/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkPainter.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

/*
 * Copyright 2004 Sandia Corporation.
 * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
 * license for use of this work by or on behalf of the
 * U.S. Government. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that this Notice and any
 * statement of authorship are reproduced on all copies.
 */

/**
 * @class   vtkPainter
 * @brief   Abstract class for drawing poly data.
 *
 *
 * This defines the interface for a Painter. Painters are helpers used
 * by Mapper to perform the rendering. The mapper sets up a chain of painters
 * and passes the render request to the painter. Every painter may have a
 * delegate painter to which the render request is forwarded. The Painter may
 * modify the request or data before passing it to the delegate painter.
 * All the information to control the rendering must be passed to the painter
 * using the vtkInformation object. A concrete painter may read special keys
 * from the vtkInformation object and affect the rendering.
 *
 * @sa
 * vtkPainterPolyDataMapper
*/

#ifndef vtkPainter_h
#define vtkPainter_h

#include "vtkRenderingOpenGLModule.h" // For export macro
#include "vtkObject.h"
#include "vtkWeakPointer.h" // needed for vtkWeakPointer.

class vtkAbstractArray;
class vtkActor;
class vtkDataObject;
class vtkDataSet;
class vtkInformation;
class vtkInformationIntegerKey;
class vtkPainterObserver;
class vtkRenderer;
class vtkTimerLog;
class vtkWindow;

class VTKRENDERINGOPENGL_EXPORT vtkPainter : public vtkObject
{
public:
  vtkTypeMacro(vtkPainter, vtkObject);
  void PrintSelf(ostream &os, vtkIndent indent) override;

  /**
   * Keys used to specify control the behaviour of the painter.
   * When on, the painter assumes that the poly data changes infrequently.
   * It is thus more likely to take time and memory to build auxiliary data
   * structures for faster frame rates.  Is off by default.
   */
  static vtkInformationIntegerKey* STATIC_DATA();

  /**
   * Keys used to specify control the behaviour of the painter.
   * When on, the painter avoids using more memory than it has to.  Thus,
   * auxiliary data structures for faster rendering may not be built.  Is off
   * by default.
   */
  static vtkInformationIntegerKey* CONSERVE_MEMORY();

  /**
   * Keys used to specify control the behaviour of the painter.
   * When off, the painter may make approximations that will make the rendering
   * go faster but may degrade image quality.  Is on by default.
   */
  static vtkInformationIntegerKey* HIGH_QUALITY();

  //@{
  /**
   * Get/Set the information object associated with this painter.
   */
  vtkGetObjectMacro(Information, vtkInformation);
  virtual void SetInformation(vtkInformation*);
  //@}

  //@{
  /**
   * Set/Get the painter to which this painter should propagare its draw calls.
   */
  vtkGetObjectMacro(DelegatePainter, vtkPainter);
  virtual void SetDelegatePainter(vtkPainter*);
  //@}

  //@{
  /**
   * Take part in garbage collection.
   */
  void Register(vtkObjectBase *o) override;
  void UnRegister(vtkObjectBase *o) override;
  //@}

  enum {
    VERTS = 0x1,
    LINES = 0x2,
    POLYS = 0x4,
    STRIPS = 0x8
  };

  /**
   * Generates rendering primitives of appropriate type(s). Multiple types
   * of primitives can be requested by or-ring the primitive flags.
   * Default implementation calls UpdateDelegatePainter() to update the
   * deletagate painter and then calls RenderInternal().
   * forceCompileOnly is passed to the display list painters.
   */
  virtual void Render(vtkRenderer* renderer, vtkActor* actor,
                      unsigned long typeflags, bool forceCompileOnly);

  /**
   * Release any graphics resources that are being consumed by this painter.
   * The parameter window could be used to determine which graphic
   * resources to release.
   * The call is propagated to the delegate painter, if any.
   */
  virtual void ReleaseGraphicsResources(vtkWindow *);

  //@{
  /**
   * Set/Get the execution progress of a process object.
   */
  vtkSetClampMacro(Progress,double,0.0,1.0);
  vtkGetMacro(Progress,double);
  //@}

  /**
   * Get the time required to draw the geometry last time it was rendered.
   * Default implementation adds the current TimeToDraw with that of the
   * delegate painter.
   */
  virtual double GetTimeToDraw();

  /**
   * Expand or shrink the estimated bounds of the object based on the
   * geometric transformations performed in the painter. If the painter
   * does not modify the geometry, the bounds are passed through.
   */
  virtual void UpdateBounds(double bounds[6]);

  //@{
  /**
   * Set the data object to paint. Currently we only support one data object per
   * painter chain.
   */
  void SetInput(vtkDataObject*);
  vtkGetObjectMacro(Input, vtkDataObject);
  //@}

  /**
   * Get the output data object from this painter. The default implementation
   * simply forwards the input data object as the output.
   */
  virtual vtkDataObject* GetOutput()
    { return this->Input; }

protected:
  vtkPainter();
  ~vtkPainter() override;

  /**
   * Take part in garbage collection.
   */
  void ReportReferences(vtkGarbageCollector *collector) override;

  /**
   * Updates the delegate painter. This method is called just before
   * the Render call is passed on to the DelegatePainter.
   * Hence, it gets called only if the DelegatePainter is set.
   * Internally calls PassInformation with argument as
   * this->DelegatePainter. Subclasses must not override this method,
   * instead override PassInformation().
   */
  void UpdateDelegatePainter();

  /**
   * Pass on the information and data (output) from the
   * this to the argument painter. The method passes
   * the information only if it has changed.
   */
  virtual void PassInformation(vtkPainter* toPainter);

  /**
   * Some subclasses may need to do some preprocessing
   * before the actual rendering can be done eg. build efficient
   * representation for the data etc. This should be done here.
   * This method get called after the ProcessInformation()
   * but before RenderInternal().
   */
  virtual void PrepareForRendering(vtkRenderer*, vtkActor*) { }

  /**
   * Performs the actual rendering. Subclasses may override this method.
   * default implementation merely call a Render on the DelegatePainter,
   * if any. When RenderInternal() is called, it is assured that the
   * DelegatePainter is in sync with this painter i.e. UpdateDelegatePainter()
   * has been called.
   */
  virtual void RenderInternal(vtkRenderer* renderer, vtkActor* actor,
                              unsigned long typeflags, bool forceCompileOnly);

  /**
   * Called when the delegate painter reports its progress.
   * Default implementation reports the delegate's progress
   * as its own.
   */
  virtual void UpdateDelegateProgress(vtkPainter* delegate, double amount);

  /**
   * Called before RenderInternal() if the Information has been changed
   * since the last time this method was called.
   */
  virtual void ProcessInformation(vtkInformation*) { }

  /**
   * Adds a progress event observer to toObserve. This provides a means
   * for the subclasses to observe progress events from painters.
   */
  virtual void ObserverPainterProgress(vtkPainter* toObserve);

  /**
   * Update the progress of the process object. Then set the Progress ivar to
   * amount. The parameter amount should range between (0,1).
   * Raises vtkCommand::ProgressEvent.
   */
  void UpdateProgress(double amount);

  //@{
  /**
   * Helper method to get input array to process.
   */
  vtkAbstractArray* GetInputArrayToProcess(int fieldAssociation,
    int fieldAttributeType,
    vtkDataSet* ds,
    bool *use_cell_data=0);
  vtkAbstractArray* GetInputArrayToProcess(int fieldAssociation,
    const char* name, vtkDataSet* dsl,
    bool *use_cell_data=0);
  //@}

  // Time of most recent call to ProcessInformation().
  vtkTimeStamp InformationProcessTime;
  friend class vtkPainterObserver;
  vtkPainterObserver* Observer;

  vtkInformation* Information;
  vtkPainter* DelegatePainter;

  double Progress;
  double ProgressOffset;
  double ProgressScaleFactor;

  double TimeToDraw;
  vtkTimerLog* Timer;


  vtkWeakPointer<vtkWindow> LastWindow; // Window used for previous render.
                         // This is not reference counted.
private:
  vtkPainter(const vtkPainter &) = delete;
  void operator=(const vtkPainter &) = delete;

  vtkDataObject* Input;

};

#endif //vtkPainter_h