/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield * * This library is open source and may be redistributed and/or modified under * the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or * (at your option) any later version. The full license is in LICENSE file * included with this distribution, and on the openscenegraph.org website. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * OpenSceneGraph Public License for more details. */ #ifndef OSG_TRANSFORM #define OSG_TRANSFORM 1 #include #include #ifndef GL_RESCALE_NORMAL #define GL_RESCALE_NORMAL 0x803A #endif #ifndef GL_NORMALIZE #define GL_NORMALIZE 0x0BA1 #endif namespace osg { /** Compute the matrix which transforms objects in local coords to world coords, * by accumulating the Transform local to world matrices along the specified node path. */ extern OSG_EXPORT Matrix computeLocalToWorld(const NodePath& nodePath, bool ignoreCameras = true); /** Compute the matrix which transforms objects in world coords to local coords, * by accumulating the Transform world to local matrices along the specified node path. */ extern OSG_EXPORT Matrix computeWorldToLocal(const NodePath& nodePath, bool ignoreCameras = true); /** Compute the matrix which transforms objects in local coords to eye coords, * by accumulating the Transform local to world matrices along the specified node path * and multiplying by the supplied initial camera modelview. */ extern OSG_EXPORT Matrix computeLocalToEye(const Matrix& modelview, const NodePath& nodePath, bool ignoreCameras = true); /** Compute the matrix which transforms objects in eye coords to local coords, * by accumulating the Transform world to local matrices along the specified node path * and multiplying by the inverse of the supplied initial camera modelview. */ extern OSG_EXPORT Matrix computeEyeToLocal(const Matrix& modelview, const NodePath& nodePath, bool ignoreCameras = true); /** A Transform is a group node for which all children are transformed by * a 4x4 matrix. It is often used for positioning objects within a scene, * producing trackball functionality or for animation. * * Transform itself does not provide set/get functions, only the interface * for defining what the 4x4 transformation is. Subclasses, such as * MatrixTransform and PositionAttitudeTransform support the use of an * osg::Matrix or a osg::Vec3/osg::Quat respectively. * * 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. This can be done transparently through OpenGL's * use of either GL_NORMALIZE and GL_RESCALE_NORMAL modes. For further * background reading see the glNormalize documentation in the OpenGL * Reference Guide (the blue book). To enable it in the OSG, you simply * 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 OSG_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); META_Node(osg, Transform); virtual Transform* asTransform() { return this; } virtual const Transform* asTransform() const { return this; } virtual MatrixTransform* asMatrixTransform() { return 0; } virtual const MatrixTransform* asMatrixTransform() const { return 0; } virtual PositionAttitudeTransform* asPositionAttitudeTransform() { return 0; } virtual const PositionAttitudeTransform* asPositionAttitudeTransform() const { return 0; } enum ReferenceFrame { RELATIVE_RF, ABSOLUTE_RF, ABSOLUTE_RF_INHERIT_VIEWPOINT }; /** Set the transform's ReferenceFrame, either to be relative to its * parent reference frame, or relative to an absolute coordinate * frame. RELATIVE_RF is the default. * Note: Setting the ReferenceFrame to be ABSOLUTE_RF will * also set the CullingActive flag on the transform, and hence all * of its parents, to false, thereby disabling culling of it and * all its parents. This is necessary to prevent inappropriate * culling, but may impact cull times if the absolute transform is * deep in the scene graph. It is therefore recommended to only use * absolute Transforms at the top of the scene, for such things as * heads up displays. * ABSOLUTE_RF_INHERIT_VIEWPOINT is the same as ABSOLUTE_RF except it * adds the ability to use the parents view points position in world coordinates * as its local viewpoint in the new coordinates frame. This is useful for * Render to texture Cameras that wish to use the main views LOD range computation * (which uses the viewpoint rather than the eye point) rather than use the local * eye point defined by the this Transforms' absolute view matrix. */ void setReferenceFrame(ReferenceFrame rf); ReferenceFrame getReferenceFrame() const { return _referenceFrame; } virtual bool computeLocalToWorldMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_RF) { return false; } else // absolute { matrix.makeIdentity(); return true; } } virtual bool computeWorldToLocalMatrix(Matrix& matrix,NodeVisitor*) const { if (_referenceFrame==RELATIVE_RF) { return false; } else // absolute { matrix.makeIdentity(); return true; } } /** Overrides 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 BoundingSphere computeBound() const; protected : virtual ~Transform(); ReferenceFrame _referenceFrame; }; } #endif