/********************************************************************
aGLSL.cpp
Version: 0.9.4 - For OpenGL 2.0

License: BSD
(c) 2003-2005 by Martin Christen. All Rights reserved.
*********************************************************************/

#include "glsl.h"

using namespace std;

//-----------------------------------------------------------------------------
// Error, Warning and Info Strings
char* aGLSLStrings[] = {
        "[e00] GLSL is not available!",
        "[e01] Not a valid program object!",
        "[e02] Not a valid object!",
        "[e03] Out of memory!",
        "[e04] Unknown compiler error!",
        "[e05] Linker log is not available!",
        "[e06] Compiler log is not available!",
        "[Empty]"
        };
//-----------------------------------------------------------------------------      
 
// GL ERROR CHECK
int CheckGLError(char *file, int line)
{
	//return 0;
	GLenum glErr,glErr2;
	int retCode = 0;

	glErr = glErr2 = glGetError();
	while (glErr != GL_NO_ERROR) 
	{
	   char* str1 = (char*)gluErrorString(glErr);
	   if (str1)
			cout << "GL Error #" << glErr << "(" << str1 << ") " << " in File " << file << " at line: " << line << endl;
	   else
			cout << "GL Error #" << glErr << " in File " << file << " at line: " << line << endl;
		retCode = 1;
		glErr = glGetError();
	}
	if (glErr2 != GL_NO_ERROR) while(1)Sleep(100);;

	return 0;
}


//----------------------------------------------------------------------------- 

// ************************************************************************
// Implementation of glShader class
// ************************************************************************
 
glShader::glShader()
{
	ProgramObject = 0;
	linker_log = 0;
	is_linked = false; 
	enabled = false;
	_mM = false;
	_noshader = true;

	ProgramObject = glCreateProgram();
}

//----------------------------------------------------------------------------- 

glShader::~glShader()
{
	if (linker_log!=0) free(linker_log);

	for (unsigned int i=0;i<ShaderList.size();i++)
	{
		glDetachShader(ProgramObject, ShaderList[i]->ShaderObject);
		CHECK_GL_ERROR(); // if you get an error here, you deleted the Program object first and then
					   // the ShaderObject! Always delete ShaderObjects last!
		if (_mM) delete ShaderList[i]; 
	}
	glDeleteShader(ProgramObject);
	CHECK_GL_ERROR();
}

//----------------------------------------------------------------------------- 

void glShader::addShader(glShaderObject* ShaderProgram)
{
   if (ShaderProgram==0) return;
   if (!ShaderProgram->is_compiled)
   {
        cout << "**warning** please compile program before adding object! trying to compile now...\n";
        if (!ShaderProgram->compile())
        {
            cout << "...compile ERROR!\n";
            return;
        }
        else
        {   
            cout << "...ok!\n";
        }
   }
   ShaderList.push_back(ShaderProgram); 
}

//----------------------------------------------------------------------------- 

bool glShader::link(void)
{
	unsigned int i;

    if (is_linked)  // already linked, detach everything first
    {
       cout << "**warning** Object is already linked, trying to link again" << endl;
       for (i=0;i<ShaderList.size();i++)
       {
            glDetachShader(ProgramObject, ShaderList[i]->ShaderObject);
            CHECK_GL_ERROR();
       }
    }
    
    for (i=0;i<ShaderList.size();i++)
    {
        glAttachShader(ProgramObject, ShaderList[i]->ShaderObject);
        CHECK_GL_ERROR();
        //cout << "attaching ProgramObj [" << i << "] @ 0x" << hex << ShaderList[i]->ProgramObject << " in ShaderObj @ 0x"  << ShaderObject << endl;
    }
    
    int linked;
    glLinkProgram(ProgramObject);
    CHECK_GL_ERROR();
    glGetProgramiv(ProgramObject, GL_LINK_STATUS, &linked);
    CHECK_GL_ERROR();

    if (linked)
    {
        is_linked = true;
        return true;
    }
    else
    {
        cout << "**linker error**\n";
    }
return false;
}

//----------------------------------------------------------------------------- 
// Compiler Log: Ausgabe der Compiler Meldungen in String

char* glShader::getLinkerLog(void)
{    
 int blen = 0;	
 int slen = 0;	

 if (ProgramObject==0) return aGLSLStrings[2];
 glGetProgramiv(ProgramObject, GL_INFO_LOG_LENGTH , &blen);
 CHECK_GL_ERROR();

 if (blen > 1)
 {
    if (linker_log!=0) 
    {   
        free(linker_log);
        linker_log =0;
    }
    if ((linker_log = (GLcharARB*)malloc(blen)) == NULL) 
     {
        printf("ERROR: Could not allocate compiler_log buffer\n");
        return aGLSLStrings[3];
    }

    glGetProgramInfoLog(ProgramObject, blen, &slen, linker_log);
    CHECK_GL_ERROR();
 }
 if (linker_log!=0)
    return (char*) linker_log;    
 else
    return aGLSLStrings[5];
   
 return aGLSLStrings[4];
}

void glShader::begin(void)
{
	enabled = true;

	if (ProgramObject == 0) return;
	if (!_noshader) return;

    if (is_linked)
    {
        glUseProgram(ProgramObject);
        CHECK_GL_ERROR();
    }
}

//----------------------------------------------------------------------------- 

void glShader::end(void)
{
	enabled = false;

	if (!_noshader) return;
    glUseProgram(0);
    CHECK_GL_ERROR();
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform1f(char* varname, GLfloat v0)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform1f(loc, v0);
    
    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform2f(char* varname, GLfloat v0, GLfloat v1)
{
   if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform2f(loc, v0, v1);
    
    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform3f(char* varname, GLfloat v0, GLfloat v1, GLfloat v2)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform3f(loc, v0, v1, v2);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform4f(char* varname, GLfloat v0, GLfloat v1, GLfloat v2, GLfloat v3)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform4f(loc, v0, v1, v2, v3);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform1i(char* varname, GLint v0)
{ 
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform1i(loc, v0);
    
    return true;
}
bool glShader::setUniform2i(char* varname, GLint v0, GLint v1)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform2i(loc, v0, v1);


    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform3i(char* varname, GLint v0, GLint v1, GLint v2)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform3i(loc, v0, v1, v2);

    return true;
}
bool glShader::setUniform4i(char* varname, GLint v0, GLint v1, GLint v2, GLint v3)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform4i(loc, v0, v1, v2, v3);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform1fv(char* varname, GLsizei count, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform1fv(loc, count, value);

    return true;
}
bool glShader::setUniform2fv(char* varname, GLsizei count, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform2fv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform3fv(char* varname, GLsizei count, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform3fv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform4fv(char* varname, GLsizei count, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform4fv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform1iv(char* varname, GLsizei count, GLint *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform1iv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform2iv(char* varname, GLsizei count, GLint *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform2iv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform3iv(char* varname, GLsizei count, GLint *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform3iv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniform4iv(char* varname, GLsizei count, GLint *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniform4iv(loc, count, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniformMatrix2fv(char* varname, GLsizei count, GLboolean transpose, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniformMatrix2fv(loc, count, transpose, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniformMatrix3fv(char* varname, GLsizei count, GLboolean transpose, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniformMatrix3fv(loc, count, transpose, value);

    return true;
}

//----------------------------------------------------------------------------- 

bool glShader::setUniformMatrix4fv(char* varname, GLsizei count, GLboolean transpose, GLfloat *value)
{
    if (!_noshader) return true;
    
    GLint loc = GetUniLoc(varname);
    if (loc==-1) return false;  // can't find variable
    
    glUniformMatrix4fv(loc, count, transpose, value);
	CHECK_GL_ERROR();

    return true;
}

//----------------------------------------------------------------------------- 

GLint glShader::GetUniLoc(const GLcharARB *name)
{
	GLint loc;

	loc = glGetUniformLocation(ProgramObject, name);
	if (loc == -1) 
	{
        cout << "Error: can't find uniform variable \"" << name << "\"\n";
	}
    CHECK_GL_ERROR();
	return loc;
}

//----------------------------------------------------------------------------- 

void glShader::GetUniformfv(char* name, GLfloat* values)
{
    GLint loc;

	loc = glGetUniformLocation(ProgramObject, name);
	if (loc == -1) 
	{
        cout << "Error: can't find uniform variable \"" << name << "\"\n";
	}
	glGetUniformfv(ProgramObject, loc, values);
	
}

//----------------------------------------------------------------------------- 

void glShader::GetUniformiv(char* name, GLint* values)
{
    GLint loc;

	loc = glGetUniformLocation(ProgramObject, name);
	if (loc == -1) 
	{
        cout << "Error: can't find uniform variable \"" << name << "\"\n";
	}
	
	glGetUniformiv(ProgramObject, loc, values);

}

bool glShader::setVertexAttrib1f(GLuint index, GLfloat v0)
{
   if (!_noshader) return true;

   glVertexAttrib1f(index, v0);

   return true;
}

bool glShader::setVertexAttrib2f(GLuint index, GLfloat v0, GLfloat v1)
{
   if (!_noshader) return true;

   glVertexAttrib2f(index, v0, v1);
   
   return true;
}

bool glShader::setVertexAttrib3f(GLuint index, GLfloat v0, GLfloat v1, GLfloat v2)
{
   if (!_noshader) return true;
   
    glVertexAttrib3f(index, v0, v1, v2);
    
    return true;
}

bool glShader::setVertexAttrib4f(GLuint index, GLfloat v0, GLfloat v1, GLfloat v2, GLfloat v3)
{
   if (!_noshader) return true;
   
   glVertexAttrib4f(index, v0, v1, v2, v3);
   
   return true;
}

// ************************************************************************
// Shader Program : Manage Shader Programs (Vertex/Fragment)
// ************************************************************************


glShaderObject::glShaderObject(int type)
{
	program_type = type;
	program_str = "empty";

	if (type==GL_VERTEX_SHADER) program_str=string("GL_VERTEX_SHADER");
	if (type==GL_TESS_CONTROL_SHADER) program_str=string("GL_TESS_CONTROL_SHADER");
	if (type==GL_TESS_EVALUATION_SHADER) program_str=string("GL_TESS_EVALUATION_SHADER");
	if (type==GL_GEOMETRY_SHADER) program_str=string("GL_GEOMETRY_SHADER");
	if (type==GL_FRAGMENT_SHADER) program_str=string("GL_FRAGMENT_SHADER");

	//GL_VERTEX_SHADER
	//GL_TESS_CONTROL_SHADER
	//GL_TESS_EVALUATION_SHADER
	//GL_GEOMETRY_SHADER
	//GL_FRAGMENT_SHADER

	ShaderObject = glCreateShaderObjectARB(type);
	
	CHECK_GL_ERROR();

    compiler_log = 0;
    is_compiled = false;
    ShaderObject = 0;
    ShaderSource = 0;
    _memalloc = false;
   
}

//----------------------------------------------------------------------------- 

glShaderObject::~glShaderObject()
{
   if (compiler_log!=0) free(compiler_log);
   if (ShaderSource!=0)   
   {
        if (_memalloc)
            delete[] ShaderSource;  // free ASCII Source
   }
   
   if (is_compiled)
   { 
        glDeleteObjectARB(ShaderObject);
        CHECK_GL_ERROR();
   }
}

//----------------------------------------------------------------------------- 
unsigned long getFileLength(ifstream& file)
{
    if(!file.good()) return 0;
    
    unsigned long pos=file.tellg();
    file.seekg(0,ios::end);
    unsigned long len = file.tellg();
    file.seekg(ios::beg);
    
    return len;
}


//----------------------------------------------------------------------------- 

int glShaderObject::load(char* filename)
{
	printf("Loading Shader %s ...\n",filename);

    ifstream file;
    file.open(filename, ios::in);
    if(!file) 
	{
		printf("File not found :%s ...\n",filename);
		while(1);
	};
   
    unsigned long len = getFileLength(file);
    file.close();
    
    if (len==0) return -2;   // "Empty File" 
    
    if (ShaderSource!=0)    // there is already a source loaded, free it!
    {
        if (_memalloc)
        delete[] ShaderSource;
    }
    
    ShaderSource = (GLubyte*) new char[len+1];
    if (ShaderSource == 0) return -3;   // can't reserve memory
    _memalloc = true;
    
	printf("Loading Shader %s ...\n",filename);
    ShaderSource[len] = 0;  // len isn't always strlen cause some characters are stripped in ascii read...
                            // it is important to 0-terminate the real length later, len is just max possible value...
   
	FILE* fn=fopen(filename, "rb");
	fseek(fn,0,SEEK_SET);
	int numbytes=(int)fread(ShaderSource, 1 , len, fn);
	fclose(fn);

	printf("Read %d of %d bytes\n",numbytes,len);
	//printf("Program: %s\n",ShaderSource);
      
return 0;
}

//----------------------------------------------------------------------------- 

void glShaderObject::loadFromMemory(const char* program)
{
    if (ShaderSource!=0)    // there is already a source loaded, free it!
    {
        if (_memalloc)
        delete[] ShaderSource;
    }
   _memalloc = false;
   ShaderSource = (GLubyte*) program;
      
}


// ----------------------------------------------------------------------------
// Compiler Log: Ausgabe der Compiler Meldungen in String

char* glShaderObject::getCompilerLog(void)
{    
 int blen = 0;	
 int slen = 0;	

 if (ShaderObject==0) return aGLSLStrings[1]; // not a valid program object

 glGetShaderiv(ShaderObject, GL_INFO_LOG_LENGTH , &blen);
 CHECK_GL_ERROR();

 if (blen > 1)
 {
    if (compiler_log!=0) 
    {   
        free(compiler_log);
        compiler_log =0;
    }
    if ((compiler_log = (GLcharARB*)malloc(blen)) == NULL) 
     {
        printf("ERROR: Could not allocate compiler_log buffer\n");
        return aGLSLStrings[3];
    }

     glGetInfoLogARB(ShaderObject, blen, &slen, compiler_log);
     CHECK_GL_ERROR();
     //cout << "compiler_log: \n", compiler_log);     
 }
 if (compiler_log!=0)
    return (char*) compiler_log;
 else
   return aGLSLStrings[6];       

 return aGLSLStrings[4];
}

// ----------------------------------------------------------------------------

bool glShaderObject::compile(void)
{
is_compiled = false;

int compiled = 0;

  if (ShaderSource==0) return false;

  GLint	length = (GLint) strlen((const char*)ShaderSource);
  CHECK_GL_ERROR();
  glShaderSource(ShaderObject, 1, (const GLchar **)&ShaderSource, &length);
  CHECK_GL_ERROR();

  glCompileShader(ShaderObject); 
  CHECK_GL_ERROR();
  glGetObjectParameterivARB(ShaderObject, GL_COMPILE_STATUS, &compiled);
  CHECK_GL_ERROR();

  if (compiled) is_compiled=true;
 
return is_compiled;
}

// ----------------------------------------------------------------------------

GLint glShaderObject::getAttribLocation(char* attribName)
{
   return glGetAttribLocationARB(ShaderObject, attribName);
}

// ----------------------------------------------------------------------------
// ShaderManager: Easy use of (multiple) Shaders

glShaderManager::glShaderManager()
{

}

glShaderManager::~glShaderManager()
{
   // free objects
   vector<glShader*>::iterator  i=_shaderObjectList.begin();
   while (i!=_shaderObjectList.end()) 
   {
        //glShader* o = *i;
        i=_shaderObjectList.erase(i);
        //delete o;
   }
}

// ----------------------------------------------------------------------------
glShader* glShaderManager::loadfromFile(char* vertexFile, char* fragmentFile, char* tesscontrolFile, char* tessevalFile, char* geometryFile)
{
  glShader* o = new glShader();
  
  glShaderObject* shaders[5];
  shaders[0]= new glShaderObject(GL_VERTEX_SHADER);
  shaders[1]= new glShaderObject(GL_TESS_CONTROL_SHADER);
  shaders[2]= new glShaderObject(GL_TESS_EVALUATION_SHADER);
  shaders[3]= new glShaderObject(GL_GEOMETRY_SHADER);
  shaders[4]= new glShaderObject(GL_FRAGMENT_SHADER);

  char* filename[5];
  filename[0]=vertexFile;
  filename[1]=tesscontrolFile;
  filename[2]=tessevalFile;
  filename[3]=geometryFile;
  filename[4]=fragmentFile;

  for (int i=0;i<5;i++)
  {
	  if(filename[i]!=0)
	  {
		  printf("Loading: %s\n",filename[i]);
		  // Load program
		  if (shaders[i]->load(filename[i]) != 0) 
		  {
			cout << "error: can't load " << filename[i] << endl;
			while(1);
		  }
		  printf("Compiling: %s\n",filename[i]);

		  // Compile vertex program
		  if (!shaders[i]->compile())
		  {
			  cout << "***COMPILER ERROR (" << shaders[i]->program_str.c_str() << "):\n";
			  cout << shaders[i]->getCompilerLog() << endl;
			  while(1);
		  }

		  cout << "***GLSL Compiler Log (" << shaders[i]->program_str.c_str() << "):\n";
		  cout << shaders[i]->getCompilerLog() << "\n";

		  // Add to object    
		  o->addShader(shaders[i]);
	  }
  }
  
  // link 
  if (!o->link())
  {
     cout << "**LINKER ERROR\n";
     cout << o->getLinkerLog() << endl;
	 while(1);
  }
  cout << "***GLSL Linker Log:\n";
  cout << o->getLinkerLog() << endl;
  
  _shaderObjectList.push_back(o);
  o->manageMemory();

   return o;
}

// ----------------------------------------------------------------------------

glShader* glShaderManager::loadfromMemory(char* vertexMem, char* fragmentMem, char* tesscontrolMem, char* tessevalMem, char* geometryMem)
{
  glShader* o = new glShader();
  
  glShaderObject* shaders[5];
  shaders[0]= new glShaderObject(GL_VERTEX_SHADER);
  shaders[1]= new glShaderObject(GL_TESS_CONTROL_SHADER);
  shaders[2]= new glShaderObject(GL_TESS_EVALUATION_SHADER);
  shaders[3]= new glShaderObject(GL_GEOMETRY_SHADER);
  shaders[4]= new glShaderObject(GL_FRAGMENT_SHADER);

  char* mem[5];
  mem[0]=vertexMem;
  mem[1]=tesscontrolMem;
  mem[2]=tessevalMem;
  mem[3]=geometryMem;
  mem[4]=fragmentMem;

  for (int i=0;i<5;i++)
  {
	  if(mem[i]!=0)
	  {
		  // Load program
		  shaders[i]->loadFromMemory(mem[i]);

		  // Compile vertex program
		  if (!shaders[i]->compile())
		  {
			  cout << "***COMPILER ERROR (" << shaders[i]->program_str.c_str() << "):\n";
			  cout << shaders[i]->getCompilerLog() << endl;
			  while(1);
		  }

		  cout << "***GLSL Compiler Log (" << shaders[i]->program_str.c_str() << "):\n";
		  cout << shaders[i]->getCompilerLog() << "\n";

		  // Add to object    
		  o->addShader(shaders[i]);
	  }
  }
  
  // link 
  if (!o->link())
  {
     cout << "**LINKER ERROR\n";
     cout << o->getLinkerLog() << endl;
	 while(1);
  }
  cout << "***GLSL Linker Log:\n";
  cout << o->getLinkerLog() << endl;
  
  _shaderObjectList.push_back(o);
  o->manageMemory();

   return o;
}

// ----------------------------------------------------------------------------

 bool  glShaderManager::free(glShader* o)
 {
   vector<glShader*>::iterator  i=_shaderObjectList.begin();
   while (i!=_shaderObjectList.end()) 
   {
        if ((*i)==o)
        {
            _shaderObjectList.erase(i);
            delete o;
            return true;
        }
        i++;
   }   
   return false;
 }