vtkShaderProgram.h

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

  Program:   Visualization Toolkit

  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.

=========================================================================*/
#ifndef vtkShaderProgram_h
#define vtkShaderProgram_h

#include "vtkRenderingOpenGL2Module.h" // for export macro
#include "vtkObject.h"

#include <string> // For member variables.
#include <map>    // For member variables.

class vtkMatrix3x3;
class vtkMatrix4x4;
class vtkTransformFeedback;
class vtkShader;
class VertexArrayObject;
class vtkWindow;

class VTKRENDERINGOPENGL2_EXPORT vtkShaderProgram : public vtkObject
{
public:
  static vtkShaderProgram *New();
  vtkTypeMacro(vtkShaderProgram, vtkObject);
  void PrintSelf(ostream& os, vtkIndent indent) override;


  vtkGetObjectMacro(VertexShader, vtkShader);
  void SetVertexShader(vtkShader*);


  vtkGetObjectMacro(FragmentShader, vtkShader);
  void SetFragmentShader(vtkShader*);


  vtkGetObjectMacro(GeometryShader, vtkShader);
  void SetGeometryShader(vtkShader*);


  vtkGetObjectMacro(TransformFeedback, vtkTransformFeedback);
  void SetTransformFeedback(vtkTransformFeedback *tfc);


  vtkGetMacro(Compiled, bool);
  vtkSetMacro(Compiled, bool);
  vtkBooleanMacro(Compiled, bool);

  std::string GetMD5Hash() const { return this->MD5Hash; }
  void SetMD5Hash(const std::string &hash) { this->MD5Hash = hash; }


  enum NormalizeOption {
    Normalize,
    NoNormalize
  };


  bool isBound() const { return this->Bound; }

  void ReleaseGraphicsResources(vtkWindow *win);

  int GetHandle() const { return Handle; }

  std::string GetError() const { return Error; }

  bool EnableAttributeArray(const char *name);

  bool DisableAttributeArray(const char *name);

  bool UseAttributeArray(const char *name, int offset, size_t stride,
                         int elementType, int elementTupleSize,
                         NormalizeOption normalize);

  template <class T>
  bool SetAttributeArray(const char *name, const T &array,
                         int tupleSize, NormalizeOption normalize);

  bool SetUniformi(const char *name, int v);
  bool SetUniformf(const char *name, float v);
  bool SetUniform2i(const char *name, const int v[2]);
  bool SetUniform2f(const char *name, const float v[2]);
  bool SetUniform3f(const char *name, const float v[3]);
  bool SetUniform3f(const char *name, const double v[3]);
  bool SetUniform4f(const char *name, const float v[4]);
  bool SetUniform3uc(const char *name, const unsigned char v[3]); // maybe remove
  bool SetUniform4uc(const char *name, const unsigned char v[4]); // maybe remove
  bool SetUniformMatrix(const char *name, vtkMatrix3x3 *v);
  bool SetUniformMatrix(const char *name, vtkMatrix4x4 *v);
  bool SetUniformMatrix3x3(const char *name, float *v);
  bool SetUniformMatrix4x4(const char *name, float *v);

  bool SetUniform1iv(const char *name, const int count, const int *f);
  bool SetUniform1fv(const char *name, const int count, const float *f);
  bool SetUniform2fv(const char *name, const int count, const float (*f)[2]);
  bool SetUniform3fv(const char *name, const int count, const float (*f)[3]);
  bool SetUniform4fv(const char *name, const int count, const float (*f)[4]);
  bool SetUniformMatrix4x4v(const char *name, const int count, float *v);

  // How many outputs does this program produce
  // only valid for OpenGL 3.2 or later
  vtkSetMacro(NumberOfOutputs,unsigned int);

  static bool Substitute(
    std::string &source,
    const std::string &search,
    const std::string &replace,
    bool all = true);

  static bool Substitute(
    vtkShader* shader,
    const std::string &search,
    const std::string &replace,
    bool all = true);

  bool IsUniformUsed(const char *);

  bool IsAttributeUsed(const char *name);

  // maps of std::string are super slow when calling find
  // with a string literal or const char * as find
  // forces construction/copy/destruction of a
  // std::string copy of the const char *
  // In spite of the doubters this can really be a
  // huge CPU hog.
  struct cmp_str
  {
     bool operator()(const char *a, const char *b) const
     {
        return strcmp(a, b) < 0;
     }
  };


  vtkSetStringMacro(FileNamePrefixForDebugging);
  vtkGetStringMacro(FileNamePrefixForDebugging);


  enum UniformGroups {
    CameraGroup,
    LightingGroup,
    UserGroup, // always will be last
  };
  void SetUniformGroupUpdateTime(int, vtkMTimeType tm);
  vtkMTimeType GetUniformGroupUpdateTime(int);

  // returns the location for a uniform or attribute in
  // this program. Is cached for performance.
  int FindUniform(const char *name);
  int FindAttributeArray(const char *name);

protected:
  vtkShaderProgram();
  ~vtkShaderProgram() override;

  /***************************************************************
   * The following functions are only for use by the shader cache
   * which is why they are protected and that class is a friend
   * you need to use the shader cache to compile/link/bind your shader
   * do not try to do it yourself as it will screw up the cache
   ***************************************************************/
   friend class vtkOpenGLShaderCache;

  bool AttachShader(const vtkShader *shader);

  bool DetachShader(const vtkShader *shader);

  virtual int CompileShader();

  bool Link();

  bool Bind();

  void Release();

  /************* end **************************************/

  vtkShader *VertexShader;
  vtkShader *FragmentShader;
  vtkShader *GeometryShader;
  vtkTransformFeedback *TransformFeedback;

  // hash of the shader program
  std::string MD5Hash;

  bool SetAttributeArrayInternal(const char *name, void *buffer,
                                 int type, int tupleSize,
                                 NormalizeOption normalize);
  int Handle;
  int VertexShaderHandle;
  int FragmentShaderHandle;
  int GeometryShaderHandle;

  bool Linked;
  bool Bound;
  bool Compiled;

  // for glsl 1.5 or later, how many outputs
  // does this shader create
  // they will be bound in order to
  // fragOutput0 fragOutput1 etc...
  unsigned int NumberOfOutputs;

  std::string Error;

  // since we are using const char * arrays we have to
  // free our memory :-)
  void ClearMaps();
  std::map<const char *, int, cmp_str> AttributeLocs;
  std::map<const char *, int, cmp_str> UniformLocs;

  std::map<int, vtkMTimeType> UniformGroupMTimes;

  friend class VertexArrayObject;

private:
  vtkShaderProgram(const vtkShaderProgram&) = delete;
  void operator=(const vtkShaderProgram&) = delete;

  char* FileNamePrefixForDebugging;
};


#endif