source: GTP/trunk/Lib/Vis/OnlineCullingCHC/include/CoherentHierarchicalCullingManager.h @ 2332

#ifndef _CoherentHierarchicalCullingManager_H__
#define _CoherentHierarchicalCullingManager_H__

#include "CullingManager.h"
#include "HierarchyInterface.h"


namespace GtpVisibility
{

/** Renders the scene with the coherent hierarchical culling algorithm. 
*/
class CoherentHierarchicalCullingManager : public CullingManager
{
public:
        CoherentHierarchicalCullingManager();
        /** Constructor taking the assumed visibility into account, i.e., the estimation
                for how many frames the current visibility is considered to be valid
        */
        CoherentHierarchicalCullingManager(const unsigned int assumedVisibility);

        void RenderScene();
        /** Sets assumed visibility (i.e., an estimation for 
                how many frames the visibility is considered to be valid).
                @param assumedVisibility indicates for how many frames the 
                same visibility is be assumed.
                if 0, the visibility is tested deterministically for each frame.
        */
        void SetAssumedVisibility(const unsigned int assumedVisibility);

protected:

        /** Decides if node is considered to be visible depeding on the 
                assumed visibility factor.
                @returns if node is considered to be visible
        */
        bool DecideVisible(HierarchyNode *node) const;

        /** Skip query for this node.
        */
        void SkipQuery(HierarchyNode *node) const;

        /** If this node is still valid for traversal in this frame.
                It is possible that the parent was tested invisible before
                so this node can be skipped.
        */
        bool NodeInvalid(HierarchyNode *node) const;

        /** number of steps the visibility is assumed to be valid.
        */
        unsigned int mAssumedVisibility;

        /** Threshold for rand function to return positive result with respect to
                mAssumedVisibility.
        */
        int mThreshold;
};

} // namespace GtpVisibility

#endif // CoherentHierarchicalCullingManager_H