gfxGLOcclusionQuery.cpp

Engine/source/gfx/gl/gfxGLOcclusionQuery.cpp

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Detailed Description

  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#include "platform/platform.h"
 25#include "gfx/gl/gfxGLOcclusionQuery.h"
 26#include "gfx/gl/tGL/tGL.h"
 27
 28GFXGLOcclusionQuery::GFXGLOcclusionQuery(GFXDevice* device) : 
 29   GFXOcclusionQuery(device), 
 30   mQuery(-1), 
 31   mTesting(false)
 32{
 33   
 34}
 35
 36GFXGLOcclusionQuery::~GFXGLOcclusionQuery()
 37{
 38   glDeleteQueries(1, &mQuery);
 39}
 40
 41bool GFXGLOcclusionQuery::begin()
 42{
 43   if (GFXDevice::getDisableOcclusionQuery())
 44      return true;
 45
 46   if (!glIsQuery(mQuery))
 47      glGenQueries(1, &mQuery);
 48
 49   if (!mTesting)
 50   {
 51      glBeginQuery(GL_SAMPLES_PASSED, mQuery);
 52      mTesting = true;
 53   }
 54   return true;
 55}
 56
 57void GFXGLOcclusionQuery::end()
 58{
 59   if (GFXDevice::getDisableOcclusionQuery())
 60      return;
 61
 62   if (!glIsQuery(mQuery))
 63      return;
 64   glEndQuery(GL_SAMPLES_PASSED);
 65   mTesting = false;
 66}
 67
 68GFXOcclusionQuery::OcclusionQueryStatus GFXGLOcclusionQuery::getStatus(bool block, U32* data)
 69{
 70   // If this ever shows up near the top of a profile 
 71   // then your system is GPU bound.
 72   PROFILE_SCOPE(GFXGLOcclusionQuery_getStatus);
 73
 74   if (GFXDevice::getDisableOcclusionQuery())
 75      return NotOccluded;
 76
 77   if (!glIsQuery(mQuery))
 78      return NotOccluded;
 79   
 80   GLint numPixels = 0;
 81   GLint queryDone = false;
 82   
 83   if (block)
 84   {
 85      while (!queryDone)
 86      {
 87         //If we're stalled out, proceed with worst-case scenario -BJR
 88         if (GFX->mFrameTime->getElapsedMs()>4)
 89         {
 90            this->begin();
 91            this->end();
 92            return NotOccluded;
 93         }
 94         glGetQueryObjectiv(mQuery, GL_QUERY_RESULT_AVAILABLE, &queryDone);
 95      }
 96   }
 97   else
 98   {
 99      glGetQueryObjectiv(mQuery, GL_QUERY_RESULT_AVAILABLE, &queryDone);
100   }
101   
102   if (queryDone)
103      glGetQueryObjectiv(mQuery, GL_QUERY_RESULT, &numPixels);
104   else
105      return Waiting;
106   
107   if (data)
108      *data = numPixels;
109   
110   return numPixels > 0 ? NotOccluded : Occluded;
111}
112
113void GFXGLOcclusionQuery::zombify()
114{
115   glDeleteQueries(1, &mQuery);
116   mQuery = 0;
117}
118
119void GFXGLOcclusionQuery::resurrect()
120{
121   glGenQueries(1, &mQuery);
122}
123
124const String GFXGLOcclusionQuery::describeSelf() const
125{
126   // We've got nothing
127   return String();
128}
129