NAME
SbLineProjector -
The SbLineProjector class projects 2D points to 3D points along a line.
The 3D projection of the 2D coordinates is for this projector class
constrained to lie along a pre-defined line.
SYNOPSIS
#include <Inventor/projectors/SbLineProjector.h>
Inherits SbProjector.
Public Member Functions
SbLineProjector (void)
virtual SbProjector * copy (void) const
virtual SbVec3f project (const SbVec2f &point)
virtual SbBool tryProject (const SbVec2f &point, const float epsilon,
SbVec3f &result)
void setLine (const SbLine &line)
const SbLine & getLine (void) const
virtual SbVec3f getVector (const SbVec2f &viewpos1, const SbVec2f
&viewpos2)
virtual SbVec3f getVector (const SbVec2f &viewpos)
void setStartPosition (const SbVec2f &viewpos)
void setStartPosition (const SbVec3f &point)
Protected Attributes
SbLine line
SbVec3f lastPoint
Detailed Description
The SbLineProjector class projects 2D points to 3D points along a line.
The 3D projection of the 2D coordinates is for this projector class
constrained to lie along a pre-defined line.
Among other places, this is useful within the translation draggers,
like for instance SoTranslate1Dragger, where we want to move ’pieces’
along one or more axes.
Constructor & Destructor Documentation
SbLineProjector::SbLineProjector (void) Constructor. Intializes the
projector instance to use a line from <0, 0, 0> to <0, 1, 0>.
Member Function Documentation
SbProjector * SbLineProjector::copy (void) const [virtual] Construct and
return a copy of this projector. The caller is responsible for
destructing the new instance.
Note that if the Coin library has been built as a DLL under Microsoft
Windows and you use this method from application code, you must make
sure that both the Coin DLL and the application executable is using the
same instance of a C Run-Time (CRT) library. Otherwise, you will get
memory heap corruption upon deallocating the returned instances,
eventually leading to mysterious crashes.
Implements SbProjector.
SbVec3f SbLineProjector::project (const SbVec2f & point) [virtual] Project
the 2D point from normalized viewport coordinates to a 3D point. The
mapping will be done in accordance with the type of the projector.
Implements SbProjector.
SbBool SbLineProjector::tryProject (const SbVec2f & point, const float
epsilon, SbVec3f & result) [virtual] Try projecting the 2D point from
normalized viewport coordinates to a 3D point. The mapping will be done
in accordance with the type of the projector.
If the projection can’t be done safely (for instance when the
projection plane or line is parallel to the view volume projection),
this function should return FALSE.
Default implementation will call project() and always return TRUE, but
subclasses can override this behavior to support safe projections.
Since:
Coin 3.0
Reimplemented from SbProjector.
void SbLineProjector::setLine (const SbLine & lineref) Set a new projection
line. 3D points will be mapped to be on this line.
const SbLine & SbLineProjector::getLine (void) const Returns the currently
set projection line.
SbVec3f SbLineProjector::getVector (const SbVec2f & viewpos1, const SbVec2f
& viewpos2) [virtual] Calculates and returns a vector between the
projected 3D position of viewpos1 and viewpos2.
SbVec3f SbLineProjector::getVector (const SbVec2f & viewpos) [virtual]
Returns the 3D vector between the last projection and the one
calculated for viewpos.
void SbLineProjector::setStartPosition (const SbVec2f & viewpos) Explicitly
set position of initial projection, so we get correct values for later
calls to getVector() etc.
void SbLineProjector::setStartPosition (const SbVec3f & point) Explicitly
set position of initial projection, so we get correct values for later
calls to getVector() etc.
Member Data Documentation
SbLineProjector::line [protected] The projection line. Projected 3D points
will be constrained to be on this line.
SbLineProjector::lastPoint [protected] The last projected point.
Author
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