text: /*
  -----------------------------------------------------------------------------
  This source file is part of OGRE
      (Object-oriented Graphics Rendering Engine)
  For the latest info, see http://www.ogre3d.org
  
  Copyright (c) 2000-2009 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 "OgreGLPBRenderTexture.h"
  #include "OgreGLContext.h"
  #include "OgreGLPixelFormat.h"
  #include "OgreLogManager.h"
  #include "OgreStringConverter.h"
  #include "OgreRoot.h"
  #include "OgreGLHardwarePixelBuffer.h"
  
  namespace Ogre {
  //-----------------------------------------------------------------------------  
      GLPBuffer::GLPBuffer(PixelComponentType format, size_t width, size_t height):
          mFormat(format),
          mWidth(width),
          mHeight(height)
      {
      }
      GLPBuffer::~GLPBuffer()
      {
      }
  
  //-----------------------------------------------------------------------------  
      GLPBRenderTexture::GLPBRenderTexture(GLPBRTTManager *manager, const String &name, 
  		const GLSurfaceDesc &target, bool writeGamma, uint fsaa):
          GLRenderTexture(name, target, writeGamma, fsaa),
          mManager(manager)
      {
          mPBFormat = PixelUtil::getComponentType(target.buffer->getFormat());
          
          mManager->requestPBuffer(mPBFormat, mWidth, mHeight);
      }
      GLPBRenderTexture::~GLPBRenderTexture()
      {
          // Release PBuffer
          mManager->releasePBuffer(mPBFormat);
      }
      void GLPBRenderTexture::getCustomAttribute(const String& name, void* pData)
      {
          if(name=="TARGET")
          {
  			GLSurfaceDesc &target = *static_cast<GLSurfaceDesc*>(pData);
  			target.buffer = static_cast<GLHardwarePixelBuffer*>(mBuffer);
  			target.zoffset = mZOffset;
          }
          else if(name=="GLCONTEXT")
          {
              // Get PBuffer for our internal format
              *static_cast<GLContext**>(pData) = mManager->getContextFor(mPBFormat, mWidth, mHeight);
          }
      }
  //-----------------------------------------------------------------------------  
      GLPBRTTManager::GLPBRTTManager(GLSupport *support, RenderTarget *mainwindow):
          mSupport(support),
  		mMainWindow(mainwindow),
  		mMainContext(0)
      {
  		mMainWindow->getCustomAttribute("GLCONTEXT", &mMainContext);
      }  
      GLPBRTTManager::~GLPBRTTManager()
      {
          // Delete remaining PBuffers
          for(size_t x=0; x<PCT_COUNT; ++x)
          {
              delete mPBuffers[x].pb;
          }
      }
  
      RenderTexture *GLPBRTTManager::createRenderTexture(const String &name, 
  		const GLSurfaceDesc &target, bool writeGamma, uint fsaa)
      {
          return new GLPBRenderTexture(this, name, target, writeGamma, fsaa);
      }
      
      bool GLPBRTTManager::checkFormat(PixelFormat format) 
      { 
          return true; 
      }
  
      void GLPBRTTManager::bind(RenderTarget *target)
      {
          // Nothing to do here
          // Binding of context is done by GL subsystem, as contexts are also used for RenderWindows
      }
  
      void GLPBRTTManager::unbind(RenderTarget *target)
      { 
  		// Copy on unbind
          GLSurfaceDesc surface;
  		surface.buffer = 0;
          target->getCustomAttribute("TARGET", &surface);
          if(surface.buffer)
              static_cast<GLTextureBuffer*>(surface.buffer)->copyFromFramebuffer(surface.zoffset);
      }
      
      void GLPBRTTManager::requestPBuffer(PixelComponentType ctype, size_t width, size_t height)
      {
          //Check size
          if(mPBuffers[ctype].pb)
          {
              if(mPBuffers[ctype].pb->getWidth()<width || mPBuffers[ctype].pb->getHeight()<height)
              {
                  // If the current PBuffer is too small, destroy it and create a new one
                  delete mPBuffers[ctype].pb;
                  mPBuffers[ctype].pb = 0;
              }
          }
          if(!mPBuffers[ctype].pb)
          {
              // Create pbuffer via rendersystem
              mPBuffers[ctype].pb = mSupport->createPBuffer(ctype, width, height);
          }
          
          ++mPBuffers[ctype].refcount;
      }
      
      void GLPBRTTManager::releasePBuffer(PixelComponentType ctype)
      {
          --mPBuffers[ctype].refcount;
          if(mPBuffers[ctype].refcount == 0)
          {
              delete mPBuffers[ctype].pb;
              mPBuffers[ctype].pb = 0;
          }
      }
      
      GLContext *GLPBRTTManager::getContextFor(PixelComponentType ctype, size_t width, size_t height)
      {
          // Faster to return main context if the RTT is smaller than the window size
          // and ctype is PCT_BYTE. This must be checked every time because the window might have been resized
  		if(ctype == PCT_BYTE)
  		{
  			if(width <= mMainWindow->getWidth() && height <= mMainWindow->getHeight())
  				return mMainContext;
  		}
          assert(mPBuffers[ctype].pb);
          return mPBuffers[ctype].pb->getContext();
      }
  //---------------------------------------------------------------------------------------------
  
  }
  
  