text: /*
  Open Asset Import Library (assimp)
  ----------------------------------------------------------------------
  
  Copyright (c) 2006-2018, assimp team
  
  
  All rights reserved.
  
  Redistribution and use of this software in source and binary forms,
  with or without modification, are permitted provided that the
  following conditions are met:
  
  * Redistributions of source code must retain the above
    copyright notice, this list of conditions and the
    following disclaimer.
  
  * Redistributions in binary form must reproduce the above
    copyright notice, this list of conditions and the
    following disclaimer in the documentation and/or other
    materials provided with the distribution.
  
  * Neither the name of the assimp team, nor the names of its
    contributors may be used to endorse or promote products
    derived from this software without specific prior
    written permission of the assimp team.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  ----------------------------------------------------------------------
  */
  
  /** @file ProgressHandler.hpp
   *  @brief Abstract base class 'ProgressHandler'.
   */
  #pragma once
  #ifndef AI_PROGRESSHANDLER_H_INC
  #define AI_PROGRESSHANDLER_H_INC
  
  #include "types.h"
  
  namespace Assimp    {
  
  // ------------------------------------------------------------------------------------
  /** @brief CPP-API: Abstract interface for custom progress report receivers.
   *
   *  Each #Importer instance maintains its own #ProgressHandler. The default
   *  implementation provided by Assimp doesn't do anything at all. */
  class ASSIMP_API ProgressHandler
  #ifndef SWIG
      : public Intern::AllocateFromAssimpHeap
  #endif
  {
  protected:
      /** @brief  Default constructor */
      ProgressHandler () {
      }
  public:
      /** @brief  Virtual destructor  */
      virtual ~ProgressHandler () {
      }
  
      // -------------------------------------------------------------------
      /** @brief Progress callback.
       *  @param percentage An estimate of the current loading progress,
       *    in percent. Or -1.f if such an estimate is not available.
       *
       *  There are restriction on what you may do from within your
       *  implementation of this method: no exceptions may be thrown and no
       *  non-const #Importer methods may be called. It is
       *  not generally possible to predict the number of callbacks
       *  fired during a single import.
       *
       *  @return Return false to abort loading at the next possible
       *   occasion (loaders and Assimp are generally allowed to perform
       *   all needed cleanup tasks prior to returning control to the
       *   caller). If the loading is aborted, #Importer::ReadFile()
       *   returns always NULL.
       *   */
      virtual bool Update(float percentage = -1.f) = 0;
  
      // -------------------------------------------------------------------
      /** @brief Progress callback for file loading steps
       *  @param numberOfSteps The number of total post-processing
       *   steps
       *  @param currentStep The index of the current post-processing
       *   step that will run, or equal to numberOfSteps if all of
       *   them has finished. This number is always strictly monotone
       *   increasing, although not necessarily linearly.
       *
       *  @note This is currently only used at the start and the end
       *   of the file parsing.
       *   */
      virtual void UpdateFileRead(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
          float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
          Update( f * 0.5f );
      }
  
      // -------------------------------------------------------------------
      /** @brief Progress callback for post-processing steps
       *  @param numberOfSteps The number of total post-processing
       *   steps
       *  @param currentStep The index of the current post-processing
       *   step that will run, or equal to numberOfSteps if all of
       *   them has finished. This number is always strictly monotone
       *   increasing, although not necessarily linearly.
       *   */
      virtual void UpdatePostProcess(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
          float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
          Update( f * 0.5f + 0.5f );
      }
  
  }; // !class ProgressHandler
  // ------------------------------------------------------------------------------------
  } // Namespace Assimp
  
  #endif // AI_PROGRESSHANDLER_H_INC
  