OpenSceneGraph/include/osg/MatrixTransform
2002-07-16 20:07:32 +00:00

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//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.
#ifndef OSG_MATRIXTRANSFORM
#define OSG_MATRIXTRANSFORM 1
#include <osg/Transform>
namespace osg {
/** Transform - is group which all children are transformed by the the Transform's osg::Matrix.
* Typical uses
* of the Transform is for positioning objects within a scene or
* producing trackball functionality or for animation.
* The Transform node can be customized via the ComputeTransfromCallback which can be
* attached to the node, this might be used to convert internal representations of the transformation
* into generic osg::Matrix'c which are used during scene grpah traversal, such as CullTraversal and IntersectionTraversal.
* Note, if the transformation matrix scales the subgraph then the
* normals of the underlying geometry will need to be renormalized to
* be unit vectors once more. One can done transparently through OpenGL's
* use of either GL_NORMALIZE and GL_SCALE_NORMALIZE modes. Further
* background reading see the glNormalize documentation in the OpenGL Reference
* Guide (the blue book). To enable it in the OSG, you simple need to
* attach a local osg::StateSet to the osg::Transform, and set the appropriate
* mode to on via stateset->setMode(GL_NORMALIZE,osg::StateAttribute::ON);.
*/
class SG_EXPORT MatrixTransform : public Transform
{
public :
MatrixTransform();
/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
MatrixTransform(const MatrixTransform&,const CopyOp& copyop=CopyOp::SHALLOW_COPY);
MatrixTransform(const Matrix& matix);
META_Node(osg, MatrixTransform);
/** Set the transform's matrix.*/
void setMatrix(const Matrix& mat) { (*_matrix) = mat; _inverseDirty=true; computeInverse(); dirtyBound(); }
/** Get the transform's matrix. */
inline const Matrix& getMatrix() const { return *_matrix; }
/** preMult transform.*/
void preMult(const Matrix& mat) { _matrix->preMult(mat); _inverseDirty=true; computeInverse(); dirtyBound(); }
/** postMult transform.*/
void postMult(const Matrix& mat) { _matrix->postMult(mat); _inverseDirty=true; computeInverse(); dirtyBound(); }
virtual const bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor*) const
{
if (_referenceFrame==RELATIVE_TO_PARENTS)
{
matrix.preMult(*_matrix);
}
else // absolute
{
matrix = *_matrix;
}
return true;
}
virtual const bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor*) const
{
if (_referenceFrame==RELATIVE_TO_PARENTS)
{
matrix.postMult(*_inverse);
}
else // absolute
{
matrix = *_inverse;
}
return true;
}
protected :
virtual ~MatrixTransform();
inline void computeInverse() const
{
if (_inverseDirty)
{
_inverse->invert(*_matrix);
_inverseDirty = false;
}
}
ref_ptr<Matrix> _matrix;
mutable ref_ptr<Matrix> _inverse;
mutable bool _inverseDirty;
};
}
#endif