text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
  (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2016 Torus Knot Software Ltd
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.
  -----------------------------------------------------------------------------
  */
  #include "OgreTerrainPagedWorldSection.h"
  #include "OgreTerrainGroup.h"
  #include "OgreGrid2DPageStrategy.h"
  #include "OgrePagedWorld.h"
  #include "OgrePageManager.h"
  #include "OgreRoot.h"
  #include "OgreTimer.h"
  
  namespace Ogre
  {
      const uint16 TerrainPagedWorldSection::WORKQUEUE_LOAD_TERRAIN_PAGE_REQUEST = 1;
  
      //---------------------------------------------------------------------
      TerrainPagedWorldSection::TerrainPagedWorldSection(const String& name, PagedWorld* parent, SceneManager* sm)
          : PagedWorldSection(name, parent, sm)
          , mTerrainGroup(0)
          , mTerrainDefiner(0)
          , mHasRunningTasks(false)
          , mLoadingIntervalMs(900)
      {
          // we always use a grid strategy
          setStrategy(parent->getManager()->getStrategy("Grid2D"));
  
          WorkQueue* wq = Root::getSingleton().getWorkQueue();
          mWorkQueueChannel = wq->getChannel("Ogre/TerrainPagedWorldSection");
          wq->addRequestHandler(mWorkQueueChannel, this);
          wq->addResponseHandler(mWorkQueueChannel, this);
  
          mNextLoadingTime = Root::getSingletonPtr()->getTimer()->getMilliseconds();
      }
      //---------------------------------------------------------------------
      TerrainPagedWorldSection::~TerrainPagedWorldSection()
      {
          //remove the pending tasks, but keep the front one, as it may have been in running
          if(!mPagesInLoading.empty())
              mPagesInLoading.erase( ++mPagesInLoading.begin(), mPagesInLoading.end() );
  
          while(!mPagesInLoading.empty())
          {
              OGRE_THREAD_SLEEP(50);
              Root::getSingleton().getWorkQueue()->processResponses();
          }
  
          WorkQueue* wq = Root::getSingleton().getWorkQueue();
          wq->removeRequestHandler(mWorkQueueChannel, this);
          wq->removeResponseHandler(mWorkQueueChannel, this);
  
          OGRE_DELETE mTerrainGroup;
          if(mTerrainDefiner)
              OGRE_DELETE mTerrainDefiner;
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::init(TerrainGroup* grp)
      {
          if (mTerrainGroup == grp)
              return;
  
          if (mTerrainGroup)
              OGRE_DELETE mTerrainGroup;
  
          mTerrainGroup = grp;
          syncSettings();
  
          // Unload all existing terrain pages, because we want the paging system
          // to be in charge of this
          mTerrainGroup->removeAllTerrains();
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::syncSettings()
      {
  
          // Base grid on terrain settings
          Grid2DPageStrategyData* gridData = getGridStrategyData();
          switch (mTerrainGroup->getAlignment())
          {
          case Terrain::ALIGN_X_Y:
              gridData->setMode(G2D_X_Y);
              break;
          case Terrain::ALIGN_X_Z:
              gridData->setMode(G2D_X_Z);
              break;
          case Terrain::ALIGN_Y_Z:
              gridData->setMode(G2D_Y_Z);
              break;
          }
          gridData->setOrigin(mTerrainGroup->getOrigin());
  
          gridData->setCellSize(mTerrainGroup->getTerrainWorldSize());
  
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setLoadRadius(Real sz)
      {
          getGridStrategyData()->setLoadRadius(sz);
      }
      //---------------------------------------------------------------------
      Real TerrainPagedWorldSection::getLoadRadius() const
      {
          return getGridStrategyData()->getLoadRadius();
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setHoldRadius(Real sz)
      {
          getGridStrategyData()->setHoldRadius(sz);
      }
      //---------------------------------------------------------------------
      Real TerrainPagedWorldSection::getHoldRadius()
      {
          return getGridStrategyData()->getHoldRadius();
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setPageRange(int32 minX, int32 minY, int32 maxX, int32 maxY)
      {
          getGridStrategyData()->setCellRange(minX, minY, maxX, maxY);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setPageRangeMinX(int32 minX)
      {
          getGridStrategyData()->setCellRangeMinX(minX);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setPageRangeMinY(int32 minY)
      {
          getGridStrategyData()->setCellRangeMinY(minY);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setPageRangeMaxX(int32 maxX)
      {
          getGridStrategyData()->setCellRangeMaxX(maxX);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setPageRangeMaxY(int32 maxY)
      {
          getGridStrategyData()->setCellRangeMaxY(maxY);
      }
      //---------------------------------------------------------------------
      int32 TerrainPagedWorldSection::getPageRangeMinX() const
      {
          return getGridStrategyData()->getCellRangeMinX();
      }
      //---------------------------------------------------------------------
      int32 TerrainPagedWorldSection::getPageRangeMinY() const
      {
          return getGridStrategyData()->getCellRangeMinY();
      }
      //---------------------------------------------------------------------
      int32 TerrainPagedWorldSection::getPageRangeMaxX() const
      {
          return getGridStrategyData()->getCellRangeMaxX();
      }
      //---------------------------------------------------------------------
      int32 TerrainPagedWorldSection::getPageRangeMaxY() const
      {
          return getGridStrategyData()->getCellRangeMaxY();
      }
      //---------------------------------------------------------------------
      Grid2DPageStrategy* TerrainPagedWorldSection::getGridStrategy() const
      {
          return static_cast<Grid2DPageStrategy*>(this->getStrategy());
      }
      //---------------------------------------------------------------------
      Grid2DPageStrategyData* TerrainPagedWorldSection::getGridStrategyData() const
      {
          return static_cast<Grid2DPageStrategyData*>(mStrategyData);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::setLoadingIntervalMs(uint32 loadingIntervalMs)
      {
          mLoadingIntervalMs = loadingIntervalMs;
      }
      //---------------------------------------------------------------------
      uint32 TerrainPagedWorldSection::getLoadingIntervalMs() const
      {
          return mLoadingIntervalMs;
      }
  
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::loadSubtypeData(StreamSerialiser& ser)
      {
          // we load the TerrainGroup information from here
          if (!mTerrainGroup)
              mTerrainGroup = OGRE_NEW TerrainGroup(getSceneManager());
  
          mTerrainGroup->loadGroupDefinition(ser);
  
          // params that are in the Grid2DStrategyData will have already been loaded
          // as part of the main load() routine
  
          syncSettings();
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::saveSubtypeData(StreamSerialiser& ser)
      {
          mTerrainGroup->saveGroupDefinition(ser);
  
          // params that are in the Grid2DStrategyData will have already been saved
          // as part of the main save() routine
  
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::loadPage(PageID pageID, bool forceSynchronous)
      {
          if (!mParent->getManager()->getPagingOperationsEnabled())
              return;
  
          PageMap::iterator i = mPages.find(pageID);
          if (i == mPages.end())
          {
              std::list<PageID>::iterator it = find( mPagesInLoading.begin(), mPagesInLoading.end(), pageID);
              if(it==mPagesInLoading.end())
              {
                  mPagesInLoading.push_back(pageID);
                  mHasRunningTasks = true;
              }
              
              // no running tasks, start the new one
              if(mPagesInLoading.size()==1)
              {
                  Root::getSingleton().getWorkQueue()->addRequest(
                      mWorkQueueChannel, WORKQUEUE_LOAD_TERRAIN_PAGE_REQUEST, 
                      Any(), 0, forceSynchronous);
              }
          }
  
          PagedWorldSection::loadPage(pageID, forceSynchronous);
      }
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::unloadPage(PageID pageID, bool forceSynchronous)
      {
          if (!mParent->getManager()->getPagingOperationsEnabled())
              return;
  
          PagedWorldSection::unloadPage(pageID, forceSynchronous);
  
          std::list<PageID>::iterator it = find( mPagesInLoading.begin(), mPagesInLoading.end(), pageID);
          // hasn't been loaded, just remove from the queue
          if(it!=mPagesInLoading.end())
          {
              mPagesInLoading.erase(it);
          }
          else
          {
              // trigger terrain unload
              long x, y;
              // pageID is the same as a packed index
              mTerrainGroup->unpackIndex(pageID, &x, &y);
              mTerrainGroup->unloadTerrain(x, y);
          }
      }
      //---------------------------------------------------------------------
      WorkQueue::Response* TerrainPagedWorldSection::handleRequest(const WorkQueue::Request* req, const WorkQueue* srcQ)
      {
          if(mPagesInLoading.empty())
          {
              mHasRunningTasks = false;
              req->abortRequest();
              return OGRE_NEW WorkQueue::Response(req, true, Any());
          }
  
          unsigned long currentTime = Root::getSingletonPtr()->getTimer()->getMilliseconds();
          if(currentTime < mNextLoadingTime)
          {
              // Wait until the next page is to be loaded -> we are in background thread here
              OGRE_THREAD_SLEEP(mNextLoadingTime - currentTime);
          }
  
          PageID pageID = mPagesInLoading.front();
  
          // call the TerrainDefiner from the background thread
          long x, y;
          // pageID is the same as a packed index
          mTerrainGroup->unpackIndex(pageID, &x, &y);
  
          if(!mTerrainDefiner)
              mTerrainDefiner = OGRE_NEW TerrainDefiner();
          mTerrainDefiner->define(mTerrainGroup, x, y);
  
          // continue loading in main thread
          return OGRE_NEW WorkQueue::Response(req, true, Any());
      }
  
      //---------------------------------------------------------------------
      void TerrainPagedWorldSection::handleResponse(const WorkQueue::Response* res, const WorkQueue* srcQ)
      {
          if(!mPagesInLoading.empty())
          {
              PageID pageID = mPagesInLoading.front();
  
              // trigger terrain load
              long x, y;
              // pageID is the same as a packed index
              mTerrainGroup->unpackIndex(pageID, &x, &y);
              mTerrainGroup->loadTerrain(x, y, false);
              mPagesInLoading.pop_front();
  
              unsigned long currentTime = Root::getSingletonPtr()->getTimer()->getMilliseconds();
              mNextLoadingTime = currentTime + mLoadingIntervalMs;
  
              // Continue loading other pages
              Root::getSingleton().getWorkQueue()->addRequest(
                      mWorkQueueChannel, WORKQUEUE_LOAD_TERRAIN_PAGE_REQUEST, 
                      Any(), 0, false);
          }
          else
              mHasRunningTasks = false;
      }
  }
  
  