OpenSceneGraph/include/osgSim/ImpostorSprite

220 lines
7.9 KiB
C++

/* -*-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_ImpostorSprite
#define OSG_ImpostorSprite 1
#include <osg/Vec2>
#include <osg/Geometry>
#include <osg/AlphaFunc>
#include <osg/TexEnv>
#include <osg/Texture2D>
#include <osg/Camera>
#include <osgSim/Export>
namespace osgSim {
class Impostor;
class ImpostorSpriteManager;
/** An ImposterSprite is a textured quad which is rendered in place of
* 3D geometry. The ImposterSprite is generated by rendering the original
* 3D geometry to a texture as an image cache. The ImpostorSprite is
* automatically generated by the osgUtil::CullVisitor so it not
* necessary to deal with it directly.
*/
class OSGSIM_EXPORT ImpostorSprite : public osg::Geometry
{
public:
ImpostorSprite();
/** Clone an object of the same type as an ImpostorSprite. */
virtual osg::Object* cloneType() const { return new ImpostorSprite(); }
/** Clone on ImpostorSprite just returns a clone of type,
* since it is not appropriate to share data of an ImpostorSprite.
*/
virtual osg::Object* clone(const osg::CopyOp&) const { return new ImpostorSprite(); }
virtual bool isSameKindAs(const osg::Object* obj) const { return dynamic_cast<const ImpostorSprite*>(obj)!=NULL; }
virtual const char* libraryName() const { return "osgSim"; }
virtual const char* className() const { return "ImpostorSprite"; }
/** Set the parent, which must be an Impostor.
* Unlike conventional Drawables, ImpostorSprites can only ever have
* one parent.
*/
void setParent(Impostor* parent) { _parent = parent; }
/** Get the parent, which is an Impostor. */
Impostor* getParent() { return _parent; }
/** Get the const parent, which is an Impostor. */
const Impostor* getParent() const { return _parent; }
/** Set the eye point for when the ImpostorSprite was snapped. */
inline void setStoredLocalEyePoint(const osg::Vec3& v) { _storedLocalEyePoint=v; }
/** Get the eye point for when the ImpostorSprite was snapped. */
inline const osg::Vec3& getStoredLocalEyePoint() const { return _storedLocalEyePoint; }
/** Set the frame number for when the ImpostorSprite was last used in rendering. */
inline void setLastFrameUsed(unsigned int frameNumber) { _lastFrameUsed = frameNumber; }
/** Get the frame number for when the ImpostorSprite was last used in rendering. */
inline unsigned int getLastFrameUsed() const { return _lastFrameUsed; }
void dirty();
/** Get the coordinates of the corners of the quad.
* Stored in the order, [0] - top_left, [1] - bottom_left, [2] - bottom_right, [3] - top_left.
*/
inline osg::Vec3* getCoords() { return &(_coords->front()); }
/** Get the const coordinates of the corners of the quad. */
inline const osg::Vec3* getCoords() const { return &(_coords->front()); }
/** Get the texture coordinates of the corners of the quad.
* Stored in the order, [0] - top_left, [1] - bottom_left, [2] - bottom_right, [3] - top_left.
*/
inline osg::Vec2* getTexCoords() { return &(_texcoords->front()); }
/** Get the const texture coordinates of the corners of the quad. */
inline const osg::Vec2* getTexCoords() const { return &(_texcoords->front()); }
/** Get the control coordinates of the corners of the quad.
* The control coordinates are the corners of the quad projected
* out onto the front face of bounding box which enclosed the impostor
* geometry when it was pre-rendered into the impostor sprite's texture.
* At the point of creation/or update of the impostor sprite the control
* coords will lie on top of the corners of the quad in screen space - with a pixel error
* of zero. Once the camera moves relative to the impostor sprite the
* control coords will no longer lie on top of the corners of the quad in
* screen space - a pixel error will have accumulated. This pixel error
* can then be used to determine whether the impostor needs to be updated.
* Stored in the order, [0] - top_left, [1] - bottom_left, [2] - bottom_right, [3] - top_left.
*/
inline osg::Vec3* getControlCoords() { return _controlcoords; }
/** Get the const control coordinates of the corners of the quad. */
inline const osg::Vec3* getControlCoords() const { return _controlcoords; }
/** Calculate the pixel error value for passing in the ModelViewProjectionWindow transform,
* which transform local coords into screen space.
*/
float calcPixelError(const osg::Matrix& MVPW) const;
void setTexture(osg::Texture2D* tex,int s,int t);
osg::Texture2D* getTexture() { return _texture; }
const osg::Texture2D* getTexture() const { return _texture; }
int s() const { return _s; }
int t() const { return _t; }
/** Set the camera node to use for pre rendering the impostor sprite's texture.*/
void setCamera(osg::Camera* camera) { _camera = camera; }
/** Get the camera node to use for pre rendering the impostor sprite's texture.*/
osg::Camera* getCamera() { return _camera.get(); }
/** Get the const camera node to use for pre rendering the impostor sprite's texture.*/
const osg::Camera* getCamera() const { return _camera.get(); }
protected:
ImpostorSprite(const ImpostorSprite&);
ImpostorSprite& operator = (const ImpostorSprite&) { return *this;}
virtual ~ImpostorSprite();
void init();
Impostor* _parent;
friend class osgSim::ImpostorSpriteManager;
// camera node for doing the pre rendering.
osg::ref_ptr<osg::Camera> _camera;
// support for a double linked list managed by the
// ImposotorSpriteManager.
ImpostorSpriteManager* _ism;
ImpostorSprite* _previous;
ImpostorSprite* _next;
unsigned int _lastFrameUsed;
osg::Vec3 _storedLocalEyePoint;
osg::ref_ptr<osg::Vec3Array> _coords;
osg::ref_ptr<osg::Vec2Array> _texcoords;
osg::Vec3 _controlcoords[4];
osg::Texture2D* _texture;
int _s;
int _t;
};
/** Helper class for managing the reuse of ImpostorSprite resources. */
class OSGSIM_EXPORT ImpostorSpriteManager : public osg::Referenced
{
public:
ImpostorSpriteManager();
bool empty() const { return _first==0; }
ImpostorSprite* first() { return _first; }
ImpostorSprite* last() { return _last; }
void push_back(ImpostorSprite* is);
void remove(ImpostorSprite* is);
ImpostorSprite* createOrReuseImpostorSprite(int s,int t,unsigned int frameNumber);
osg::StateSet* createOrReuseStateSet();
void reset();
protected:
~ImpostorSpriteManager();
osg::ref_ptr<osg::TexEnv> _texenv;
osg::ref_ptr<osg::AlphaFunc> _alphafunc;
ImpostorSprite* _first;
ImpostorSprite* _last;
typedef std::vector< osg::ref_ptr<osg::StateSet> > StateSetList;
StateSetList _stateSetList;
unsigned int _reuseStateSetIndex;
};
}
#endif