/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

### File Specific:
   main-programmer: hdavid, amaechler
*/

#include "volfog_effect.h"

#include "util/loading/load_param.h"
#include "util/loading/factory.h"

#include "glincl.h"
#include "shell_command.h"

using namespace std;

CREATE_FACTORY(VolFogEffect, CL_VOLFOG_EFFECT);

VolFogEffect::VolFogEffect(const TiXmlElement* root)
{
  this->setClassID(CL_VOLFOG_EFFECT, "VolFogEffect");

  if (root != NULL)
    this->loadParams(root);

  // Initialize Effect
  this->init();

  // Activate Effect
  this->activate();
}


VolFogEffect::~VolFogEffect()
{
  this->deactivate();
}

void VolFogEffect::loadParams(const TiXmlElement* root)
{
  WeatherEffect::loadParams(root);
}

bool VolFogEffect::init()
{
  PRINTF(0)("Initalize VolFogEffect\n");
  
  if (glewInit() == GLEW_OK)
    PRINTF(0)("glewInit OK\n");
  else
    PRINTF(0)("glewInit failed\n");

  // Set fog color
  float fogColor[4] = {0.2, 0.2, 0.2, 1.0};

  /* set up fog params */	
  glEnable(GL_FOG);						// Enable Fog
  glFogi(GL_FOG_MODE, GL_LINEAR);				// Fog Fade Is Linear
  glFogfv(GL_FOG_COLOR, fogColor);				// Set The Fog Color
  glFogf(GL_FOG_START, 0.0f);					// Set The Fog Start
  glFogf(GL_FOG_END, 10.0f);					// Set The Fog End
  glFogi(GL_FOG_COORDINATE_SOURCE_EXT, GL_FOG_COORDINATE_EXT);	// Set The Fog based on vertice coordinates
  // glHint(GL_FOG_HINT, GL_NICEST);				// Per-Pixel Fog Calculation

  // glClearColor(0.0, 0.0, 0.0, 1.0);  //sets bg color?!

  /* enable texturing & set texturing function */
  // glEnable(GL_TEXTURE_2D);
  // glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

  if (glewGetExtension("GL_EXT_fog_coord"))
  {
    PRINTF(0)("GL_EXT_fog_coord extension found\n");
    return true;
  }
  else
  {
    PRINTF(0)("GL_EXT_fog_coord extension NOT found\n");
    return false;
  }
}


bool VolFogEffect::activate()
{
  PRINTF(0)("Activating VolFogEffect\n");
}

bool VolFogEffect::deactivate()
{
  PRINTF(0)("Deactivating VolFogEffect\n");
}


/**
 * draws the effect, if needed
 */
void VolFogEffect::draw() const
{
	//glPushAttrib(GL_ENABLE_BIT);
	
	/* clear all pixels in colour buffer */
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	//glEnable(GL_BLEND);
	//glBlendFunc(GL_SRC_ALPHA, GL_DST_ALPHA);

	//glLoadIdentity ();	// Reset The Modelview Matrix

	// glBindTexture(GL_TEXTURE_2D, 0);
	/* draw the panels */
	glBegin(GL_QUADS); // Floor
		glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f,0.0f);
		glFogCoordfEXT(0.0f);	glVertex3f(100.0f,0.0f,0.0f);
		glFogCoordfEXT(0.0f);	glVertex3f(100.0f,0.0f, 100.0f);
		glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f, 100.0f);
	glEnd();

	glBegin(GL_QUADS); // Roof
		glFogCoordfEXT(5.0f);	glVertex3f(0.0f, 100.0f,0.0f);
		glFogCoordfEXT(5.0f);	glVertex3f( 100.0f, 100.0f,0.0f);
		glFogCoordfEXT(5.0f);	glVertex3f( 100.0f, 100.0f, 100.0f);
		glFogCoordfEXT(5.0f);	glVertex3f(0.0f, 100.0f, 100.0f);
	glEnd();

	glBegin(GL_QUADS); // Back Wall
	 	glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f,0.0f);
		glFogCoordfEXT(0.0f);	glVertex3f( 100.0f,0.0f,0.0f);
		glFogCoordfEXT(5.0f);	glVertex3f( 100.0f, 100.0f,0.0f);
		glFogCoordfEXT(5.0f);	glVertex3f(0.0f, 100.0f,0.0f);
	glEnd();

	glBegin(GL_QUADS); // Front Wall
	 	glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f,100.0f);
		glFogCoordfEXT(0.0f);	glVertex3f( 100.0f,0.0f,100.0f);
		glFogCoordfEXT(50.0f);	glVertex3f( 100.0f, 100.0f,100.0f);
		glFogCoordfEXT(50.0f);	glVertex3f(0.0f, 100.0f,100.0f);
	glEnd();

	glBegin(GL_QUADS); // Right Wall
		glFogCoordfEXT(0.0f);	glVertex3f( 100.0f,0.0f, 100.0f);
		glFogCoordfEXT(5.0f);	glVertex3f( 100.0f, 100.0f, 100.0f);
		glFogCoordfEXT(5.0f);	glVertex3f( 100.0f, 100.0f,0.0f);
		glFogCoordfEXT(0.0f);	glVertex3f( 100.0f,0.0f,0.0f);
	glEnd();

	glBegin(GL_QUADS); // Left Wall
	 	glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f, 100.0f);
		glFogCoordfEXT(5.0f);	glVertex3f(0.0f, 100.0f, 100.0f);
		glFogCoordfEXT(5.0f);	glVertex3f(0.0f, 100.0f,0.0f);
		glFogCoordfEXT(0.0f);	glVertex3f(0.0f,0.0f,0.0f);
	glEnd();
	
	/* process all buffered OpenGL commands */
	glFlush();

	// glPopAttrib();
}


/**
 * ticks the effect if there is any time dependancy
 */
void VolFogEffect::tick(float dt)	
{
}