VRS::ScenePicker Class Reference

This class provides functionality for picking scene objects. More...

#include <vrs/sg/scenepicker.h>

Inheritance diagram for VRS::ScenePicker:

List of all members.

Public Types
typedef Callback3< SO < Iterator< PickResult > >, unsigned int, unsigned int >	SelectionCallback
typedef CallbackR1< unsigned int, SO< Shape > >	IdCreationCallback
Public Member Functions
	ScenePicker (SO< SceneThing > scene, SO< IdCreationCallback > idCreationCallback, SO< SelectionCallback > pickingCallback, SO< GLCanvas > canvas, unsigned int textureUnit, unsigned int numberOfIdsToReserve=10000, bool renderPositionBuffer=true, SO< Iterator< ScenePicker::MouseButtonFunctionID > > buttonFunctionsToRegister=0)
void	setupFBO (SO< GLCanvas > canvas)
virtual void	onActivation ()
	Called each time a InteractionTechnique is activated, i.e.
virtual void	onDeactivation ()
	Called each time a InteractionTechnique is deactivated, i.e.
virtual void	onDragStart (int x, int y, SO< ButtonEvent >, MouseButtonFunctionID id)
virtual void	onDragMotion (int x, int y, SO< MotionEvent >, MouseButtonFunctionID id, int startX, int startY)
virtual void	onDragEnd (int x, int y, SO< ButtonEvent >, MouseButtonFunctionID id, int startX, int startY)
virtual void	onEvent (SO< Event > e)
	For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.
void	updatePickingBuffers ()
	This method updates the lookup image(s) for picking.
bool	preservingViewDirectionRequired ()
	Rendered Id buffers are view dependent.
bool	getRangeSelectionEnabled () const
void	setRangeSelectionEnabled (bool val)
	Enables or Disables selection of multiple Objects by dragging a rectangle over the view plane.
void	registerSelectionCallback (const SO< SelectionCallback > newSelectionCallback)
	Register a callback which is called in case of picking If the "callOnNoHit" flag is set the method is also called when no (registered) geometry was hit.
void	unregisterSelectionCallback (const SO< SelectionCallback > exisitingSelectioncallback)
void	clearSelectionCallbacks ()
void	assignIdValues (SO< SceneThing > scene, SO< IdCreationCallback > idCreationCallback, unsigned int numberOfIdValues, unsigned int startId=0)
	Creates a mapping from ids returned by the given callback to PolygonSets contained in the given scene.
void	setSceneForRender (SO< SceneThing > scene)
	Sets the scene containing the visible content.
const Vector	addPolygonSet (unsigned int id, SO< PolygonSet > pset, bool updateLookupTexture=false)
	Makes the polygon set identifiable by assigning the id.
void	incrementTextureCoordinate ()
SO< Iterator< Vector > >	addPolygonSets (SO< Iterator< unsigned int > > ids, SO< Iterator< SO< PolygonSet > > > psets, bool updateLookupTexture=false)
	Makes the polygon set identifiable by assigning an id per polygonset.
SO< Iterator< Vector > >	addPolygonSets (SO< Iterator< unsigned int > > ids, SO< Iterator< SO< Iterator< SO< PolygonSet > > > > > psets, bool updateLookupTexture=false)
	Assign ids to groups of polygonsets.
void	addSceneThing (SO< SceneThing > scene, unsigned int id, bool updateLookupTexture=false)
	Assigns the given id to every PolygonSet in the given scene.
const SO< GLImage >	getPixelPositions () const
const SO< GLImage >	getIdBufferImage ()
const bool	getCameraSpaceCoordinateForPixel (unsigned int x, unsigned int y, Vector &coordinate) const
	Reads the position in camera space coordinates associated with the pixel displayed To obtain world space coordinates the camera for the specific object / pixel must be known.
const unsigned int	getIdForPixel (unsigned int x, unsigned int y) const
	Reads the object id of the object displayed at the given pixel position.
bool	getCallOnNoHit () const
void	setCallOnNoHit (bool val)
bool	ScenePicker::hasUnassignedIds (unsigned int numberOfRequiredIds)
unsigned int	getTextureUnit ()
	VRS_TYPEINFO (ScenePicker, InteractionTechnique)
Static Public Member Functions
static VRS::UINT32	getIdForColor (const Color &c)
static Color	getColorForId (VRS::UINT32 id)
static unsigned int	ScenePicker::getPixelForCoordinate (float coordinate, unsigned int size)
	Calculates the pixel corresponding to the given coordinate in one dimension.
static float	getCoordinateForPixel (unsigned pixel, unsigned int size)
Static Public Attributes
static const MouseButtonFunctionID	pickFunction
Classes
class	GLImage
struct	PickResult

---

Detailed Description

This class provides functionality for picking scene objects.

Once initialized with a scene an id is assigned to each polygonset using an ID texture and an additional texture coordinate channel. Afterwards the identification color image has to be updated when the scene view changes or the canvas is resized. After registering a scene the polygonsets can be merged or transformed as long as the texture coordinates stay the same.

---

Member Typedef Documentation

typedef Callback3<SO<Iterator<PickResult> >,unsigned int, unsigned int> VRS::ScenePicker::SelectionCallback

typedef CallbackR1<unsigned int,SO<Shape> > VRS::ScenePicker::IdCreationCallback

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Constructor & Destructor Documentation

VRS::ScenePicker::ScenePicker	(	SO< SceneThing >	scene,
		SO< IdCreationCallback >	idCreationCallback,
		SO< SelectionCallback >	pickingCallback,
		SO< GLCanvas >	canvas,
		unsigned int	textureUnit,
		unsigned int	numberOfIdsToReserve = 10000,
		bool	renderPositionBuffer = true,
		SO< Iterator< ScenePicker::MouseButtonFunctionID > >	buttonFunctionsToRegister = 0
	)

Parameters:

		SO<SceneThing> scene
		SO<IdCreationCallback> idCreationCallback Function or method receiving a SO<Shape> and returning an id in the range of [1,MAXUINT]
		SO<SelectionCallback> pickingCallback
		SO<GLCanvas> canvas
		unsigned int textureUnit
		unsigned int numberOfIdsToReserve Maxium number of Ids that should be given. Defines the pixel size of the id image.
		bool renderPositionBuffer
		buttonFunctionsToRegister Additional ids to register (each id can be connected with one mouse button / modifier combination). The Sceen

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Member Function Documentation

void VRS::ScenePicker::setupFBO

(

SO< GLCanvas >

canvas

)

virtual void VRS::ScenePicker::onActivation

(

)

[virtual]

Called each time a InteractionTechnique is activated, i.e.

selected as active Interaction of a InteractionMode. It can be implemented by derivatives to initialize internal parameters.

Reimplemented from VRS::InteractionTechnique.

virtual void VRS::ScenePicker::onDeactivation

(

)

[virtual]

Called each time a InteractionTechnique is deactivated, i.e.

deselected as active Interaction of a InteractionMode. It can be implemented by derivatives to reset internal parameters.

Reimplemented from VRS::InteractionTechnique.

virtual void VRS::ScenePicker::onDragStart	(	int	x,
		int	y,
		SO< ButtonEvent >	,
		MouseButtonFunctionID	id
	)			[virtual]

virtual void VRS::ScenePicker::onDragMotion	(	int	x,
		int	y,
		SO< MotionEvent >	,
		MouseButtonFunctionID	id,
		int	startX,
		int	startY
	)			[virtual]

virtual void VRS::ScenePicker::onDragEnd	(	int	x,
		int	y,
		SO< ButtonEvent >	,
		MouseButtonFunctionID	id,
		int	startX,
		int	startY
	)			[virtual]

virtual void VRS::ScenePicker::onEvent

(

SO< Event >

e

)

[virtual]

For each incoming event the base class checks the event type and passes the event to the corresponding virtual method.

In addition each event() method is called for each event.

Reimplemented from VRS::InteractionTechnique.

void VRS::ScenePicker::updatePickingBuffers

(

)

This method updates the lookup image(s) for picking.

bool VRS::ScenePicker::preservingViewDirectionRequired

(

)

[inline]

Rendered Id buffers are view dependent.

Force the view direction to be preserved. Does always return 'false'

bool VRS::ScenePicker::getRangeSelectionEnabled

(

)

const [inline]

void VRS::ScenePicker::setRangeSelectionEnabled

(

bool

val

)

[inline]

Enables or Disables selection of multiple Objects by dragging a rectangle over the view plane.

void VRS::ScenePicker::registerSelectionCallback

(

const SO< SelectionCallback >

newSelectionCallback

)

Register a callback which is called in case of picking If the "callOnNoHit" flag is set the method is also called when no (registered) geometry was hit.

The id for this case is 0; The position included in the result is in Camera coordinates. Apply the inverse Orientation Matrix to get World Coordinates

Parameters:

const SO<SelectionCallback> newSelectionCallback Function or Method callback taking the id of the object and the position of the pixel which has been hit.

void VRS::ScenePicker::unregisterSelectionCallback

(

const SO< SelectionCallback >

exisitingSelectioncallback

)

void VRS::ScenePicker::clearSelectionCallbacks

(

)

void VRS::ScenePicker::assignIdValues	(	SO< SceneThing >	scene,
		SO< IdCreationCallback >	idCreationCallback,
		unsigned int	numberOfIdValues,
		unsigned int	startId = 0
	)

Creates a mapping from ids returned by the given callback to PolygonSets contained in the given scene.

Parameters:

		SO<SceneThing> scene Scene containing the objects to be destinguished
		SO<CallbackR1<unsigned int,SO<PolygonSet> > > idCreationCallback CallbackFunction or method that returns an identifier for the given Polygonset. The id returned must be included in the interval [1,MAXUINT-1). Otherwise an exeption will be thrown.
	numberOfIdValues	Number of distinct element ids that should be reserved. Influences the size of the id texture generated.

void VRS::ScenePicker::setSceneForRender

(

SO< SceneThing >

scene

)

Sets the scene containing the visible content.

A camera must be contained in the scene. The scene can be an optimized version of the id-assigned scene which has been processed by assignIdValues as long as the generated texture coordinates are still available at the right place.

Parameters:

SO<SceneThing> scene Scene containing all PolygonSets which shall be pickable. It must contain a scene camera and therefore be displayed equally on the canvas

const Vector VRS::ScenePicker::addPolygonSet	(	unsigned int	id,
		SO< PolygonSet >	pset,
		bool	updateLookupTexture = false
	)

Makes the polygon set identifiable by assigning the id.

The id is only assigned if there are enough ids left in the id image. Otherwise an exception is thrown.

Parameters:

		unsigned int id
		SO<PolygonSet> pset
		bool updateLookupTexture Call updateTextures after entry creation

Returns:

: Texture coordinates set at the given position

void VRS::ScenePicker::incrementTextureCoordinate

(

)

SO<Iterator<Vector> > VRS::ScenePicker::addPolygonSets	(	SO< Iterator< unsigned int > >	ids,
		SO< Iterator< SO< PolygonSet > > >	psets,
		bool	updateLookupTexture = false
	)

Makes the polygon set identifiable by assigning an id per polygonset.

The iterators of ids and polygonsets must have an equal length

Returns:

: SO<Iterator<const Vector> > Texture coordinates assigned to each polygonset

Parameters:

		SO<Iterator<unsigned int> > ids ids to assing to corresponding polygonset
		SO<Iterator<SO<PolygonSet> > > psets Polygonsets
		bool updateLookupTexture

SO<Iterator<Vector> > VRS::ScenePicker::addPolygonSets	(	SO< Iterator< unsigned int > >	ids,
		SO< Iterator< SO< Iterator< SO< PolygonSet > > > > >	psets,
		bool	updateLookupTexture = false
	)

Assign ids to groups of polygonsets.

Returns:

: SO<Iterator<const Vector> > Texture coordinates assigned to each polygonset group

Parameters:

		SO<Iterator<unsigned int> > ids
		SO<Iterator<SO<Iterator<SO<PolygonSet> > > > > psets
		bool updateLookupTexture

void VRS::ScenePicker::addSceneThing	(	SO< SceneThing >	scene,
		unsigned int	id,
		bool	updateLookupTexture = false
	)

Assigns the given id to every PolygonSet in the given scene.

Parameters:

		SO<SceneThing> scene
		unsigned int id
		bool updateLookupTexture

const SO<GLImage> VRS::ScenePicker::getPixelPositions

(

)

const [inline]

const SO<GLImage> VRS::ScenePicker::getIdBufferImage

(

)

const bool VRS::ScenePicker::getCameraSpaceCoordinateForPixel	(	unsigned int	x,
		unsigned int	y,
		Vector &	coordinate
	)			const

Reads the position in camera space coordinates associated with the pixel displayed To obtain world space coordinates the camera for the specific object / pixel must be known.

Returns:

: const bool The value for the coordinate vector could be set

Parameters:

		unsigned int x X position in screen coordinates
		unsigned int y Y Position in screen coordinates
		Vector & coordinate in/out parameter holding the position value after successful read

const unsigned int VRS::ScenePicker::getIdForPixel	(	unsigned int	x,
		unsigned int	y
	)			const

Reads the object id of the object displayed at the given pixel position.

Returns:

: const unsigned int Object id -> '0' if no known object is displayed at the position

Parameters:

		unsigned int x
		unsigned int y

bool VRS::ScenePicker::getCallOnNoHit

(

)

const [inline]

void VRS::ScenePicker::setCallOnNoHit

(

bool

val

)

[inline]

static VRS::UINT32 VRS::ScenePicker::getIdForColor

(

const Color &

c

)

[static]

static Color VRS::ScenePicker::getColorForId

(

VRS::UINT32

id

)

[static]

static unsigned int VRS::ScenePicker::ScenePicker::getPixelForCoordinate	(	float	coordinate,
		unsigned int	size
	)			[static]

Calculates the pixel corresponding to the given coordinate in one dimension.

Parameters:

		float coordinate Texture coordinate in [0,1]
		unsigned int size number of pixel in the required dimension

static float VRS::ScenePicker::getCoordinateForPixel	(	unsigned	pixel,
		unsigned int	size
	)			[static]

bool VRS::ScenePicker::ScenePicker::hasUnassignedIds

(

unsigned int

numberOfRequiredIds

)

unsigned int VRS::ScenePicker::getTextureUnit

(

)

[inline]

VRS::ScenePicker::VRS_TYPEINFO	(	ScenePicker	,
		InteractionTechnique
	)

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Member Data Documentation

const MouseButtonFunctionID VRS::ScenePicker::pickFunction [static]

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The documentation for this class was generated from the following file:

• scenepicker.h