/usr/include/osgShadow/ViewDependentShadowTechnique is in libopenscenegraph-dev 3.2.0~rc1-4.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 | /* -*-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.
*
* ViewDependentShadow codes Copyright (C) 2008 Wojciech Lewandowski
* Thanks to to my company http://www.ai.com.pl for allowing me free this work.
*/
#ifndef OSGSHADOW_VIEWDEPENDENTSHADOWTECHINIQUE
#define OSGSHADOW_VIEWDEPENDENTSHADOWTECHINIQUE 1
#include <osgShadow/ShadowTechnique>
#include <map>
#include <osgShadow/Export>
namespace osgShadow {
/**
META_ViewDependentShadowTechniqueData macro defines initViewDependentData
method used by derived shadow techniques to initialize their specific
ViewData objects. initViewDependentData will be called from
ViewDependentShadowTechnique base class to init derived class
*/
#define META_ViewDependentShadowTechniqueData( ShadowTechnique, TechniqueData )\
virtual ViewDependentShadowTechnique::ViewData * initViewDependentData \
( osgUtil::CullVisitor *cv, ViewDependentShadowTechnique::ViewData * vd ) \
{ \
TechniqueData* td = dynamic_cast<TechniqueData*>( vd ); \
if ( !td ) td = new TechniqueData; \
td->init( this, cv ); \
return td; \
}
/**
ViewDependentShadowTechnique is a base class for all
View Dependent Shadow techniques. It defines fundamental object structure
and methods to manage separate shadow resources for each view of the scene.
By view we understand osg::View or SceneView instance and their associated
Camera. Typical osg application has one or more such views. View Dependent
Shadow techniques manage shadow generation for them.
View Dependent Shadow techniques are used to optimize shadow algorithms for
part of the scene seen on the view. If rest of the scene is behind view
frustum, there is no sense in computing shadows for it. Since in practice we
often use 3d databases extending far beyond current camera frustum View
Dependent Shadow approach may produce much better shadows.
The other goal is to provide framework for thread safe rendering of
the shadows. It allows to use shadows with different OSG threading models.
Conceptually ViewDependentShadowTechnique is similar to osgSim::OverlayNode.
Its a container class for number of ViewData (or ViewData derived) objects
doing actual shadow work for each of the scene views.
But ViewDependentShadowTechnique is intended as foundation layer for all
derived classes so in some way it extends osgSim::OverlayNode approach a bit.
HOW IT WORKS:
ViewDependendentShadowTechnique is derived from osgShadow::ShadowTechnique
and as such overrides virtual methods of osgShadow::ShadowTechnique.
But most of the shadow dirty work is done by ViewData objects,
ViewDependendentShadowTechnique::cull is the only osgShadow::ShadowTechnique
method where ViewDependendentShadowTechnique does something significant:
What ViewDependentShadowTechnique::cull( CullVisitor & cv ) does ?
It identifies View. CullVisitor ptr is used as View identificator.
In practice we do not check and interpret what are actual Views and SceneViews
set up by application. We focus on Camera and CullVisitors as a identificators
of views. We can safely do this because each such view will have associated
unique CullVisitor used to cull the scene in every frame.
Based on CullVisitor ptr passed to cull method, associated Technique::ViewData
object is created (if neccessary) and then seleced. Then control is passed to
this ViewData object. So, each view has its associated unique ViewData
(or derived) object performing dirty work of shadow resources management and
shadow generation for the view.
To support creation of classes derived from ViewDependentShadowTechnique it
was neccessary to provide mechanism to override ViewData and allow for
initialization of new derived ViewData objects. Creation and initialization
is performed when ViewDependendentShadowTechnique::cull gets called with
CullVistor ptr which does not yet have associated ViewData object. When it
happens, virtual initViewDependentData method is called to give
derived techniques a chance to allocate and iniitalize its specific
resources as new ViewData derived instance. In practice initViewDependentData
in derived techniques should look the same as in base class so as a convenience
it was defined as META_ViewDependentShadowTechnique macro. Derived techniques
use this macro to override initViewDependentData method for their usage.
After ViewData derived object is construted and selected, control is passed
to this object by call to virtual ViewData::cull method. The rest of work
is the done by this object. ViewDependentShadowTechnique::ViewData is intended
as a base class so it does nothing. In practice the rest of dirty work will
do new ViewData classes implemented in derived techniques.
*/
class OSGSHADOW_EXPORT ViewDependentShadowTechnique
: public osgShadow::ShadowTechnique
{
public:
/**
osgShadow::ShadowTechnique equivalent methods for view dependent techniques
*/
/** Classic OSG constructor */
ViewDependentShadowTechnique( void );
/** Classic OSG cloning constructor */
ViewDependentShadowTechnique(
const ViewDependentShadowTechnique& vdst,
const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY );
/** Declaration of standard OSG object methods */
META_Object( osgShadow, ViewDependentShadowTechnique );
/** Dirty view data bits and force update of view data resources */
virtual void dirty();
/** Initialize the ShadowedScene and some data structures.*/
virtual void init();
/** Run the update traversal of the ShadowedScene and update any local cached data structures.*/
virtual void update(osg::NodeVisitor& nv);
/** Run the cull traversal of the ShadowedScene and set up the rendering for this ShadowTechnique.*/
virtual void cull(osgUtil::CullVisitor& cv);
/** Clean scene graph from any shadow technique specific nodes, state and drawables.*/
virtual void cleanSceneGraph();
/** Traverse shadow scene graph.*/
virtual void traverse(osg::NodeVisitor& nv);
protected:
/** Classic protected OSG destructor */
~ViewDependentShadowTechnique( void );
/**
Base container class for view dependent shadow resources.
Techniques based on ViewDependentShadowTechnique will usually define
similar struct and derive it from ViewData to contain their specufic resources.
*/
struct OSGSHADOW_EXPORT ViewData: public osg::Referenced
{
virtual const char* className() const { return "ViewData"; }
/**
Method called upon ViewData instance to initialize internal variables
*/
virtual void init
( ViewDependentShadowTechnique *st, osgUtil::CullVisitor *cv );
/**
Method called by ViewDependentShadowTechnique to allow ViewData
do the hard work computing shadows for its associated view
*/
virtual void cull();
/**
Dirty is called by parent ViewDependentShadowTechnique to force
update of resources after some of them were modified in parent technique
*/
virtual void dirty( bool flag );
/**
Simple constructor zeroing all variables.
*/
ViewData(): _dirty( true ), _cv( NULL ), _st( NULL ) { };
/**
Mutex used to guard _dirty flag from override in case when parent technique calls
dirty() simultaneously with ViewData while it is updating resources inside init method.
*/
OpenThreads::Mutex _mutex;
/**
Dirty flag tells this instance to update its resources
*/
bool _dirty;
/**
View's CullVisitor associated with this ViewData instance
*/
osg::observer_ptr< osgUtil::CullVisitor > _cv;
/**
Parent ViewDependentShadowTechnique
*/
osg::observer_ptr< ViewDependentShadowTechnique > _st;
};
/**
Map of view dependent data per view cull visitor (CVs are used as indices)
ViewDependentShadowTechnique uses this map to find VieData for each cull vitior
*/
typedef std::map< osg::ref_ptr< osgUtil::CullVisitor >,
osg::ref_ptr< ViewData > > ViewDataMap;
ViewDataMap _viewDataMap;
/**
Mutex used to serialize accesses to ViewDataMap
*/
OpenThreads::Mutex _viewDataMapMutex;
/** Return view dependent data for the cull visitor */
virtual ViewDependentShadowTechnique::ViewData * getViewDependentData( osgUtil::CullVisitor * cv );
/** Define view dependent data for the cull visitor */
virtual void setViewDependentData( osgUtil::CullVisitor * cv, ViewDependentShadowTechnique::ViewData * data );
/**
Declare standard initViewDependentData method.
*/
META_ViewDependentShadowTechniqueData( ViewDependentShadowTechnique, ViewData )
};
} // namespace osgShadow
#endif
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