/*!
 * @file shader.h
 * @brief Definition of the Shader rendering class
*/

#ifndef _SHADER_H
#define _SHADER_H

#include "base_object.h"
#include "glincl.h"
#include <vector>


// FORWARD DECLARATION


//! A class for ...
class Shader : public BaseObject
{
  public:
  typedef enum
  {
    None       = 0,
    Fragment   = 1,
    Vertex     = 2,

    Program    = 4,
  } Type;

  public:
  Shader(const std::string& vertexShaderFile = "", const std::string& fragmentShaderFile = "");
  virtual ~Shader();
  static Shader* getShader(const std::string& vertexShaderFile, const std::string& fragmentShaderFile);
  static bool unload(Shader* shader);


  static bool checkShaderAbility();
  void activateShader();
  static void deactivateShader();


  bool loadShaderProgramm(Shader::Type type, const std::string& fileName);
  void deleteProgram(Shader::Type type);

  void linkShaderProgram();


  char* fileRead(const std::string& fileName);
  std::vector<char*>* fileReadArray(const std::string& fileName);


  inline static bool shaderActive() { return (Shader::storedShader != NULL)? true : false; };
  inline static Shader* getActiveShader() { return Shader::storedShader; };
  inline static void suspendShader() { Shader* currShader = storedShader; if (storedShader!= NULL) { Shader::deactivateShader(); Shader::storedShader = currShader;} };
  inline static void restoreShader() { if (storedShader != NULL) storedShader->activateShader(); storedShader = NULL; };


  GLhandleARB getProgram() const { return this->shaderProgram; }
  GLhandleARB getVertexS() const { return this->vertexShader; }
  GLhandleARB getFragmentS() const { return this->fragmentShader; }

  void debug() const;

  static void printError(GLhandleARB program);


 private:
   std::string            fragmentShaderFile;
   std::string            vertexShaderFile;

   GLhandleARB            shaderProgram;

   GLhandleARB            vertexShader;
   GLhandleARB            fragmentShader;

   static Shader*         storedShader;
};

#endif /* _SHADER_H */