SbProjection Class Reference
[Basics]

Base class for coordinate projection classes. More...

#include <Inventor/projection/SbProjection.h>

Inheritance diagram for SbProjection:
SbCylindricalProjection SbProj4Projection SbSphericalProjection SbTransformProjection

List of all members.

Public Member Functions

 SbProjection ()
 SbProjection (SoProjection *node)
 SbProjection (const SbProjection &proj)
virtual ~SbProjection ()
virtual void init ()
virtual void exit ()
virtual void inverse (SbVec3f &point)
virtual bool getProjectedBoundingBox (SbBox3f &bbox)
void project (SbVec3f &point)
void project (int numPoints, float *points)
void project (int32_t numCoords, const SbVec3f *coords, SbVec3f *projectedCoords)
SoProjectiongetProjectionNode () const
virtual void setParameter (int parameterId, const SbString &parameterString)
virtual void setParameter (int parameterId, const float &parameterFloat)
void setNumStringParameters (int numParameters)
void setNumFloatParameters (int numParameters)
int getNumStringParameters () const
int getNumFloatParameters () const
SbBool getParameter (int pos, SbString &parameter) const
SbBool getParameter (int pos, float &parameter) const

Detailed Description

Base class for coordinate projection classes.

This is the base class for classes that define a coordinate projection. The projection of a point P consists of computing a point P' and replacing internally the coordinates of P with the coordinates of P'. Projections can modify points in complex ways that are not possible with a transformation matrix. For example, projections allow the use of spherical coordinates, geospatial coordinates and others. An SoProjection node applies a coordinate projection to geometry nodes. A valid instance of a SbProjection class is needed by an SoProjection node put in a scene graph.

To create a new projection class, implement a class inheriting from SbProjection. The only mandatory method to define a projection is the apply() method. To obtain the result of a projected point, call the project() method, which internally computes the result and calls apply(). You can also define the inverse() method, which is only used for applications that must compute the inverse of a projected point.

The applyPreProjection() method can be defined and will be called just before a point is projected. The applyPostProjection() method can be defined and will be called just after a point has been projected.

A projection class stores a list of string parameters and a list of float parameters. You can set or inquire a parameter using setParameter() or getParameter()

The projection routine can get parameter values from the fields of the associated SoProjection node (if any). The parameters for a projection should be stored in the SoProjection node, as it is the only entry in the scene graph. The SoProjection::floatParameters field stores the float values that are synchronized with the float parameters of the projection class. The SoProjection::parameters field stores the string values that are synchronized with the string parameters of the projection class.

The init() method is called each time a parameter of the associated SoProjection node is modified. The exit() method is called at the SbProjection instance destruction.

If using the VolumeViz extension, defining the getProjectedBoundingBox() method will improve the rendering speed (see getProjectedBoundingBox comments).

SEE ALSO

SbProj4Projection, SbSphericalProjection, SoProjection, SoGeoProjection, SbProjectionCoordinates


Constructor & Destructor Documentation

SbProjection::SbProjection (  ) 

Constructor.

SbProjection::SbProjection ( SoProjection node  ) 

Constructor.

SbProjection::SbProjection ( const SbProjection proj  ) 

Copy constructor.

virtual SbProjection::~SbProjection (  )  [virtual]

Destructor.


Member Function Documentation

virtual void SbProjection::exit (  )  [inline, virtual]

Exit method.

Reimplemented in SbProj4Projection.

int SbProjection::getNumFloatParameters (  )  const

Get number of used float parameters.

int SbProjection::getNumStringParameters (  )  const

Get number of used string parameters.

SbBool SbProjection::getParameter ( int  pos,
float &  parameter 
) const

Get float parameter at position pos.

SbBool SbProjection::getParameter ( int  pos,
SbString parameter 
) const

Get string parameter at position pos.

bool SbProjection::getProjectedBoundingBox ( SbBox3f bbox  )  [inline, virtual]

Return projected bounding box if available.

Note: Projecting a bounding box is most of the time not equivalent to the result of a bounding box that contains all projected point.

It depends on the projection, and it is why by default it returns false, and should be redefined by the specific inherited projection class if it make sense.

Reimplemented in SbCylindricalProjection, SbSphericalProjection, and SbTransformProjection.

SoProjection* SbProjection::getProjectionNode (  )  const [inline]

Return associated projection node.

virtual void SbProjection::init ( void   )  [inline, virtual]

Initialisation method.

Reimplemented in SbProj4Projection.

void SbProjection::inverse ( SbVec3f point  )  [inline, virtual]

Apply the inverse coordinate to one point.

Modifies the given object.

Reimplemented in SbCylindricalProjection, SbProj4Projection, and SbSphericalProjection.

void SbProjection::project ( int32_t  numCoords,
const SbVec3f coords,
SbVec3f projectedCoords 
)

Apply the complete computation to a set of coordinates.

void SbProjection::project ( int  numPoints,
float *  points 
)

Apply the complete computation to a set of points.

Modifies the given objects.

void SbProjection::project ( SbVec3f point  ) 

Apply the complete computation (matrix, pre-projection, projection, post-projection) to one point.

Modifies the given object.

void SbProjection::setNumFloatParameters ( int  numParameters  ) 

Set number of float parameters to use.

void SbProjection::setNumStringParameters ( int  numParameters  ) 

Set number of string parameters to use.

virtual void SbProjection::setParameter ( int  parameterId,
const float &  parameterFloat 
) [virtual]

Set float parameter.

virtual void SbProjection::setParameter ( int  parameterId,
const SbString parameterString 
) [virtual]

Set string parameter.


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

Open Inventor Toolkit reference manual, generated on 8 Apr 2021
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