//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_TRANSFORM #define OSG_TRANSFORM 1 #include #include 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 Transform : public Group { public : Transform(); /** Copy constructor using CopyOp to manage deep vs shallow copy.*/ Transform(const Transform&,const CopyOp& copyop=CopyOp::SHALLOW_COPY); #ifdef USE_DEPRECATED_API Transform(const Matrix& matix); #endif META_Node(osg, Transform); enum ReferenceFrame { RELATIVE_TO_PARENTS, RELATIVE_TO_ABSOLUTE }; /** Set the transform's ReferenceFrame, either to be realtive to its parent reference frame, * or relative to an absolute coordinate frame. RELATIVE_TO_PARENTS is the default. * Note, setting the RefrenceFrame to be RELATIVE_TO_ABSOLUTE will also set the CullingActive flag on the * transform, and hence all its parents, to false, therby disabling culling of it and all its * parents. This is neccessary to prevent inappropriate culling, but may impact of cull times * if the absolute transform is deep in the scene graph, it is therefore recommend to only use * abolsoute Transforms at the top of the scene, for such things as headlight LightSource's or * Head up displays.*/ void setReferenceFrame(ReferenceFrame rf); const ReferenceFrame getReferenceFrame() const { return _referenceFrame; } /** Callback attached to an Transform to specifiy how to compute the modelview transformation * for the transform below the Transform node.*/ struct ComputeTransformCallback : public osg::Referenced { /** Get the transformation matrix which moves from local coords to world coords.*/ virtual const bool computeLocalToWorldMatrix(Matrix& matrix,const Transform* transform, NodeVisitor* nv) const = 0; /** Get the transformation matrix which moves from world coords to local coords.*/ virtual const bool computeWorldToLocalMatrix(Matrix& matrix,const Transform* transform, NodeVisitor* nv) const = 0; }; /** Set the ComputerTransfromCallback which allows users to attach custom computation of the local transformation as * seen by cull traversers and alike.*/ void setComputeTransformCallback(ComputeTransformCallback* ctc) { _computeTransformCallback=ctc; dirtyBound(); } /** Get the non const ComputerTransfromCallback.*/ ComputeTransformCallback* getComputeTransformCallback() { return _computeTransformCallback.get(); } /** Get the const ComputerTransfromCallback.*/ const ComputeTransformCallback* getComputeTransformCallback() const { return _computeTransformCallback.get(); } /** Get the transformation matrix which moves from local coords to world coords. * Return true if Matrix passed in has been modified and */ inline const bool getLocalToWorldMatrix(Matrix& matrix,NodeVisitor* nv) const { if (_computeTransformCallback.valid()) return _computeTransformCallback->computeLocalToWorldMatrix(matrix,this,nv); else return computeLocalToWorldMatrix(matrix,nv); } /** Get the transformation matrix which moves from world coords to local coords. * Return true if Matrix passed in has been modified and */ inline const bool getWorldToLocalMatrix(Matrix& matrix,NodeVisitor* nv) const { if (_computeTransformCallback.valid()) return _computeTransformCallback->computeWorldToLocalMatrix(matrix,this,nv); else return computeWorldToLocalMatrix(matrix,nv); } #ifndef USE_DEPRECATED_API virtual const bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_ABSOLUTE) { return false; } else // absolute { matrix.makeIdentity(); return true; } } virtual const bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_ABSOLUTE) { return false; } else // absolute { matrix.makeIdentity(); return true; } } #else /** Set the transform's matrix.*/ void setMatrix(const Matrix& mat) { (*_deprecated_matrix) = mat; _deprecated_inverseDirty=true; computeInverse(); dirtyBound(); } /** Get the transform's matrix. */ inline const Matrix& getMatrix() const { return *_deprecated_matrix; } /** preMult transform.*/ void preMult(const Matrix& mat) { _deprecated_matrix->preMult(mat); _deprecated_inverseDirty=true; computeInverse(); dirtyBound(); } /** postMult transform.*/ void postMult(const Matrix& mat) { _deprecated_matrix->postMult(mat); _deprecated_inverseDirty=true; computeInverse(); dirtyBound(); } virtual const bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_PARENTS) { matrix.preMult(*_deprecated_matrix); } else // absolute { matrix = *_deprecated_matrix; } return true; } virtual const bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_TO_PARENTS) { matrix.postMult(*_deprecated_inverse); } else // absolute { matrix = *_deprecated_inverse; } return true; } #endif protected : virtual ~Transform(); /** Override's Group's computeBound. * There is no need to override in subclasses from osg::Transform since this computeBound() uses * the underlying matrix (calling computeMatrix if required.) */ virtual const bool computeBound() const; ref_ptr _computeTransformCallback; ReferenceFrame _referenceFrame; #ifdef USE_DEPRECATED_API inline void computeInverse() const { if (_deprecated_inverseDirty) { _deprecated_inverse->invert(*_deprecated_matrix); _deprecated_inverseDirty = false; } } ref_ptr _deprecated_matrix; mutable ref_ptr _deprecated_inverse; mutable bool _deprecated_inverseDirty; #endif }; } #endif