text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
  (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org/
  
  Copyright (c) 2000-2014 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 "OgreTerrainMaterialGeneratorA.h"
  #include "OgreRoot.h"
  #include "OgreHardwarePixelBuffer.h"
  #include "OgreTextureManager.h"
  #include "OgreTexture.h"
  #include "OgreTerrain.h"
  #include "OgreManualObject.h"
  #include "OgreCamera.h"
  #include "OgreViewport.h"
  #include "OgreRenderSystem.h"
  #include "OgreRenderTarget.h"
  #include "OgreRenderTexture.h"
  #include "OgreSceneNode.h"
  #include "OgreRectangle2D.h"
  
  #if OGRE_COMPILER == OGRE_COMPILER_MSVC
  // we do lots of conversions here, casting them all is tedious & cluttered, we know what we're doing
  #   pragma warning (disable : 4244)
  #endif
  
  
  namespace Ogre
  {
      //---------------------------------------------------------------------
      TerrainMaterialGenerator::TerrainMaterialGenerator() 
          : mActiveProfile(0)
          , mChangeCounter(0)
          , mDebugLevel(0) 
          , mCompositeMapSM(0)
          , mCompositeMapCam(0)
          , mCompositeMapRTT(0)
          , mCompositeMapPlane(0)
          , mCompositeMapLight(0)
      {
  
      }
      //---------------------------------------------------------------------
      TerrainMaterialGenerator::~TerrainMaterialGenerator()
      {
          for (ProfileList::iterator i = mProfiles.begin(); i != mProfiles.end(); ++i)
              OGRE_DELETE *i;
  
          if (mCompositeMapRTT && TextureManager::getSingletonPtr())
          {
              TextureManager::getSingleton().remove(mCompositeMapRTT->getHandle());
              mCompositeMapRTT = 0;
          }
          if (mCompositeMapSM && Root::getSingletonPtr())
          {
              // will also delete cam and objects etc
              Root::getSingleton().destroySceneManager(mCompositeMapSM);
              mCompositeMapSM = 0;
              mCompositeMapCam = 0;
              mCompositeMapLight = 0;
              mLightNode = 0;
          }
          delete mCompositeMapPlane;
      }
      //---------------------------------------------------------------------
      void TerrainMaterialGenerator::_renderCompositeMap(size_t size, 
          const Rect& rect, const MaterialPtr& mat, const TexturePtr& destCompositeMap)
      {
          if (!mCompositeMapSM)
          {
              // dedicated SceneManager
              mCompositeMapSM = Root::getSingleton().createSceneManager(DefaultSceneManagerFactory::FACTORY_TYPE_NAME);
              mCompositeMapCam = mCompositeMapSM->createCamera("cam");
              mCompositeMapSM->getRootSceneNode()->attachObject(mCompositeMapCam);
              mCompositeMapCam->setProjectionType(PT_ORTHOGRAPHIC);
              mCompositeMapCam->setNearClipDistance(0.5);
              mCompositeMapCam->setFarClipDistance(1.5);
              mCompositeMapCam->setOrthoWindow(2, 2);
  
              // Just in case material relies on light auto params
              mCompositeMapLight = mCompositeMapSM->createLight();
              mCompositeMapLight->setType(Light::LT_DIRECTIONAL);
              mLightNode = mCompositeMapSM->getRootSceneNode()->createChildSceneNode();
              mLightNode->attachObject(mCompositeMapLight);
  
              RenderSystem* rSys = Root::getSingleton().getRenderSystem();
              Real hOffset = rSys->getHorizontalTexelOffset() / (Real)size;
              Real vOffset = rSys->getVerticalTexelOffset() / (Real)size;
  
  
              // set up scene
              mCompositeMapPlane = new Rectangle2D(true);
              mCompositeMapPlane->setCorners(-1, 1, 1, -1);
              mCompositeMapPlane->setUVs({0 - hOffset, 0 - vOffset}, {0 - hOffset, 1 - vOffset},
                                         {1 - hOffset, 0 - vOffset}, {1 - hOffset, 1 - vOffset});
              mCompositeMapPlane->setBoundingBox(AxisAlignedBox::BOX_INFINITE);
  
              mCompositeMapSM->getRootSceneNode()->attachObject(mCompositeMapPlane);
  
          }
  
          // update
          mCompositeMapPlane->setMaterial(mat);
          TerrainGlobalOptions& globalopts = TerrainGlobalOptions::getSingleton();
          mLightNode->setDirection(globalopts.getLightMapDirection(), Node::TS_WORLD);
          mCompositeMapLight->setDiffuseColour(globalopts.getCompositeMapDiffuse());
          mCompositeMapSM->setAmbientLight(globalopts.getCompositeMapAmbient());
  
  
          // check for size change (allow smaller to be reused)
          if (mCompositeMapRTT && size != mCompositeMapRTT->getWidth())
          {
              TextureManager::getSingleton().remove(mCompositeMapRTT->getHandle());
              mCompositeMapRTT = 0;
          }
  
          if (!mCompositeMapRTT)
          {
              mCompositeMapRTT = TextureManager::getSingleton().createManual(
                  mCompositeMapSM->getName() + "/compRTT", mat->getGroup(),
                  TEX_TYPE_2D, static_cast<uint>(size), static_cast<uint>(size), 0,
                  PF_BYTE_RGBA, TU_RENDERTARGET).get();
              RenderTarget* rtt = mCompositeMapRTT->getBuffer()->getRenderTarget();
              // don't render all the time, only on demand
              rtt->setAutoUpdated(false);
              Viewport* vp = rtt->addViewport(mCompositeMapCam);
              // don't render overlays
              vp->setOverlaysEnabled(false);
  
          }
  
          // calculate the area we need to update
          Real vpleft = (Real)rect.left / (Real)size;
          Real vptop = (Real)rect.top / (Real)size;
          Real vpright = (Real)rect.right / (Real)size;
          Real vpbottom = (Real)rect.bottom / (Real)size;
  
          RenderTarget* rtt = mCompositeMapRTT->getBuffer()->getRenderTarget();
          mCompositeMapCam->setWindow(vpleft, vptop, vpright, vpbottom);
  
          rtt->update();
  
          // We have an RTT, we want to copy the results into a regular texture
          // That's because in non-update scenarios we don't want to keep an RTT
          // around. We use a single RTT to serve all terrain pages which is more
          // efficient.
          Box box(rect);
          destCompositeMap->getBuffer()->blit(mCompositeMapRTT->getBuffer(), box, box);
  
          
      }
      //---------------------------------------------------------------------
      //---------------------------------------------------------------------
      void TerrainMaterialGenerator::Profile::updateCompositeMap(const Terrain* terrain, const Rect& rect)
      {
          // convert point-space rect into image space
          int32 compSize = terrain->getCompositeMap()->getWidth();
          Rect imgRect;
          Vector3 inVec, outVec;
          inVec.x = rect.left;
          inVec.y = rect.bottom - 1; // this is 'top' in image space, also make inclusive
          terrain->convertPosition(Terrain::POINT_SPACE, inVec, Terrain::TERRAIN_SPACE, outVec);
          imgRect.left = outVec.x * compSize;
          imgRect.top = (1.0f - outVec.y) * compSize;
          inVec.x = rect.right - 1;
          inVec.y = rect.top; // this is 'bottom' in image space
          terrain->convertPosition(Terrain::POINT_SPACE, inVec, Terrain::TERRAIN_SPACE, outVec);
          imgRect.right = outVec.x * (Real)compSize + 1; 
          imgRect.bottom = (1.0 - outVec.y) * compSize + 1;
  
          imgRect = imgRect.intersect({0, 0, compSize, compSize});
  
          mParent->_renderCompositeMap(
              compSize, imgRect, 
              terrain->getCompositeMapMaterial(), 
              terrain->getCompositeMap());
  
      }
  
  
  }
  
  