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

  Program:   Visualization Toolkit
  Module:    vtkMapper.h
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 1993-2002 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.

=========================================================================*/
// .NAME vtkMapper - abstract class specifies interface to map data to graphics primitives
// .SECTION Description
// vtkMapper is an abstract class to specify interface between data and 
// graphics primitives. Subclasses of vtkMapper map data through a 
// lookuptable and control the creation of rendering primitives that
// interface to the graphics library. The mapping can be controlled by 
// supplying a lookup table and specifying a scalar range to map data
// through.
//
// There are several important control mechanisms affecting the behavior of
// this object. The ScalarVisibility flag controls whether scalar data (if
// any) controls the color of the associated actor(s) that refer to the
// mapper. The ScalarMode ivar is used to determine whether scalar point data
// or cell data is used to color the object. By default, point data scalars
// are used unless there are none, in which cell scalars are used. Or you can
// explicitly control whether to use point or cell scalar data. Finally, the
// mapping of scalars through the lookup table varies depending on the
// setting of the ColorMode flag. See the documentation for the appropriate
// methods for an explanation.
//
// Another important feature of this class is whether to use immediate mode
// rendering (ImmediateModeRenderingOn) or display list rendering
// (ImmediateModeRenderingOff). If display lists are used, a data structure
// is constructed (generally in the rendering library) which can then be
// rapidly traversed and rendered by the rendering library. The disadvantage
// of display lists is that they require additionally memory which may affect
// the performance of the system.
//
// Another important feature of the mapper is the ability to shift the
// z-buffer to resolve coincident topology. For example, if you'd like to
// draw a mesh with some edges a different color, and the edges lie on the
// mesh, this feature can be useful to get nice looking lines. (See the
// ResolveCoincidentTopology-related methods.)

// .SECTION See Also
// vtkDataSetMapper vtkPolyDataMapper

#ifndef __vtkMapper_h
#define __vtkMapper_h

#include "vtkAbstractMapper3D.h"
#include "vtkScalarsToColors.h" // For VTK_COLOR_MODE_DEFAULT and _MAP_SCALARS

#define VTK_RESOLVE_OFF 0
#define VTK_RESOLVE_POLYGON_OFFSET 1
#define VTK_RESOLVE_SHIFT_ZBUFFER 2

#define VTK_GET_ARRAY_BY_ID 0
#define VTK_GET_ARRAY_BY_NAME 1

class vtkWindow;
class vtkRenderer;
class vtkActor;
class vtkDataSet;

class VTK_RENDERING_EXPORT vtkMapper : public vtkAbstractMapper3D
{
public:
  vtkTypeRevisionMacro(vtkMapper,vtkAbstractMapper3D);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Make a shallow copy of this mapper.
  void ShallowCopy(vtkAbstractMapper *m);

  // Description:
  // Overload standard modified time function. If lookup table is modified,
  // then this object is modified as well.
  unsigned long GetMTime();

  // Description:
  // Method initiates the mapping process. Generally sent by the actor 
  // as each frame is rendered.
  virtual void Render(vtkRenderer *ren, vtkActor *a) = 0;

  // Description:
  // Release any graphics resources that are being consumed by this mapper.
  // The parameter window could be used to determine which graphic
  // resources to release.
  virtual void ReleaseGraphicsResources(vtkWindow *) {};

  // Description:
  // Specify a lookup table for the mapper to use.
  void SetLookupTable(vtkScalarsToColors *lut);
  vtkScalarsToColors *GetLookupTable();

  // Description:
  // Create default lookup table. Generally used to create one when none
  // is available with the scalar data.
  virtual void CreateDefaultLookupTable();

  // Description:
  // Turn on/off flag to control whether scalar data is used to color objects.
  vtkSetMacro(ScalarVisibility,int);
  vtkGetMacro(ScalarVisibility,int);
  vtkBooleanMacro(ScalarVisibility,int);

  // Description:
  // Control how the scalar data is mapped to colors.  By default
  // (ColorModeToDefault), unsigned char scalars are treated as colors, and
  // NOT mapped through the lookup table, while everything else is. Setting
  // ColorModeToMapScalars means that all scalar data will be mapped through
  // the lookup table.  (Note that for multi-component scalars, the
  // particular component to use for mapping can be specified using the
  // SelectColorArray() method.)
  vtkSetMacro(ColorMode,int);
  vtkGetMacro(ColorMode,int);
  void SetColorModeToDefault() 
    {this->SetColorMode(VTK_COLOR_MODE_DEFAULT);};
  void SetColorModeToMapScalars() 
    {this->SetColorMode(VTK_COLOR_MODE_MAP_SCALARS);};

  // Description:
  // Return the method of coloring scalar data.
  const char *GetColorModeAsString();

  // Description:
  // Control whether the mapper sets the lookuptable range based on its
  // own ScalarRange, or whether it will use the LookupTable ScalarRange
  // regardless of it's own setting. By default the Mapper is allowed to set
  // the LookupTable range, but users who are sharing LookupTables between
  // mappers/actors will probably wish to force the mapper to use the
  // LookupTable unchanged.
  vtkSetMacro(UseLookupTableScalarRange,int);
  vtkGetMacro(UseLookupTableScalarRange,int);
  vtkBooleanMacro(UseLookupTableScalarRange,int);

  // Description:
  // Specify range in terms of scalar minimum and maximum (smin,smax). These
  // values are used to map scalars into lookup table. Has no effect when
  // UseLookupTableScalarRange is true.
  vtkSetVector2Macro(ScalarRange,float);
  vtkGetVectorMacro(ScalarRange,float,2);

  // Description:
  // Turn on/off flag to control whether data is rendered using
  // immediate mode or note. Immediate mode rendering
  // tends to be slower but it can handle larger datasets.
  // The default value is immediate mode off. If you are
  // having problems rendering a large dataset you might
  // want to consider using immediate more rendering.
  vtkSetMacro(ImmediateModeRendering,int);
  vtkGetMacro(ImmediateModeRendering,int);
  vtkBooleanMacro(ImmediateModeRendering,int);

  // Description:
  // Turn on/off flag to control whether data is rendered using
  // immediate mode or note. Immediate mode rendering
  // tends to be slower but it can handle larger datasets.
  // The default value is immediate mode off. If you are 
  // having problems rendering a large dataset you might
  // want to consider using immediate more rendering.
  static void SetGlobalImmediateModeRendering(int val);
  static void GlobalImmediateModeRenderingOn() 
    {vtkMapper::SetGlobalImmediateModeRendering(1);};
  static void GlobalImmediateModeRenderingOff() 
    {vtkMapper::SetGlobalImmediateModeRendering(0);};
  static int  GetGlobalImmediateModeRendering();

  // Description:
  // Control how the filter works with scalar point data and cell attribute
  // data.  By default (ScalarModeToDefault), the filter will use point data,
  // and if no point data is available, then cell data is used. Alternatively
  // you can explicitly set the filter to use point data
  // (ScalarModeToUsePointData) or cell data (ScalarModeToUseCellData).
  // You can also choose to get the scalars from an array in point field
  // data (ScalarModeToUsePointFieldData) or cell field data
  // (ScalarModeToUseCellFieldData).  If scalars are coming from a field
  // data array, you must call SelectColorArray before you call
  // GetColors.
  vtkSetMacro(ScalarMode,int);
  vtkGetMacro(ScalarMode,int);
  void SetScalarModeToDefault() {
    this->SetScalarMode(VTK_SCALAR_MODE_DEFAULT);};
  void SetScalarModeToUsePointData() {
    this->SetScalarMode(VTK_SCALAR_MODE_USE_POINT_DATA);};
  void SetScalarModeToUseCellData() {
    this->SetScalarMode(VTK_SCALAR_MODE_USE_CELL_DATA);};
  void SetScalarModeToUsePointFieldData() {
    this->SetScalarMode(VTK_SCALAR_MODE_USE_POINT_FIELD_DATA);};
  void SetScalarModeToUseCellFieldData() {
    this->SetScalarMode(VTK_SCALAR_MODE_USE_CELL_FIELD_DATA);};
  
  // Description:
  // When ScalarMode is set to UsePointFileData or UseCellFieldData,
  // you can specify which array to use for coloring using these methods.
  // The lookup table will decide how to convert vectors to colors.
  void SelectColorArray(int arrayNum); 
  void SelectColorArray(const char* arrayName); 

  // Description:
  // Legacy:
  // These methods used to be used to specify the array component.
  // It is better to do this in the lookup table.
  void ColorByArrayComponent(int arrayNum, int component);
  void ColorByArrayComponent(const char* arrayName, int component);
  
  // Description:
  // Get the array name or number and component to color by.
  char* GetArrayName() { return this->ArrayName; }
  int GetArrayId() { return this->ArrayId; }
  int GetArrayAccessMode() { return this->ArrayAccessMode; }
  int GetArrayComponent() { return this->ArrayComponent; }

  // Description:
  // Return the method for obtaining scalar data.
  const char *GetScalarModeAsString();

  // Description:
  // Set/Get a global flag that controls whether coincident topology (e.g., a
  // line on top of a polygon) is shifted to avoid z-buffer resolution (and
  // hence rendering problems). If not off, there are two methods to choose
  // from. PolygonOffset uses graphics systems calls to shift polygons, but
  // does not distinguish vertices and lines from one another. ShiftZBuffer
  // remaps the z-buffer to distinguish vertices, lines, and polygons, but
  // does not always produce acceptable results. If you use the ShiftZBuffer
  // approach, you may also want to set the ResolveCoincidentTopologyZShift
  // value. (Note: not all mappers/graphics systems implement this 
  // functionality.)
  static void SetResolveCoincidentTopology(int val);
  static int  GetResolveCoincidentTopology();
  static void SetResolveCoincidentTopologyToDefault();
  static void SetResolveCoincidentTopologyToOff() 
    {SetResolveCoincidentTopology(VTK_RESOLVE_OFF);}
  static void SetResolveCoincidentTopologyToPolygonOffset() 
    {SetResolveCoincidentTopology(VTK_RESOLVE_POLYGON_OFFSET);}
  static void SetResolveCoincidentTopologyToShiftZBuffer() 
    {SetResolveCoincidentTopology(VTK_RESOLVE_SHIFT_ZBUFFER);}

  // Description:
  // Used to set the polygon offset scale factor and units.
  // Used when ResolveCoincidentTopology is set to PolygonOffset. 
  // These are global variables.
  static void SetResolveCoincidentTopologyPolygonOffsetParameters(float factor,
                                                                  float units);
  static void GetResolveCoincidentTopologyPolygonOffsetParameters(float& factor,
                                                                  float& units);

  // Description:
  // Used to set the z-shift if ResolveCoincidentTopology is set to
  // ShiftZBuffer. This is a global variable.
  static void SetResolveCoincidentTopologyZShift(double val);
  static double GetResolveCoincidentTopologyZShift();

  // Description:
  // Return bounding box (array of six floats) of data expressed as
  // (xmin,xmax, ymin,ymax, zmin,zmax).
  virtual float *GetBounds();
  virtual void GetBounds(float bounds[6]) 
    {this->vtkAbstractMapper3D::GetBounds(bounds);};

  // Description:
  // This instance variable is used by vtkLODActor to determine which
  // mapper to use.  It is an estimate of the time necessary to render.
  // Setting the render time does not modify the mapper.
  void SetRenderTime(float time) {this->RenderTime = time;}
  vtkGetMacro(RenderTime, float);

  //BTX
  // Description:
  // Get the input as a vtkDataSet.  This method is overridden in
  // the specialized mapper classes to return more specific data types.
  vtkDataSet *GetInput();
  //ETX

  // Description:
  // Get the input to this mapper as a vtkDataSet, instead of as a 
  // more specialized data type that the subclass may return from
  // GetInput().  This method is provided for use in the wrapper languages,
  // C++ programmers should use GetInput() instead.
  vtkDataSet *GetInputAsDataSet() 
    {return this->GetInput();}

  // Description:
  // Map the scalars (if there are any scalars and ScalarVisibility is on)
  // through the lookup table, returning an unsigned char RGBA array. This is
  // typically done as part of the rendering process. The alpha parameter 
  // allows the blending of the scalars with an additional alpha (typically
  // which comes from a vtkActor, etc.)
  vtkUnsignedCharArray *MapScalars(float alpha);
  
  // Description:
  // Update the input to the Mapper.
  virtual void Update();

protected:
  vtkMapper();
  ~vtkMapper();

  vtkUnsignedCharArray *Colors;

  vtkScalarsToColors *LookupTable;
  int ScalarVisibility;
  vtkTimeStamp BuildTime;
  float ScalarRange[2];
  int UseLookupTableScalarRange;
  int ImmediateModeRendering;
  int ColorMode;
  int ScalarMode;

  float RenderTime;

  // for coloring by a component of a field data array
  int ArrayId;
  char ArrayName[256];
  int ArrayComponent;
  int ArrayAccessMode;
private:
  vtkMapper(const vtkMapper&);  // Not implemented.
  void operator=(const vtkMapper&);  // Not implemented.
};

#endif
