gfxOcclusionQuery.h

Engine/source/gfx/gfxOcclusionQuery.h

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  1
  2//-----------------------------------------------------------------------------
  3// Copyright (c) 2012 GarageGames, LLC
  4//
  5// Permission is hereby granted, free of charge, to any person obtaining a copy
  6// of this software and associated documentation files (the "Software"), to
  7// deal in the Software without restriction, including without limitation the
  8// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
  9// sell copies of the Software, and to permit persons to whom the Software is
 10// furnished to do so, subject to the following conditions:
 11//
 12// The above copyright notice and this permission notice shall be included in
 13// all copies or substantial portions of the Software.
 14//
 15// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 18// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 21// IN THE SOFTWARE.
 22//-----------------------------------------------------------------------------
 23
 24#ifndef _GFXOCCLUSIONQUERY_H_
 25#define _GFXOCCLUSIONQUERY_H_
 26
 27#ifndef _GFXDEVICE_H_
 28#include "gfx/gfxDevice.h"
 29#endif
 30
 31
 32/// A geometry visibility query object.
 33/// @see GFXDevice::createOcclusionQuery
 34class GFXOcclusionQuery : public GFXResource
 35{
 36protected:
 37
 38   GFXDevice *mDevice;
 39   
 40   GFXOcclusionQuery( GFXDevice *device ) 
 41      : mDevice( device )
 42   {
 43   }   
 44
 45public:
 46
 47   /// The states returned by getStatus()
 48   /// If you modify this enum you should also modify statusToString()
 49   enum OcclusionQueryStatus
 50   {
 51      Unset,         ///<      
 52      Waiting,       ///< 
 53      Error,         ///< 
 54      Occluded,
 55      NotOccluded
 56   };   
 57      
 58   virtual ~GFXOcclusionQuery() {}
 59   
 60   /// Prepares the query returning true if the last query
 61   /// has been processed and more geometry can be issued.
 62   /// @see getStatus
 63   virtual bool begin() = 0;
 64   
 65   /// Called after your geometry is drawn to submit
 66   /// the query for processing.
 67   virtual void end() = 0;   
 68   
 69   /// Returns the status of the last submitted query.  In general
 70   /// you should avoid blocking for the result until the frame 
 71   /// following your query to keep from stalling the CPU.
 72   /// @return       Status    
 73   /// @param block  If true CPU will block until the query finishes.
 74   /// @param data   Number of pixels rendered, valid only if status returned is NotOccluded.
 75   virtual OcclusionQueryStatus getStatus( bool block, U32 *data = NULL ) = 0;
 76   
 77   /// Returns a status string.
 78   static String statusToString( OcclusionQueryStatus status );
 79
 80   // GFXResource
 81   virtual void zombify() = 0;   
 82   virtual void resurrect() = 0;
 83   virtual const String describeSelf() const = 0;
 84};
 85
 86/// Handle for GFXOcclusionQuery than store last valid state
 87class GFXOcclusionQueryHandle
 88{
 89public:
 90
 91    GFXOcclusionQueryHandle() 
 92        : mLastStatus(GFXOcclusionQuery::Unset), mLastData(0), mWaiting(false) , mQuery(NULL)
 93    {}
 94
 95    ~GFXOcclusionQueryHandle()
 96    {
 97        SAFE_DELETE(mQuery);
 98    }
 99
100    bool getLastStatus( bool block, GFXOcclusionQuery::OcclusionQueryStatus *statusPtr = NULL, U32 *data = NULL );
101    GFXOcclusionQuery* getQuery() const { return mQuery; }
102
103    void clearLastStatus()
104    {
105        mLastStatus = GFXOcclusionQuery::Unset;
106        mLastData = 0;
107        mWaiting = false;
108
109        if( !mQuery )
110            return;
111
112        mQuery->begin();
113        mQuery->end();
114    }
115
116    bool isWaiting() const { return mWaiting; }
117protected:
118    GFXOcclusionQuery::OcclusionQueryStatus mLastStatus;
119    U32 mLastData;
120    bool mWaiting;
121    GFXOcclusionQuery *mQuery;
122};
123
124inline bool GFXOcclusionQueryHandle::getLastStatus( bool block, GFXOcclusionQuery::OcclusionQueryStatus *statusPtr, U32 *data )
125{
126    if( !mQuery )
127        mQuery = GFX->createOcclusionQuery();
128
129    GFXOcclusionQuery::OcclusionQueryStatus status = mQuery->getStatus( block, data );
130
131    if( status == GFXOcclusionQuery::Waiting )
132    {
133        mWaiting = true;
134        if( statusPtr )
135            *statusPtr = mLastStatus;
136        if( data )
137            *data = mLastData;
138
139        return true;
140    }
141
142    if( statusPtr )
143        *statusPtr = status;
144
145    mWaiting = false;
146    mLastStatus = status;
147    mLastData = *data;
148
149    return true;
150}
151
152
153#endif // _GFXOCCLUSIONQUERY_H_
154