source: orxonox.OLD/branches/atmospheric_engine/src/lib/graphics/effects/volfog_effect.cc @ 7523

/*
   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"

#define NUM_PANELS 6    /* number of panels in scene */

typedef struct
{
        float x;
        float y;
        float z;
} world_vector;         /* vertex data */

world_vector vertices[NUM_PANELS*4] = {
        {-50.0, -60.0, 0.0},{50.0, -60.0, 0.0},{50.0, 0.0, 0.0},{-50.0, 0.0, 0.0},
        {-50.0, -60.0, 60.0},{-50.0, -60.0, 0.0},{-50.0, 0.0, 0.0},{-50.0, 0.0, 60.0},
        {-50.0, -60.0, 20.0},{-50.0, -60.0, 60.0},{-50.0, 0.0, 60.0},{-50.0, 0.0, 20.0},
        {50.0, -60.0, 0.0},{50.0, -60.0, 60.0},{50.0, 0.0, 60.0},{50.0, 0.0, 0.0},
        {50.0, -60.0, 60.0},{50.0, -60.0, 20.0},{50.0, 0.0, 20.0},{50.0, 0.0, 60.0},
        {-50.0, -60.0, 60.0},{50.0, -60.0, 60.0},{50.0, -60.0, 0.0},{-50.0, -60.0, 0.0}
};

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);
  
  this->activate();
}


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


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

  LoadParam(root, "fog-altitude", this, VolFogEffect, setFogAltitude);
  LoadParam(root, "fog-color", this, VolFogEffect, startFogColor);
}


bool VolFogEffect::init()
{
  PRINTF(0)("Initalize VolFogEffect\n");
};



bool VolFogEffect::activate()
{
  PRINTF(0)( "Enabling Volumetric Fog Effect, altitude: %i, color %f, %f, %f\n", this->fogAltitude, this->colorVector.x, this->colorVector.y, this->colorVector.z);

}

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


void VolFogEffect::setFogColor(int v)
{
        float z;        /* distance of vertex from edge of fog volume */
        float f;        /* fog factor */

        z = 0.0 - vertices[v].y;
        f = (60.0 - z) / (60.0 - 0.0);  /* linear fog: f = (end - z)/(end - start) */
        glColor4f(this->colorVector.x, this->colorVector.y, this->colorVector.z, f);
}

// int v;               /* store of next vertex ref */

/**
 * draws the effect, if needed
 */
void VolFogEffect::draw() const
{
        int v;          /* store of next vertex ref */
        int ref;

        PRINTF(0)("DRAW VolFogEffect\n");

        for (ref=0; ref<NUM_PANELS; ref++) {

                /* disable writes to z buffer (if fog area) */
                glDepthMask(GL_FALSE);
        
                /* restore z buffer writes, set blend params & disable texturing */

                glDepthMask(GL_TRUE);
                glEnable(GL_BLEND);
                glBlendFunc(GL_ONE_MINUS_SRC_ALPHA, GL_SRC_ALPHA);
                glDisable(GL_TEXTURE_2D);

                /* draw the fog panel */

                v = ref * 4;
                glBegin(GL_QUADS);
                //this->setFogColor(v);
                glVertex3f(vertices[v].x, vertices[v].y, vertices[v].z); v++;
                //this->setFogColor(v);
                glVertex3f(vertices[v].x, vertices[v].y, vertices[v].z); v++;
                //this->setFogColor(v);
                glVertex3f(vertices[v].x, vertices[v].y, vertices[v].z); v++;
                //this->setFogColor(v);
                glVertex3f(vertices[v].x, vertices[v].y, vertices[v].z);
                glEnd();

                /* restore rendering state */

                glEnable(GL_TEXTURE_2D);
                glDisable(GL_BLEND);
        }

        
}



/**
 * ticks the effect if there is any time dependancy
 */
void VolFogEffect::tick(float dt)       
{
  PRINTF(0)("TICK VolFogEffect\n");
}