OpenSceneGraph/include/osg/Billboard
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_BILLBOARD
#define OSG_BILLBOARD 1
#include <osg/Matrix>
#include <osg/Geode>
namespace osg {
/** Billboard - a Geode which orientates its child osg::Drawable's to face
the eye point. Typical uses are for trees, or particle explosions.
*/
class SG_EXPORT Billboard : public Geode
{
public:
enum Mode {
POINT_ROT_EYE,
POINT_ROT_WORLD,
AXIAL_ROT
};
Billboard();
/** Copy constructor using CopyOp to manage deep vs shallow copy.*/
Billboard(const Billboard&,const CopyOp& copyop=CopyOp::SHALLOW_COPY);
META_Node(osg, Billboard);
/** Set the billboard rotation mode. */
void setMode(const Mode mode);
/** Get the billboard rotation mode. */
inline const Mode getMode() const { return _mode; }
/** Set the axis about which all the billboard's drawable rotate. */
void setAxis(const Vec3& axis);
/** Get the axis about which all the billboard's drawable rotate. */
inline const Vec3& getAxis() const { return _axis; }
/** Set the position of specified drawable. */
inline void setPos(int i,const Vec3& pos) { _positionList[i] = pos; }
/** Get the position of specified drawable. */
inline const Vec3& getPos(int i) const { return _positionList[i]; }
/** PositionList represents a list of pivot points for each drawable.*/
typedef std::vector<Vec3> PositionList;
/** Get the PositionList from the billboard.*/
inline PositionList& getPositionList() { return _positionList; }
/** Get a const PositionList from the billboard.*/
inline const PositionList& getPositionList() const { return _positionList; }
/** Add Drawable to Billboard with default position(0,0,0);
* If gset not NULL and is not contained in Billboard then increment its
* reference count, and dirty the bounding box to cause it to recompute on
* next getBound() and return true for success. Otherwise return false.
*/
virtual const bool addDrawable( Drawable *gset );
/** Add Drawable to Geode at position pos.
* If gset not NULL and is not contained in Billboard then increment its
* reference count, and dirty the bounding box to cause it to recompute on
* next getBound() and return true for success. Otherwise return false.
*/
virtual const bool addDrawable(Drawable *gset,const Vec3& pos);
/** Remove Drawable and associated position from Billboard.
* If gset is contained in Billboard then remove it from the geoset
* list and decrement its reference count, and dirty the
* bounding box to cause it to recompute on next getBound() and
* return true for success. If gset is not found then return false
* and do not the reference count of gset is left unchanged.
*/
virtual const bool removeDrawable( Drawable *gset );
/** Callback attached to an Billboard which allows the users to customize the billboard orientation calculation during cull traversal.*/
struct ComputeBillboardCallback : public osg::Referenced
{
/** Get the transformation matrix which moves from local coords to world coords.*/
virtual const bool computeMatrix(Matrix& modelview, const Billboard* billboard, const Vec3& eye_local, const Vec3& pos_local) const = 0;
};
/** Set the ComputeBillboardCallback which allows users to attach custom computation of the local transformation as
* seen by cull traversers and alike.*/
void setComputeBillboardCallback(ComputeBillboardCallback* ctc) { _computeBillboardCallback=ctc; }
/** Get the non const ComputeBillboardCallback.*/
ComputeBillboardCallback* getComputeBillboardCallback() { return _computeBillboardCallback.get(); }
/** Get the const ComputeBillboardCallback.*/
const ComputeBillboardCallback* getComputeBillboardCallback() const { return _computeBillboardCallback.get(); }
inline const bool getMatrix(Matrix& modelview, const Vec3& eye_local, const Vec3& pos_local) const
{
if (_computeBillboardCallback.valid())
return _computeBillboardCallback->computeMatrix(modelview,this,eye_local,pos_local);
else
return computeMatrix(modelview,eye_local,pos_local);
}
virtual const bool computeMatrix(Matrix& modelview, const Vec3& eye_local, const Vec3& pos_local) const;
protected:
virtual ~Billboard();
virtual const bool computeBound() const;
enum AxisAligned
{
AXIAL_ROT_X_AXIS=AXIAL_ROT+1,
AXIAL_ROT_Y_AXIS,
AXIAL_ROT_Z_AXIS
};
Mode _mode;
Vec3 _axis;
PositionList _positionList;
ref_ptr<ComputeBillboardCallback> _computeBillboardCallback;
// used internally as cache of which what _axis is aligned to help
// deicde which method of rotation to use.
int _cachedMode;
void setCachedMode();
};
}
#endif