OpenSceneGraph/include/osgUtil/DisplayListVisitor
2001-09-28 12:36:40 +00:00

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#ifndef OSGUTIL_DISPLAYLISTVISITOR
#define OSGUTIL_DISPLAYLISTVISITOR 1
#include <osg/NodeVisitor>
#include <osg/Geode>
#include <osg/State>
#include <osgUtil/Export>
namespace osgUtil {
/** Visitor for traversing scene graph and setting each osg::GeoSet's _useDisplayList flag,
* with option to immediately compile osg::GeoSet's OpenGL Display lists.
* The mode of operation
* of the visitor is controlled by setting the DisplayListMode either on visitor
* constructor or via the setDisplayListMode() method. DisplayListMode options are:
* _displayListMode == SWITCH_ON_AND_COMPILE_DISPLAY_LISTS cals gset->compile() on
* all Geode children. Note, the visitor must only be used within a valid
* OpenGL context as compile uses OpenGL calls.
* _displayListMode == SWITCH_ON_DISPLAY_LISTS sets the Geode's children with
* gset->setUseDisplayList(true), this method does not directly create display list,
* or uses OpenGL calls so if safe to use before a valid OpenGL context has been set up.
* On the next redraw of the scene, the gset's draw methods will be called
* which then will respond to their _useDisplayList being set by creating display lists
* automatically.
* _displayListMode == SWITCH_OFF_DISPLAY_LISTS sets the Geode's children with
* gset->setUseDisplayList(false), this method does not directly create display list,
* or uses OpenGL calls so if safe to use before a valid OpenGL context has been set up.
*/
class OSGUTIL_EXPORT DisplayListVisitor : public osg::NodeVisitor
{
public:
/** Operation modes of the DisplayListVisitor.*/
enum DisplayListMode
{
SWITCH_ON_AND_COMPILE_DISPLAY_LISTS,
COMPILE_ON_DISPLAY_LISTS,
SWITCH_ON_DISPLAY_LISTS,
SWITCH_OFF_DISPLAY_LISTS
};
/** Construct a CompileGeoSetsVisior to traverse all child,
* with set specified display list mode. Default mode is to
* gset->setUseDisplayList(true).
*/
DisplayListVisitor(DisplayListMode mode=SWITCH_ON_DISPLAY_LISTS);
/** Set the operational mode of how the visitor should set up osg::GeoSet's.*/
void setDisplayListMode(DisplayListMode mode) { _displayListMode = mode; }
/** Get the operational mode.*/
DisplayListMode getDisplayListMode() const { return _displayListMode; }
/** Set the State to use during traversal. */
void setState(osg::State* state)
{
_externalState = state;
if (_externalState.valid()) _activeState = _externalState;
else _activeState = _localState;
}
osg::State* getState()
{
return _activeState.get();
}
/** Simply traverse using standard NodeVisitor traverse method.*/
virtual void apply(osg::Node& node)
{
traverse(node);
}
/** For each Geode visited set the display list usage according to the
* _displayListMode.
*/
virtual void apply(osg::Geode& node);
protected:
DisplayListMode _displayListMode;
/** local state is created in constructor and used as the default state during traversal.*/
osg::ref_ptr<osg::State> _localState;
/** external state is used to override the default state.*/
osg::ref_ptr<osg::State> _externalState;
/** active state is equal to _externalState when it is valid, otherwise defaults to _localState.*/
osg::ref_ptr<osg::State> _activeState;
};
};
#endif