision, but also push the near plane further away from the
       projection point.
       The CONSTANT_NEAR_PLANE strategy simply sets the near plane to value.
       If value at some point approaches the far clipping plane distance, the
       near plane distance will be set to far plane distance divided by
       5000.0.
       The default strategy is VARIABLE_NEAR_PLANE.
       It is also possible to register a callback method cb, which will then
       be invoked after the near and far clipping planes has been calculated
       by the SoQtViewer code. The callback can then adjust the values for the
       distance to the near and far planes to exactly match the needs of the
       application (for instance at specific parts in the scene), to limit the
       distance to either plane, or whatever else needs to be controlled.
       The signature of the SoQtAutoClippingCB callback must match:
         SbVec2f myfunc(void * data, const SbVec2f & nearfar);

       The first argument is the cbuserdata passed in along with the callback
       function pointer itself (ie the callback function’s closure). The
       second argument is the near and far clipping plane distances from the
       camera position, as calculated internally by the viewer, including
       ’slack’.
       The function callback can then modify the near and far clipping plane
       distances to what will actually be used by the viewer. These values
       will then be used unmodified for the viewer’s camera.
       This is a good way of dynamically modifying the near and far distances
       such that they at all times exactly matches the specific layout of the
       application scene, for instance with regard to the trade-off between z-
       buffer resolution and how early geometry is clipped at the near plane
       (or at the far plane).
       Note that the internal near/far calculations should be good enough for
       the vast majority of scenes. Application programmers should only need
       to set up their own adjustments upon ’unusual’ scenes, like for
       instance scenes with a large world space, but where one would still
       like to be able to get up extremely close on details in some parts of
       the scene.
       See also:
           setAutoClipping()

       References SoQtRenderArea::scheduleRedraw(), and VARIABLE_NEAR_PLANE.
   void SoQtViewer::setStereoViewing (SbBool enable) [virtual]
       Turn stereo viewing on or off.
       Note: this function is being obsoleted, you should use the
       setStereoType() function instead.
       Coin does ’correct’ stereo rendering, using the method known as
       ’parallel axis asymmetric frustum perspective projection’. For more
       information, see this link:
       http://astronomy.swin.edu.au/~pbourke/opengl/stereogl/
       See also:
           isStereoViewing(), setStereoType()

       References SoQtRenderArea::scheduleRedraw().
       Referenced by setStereoType().
   SbBool SoQtViewer::isStereoViewing (void) const
       Returns a boolean indicating whether or not we’re in stereo viewing
       mode.
       NOTE: in the original InventorXt API, this method was virtual. It is
       not virtual here.
       See also:
           setStereoViewing(), getStereoType()

       Referenced by getStereoType().
   void SoQtViewer::setStereoOffset (const float dist) [virtual]
       Set the offset between the two viewpoints when in stereo mode. Default
       value is 0.1.
       NOTE: In the original InventorXt API, this method was not virtual.
       See also:
           getStereoOffset()

       References SoQtRenderArea::scheduleRedraw().
   float SoQtViewer::getStereoOffset (void) const
       Return the offset distance between the two viewpoints when in stereo
       mode.
       See also:
           setStereoOffset()

   SbBool SoQtViewer::setStereoType (SoQtViewer::StereoType s)
       Set up stereo rendering.
       Coin does ’correct’ stereo rendering, using the method known as
       ’parallel axis asymmetric frustum perspective projection’. For more
       information, see this link:
       http://astronomy.swin.edu.au/~pbourke/opengl/stereogl/
       Note: it is prefered that one uses this function for control of which
       type of stereo rendering to use, instead of the older
       SoQtViewer::setStereoViewing() and SoQtGLWidget::setQuadBufferStereo()
       functions.
       The default is to do monoscopic rendering, i.e. the default
       SoQtViewer::StereoType value is SoQtViewer::STEREO_NONE.
       See also:
           SoQtViewer::StereoType, SoCamera::setStereoAdjustment
       Since:
           SoQt 1.2

       References SoQtGLWidget::getStencilBuffer(), getStereoType(),
       SoQtGLWidget::isQuadBufferStereo(),
       SoQtGLWidget::setQuadBufferStereo(), SoQtGLWidget::setStencilBuffer(),
       setStereoViewing(), STEREO_ANAGLYPH, STEREO_INTERLEAVED_COLUMNS,
       STEREO_INTERLEAVED_ROWS, STEREO_NONE, and STEREO_QUADBUFFER.
   SoQtViewer::StereoType SoQtViewer::getStereoType (void) const
       Returns the current type of stereo rendering used (or
       SoQtViewer::STEREO_NONE if monoscopic).
       References SoQtGLWidget::isQuadBufferStereo(), isStereoViewing(),
       STEREO_ANAGLYPH, and STEREO_QUADBUFFER.
       Referenced by actualRedraw(), and setStereoType().
   void SoQtViewer::setAnaglyphStereoColorMasks (const SbBool left[3], const
       SbBool right[3])
       If display is configured to render in anaglyph stereo, this function
       can be used to control which filter is used for each eye.
       The default filters are red (i.e. color vector [TRUE,FALSE,FALSE]) for
       the left eye, and cyan (color vector [FALSE,TRUE,TRUE]) for the right
       eye.
       See also:
           SoQtViewer::StereoType, setStereoType()

       References SoQtRenderArea::scheduleRedraw().
   void SoQtViewer::getAnaglyphStereoColorMasks (SbBool left[3], SbBool
       right[3])
       Returns color masks for left and right eye filters in anaglyph stereo.
       See also:
           setAnaglyphStereoColorMasks()

   void SoQtViewer::setDetailSeek (const SbBool on)
       Toggle between seeking to a point or seeking to an object.
       Default is to seek to a point.
       See also:
           isDetailSeek()

   SbBool SoQtViewer::isDetailSeek (void) const
       Returns a value indicating whether or not seeks will be performed to
       the exact point of picking or just towards the picked object.
       See also:
           setDetailSeek()

   void SoQtViewer::setSeekTime (const float seconds)
       Set the duration of animating the camera repositioning after a
       successful seek. Call with seconds equal to 0.0 to make the camera jump
       immediately to the correct spot.
       Default value is 2 seconds.
       See also:
           getSeekTime()

   float SoQtViewer::getSeekTime (void) const
       Returns the camera repositioning duration following a seek action.
       See also:
           setSeekTime()

   void SoQtViewer::addStartCallback (SoQtViewerCB * func, void * data = NULL)
       Add a function to call when user interaction with the scene starts.
       See also:
           removeStartCallback(), addFinishCallback()

       Referenced by SoQtViewer().
   void SoQtViewer::addFinishCallback (SoQtViewerCB * func, void * data =
       NULL)
       Add a function to call when user interaction with the scene ends.
       See also:
           removeFinishCallback(), addStartCallback()

       Referenced by SoQtViewer().
   void SoQtViewer::removeStartCallback (SoQtViewerCB * func, void * data =
       NULL)
       Remove one of the functions which has been set up to be called when
       user interaction with the scene starts.
       See also:
           addStartCallback(), removeFinishCallback()

   void SoQtViewer::removeFinishCallback (SoQtViewerCB * func, void * data =
       NULL)
       Remove one of the functions which has been set up to be called when
       user interaction with the scene ends.
       See also:
           addFinishCallback(), removeStartCallback()

   void SoQtViewer::setWireframeOverlayColor (const SbColor & color)
       Set the color of the overlay wireframe to color.
       See also:
           getWireframeOverlayColor()

       References SoQtRenderArea::scheduleRedraw().
   const SbColor & SoQtViewer::getWireframeOverlayColor (void) const
       Returns the current color of the overlay wireframe. The default color
       is [1,0,0], ie pure red.
       See also:
           setWireframeOverlayColor()

   void SoQtViewer::setDoubleBuffer (const SbBool on) [virtual]
       Overloaded to update the local bufferingtype variable.
       See also:
           setBufferingType(), getBufferingType()

       Reimplemented from SoQtGLWidget.
       References BUFFER_DOUBLE, and BUFFER_SINGLE.
       Referenced by setBufferingType().
   void SoQtViewer::setSceneGraph (SoNode * root) [virtual]
       Give the viewer a scenegraph to render and interact with. Overridden
       from parent class so the viewer can add it’s own nodes to control
       rendering in different styles, rendering with a headlight, etc.
       The root node will be inserted under the viewers root node, which also
       covers the nodes necessary to implement the different preferences
       drawing style settings.
       If no camera is part of the scene graph under root, one will
       automatically be instantiated and added. You can get a reference to
       this camera by using the SoQtViewer::getCamera() method.
       See also:
           getSceneGraph(), setCameraType()

       Reimplemented from SoQtRenderArea.
       References BROWSER, getCamera(), SoQtObject::getClassTypeId(),
       SoQtRenderArea::getViewportRegion(), and setCamera().
       Referenced by ~SoQtViewer().
   SoNode * SoQtViewer::getSceneGraph (void) [virtual]
       This method returns a reference to the scene graph root node as set by
       the user.
       See also:
           SoQtRenderArea::getSceneManager()

       Reimplemented from SoQtRenderArea.
   void SoQtViewer::sizeChanged (const SbVec2s & size) [protected, virtual]
       Called internally from within the SoQt library when the widget embedded
       in a component changes it size, which is usually triggered by end-user
       interaction.
       This method is then invoked to notify the component that the size has
       changed. It is called from the top and all the way down to the bottom,
       the size being adjusted to take into account extra decorations having
       been added at each level in the component class hierarchy.
       Reimplemented from SoQtRenderArea.
       Reimplemented in SoQtFullViewer.
   void SoQtViewer::setSeekMode (SbBool enable) [protected, virtual]
       Put the viewer in or out of ’waiting-to-seek’ mode.
       If the user performs a mouse button click when the viewer is in
       ’waiting-to-seek’ mode, the camera will be repositioned so the camera
       focal point lies on the point of the geometry under the mouse cursor.
       See also:
           isSeekMode(), setDetailSeek()

       Reimplemented in SoQtPlaneViewer, SoQtExaminerViewer, and
       SoQtFlyViewer.
       References interactiveCountDec(), and isViewing().
       Referenced by processSoEvent(), and seekToPoint().
   SbBool SoQtViewer::isSeekMode (void) const [protected]
       Return a flag which indicates whether or not the viewer is in ’waiting-
       to-seek’ mode.
       (The actual animated translation will not occur until the end user
       really starts the seek operation, typically by clicking with the left
       mousebutton.)
       See also:
           setSeekMode()

       Referenced by processSoEvent(), SoQtPlaneViewer::processSoEvent(),
       SoQtFlyViewer::processSoEvent(), SoQtExaminerViewer::processSoEvent(),
       SoQtPlaneViewer::setSeekMode(), SoQtFlyViewer::setSeekMode(), and
       SoQtExaminerViewer::setSeekMode().
   SbBool SoQtViewer::seekToPoint (const SbVec2s screenpos) [protected]
       Call this method to initiate a seek action towards the 3D intersection
       of the scene and the ray from the screen coordinate’s point and in the
       same direction as the camera is pointing.
       Returns TRUE if the ray from the screenpos position intersect with any
       parts of the onscreen geometry, otherwise FALSE.
       References SoQtRenderArea::getViewportRegion(), interactiveCountInc(),
       and setSeekMode().
       Referenced by processSoEvent(), SoQtPlaneViewer::processSoEvent(), and
       SoQtExaminerViewer::processSoEvent().
   void SoQtViewer::seekToPoint (const SbVec3f & scenepos) [protected]
       Call this method to initiate a seek action towards the give 3D world
       coordinate point in the scene, scenepos.
       Since:
           SoQt 1.3.0

       References computeSeekFinalOrientation(), interactiveCountDec(), and
       interactiveCountInc().
   void SoQtViewer::computeSeekFinalOrientation (void) [protected, virtual]
       This method can be overridden in subclasses if the final orientation of
       the camera after a seek should be something other than what is computed
       in SoQtViewer::seekToPoint(const SbVec3f & scenepos)
       Reimplemented in SoQtPlaneViewer.
       Referenced by seekToPoint().
   void SoQtViewer::actualRedraw (void) [protected, virtual]
       This method instantly redraws the normal (non-overlay) scenegraph by
       calling SoSceneManager::render().
       Subclasses may override this method to add their own rendering before
       or after Coin renders it’s scenegraph.
       The following is a complete example that demonstrates one way of adding
       both a background image and foreground (overlay) geometry to the
       ’normal’ rendering:
         // This example shows how to put a permanent background image on your
         // viewer canvas, below the 3D graphics, plus overlay foreground
         // geometry.  Written by mortene.  Copyright Systems in Motion 2002.

         // *************************************************************************

         #include <Inventor/Qt/SoQt.h>
         #include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
         #include <Inventor/nodes/SoBaseColor.h>
         #include <Inventor/nodes/SoCone.h>
         #include <Inventor/nodes/SoCube.h>
         #include <Inventor/nodes/SoImage.h>
         #include <Inventor/nodes/SoLightModel.h>
         #include <Inventor/nodes/SoOrthographicCamera.h>
         #include <Inventor/nodes/SoRotationXYZ.h>
         #include <Inventor/nodes/SoSeparator.h>
         #include <Inventor/nodes/SoTranslation.h>

         #include <GL/gl.h>

         // *************************************************************************

         class MyExaminerViewer : public SoQtExaminerViewer {

         public:
           MyExaminerViewer(QWidget * parent, const char * filename);
           ~MyExaminerViewer();

         protected:
           virtual void actualRedraw(void);

         private:
           SoSeparator * bckgroundroot;
           SoSeparator * foregroundroot;
           SoRotationXYZ * arrowrotation;
         };

         MyExaminerViewer::MyExaminerViewer(QWidget * parent, const char * filename)
           : SoQtExaminerViewer(parent)
         {
           // Coin should not clear the pixel-buffer, so the background image
           // is not removed.
           this->setClearBeforeRender(FALSE, TRUE);

           // Set up background scenegraph with image in it.

           this->bckgroundroot = new SoSeparator;
           this->bckgroundroot->ref();

           SoOrthographicCamera * cam = new SoOrthographicCamera;
           cam->position = SbVec3f(0, 0, 1);
           cam->height = 1;
           // SoImage will be at z==0.0.
           cam->nearDistance = 0.5;
           cam->farDistance = 1.5;

           SoImage * img = new SoImage;
           img->vertAlignment = SoImage::HALF;
           img->horAlignment = SoImage::CENTER;
           img->filename = filename;

           this->bckgroundroot->addChild(cam);
           this->bckgroundroot->addChild(img);

           // Set up foreground, overlayed scenegraph.

           this->foregroundroot = new SoSeparator;
           this->foregroundroot->ref();

           SoLightModel * lm = new SoLightModel;
           lm->model = SoLightModel::BASE_COLOR;

           SoBaseColor * bc = new SoBaseColor;
           bc->rgb = SbColor(1, 1, 0);

           cam = new SoOrthographicCamera;
           cam->position = SbVec3f(0, 0, 5);
           cam->height = 10;
           cam->nearDistance = 0;
           cam->farDistance = 10;

           const double ARROWSIZE = 2.0;

           SoTranslation * posit = new SoTranslation;
           posit->translation = SbVec3f(-2.5 * ARROWSIZE, 1.5 * ARROWSIZE, 0);

           arrowrotation = new SoRotationXYZ;
           arrowrotation->axis = SoRotationXYZ::Z;

           SoTranslation * offset = new SoTranslation;
           offset->translation = SbVec3f(ARROWSIZE/2.0, 0, 0);

           SoCube * cube = new SoCube;
           cube->width = ARROWSIZE;
           cube->height = ARROWSIZE/15.0;

           this->foregroundroot->addChild(cam);
           this->foregroundroot->addChild(lm);
           this->foregroundroot->addChild(bc);
           this->foregroundroot->addChild(posit);
           this->foregroundroot->addChild(arrowrotation);
           this->foregroundroot->addChild(offset);
           this->foregroundroot->addChild(cube);
         }

         MyExaminerViewer::~MyExaminerViewer()
         {
           this->bckgroundroot->unref();
           this->foregroundroot->unref();
         }

         void
         MyExaminerViewer::actualRedraw(void)
         {
           // Must set up the OpenGL viewport manually, as upon resize
           // operations, Coin won’t set it up until the SoGLRenderAction is
           // applied again. And since we need to do glClear() before applying
           // the action..
           const SbViewportRegion vp = this->getViewportRegion();
           SbVec2s origin = vp.getViewportOriginPixels();
           SbVec2s size = vp.getViewportSizePixels();
           glViewport(origin[0], origin[1], size[0], size[1]);

           const SbColor col = this->getBackgroundColor();
           glClearColor(col[0], col[1], col[2], 0.0f);
           glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

           // Render our scenegraph with the image.
           SoGLRenderAction * glra = this->getGLRenderAction();
           glra->apply(this->bckgroundroot);

           // Render normal scenegraph.
           SoQtExaminerViewer::actualRedraw();

           // Increase arrow angle with 1/1000 ° every frame.
           arrowrotation->angle = arrowrotation->angle.getValue() + (0.001 / M_PI * 180);
           // Render overlay front scenegraph.
           glClear(GL_DEPTH_BUFFER_BIT);
           glra->apply(this->foregroundroot);
         }

         // *************************************************************************

         int
         main(int argc, char ** argv)
         {
           if (argc != 2) {
             (void)fprintf(stderr, ’0sage: %s <image-filename>0, argv[0]);
             exit(1);
           }

           QWidget * window = SoQt::init(argv[0]);

           MyExaminerViewer * viewer = new MyExaminerViewer(window, argv[1]);

           viewer->setSceneGraph(new SoCone);
           viewer->show();

           SoQt::show(window);
           SoQt::mainLoop();

           delete viewer;
           return 0;
         }

         // *************************************************************************

       Reimplemented from SoQtRenderArea.
       Reimplemented in SoQtPlaneViewer, SoQtExaminerViewer, and
       SoQtFlyViewer.
       References SoQtRenderArea::getBackgroundColor(), getCamera(),
       SoQtRenderArea::getSceneManager(), getStereoType(),
       SoQtRenderArea::isClearBeforeRender(),
       SoQtRenderArea::isClearZBufferBeforeRender(),
       SoQtGLWidget::isDoubleBuffer(), STEREO_ANAGLYPH,
       STEREO_INTERLEAVED_COLUMNS, STEREO_INTERLEAVED_ROWS, STEREO_NONE, and
       STEREO_QUADBUFFER.
   SbBool SoQtViewer::processSoEvent (const SoEvent *const  event) [protected,
       virtual]
       Toolkit-native events are attempted converted to Coin-generic events in
       the SoQtRenderArea::processEvent() method. If this succeeds, they are
       forwarded to this method.
       This is a virtual method, and is overridden in it’s subclasses to catch
       events of particular interest to the viewer classes, for instance.
       Return TRUE iff the event was processed. If not it should be passed on
       further up in the inheritance hierarchy by the caller. This last point
       is extremely important to take note of if you are expanding the toolkit
       with your own viewer class.
       This method is not part of the original SGI InventorXt API. Note that
       you can still override the toolkit-native processEvent() method instead
       of this ’generic’ method.
       Reimplemented from SoQtRenderArea.
       Reimplemented in SoQtFullViewer, SoQtPlaneViewer, SoQtExaminerViewer,
       and SoQtFlyViewer.
       References isSeekMode(), isViewing(), resetToHomePosition(),
       seekToPoint(), setSeekMode(), and setViewing().
   void SoQtViewer::interactiveCountInc (void) [protected]
       To be able to trigger callback functions when user interaction starts
       and/or stops, we need to keep track of the viewer state (i.e. are we in
       still mode or in animation mode?).
       SoQtViewer automatically adds callbacks to switch between still and
       moving draw style, and to switch between single/double buffer when the
       buffer type is INTERACTIVE.
       See also:
           interactiveCountDec(), getInteractiveCount()
           addStartCallback(), addFinishCallback()
           removeStartCallback(), removeFinishCallback()
           setDrawStyle(), setBufferingType()

       Referenced by SoQtFullViewer::bottomWheelStart(),
       SoQtFullViewer::leftWheelStart(), SoQtFullViewer::rightWheelStart(),
       and seekToPoint().
   void SoQtViewer::interactiveCountDec (void) [protected]
       To be able to trigger callback functions when user interaction starts
       and/or stops, we need to keep track of the viewer state (i.e. are we in
       still mode or in animation mode?).
       SoQtViewer automatically adds callbacks to switch between still and
       moving draw style, and to switch between single/double buffer when the
       buffer type is INTERACTIVE.
       See also:
           interactiveCountInc(), getInteractiveCount()
           addStartCallback(), addFinishCallback()
           removeStartCallback(), removeFinishCallback()
           setDrawStyle(), setBufferingType()

       Referenced by SoQtFullViewer::bottomWheelFinish(),
       SoQtFullViewer::leftWheelFinish(), SoQtFullViewer::rightWheelFinish(),
       seekToPoint(), and setSeekMode().
   int SoQtViewer::getInteractiveCount (void) const [protected]
       Return current interaction count nesting. If equal to zero, the viewer
       is in animation mode, otherwise the camera is still.
       See also:
           interactiveCountInc(), interactiveCountDec()

   void SoQtViewer::setSeekDistance (const float distance) [protected]
       Set the value used for calculating how close the camera and
       intersection hit point should be made at the end of a seek operation.
       The value can be interpreted as an absolute value in the given world
       unit (which typically is meters) or as a percentage value of the
       distance between the camera starting position and the intersection hit
       point. This can be controlled through the setSeekValueAsPercentage()
       method. It is as default used as an absolute value.
       Default value is 50 (absolute distance or percent).
       See also:
           getSeekDistance(), setSeekValueAsPercentage(), setSeekTime()

   float SoQtViewer::getSeekDistance (void) const [protected]
       Returns the current seek distance. Value given as an absolute scalar
       length or as a percentage value of the original distance between the
       hitpoint and the camera starting position.
       See also:
           setSeekDistance(), isSeekValueAsPercentage()

   void SoQtViewer::setSeekValueAsPercentage (const SbBool on) [protected]
       Control whether or not the seek distance value should be interpreted as
       a percentage value or as an absolute distance. See documentation on
       setSeekDistance() for more information.
       See also:
           setSeekDistance(), isSeekValueAsPercentage()

       References isSeekValuePercentage().
   SbBool SoQtViewer::isSeekValuePercentage (void) const [protected]
       Returns an boolean which indicates if the seek distance value from
       getSeekDistance() should be interpreted as a percentage value or as an
       absolute value.
       See also:
           setSeekValuePercentage(), getSeekDistance()

       Referenced by setSeekValueAsPercentage().
   void SoQtViewer::changeCameraValues (SoCamera * camera) [protected,
       virtual]
       Copies the settings of camera into our current camera. Cameras must be
       of the same class type.
       Reimplemented in SoQtConstrainedViewer.
       References getCamera().
   void SoQtViewer::addSuperimposition (SoNode * scene) [protected]
       This method is for setting up a superimposed scene graph on top of the
       viewer scene graph. It will be used for adding spin-rotation coordinate
       systems, fly-viewer speed indicators and similar things.
       This method is not part of the original InventorXt API.
   void SoQtViewer::removeSuperimposition (SoNode * scene) [protected]
       This method is not part of the original InventorXt API.
       Referenced by SoQtFlyViewer::~SoQtFlyViewer(), and ~SoQtViewer().
   void SoQtViewer::setSuperimpositionEnabled (SoNode * scene, const SbBool
       enable) [protected]
       This method sets whether the superimposed scene graph should be
       traversed or not.
       This method is not part of the original InventorXt API.
       Referenced by SoQtFlyViewer::setViewing().
   SbBool SoQtViewer::getSuperimpositionEnabled (SoNode * scene) const
       [protected]
       This method returns whether the superimposed scene is rendered or not.
       This method is not part of the original InventorXt API.

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