SoPolyLineScreenDrawer Class |
Interactively draw a polyline in normalized screen space.
Namespace: OIV.Inventor.Drawers
The SoPolyLineScreenDrawer type exposes the following members.
Name | Description | |
---|---|---|
SoPolyLineScreenDrawer | Constructor. |
Name | Description | |
---|---|---|
AffectsState | Returns true if a node has an effect on the state during traversal. | |
Callback | (Inherited from SoScreenDrawer.) | |
Clear | Convenience method to clear the points in the line. | |
Copy | Calls Copy(false). (Inherited from SoNode.) | |
Copy(Boolean) | Creates and returns an exact copy of the node. | |
CopyFieldValues(SoFieldContainer) | Calls CopyFieldValues(fc, false). (Inherited from SoFieldContainer.) | |
CopyFieldValues(SoFieldContainer, Boolean) | Copies the contents of fc's fields into this object's fields. | |
Dispose |
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.) | |
Distribute | (Inherited from SoNode.) | |
DoAction | (Inherited from SoScreenDrawer.) | |
EnableNotify | Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false). | |
Equals | Determines whether the specified Object is equal to the current Object. (Inherited from Object.) | |
FieldsAreEqual | Returns true if this object's fields are exactly equal to fc's fields. | |
Get | Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string. | |
GetAllFields | Returns a list of fields, including the eventIn's and eventOut's. | |
GetAlternateRep | This method is called by actions to allow the node to provide an "alternate representation" when appropriate (typically depending on the action type). | |
GetBoundingBox | (Inherited from SoScreenDrawer.) | |
GetEventIn | Returns a the eventIn with the given name. | |
GetEventOut | Returns the eventOut with the given name. | |
GetField | Returns a the field of this object whose name is fieldName. | |
GetFieldName | Returns the name of the given field in the fieldName argument. | |
GetFields | Appends references to all of this object's fields to resultList, and returns the number of fields appended. | |
GetHashCode |
Overrides GetHashCode().
(Inherited from SoNetBase.) | |
GetMatrix | (Inherited from SoNode.) | |
GetName | Returns the name of an instance. | |
GetPrimitiveCount | (Inherited from SoScreenDrawer.) | |
GetRenderEngineMode | Returns the supported Render engine mode. | |
GetRenderUnitID | (Inherited from SoNode.) | |
GetStringName | (Inherited from SoBase.) | |
GetType | Gets the Type of the current instance. (Inherited from Object.) | |
GLRender | (Inherited from SoScreenDrawer.) | |
GLRenderBelowPath | (Inherited from SoNode.) | |
GLRenderInPath | (Inherited from SoNode.) | |
GLRenderOffPath | (Inherited from SoNode.) | |
GrabEventsCleanup | (Inherited from SoNode.) | |
GrabEventsSetup | (Inherited from SoNode.) | |
HandleEvent | Traversal routine for OIV.Inventor.Actions.SoHandleEventAction - this will call action->setHandled() if the event is handled. | |
HasDefaultValues | Returns true if all of the object's fields have their default values. | |
IsBoundingBoxIgnoring | This method is used by getBoundingBox action traversal to know if the current node must be traversed or not, ie the bounding should be ignored. | |
IsNotifyEnabled | Notification is the process of telling interested objects that this object has changed. | |
IsOverride | Returns the state of the override flag. | |
IsSynchronizable | Gets the ScaleViz synchronizable state of this object. | |
NormalizePoint | Returns position normalized in range -1..1 relative to specified viewport. | |
Pick | (Inherited from SoNode.) | |
RayPick | (Inherited from SoScreenDrawer.) | |
Reset | Clears the points in the line and resets internal state to initial values. | |
Search | (Inherited from SoNode.) | |
Set | Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format. | |
SetName | (Inherited from SoBase.) | |
SetOverride | Turns the override flag on or off. | |
SetSynchronizable | Sets this to be a ScaleViz synchronizable object. | |
SetToDefaults | Sets all fields in this object to their default values. | |
ToString |
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.) | |
Touch | Marks an instance as modified, simulating a change to it. | |
Write | (Inherited from SoNode.) |
Name | Description | |
---|---|---|
color | Color of line. | |
doCCW | Make the line counter-clockwise when it is finalized. | |
isClosed | Close the line during display (connect last point to first point). | |
IsDisposable | ISafeDisposable interface implementation.
(Inherited from SoDisposable.) | |
linePattern | Stipple pattern. | |
linePatternScaleFactor | Stipple pattern scale factor. | |
lineWidth | Width of lines. | |
point | Points of line. | |
sceneGraph | Scene graph to render. | |
simplificationThreshold | Threshold (in pixels) used to simplify line when it is finished. | |
UserData |
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.) |
Name | Description | |
---|---|---|
OnFinish | Event raised when the line is finished. | |
OnMove | Event raised during polyline drawing. | |
OnStart | Event raised when starting to draw a polyline. |
This class is a base class used to allow the user to dynamically draw line-based shapes (lasso, circle, rectangle, ...) on screen. The geometry is defined in normalized screen space ([-1, 1]x[-1, 1]).
Applications will typically use one of the derived classes, for example, OIV.Inventor.Drawers.SoEllipseScreenDrawer, OIV.Inventor.Drawers.SoRectangleScreenDrawer, OIV.Inventor.Drawers.SoPolygonScreenDrawer or OIV.Inventor.Drawers.SoLassoScreenDrawer.
The line color is specified by the OIV.Inventor.Drawers.SoPolyLineScreenDrawer.color field (default is red).
OIV.Inventor.Drawers.SoPolyLineScreenDrawer classes can automatically reduce the number of points in the shape drawn by the user. This is especially useful with OIV.Inventor.Drawers.SoLassoScreenDrawer. See the OIV.Inventor.Drawers.SoPolyLineScreenDrawer.simplificationThreshold field.
Sub-classes can implement the onMouseDown, onMouseMove, etc... methods, to add and edit points.
Notes:
Viewer:
Screen drawers, like draggers, depend on OIV.Inventor.Actions.SoHandleEventAction to get events. Therefore when using one of the Open Inventor viewer classes, screen drawers will only work when the viewer is in "selection" mode (arrow cursor). (In "viewing" mode, mouse events are handled by the viewer to control the camera.)
The escape key (ESC) can be used to cancel creation of the polyline. However, currently it also changes the viewer mode (this is a known problem).
Event handling: The drawer will automatically begin a new polyline when it sees a mouse button 1 down event. However the drawer does not call setHandled(), so other nodes in the scene graph, e.g. OIV.Inventor.Nodes.SoEventCallback or a dragger, may also handle this event.
Finish notification:
An event is raised to notify the application when the line is finished. (see OnFinish). This event is called at the end of line finalization (after simplification etc). See SbEventHandler for methods to set a callback to be notified when this event is raised.
In this callback the application can retrieve coordinates from the OIV.Inventor.Drawers.SoPolyLineScreenDrawer.point field. These points are in Open Inventor normalized device coordinates (-1 to 1), not pixel coordinates.
The drawer does not call the OIV.Inventor.Actions.SoHandleEventAction's setHandled() method for the event that finished the polyline. The application can call setHandled() in this callback.
With some drawers it is possible to get a call with zero points if the user pressed ESC to cancel the interaction. Applications should check for this case.
With some drawers it is also possible to get a call with a non-zero number of points, but all points are the same coordinate. E.g. OIV.Inventor.Drawers.SoRectangleScreenDrawer stores four points even if the mouse down/up events are at the same location.
Typically the application will want to remove the polyline from the screen in this callback. See the next note.
Part of the scene graph:
Note that the polyline remains on the screen (because it is part of the scene graph) until Clear()is called or the user starts a new interaction.
Changing the color field or the isClosed field will immediately change the appearance of a polyline currently on the screen.
Simplification: Simplification is done (if > 0) when the user releases the mouse button and also if the simplificationThreshold is changed. But note that the old points are thrown away, so you can't re-simplify with a different value.
isClosed field: If true (default), the polyline will be closed while being drawn (not just when the user releases the mouse button). The default in this class is false, but most sub-classes set it to true.
Coordinates: This node and its subclasses use screen coordinates ranging from -1 to 1. (Because this is the default view volume for an OIV.Inventor.Nodes.SoOrthographicCamera node.) Be careful because other classes in Open Inventor use normalized screen coordinates ranging from 0 to 1. In particular the OIV.Inventor.SbViewportRegion normalize() methods and the OIV.Inventor.SbViewVolume methods that project from 3D to 2D and vice-versa.
There should only be one OIV.Inventor.Drawers.SoScreenDrawer derived node in the sceneGraph (to avoid conflicts in mouse events).
Create a screen drawer, set the callback and add it to the scene graph:
SoRectangleScreenDrawer drawer = new SoRectangleScreenDrawer();
drawer.OnFinish += LineDrawerCallback;
root.AddChild(drawer);
public void LineDrawerCallback( object sender, SoPolygonScreenDrawer.EventArg eventArg ) { SoPolyLineScreenDrawer drawer = eventArg.Source; SoHandleEventAction action = eventArg.Action; int numPoints = drawer.point.Count; if (numPoints > 0) { // Use points SbVec2f point0 = drawer.point[0]; } drawer.Clear(); // Remove polyline from screen action.SetHandled(); }