source: GTP/trunk/App/Demos/Vis/CHC_revisited/OcclusionQuery.h @ 2765

#ifndef _OcclusionQuery_H__
#define _OcclusionQuery_H__

#include <vector>
#include "common.h"


namespace CHCDemo 
{ 

class BvhNode;

/** This class is an implementation for single node queries and multiqueries.
        @remark the class encapsulates hardware occlusion query calls.
*/
class OcclusionQuery
{
public:
        
        OcclusionQuery();

        virtual ~OcclusionQuery();

        bool ResultAvailable() const;
        
        unsigned int GetQueryResult() const;
        
        void BeginQuery();
        
        void EndQuery();
        
        unsigned int GetQueryId() const;
        /** Returns the first added node.
        */
        inline BvhNode *GetFrontNode() const { return mNodes[0]; }
        /** Reset the contents of this query.
        */
        inline void Reset() { mNodes.clear(); }
        /** Adds a node to the query.
        */
        inline void AddNode(BvhNode *node) { mNodes.push_back(node); }


protected:

        OcclusionQuery(unsigned int id);
        
        
        ////////////
        //-- members

        float mPFail;
        /// all nodes that are tested with the same query
        BvhNodeContainer mNodes; 
        // the query associated with this test
        unsigned int mQueryId;
        /// type of the query
        bool mIsVisibleQuery;
};


class QueryHandler
{
public:

        QueryHandler();
        ~QueryHandler() { DestroyQueries(); }

        OcclusionQuery *RequestQuery();

        /** Must be called every frame.
        */
        void ResetQueries();
        /** Destroys all the queries.
        */
        void DestroyQueries();

protected:

        int mCurrentQueryIdx;

        QueryContainer mOcclusionQueries;
};


} // namespace 
#endif // OcclusionQuery_H