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

  Program:   Visualization Toolkit
  Module:    vtkTextureObject.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.

=========================================================================*/
// .NAME vtkTextureObject - abstracts an OpenGL texture object.
// .SECTION Description
// vtkTextureObject represents an OpenGL texture object. It provides API to
// create textures using data already loaded into pixel buffer objects. It can
// also be used to create textures without uploading any data.
// .SECTION Caveats
// DON'T PLAY WITH IT YET.
#ifndef __vtkTextureObject_h
#define __vtkTextureObject_h

#include "vtkObject.h"
#include "vtkWeakPointer.h" // needed for vtkWeakPointer.

class vtkRenderWindow;
class vtkOpenGLExtensionManager;
class vtkPixelBufferObject;

class VTK_RENDERING_EXPORT vtkTextureObject : public vtkObject
{
public:

  //BTX
  // DepthTextureCompareFunction values.
  enum 
  {
    Lequal=0, // r=R<=Dt ? 1.0 : 0.0
    Gequal, // r=R>=Dt ? 1.0 : 0.0
    Less, // r=R<D_t ? 1.0 : 0.0
    Greater, // r=R>Dt ? 1.0 : 0.0
    Equal, // r=R==Dt ? 1.0 : 0.0
    NotEqual, // r=R!=Dt ? 1.0 : 0.0
    AlwaysTrue, //  r=1.0 // WARNING "Always" is macro defined in X11/X.h...
    Never, // r=0.0
    NumberOfDepthTextureCompareFunctions
  };
  
  // DepthTextureMode values.
  enum
  {
    Luminance=0, // (R,G,B,A)=(r,r,r,1)
    Intensity, // (R,G,B,A)=(r,r,r,r)
    Alpha, // (R.G.B.A)=(0,0,0,r)
    NumberOfDepthTextureModes
  };
  
  // Wrap values.
  enum
  {
    Clamp=0,
    ClampToEdge,
    Repeat,
    ClampToBorder,
    MirroredRepeat,
    NumberOfWrapModes
  };
  
  // MinificationFilter values.
  enum
  {
    Nearest=0,
    Linear,
    NearestMipmapNearest,
    NearestMipmapLinear,
    LinearMipmapNearest,
    LinearMipmapLinear,
    NumberOfMinificationModes
  };
  
  // Internal depth format
  enum
  {
    Native=0, // will try to match with the depth buffer format.
    Fixed16,
    Fixed24,
    Fixed32,
    Float32,
    NumberOfDepthFormats
  };
  
  //ETX
  
  static vtkTextureObject* New();
  vtkTypeMacro(vtkTextureObject, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent);

  // Description:
  // Get/Set the context. This does not increase the reference count of the 
  // context to avoid reference loops.
  // SetContext() may raise an error is the OpenGL context does not support the
  // required OpenGL extensions.
  void SetContext(vtkRenderWindow*);
  vtkRenderWindow* GetContext();

  // Description:
  // Get the texture dimensions.
  // These are the properties of the OpenGL texture this instance represents.
  vtkGetMacro(Width, unsigned int);
  vtkGetMacro(Height, unsigned int);
  vtkGetMacro(Depth, unsigned int);
  vtkGetMacro(Components, int);

  vtkGetMacro(NumberOfDimensions, int);

  // Description:
  // Returns OpenGL texture target to which the texture is/can be bound.
  vtkGetMacro(Target, unsigned int);

  // Description:
  // Returns the OpenGL handle.
  vtkGetMacro(Handle, unsigned int);

  // Description:
  // Activate the texture. The texture must have been created using Create().
  // RenderWindow must be set before calling this. 
  void Bind();
  void UnBind();

  // Description:
  // Tells if the texture object is bound to the active texture image unit.
  // (a texture object can be bound to multiple texture image unit).
  bool IsBound();
  
  // Description:
  // Send all the texture object parameters to the hardware if not done yet.
  // \pre is_bound: IsBound()
  void SendParameters();
  
  // Description:
  // Create a 1D texture using the PBO.
  // Eventually we may start supporting creating a texture from subset of data
  // in the PBO, but for simplicity we'll begin with entire PBO data.
  // numComps must be in [1-4].
  // shaderSupportsTextureInt is true if the shader has an alternate
  // implementation supporting sampler with integer values.
  // Even if the card supports texture int, it does not mean that
  // the implementor of the shader made a version that supports texture int.
  bool Create1D(int numComps,
                vtkPixelBufferObject *pbo,
                bool shaderSupportsTextureInt);

  // Description:
  // Create a 2D texture using the PBO.
  // Eventually we may start supporting creating a texture from subset of data
  // in the PBO, but for simplicity we'll begin with entire PBO data.
  // numComps must be in [1-4].
  bool Create2D(unsigned int width, unsigned int height, int numComps,
                vtkPixelBufferObject *pbo,
                bool shaderSupportsTextureInt);

  // Description:
  // Create a 2D depth texture using a PBO.
  // \pre: valid_internalFormat: internalFormat>=0 && internalFormat<NumberOfDepthFormats
  bool CreateDepth(unsigned int width,
                   unsigned int height,
                   int internalFormat,
                   vtkPixelBufferObject *pbo);
  
  // Description:
  // Create a 2D depth texture using a raw pointer.
  // This is a blocking call. If you can, use PBO instead.
  bool CreateDepthFromRaw(unsigned int width,
                          unsigned int height,
                          int internalFormat,
                          int rawType,
                          void *raw);
  
  // Description:
  // Create a 2D depth texture but does not initialize its values.
  bool AllocateDepth(unsigned int width,unsigned int height,
                     int internalFormat);
  
  // Description:
  // Create a 1D color texture but does not initialize its values.
  // Internal format is deduced from numComps and vtkType.
  bool Allocate1D(unsigned int width, int numComps,int vtkType);
  
  // Description:
  // Create a 2D color texture but does not initialize its values.
  // Internal format is deduced from numComps and vtkType.
  bool Allocate2D(unsigned int width,unsigned int height, int numComps,
                  int vtkType);
  
  // Description:
  // Create a 3D color texture but does not initialize its values.
  // Internal format is deduced from numComps and vtkType.
  bool Allocate3D(unsigned int width,unsigned int height,
                  unsigned int depth, int numComps,
                  int vtkType);
  
  
  // Description:
  // Create a 3D texture using the PBO.
  // Eventually we may start supporting creating a texture from subset of data
  // in the PBO, but for simplicity we'll begin with entire PBO data.
  // numComps must be in [1-4].
  bool Create3D(unsigned int width, unsigned int height, unsigned int depth, 
                int numComps, vtkPixelBufferObject *pbo,
                bool shaderSupportsTextureInt);


  // Description:
  // Create texture without uploading any data.
  // To create a DEPTH_COMPONENT texture, vtktype must be set to VTK_VOID and
  // numComps must be 1.
  bool Create2D(unsigned int width, unsigned int height, int numComps,
                int vtktype,
                bool shaderSupportsTextureInt);
  bool Create3D(unsigned int width, unsigned int height, unsigned int depth,
                int numComps, int vtktype,
                bool shaderSupportsTextureInt);

  // Description:
  // This is used to download raw data from the texture into a pixel bufer. The
  // pixel buffer API can then be used to download the pixel buffer data to CPU
  // arrays. The caller takes on the responsibility of deleting the returns
  // vtkPixelBufferObject once it done with it.
  vtkPixelBufferObject* Download();

  // Description:
  // Get the data type for the texture as a vtk type int i.e. VTK_INT etc.
  int GetDataType();

  unsigned int GetInternalFormat(int vtktype, int numComps,
                                 bool shaderSupportsTextureInt);
  unsigned int GetFormat(int vtktype, int numComps,
                         bool shaderSupportsTextureInt);
  
  // Description:
  // Wrap mode for the first texture coordinate "s"
  // Valid values are:
  // - Clamp
  // - ClampToEdge
  // - Repeat
  // - ClampToBorder
  // - MirroredRepeat
  // Initial value is Repeat (as in OpenGL spec)
  vtkGetMacro(WrapS,int);
  vtkSetMacro(WrapS,int);
  
  // Description:
  // Wrap mode for the first texture coordinate "t"
  // Valid values are:
  // - Clamp
  // - ClampToEdge
  // - Repeat
  // - ClampToBorder
  // - MirroredRepeat
  // Initial value is Repeat (as in OpenGL spec)
  vtkGetMacro(WrapT,int);
  vtkSetMacro(WrapT,int);
  
  // Description:
  // Wrap mode for the first texture coordinate "r"
  // Valid values are:
  // - Clamp
  // - ClampToEdge
  // - Repeat
  // - ClampToBorder
  // - MirroredRepeat
  // Initial value is Repeat (as in OpenGL spec)
  vtkGetMacro(WrapR,int);
  vtkSetMacro(WrapR,int);
  
  // Description:
  // Minification filter mode.
  // Valid values are:
  // - Nearest
  // - Linear
  // - NearestMipmapNearest
  // - NearestMipmapLinear
  // - LinearMipmapNearest
  // - LinearMipmapLinear
  // Initial value is Nearest (note initial value in OpenGL spec
  // is NearestMipMapLinear but this is error-prone because it makes the
  // texture object incomplete. ).
  vtkGetMacro(MinificationFilter,int);
  vtkSetMacro(MinificationFilter,int);
  
  // Description:
  // Tells if the magnification mode is linear (true) or nearest (false).
  // Initial value is false (initial value in OpenGL spec is true).
  vtkGetMacro(LinearMagnification,bool);
  vtkSetMacro(LinearMagnification,bool);
  
  // Description:
  // Border Color (RGBA). Each component is in [0.0f,1.0f].
  // Initial value is (0.0f,0.0f,0.0f,0.0f), as in OpenGL spec.
  vtkSetVector4Macro(BorderColor,float);
  vtkGetVector4Macro(BorderColor,float);
  
  // Description:
  // Priority of the texture object to be resident on the card for higher
  // performance in the range [0.0f,1.0f].
  // Initial value is 1.0f, as in OpenGL spec.
  vtkSetMacro(Priority,float);
  vtkGetMacro(Priority,float);
  
  // Description:
  // Lower-clamp the computed LOD against this value. Any float value is valid.
  // Initial value is -1000.0f, as in OpenGL spec.
  vtkSetMacro(MinLOD,float);
  vtkGetMacro(MinLOD,float);
  
  // Description:
  // Upper-clamp the computed LOD against this value. Any float value is valid.
  // Initial value is 1000.0f, as in OpenGL spec.
  vtkSetMacro(MaxLOD,float);
  vtkGetMacro(MaxLOD,float);
  
  // Description:
  // Level of detail of the first texture image. A texture object is a list of
  // texture images. It is a non-negative integer value.
  // Initial value is 0, as in OpenGL spec.
  vtkSetMacro(BaseLevel,int);
  vtkGetMacro(BaseLevel,int);
  
  // Description:
  // Level of detail of the first texture image. A texture object is a list of
  // texture images. It is a non-negative integer value.
  // Initial value is 1000, as in OpenGL spec.
  vtkSetMacro(MaxLevel,int);
  vtkGetMacro(MaxLevel,int);
  
  // Description:
  // Tells if the output of a texture unit with a depth texture uses
  // comparison or not.
  // Comparison happens between D_t the depth texture value in the range [0,1]
  // and with R the interpolated third texture coordinate clamped to range
  // [0,1]. The result of the comparison is noted `r'. If this flag is false,
  // r=D_t.
  // Initial value is false, as in OpenGL spec.
  // Ignored if the texture object is not a depth texture.
  vtkGetMacro(DepthTextureCompare,bool);
  vtkSetMacro(DepthTextureCompare,bool);
  
  // Description:
  // In case DepthTextureCompare is true, specify the comparison function in
  // use. The result of the comparison is noted `r'.
  // Valid values are:
  // - Value
  // - Lequal: r=R<=Dt ? 1.0 : 0.0
  // - Gequal: r=R>=Dt ? 1.0 : 0.0
  // - Less: r=R<D_t ? 1.0 : 0.0
  // - Greater: r=R>Dt ? 1.0 : 0.0
  // - Equal: r=R==Dt ? 1.0 : 0.0
  // - NotEqual: r=R!=Dt ? 1.0 : 0.0
  // - AlwaysTrue: r=1.0
  // - Never: r=0.0
  // If the magnification of minification factor are not nearest, percentage
  // closer filtering (PCF) is used: R is compared to several D_t and r is
  // the average of the comparisons (it is NOT the average of D_t compared
  // once to R).
  // Initial value is Lequal, as in OpenGL spec.
  // Ignored if the texture object is not a depth texture.
  vtkGetMacro(DepthTextureCompareFunction,int);
  vtkSetMacro(DepthTextureCompareFunction,int);
  
  // Description:
  // Defines the mapping from depth component `r' to RGBA components.
  // Ignored if the texture object is not a depth texture.
  // Valid modes are:
  // - Luminance: (R,G,B,A)=(r,r,r,1)
  // - Intensity: (R,G,B,A)=(r,r,r,r)
  // - Alpha: (R.G.B.A)=(0,0,0,r)
  // Initial value is Luminance, as in OpenGL spec.
  vtkGetMacro(DepthTextureMode,int);
  vtkSetMacro(DepthTextureMode,int);
  
  // Description:
  // Tells the hardware to generate mipmap textures from the first texture
  // image at BaseLevel.
  // Initial value is false, as in OpenGL spec.
  vtkGetMacro(GenerateMipmap,bool);
  vtkSetMacro(GenerateMipmap,bool);
  
  // Description:
  // Returns if the context supports the required extensions.
  static bool IsSupported(vtkRenderWindow* renWin);
  
  // Description:
  // Copy a sub-part of the texture (src) in the current framebuffer
  // at location (dstXmin,dstYmin). (dstXmin,dstYmin) is the location of the
  // lower left corner of the rectangle. width and height are the dimensions
  // of the framebuffer.
  // - texture coordinates are sent on texture coordinate processing unit 0.
  // - if the fixed-pipeline fragment shader is used, texturing has to be set
  // on texture image unit 0 and the texture object has to be bound on texture
  // image unit 0.
  // - if a customized fragment shader is used, you are free to pick the
  // texture image unit you want. You can even have multiple texture objects
  // attached on multiple texture image units. In this case, you call this
  // method only on one of them.
  // \pre positive_srcXmin: srcXmin>=0
  // \pre max_srcXmax: srcXmax<this->GetWidth()
  // \pre increasing_x: srcXmin<=srcXmax
  // \pre positive_srcYmin: srcYmin>=0
  // \pre max_srcYmax: srcYmax<this->GetHeight()
  // \pre increasing_y: srcYmin<=srcYmax
  // \pre positive_dstXmin: dstXmin>=0
  // \pre positive_dstYmin: dstYmin>=0
  // \pre positive_width: width>0
  // \pre positive_height: height>0
  // \pre x_fit: destXmin+(srcXmax-srcXmin)<width
  // \pre y_fit: destYmin+(srcYmax-srcYmin)<height
  void CopyToFrameBuffer(int srcXmin,
                         int srcYmin,
                         int srcXmax,
                         int srcYmax,
                         int dstXmin,
                         int dstYmin,
                         int width,
                         int height);
  
  
  // Description:
  // Copy a sub-part of a logical buffer of the framebuffer (color or depth)
  // to the texture object. src is the framebuffer, dst is the texture.
  // (srcXmin,srcYmin) is the location of the lower left corner of the
  // rectangle in the framebuffer. (dstXmin,dstYmin) is the location of the
  // lower left corner of the rectangle in the texture. width and height
  // specifies the size of the rectangle in pixels.
  // If the logical buffer is a color buffer, it has to be selected first with
  // glReadBuffer().
  // \pre is2D: GetNumberOfDimensions()==2
  void CopyFromFrameBuffer(int srcXmin,
                           int srcYmin,
                           int dstXmin,
                           int dstYmin,
                           int width,
                           int height);
  
  
//BTX
protected:
  vtkTextureObject();
  ~vtkTextureObject();

  // Description:
  // Load all necessary extensions.
  bool LoadRequiredExtensions(vtkOpenGLExtensionManager*);

  // Description:
  // Creates a texture handle if not already created.
  void CreateTexture();

  // Description:
  // Destory the texture.
  void DestroyTexture();
  
  int NumberOfDimensions;
  unsigned int Width;
  unsigned int Height;
  unsigned int Depth;

  unsigned int Target; // GLenum
  unsigned int Format; // GLenum
  unsigned int Type; // GLenum
  int Components;

  vtkWeakPointer<vtkRenderWindow> Context;
  unsigned int Handle;
  bool SupportsTextureInteger;
  bool SupportsTextureFloat;

  int WrapS;
  int WrapT;
  int WrapR;
  int MinificationFilter;
  bool LinearMagnification;
  float BorderColor[4];
  
  float Priority;
  float MinLOD;
  float MaxLOD;
  int BaseLevel;
  int MaxLevel;
  
  
  bool DepthTextureCompare;
  int DepthTextureCompareFunction;
  int DepthTextureMode;
  
  bool GenerateMipmap;
  
  vtkTimeStamp SendParametersTime;
  
private:
  vtkTextureObject(const vtkTextureObject&); // Not implemented.
  void operator=(const vtkTextureObject&); // Not implemented.
//ETX
};

#endif


