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.
  -----------------------------------------------------------------------------
  */
  #ifndef __RenderTarget_H__
  #define __RenderTarget_H__
  
  #include "OgrePrerequisites.h"
  
  #include "OgrePixelFormat.h"
  #include "OgreHeaderPrefix.h"
  
  /* Define the number of priority groups for the render system's render targets. */
  #ifndef OGRE_NUM_RENDERTARGET_GROUPS
      #define OGRE_NUM_RENDERTARGET_GROUPS 10
      #define OGRE_DEFAULT_RT_GROUP 4
      #define OGRE_REND_TO_TEX_RT_GROUP 2
  #endif
  
  namespace Ogre {
  
      /** \addtogroup Core
      *  @{
      */
      /** \addtogroup RenderSystem
      *  @{
      */
      /** A 'canvas' which can receive the results of a rendering
          operation.
          @remarks
              This abstract class defines a common root to all targets of rendering operations. A
              render target could be a window on a screen, or another
              offscreen surface like a texture or bump map etc.
          @author
              Steven Streeting
          @version
              1.0
       */
      class _OgreExport RenderTarget : public RenderSysAlloc
      {
      public:
          struct FrameStats
          {
              /// frames per second (FPS) based on the frames rendered in the last second
              float lastFPS;
              /// average frames per second (FPS) since call to Root::startRendering
              float avgFPS;
              /// best frames per second (FPS) since call to Root::startRendering
              float bestFPS;
              /// worst frames per second (FPS) since call to Root::startRendering
              float worstFPS;
              unsigned long bestFrameTime;
              unsigned long worstFrameTime;
              /// number of triangles rendered in the last update() call.
              size_t triangleCount;
              /// number of batches rendered in the last update() call.
              size_t batchCount;
              int vBlankMissCount; // -1 means that the value is not applicable
          };
  
          enum FrameBuffer
          {
              FB_FRONT,
              FB_BACK,
              FB_AUTO
          };
  
          RenderTarget();
          virtual ~RenderTarget();
  
          /// Retrieve target's name.
          virtual const String& getName(void) const;
  
          /// Retrieve information about the render target.
          virtual void getMetrics(unsigned int& width, unsigned int& height, unsigned int& colourDepth);
  
          virtual uint32 getWidth(void) const;
          virtual uint32 getHeight(void) const;
          virtual uint32 getColourDepth(void) const;
  
          /**
           * Sets the pool ID this RenderTarget should query from. Default value is POOL_DEFAULT.
           * Set to POOL_NO_DEPTH to avoid using a DepthBuffer (or manually controlling it) @see DepthBuffer
           *  @remarks
           *      Changing the pool Id will cause the current depth buffer to be detached unless the old
           *      id and the new one are the same
           */
          void setDepthBufferPool( uint16 poolId );
  
          //Returns the pool ID this RenderTarget should query from. @see DepthBuffer
          uint16 getDepthBufferPool() const;
  
          DepthBuffer* getDepthBuffer() const;
  
          //Returns false if couldn't attach
          virtual bool attachDepthBuffer( DepthBuffer *depthBuffer );
  
          virtual void detachDepthBuffer();
  
          /** Detaches DepthBuffer without notifying it from the detach.
              Useful when called from the DepthBuffer while it iterates through attached
              RenderTargets (@see DepthBuffer::_setPoolId())
          */
          virtual void _detachDepthBuffer();
  
          /** Tells the target to update it's contents.
              @remarks
                  If OGRE is not running in an automatic rendering loop
                  (started using Root::startRendering),
                  the user of the library is responsible for asking each render
                  target to refresh. This is the method used to do this. It automatically
                  re-renders the contents of the target using whatever cameras have been
                  pointed at it (using Camera::setRenderTarget).
              @par
                  This allows OGRE to be used in multi-windowed utilities
                  and for contents to be refreshed only when required, rather than
                  constantly as with the automatic rendering loop.
              @param swapBuffers For targets that support double-buffering, if set 
                  to true, the target will immediately
                  swap it's buffers after update. Otherwise, the buffers are
                  not swapped, and you have to call swapBuffers yourself sometime
                  later. You might want to do this on some rendersystems which 
                  pause for queued rendering commands to complete before accepting
                  swap buffers calls - so you could do other CPU tasks whilst the 
                  queued commands complete. Or, you might do this if you want custom
                  control over your windows, such as for externally created windows.
          */
          virtual void update(bool swapBuffers = true);
          /** Swaps the frame buffers to display the next frame.
              @remarks
                  For targets that are double-buffered so that no
                  'in-progress' versions of the scene are displayed
                  during rendering. Once rendering has completed (to
                  an off-screen version of the window) the buffers
                  are swapped to display the new frame.
          */
          virtual void swapBuffers() {}
  
          /** Adds a viewport to the rendering target.
              @remarks
                  A viewport is the rectangle into which rendering output is sent. This method adds
                  a viewport to the render target, rendering from the supplied camera. The
                  rest of the parameters are only required if you wish to add more than one viewport
                  to a single rendering target. Note that size information passed to this method is
                  passed as a parametric, i.e. it is relative rather than absolute. This is to allow
                  viewports to automatically resize along with the target.
              @param
                  cam The camera from which the viewport contents will be rendered (mandatory)
              @param
                  ZOrder The relative order of the viewport with others on the target (allows overlapping
                  viewports i.e. picture-in-picture). Higher Z-orders are on top of lower ones. The actual number
                  is irrelevant, only the relative Z-order matters (you can leave gaps in the numbering)
              @param
                  left The relative position of the left of the viewport on the target, as a value between 0 and 1.
              @param
                  top The relative position of the top of the viewport on the target, as a value between 0 and 1.
              @param
                  width The relative width of the viewport on the target, as a value between 0 and 1.
              @param
                  height The relative height of the viewport on the target, as a value between 0 and 1.
          */
          virtual Viewport* addViewport(Camera* cam, int ZOrder = 0, float left = 0.0f, float top = 0.0f ,
              float width = 1.0f, float height = 1.0f);
  
          /** Returns the number of viewports attached to this target.*/
          virtual unsigned short getNumViewports(void) const;
  
          /** Retrieves a pointer to the viewport with the given index. */
          virtual Viewport* getViewport(unsigned short index);
  
          /** Retrieves a pointer to the viewport with the given Z-order. 
              @remarks throws if not found.
          */
          virtual Viewport* getViewportByZOrder(int ZOrder);
  
          /** Returns true if and only if a viewport exists at the given Z-order. */
          virtual bool hasViewportWithZOrder(int ZOrder);
  
          /** Removes a viewport at a given Z-order.
          */
          virtual void removeViewport(int ZOrder);
  
          /** Removes all viewports on this target.
          */
          virtual void removeAllViewports(void);
  
          /** Retieves details of current rendering performance. */
          const FrameStats& getStatistics(void) const {
              return mStats;
          }
  
          /** Resets saved frame-rate statistices.
          */
          void resetStatistics(void);
  
          /** Retrieve a platform or API-specific piece of information
  
              This method of retrieving information should only be used if you know what you're doing.
  
              | Name        | Description                        |
              |-------------|------------------------------------|
              | WINDOW      | The native window handle. (X11 Window XID/ HWND / NSWindow*) |
              | HWND        | deprecated (same as WINDOW) |
              | GL_FBOID | the id of the OpenGL framebuffer object |
              | GL_MULTISAMPLEFBOID | the id of the OpenGL framebuffer object used for multisampling |
              | GLFBO | id of the screen OpenGL framebuffer object on iOS |
              | GLCONTEXT   | deprecated, do not use |
              | FBO | deprecated, do not use |
              | TARGET | deprecated, do not use |
              | XDISPLAY     | The X Display connection behind that context. |
              | DISPLAYNAME | The X Server name for the connected display. |
              | ATOM        | The X Atom used in client delete events. |
              | VIEW | Cocoa NSView* |
              | NSOPENGLCONTEXT | Cocoa NSOpenGLContext* |
              | NSOPENGLPIXELFORMAT | Cocoa NSOpenGLPixelFormat* |
              
              @param name The name of the attribute.
              @param pData Pointer to memory of the right kind of structure to receive the info.
          */
          virtual void getCustomAttribute(const String& name, void* pData);
  
          /** simplified API for bindings
           * 
           * @overload
           */
          uint getCustomAttribute(const String& name)
          {
              uint ret = 0;
              getCustomAttribute(name, &ret);
              return ret;
          }
  
          /** Add a listener to this RenderTarget which will be called back before & after rendering.
          @remarks
              If you want notifications before and after a target is updated by the system, use
              this method to register your own custom RenderTargetListener class. This is useful
              for potentially adding your own manual rendering commands before and after the
              'normal' system rendering.
          @par NB this should not be used for frame-based scene updates, use Root::addFrameListener for that.
          */
          virtual void addListener(RenderTargetListener* listener);
          /** same as addListener, but force the position in the vector, so we can control the call order */
          virtual void insertListener(RenderTargetListener* listener, const unsigned int pos = 0);
          /** Removes a RenderTargetListener previously registered using addListener. */
          virtual void removeListener(RenderTargetListener* listener);
          /** Removes all listeners from this instance. */
          virtual void removeAllListeners(void);
  
          /** Sets the priority of this render target in relation to the others. 
          @remarks
              This can be used in order to schedule render target updates. Lower
              priorities will be rendered first. Note that the priority must be set
              at the time the render target is attached to the render system, changes
              afterwards will not affect the ordering.
          */
          virtual void setPriority( uchar priority ) { mPriority = priority; }
          /** Gets the priority of a render target. */
          virtual uchar getPriority() const { return mPriority; }
  
          /** Used to retrieve or set the active state of the render target.
          */
          virtual bool isActive() const;
  
          /** Used to set the active state of the render target.
          */
          virtual void setActive( bool state );
  
          /** Sets whether this target should be automatically updated if Ogre's rendering
              loop or Root::_updateAllRenderTargets is being used.
          @remarks
              By default, if you use Ogre's own rendering loop (Root::startRendering)
              or call Root::_updateAllRenderTargets, all render targets are updated 
              automatically. This method allows you to control that behaviour, if 
              for example you have a render target which you only want to update periodically.
          @param autoupdate If true, the render target is updated during the automatic render
              loop or when Root::_updateAllRenderTargets is called. If false, the 
              target is only updated when its update() method is called explicitly.
          */
          virtual void setAutoUpdated(bool autoupdate);
          /** Gets whether this target is automatically updated if Ogre's rendering
              loop or Root::_updateAllRenderTargets is being used.
          */
          virtual bool isAutoUpdated(void) const;
  
          /** Copies the current contents of the render target to a pixelbox. 
          @remarks See suggestPixelFormat for a tip as to the best pixel format to
              extract into, although you can use whatever format you like and the 
              results will be converted.
          */
          virtual void copyContentsToMemory(const Box& src, const PixelBox &dst, FrameBuffer buffer = FB_AUTO) = 0;
  
          /** @overload
          @deprecated This function is deprecated as behavior for dst.size < RenderTarget.size
              was inconsistent in previous versions of Ogre. Sometimes the whole rect was used as a source,
              sometimes the rect with the size equal to the size of destination rect but located
              in the top left corner of the render target, sometimes the destination rect itself.
              Use the overload with explicitly specified source and destination boxes instead.
          */
          OGRE_DEPRECATED void copyContentsToMemory(const PixelBox &dst, FrameBuffer buffer = FB_AUTO) { copyContentsToMemory(Box(0, 0, mWidth, mHeight), dst, buffer); }
  
          /** Suggests a pixel format to use for extracting the data in this target, 
              when calling copyContentsToMemory.
          */
          virtual PixelFormat suggestPixelFormat() const { return PF_BYTE_RGBA; }
          
          /** Writes the current contents of the render target to the named file. */
          void writeContentsToFile(const String& filename);
  
          /** Writes the current contents of the render target to the (PREFIX)(time-stamp)(SUFFIX) file.
              @return the name of the file used.*/
          virtual String writeContentsToTimestampedFile(const String& filenamePrefix, const String& filenameSuffix);
  
          virtual bool requiresTextureFlipping() const = 0;
  
          /** Utility method to notify a render target that a camera has been removed,
          incase it was referring to it as a viewer.
          */
          virtual void _notifyCameraRemoved(const Camera* cam);
  
          /** Indicates whether this target is the primary window. The
              primary window is special in that it is destroyed when
              ogre is shut down, and cannot be destroyed directly.
              This is the case because it holds the context for vertex,
              index buffers and textures.
          */
          virtual bool isPrimary(void) const;
  
  		/** Indicates whether stereo is currently enabled for this target. Default is false. */
  		virtual bool isStereoEnabled(void) const;
  		
          /** Indicates whether on rendering, linear colour space is converted to 
              sRGB gamma colour space. This is the exact opposite conversion of
              what is indicated by Texture::isHardwareGammaEnabled, and can only
              be enabled on creation of the render target. For render windows, it's
              enabled through the 'gamma' creation misc parameter. For textures, 
              it is enabled through the hwGamma parameter to the create call.
          */
          virtual bool isHardwareGammaEnabled() const { return mHwGamma; }
  
          /** Indicates whether multisampling is performed on rendering and at what level.
          */
          virtual uint getFSAA() const { return mFSAA; }
  
          /// RenderSystem specific FSAA option. See @ref RenderSystem::_createRenderWindow for details.
          virtual const String& getFSAAHint() const { return mFSAAHint; }
  
          /** Set the level of multisample AA to be used if hardware support it.
              This option will be ignored if the hardware does not support it 
              or setting can not be changed on the fly on per-target level. 
              @param fsaa The number of samples
              @param fsaaHint @copybrief getFSAAHint
          */
          virtual void setFSAA(uint fsaa, const String& fsaaHint) { }
  
          /** Method for manual management of rendering : fires 'preRenderTargetUpdate'
              and initialises statistics etc.
          @remarks 
          <ul>
          <li>_beginUpdate resets statistics and fires 'preRenderTargetUpdate'.</li>
          <li>_updateViewport renders the given viewport (even if it is not autoupdated),
          fires preViewportUpdate and postViewportUpdate and manages statistics.</li>
          <li>_updateAutoUpdatedViewports renders only viewports that are auto updated,
          fires preViewportUpdate and postViewportUpdate and manages statistics.</li>
          <li>_endUpdate() ends statistics calculation and fires postRenderTargetUpdate.</li>
          </ul>
          you can use it like this for example :
          <pre>
              renderTarget->_beginUpdate();
              renderTarget->_updateViewport(1); // which is not auto updated
              renderTarget->_updateViewport(2); // which is not auto updated
              renderTarget->_updateAutoUpdatedViewports();
              renderTarget->_endUpdate();
              renderTarget->swapBuffers();
          </pre>
              Please note that in that case, the zorder may not work as you expect,
              since you are responsible for calling _updateViewport in the correct order.
          */
          virtual void _beginUpdate();
  
          /** Method for manual management of rendering - renders the given 
          viewport (even if it is not autoupdated)
          @remarks
          This also fires preViewportUpdate and postViewportUpdate, and manages statistics.
          You should call it between _beginUpdate() and _endUpdate().
          @see _beginUpdate for more details.
          @param zorder The zorder of the viewport to update.
          @param updateStatistics Whether you want to update statistics or not.
          */
          virtual void _updateViewport(int zorder, bool updateStatistics = true);
  
          /** Method for manual management of rendering - renders the given viewport (even if it is not autoupdated)
          @remarks
          This also fires preViewportUpdate and postViewportUpdate, and manages statistics
          if needed. You should call it between _beginUpdate() and _endUpdate().
          @see _beginUpdate for more details.
          @param viewport The viewport you want to update, it must be bound to the rendertarget.
          @param updateStatistics Whether you want to update statistics or not.
          */
          virtual void _updateViewport(Viewport* viewport, bool updateStatistics = true);
  
          /** Method for manual management of rendering - renders only viewports that are auto updated
          @remarks
          This also fires preViewportUpdate and postViewportUpdate, and manages statistics.
          You should call it between _beginUpdate() and _endUpdate().
          See _beginUpdate for more details.
          @param updateStatistics Whether you want to update statistics or not.
          @see _beginUpdate()
          */
          virtual void _updateAutoUpdatedViewports(bool updateStatistics = true);
          
          /** Method for manual management of rendering - finishes statistics calculation 
              and fires 'postRenderTargetUpdate'.
          @remarks
          You should call it after a _beginUpdate
          @see _beginUpdate for more details.
          */
          virtual void _endUpdate();
  
      protected:
          /// The name of this target.
          String mName;
          /// The priority of the render target.
          uchar mPriority;
  
          uint32 mWidth;
          uint32 mHeight;
          uint32 mColourDepth;
          uint16       mDepthBufferPoolId;
          DepthBuffer *mDepthBuffer;
  
          // Stats
          FrameStats mStats;
          
          Timer* mTimer ;
          unsigned long mLastSecond;
          unsigned long mLastTime;
          size_t mFrameCount;
  
          bool mActive;
          bool mAutoUpdate;
          // Hardware sRGB gamma conversion done on write?
          bool mHwGamma;
          // FSAA performed?
          uint mFSAA;
          String mFSAAHint;
  		bool mStereoEnabled;
  
          virtual void updateStats(void);
  
          typedef std::map<int, Viewport*> ViewportList;
          /// List of viewports, map on Z-order
          ViewportList mViewportList;
  
          typedef std::vector<RenderTargetListener*> RenderTargetListenerList;
          RenderTargetListenerList mListeners;
      
  
          /// internal method for firing events
          virtual void firePreUpdate(void);
          /// internal method for firing events
          virtual void firePostUpdate(void);
          /// internal method for firing events
          virtual void fireViewportPreUpdate(Viewport* vp);
          /// internal method for firing events
          virtual void fireViewportPostUpdate(Viewport* vp);
          /// internal method for firing events
          virtual void fireViewportAdded(Viewport* vp);
          /// internal method for firing events
          virtual void fireViewportRemoved(Viewport* vp);
          
          /// Internal implementation of update()
          virtual void updateImpl();
      };
      /** @} */
      /** @} */
  
  } // Namespace
  
  #include "OgreHeaderSuffix.h"
  
  #endif
  