//-----------------------------------------------------------------------------------
//
//   Torque Network Library - ZAP example multiplayer vector graphics space game
//   Copyright (C) 2004 GarageGames.com, Inc.
//   For more information see http://www.opentnl.org
//
//   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 of the License, or
//   (at your option) any later version.
//
//   For use in products that are not compatible with the terms of the GNU
//   General Public License, alternative licensing options are available
//   from GarageGames.com.
//
//   This program is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU General Public License for more details.
//
//   You should have received a copy of the GNU General Public License
//   along with this program; if not, write to the Free Software
//   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
//------------------------------------------------------------------------------------

#include "sparkManager.h"
#include "glutInclude.h"
#include "teleporter.h"
#include "gameObjectRender.h"

using namespace TNL;

namespace Zap
{

namespace FXManager
{

struct Spark
{
   Point pos;
   Color color;
   F32 alpha;
   F32 ttl;
   Point vel;
};

enum {
   MaxSparks = 8192,
};

U32 firstFreeIndex = 0;
U32 grabIndex      = MaxSparks/2;
Spark gSparks[MaxSparks];

void emitSpark(Point pos, Point vel, Color color, F32 ttl)
{
   Spark *s;

   if(firstFreeIndex >= MaxSparks)
   {
      s = gSparks + grabIndex;

      // Bump an arbitrary amount ahead to avoid noticable artifacts.
      grabIndex = (grabIndex + 100) % MaxSparks;
   }
   else
   {
      s = gSparks + firstFreeIndex;
      firstFreeIndex++;  
   }

   s->pos = pos;
   s->vel = vel;
   s->color = color;
   
   if(!ttl)
      s->ttl = 15 * Random::readF() * Random::readF();
   else
      s->ttl = ttl;
}

struct TeleporterEffect
{
   Point pos;
   S32 time;
   U32 type;
   TeleporterEffect *nextEffect;
};

TeleporterEffect *teleporterEffects = NULL;

void emitTeleportInEffect(Point pos, U32 type)
{
   TeleporterEffect *e = new TeleporterEffect;
   e->pos = pos;
   e->time = 0;
   e->type = type;
   e->nextEffect = teleporterEffects;
   teleporterEffects = e;
}

void tick( F32 dT )
{
   for(U32 i = 0; i < firstFreeIndex; )
   {
      Spark *theSpark = gSparks + i;
      if(theSpark->ttl <= dT)
      {
         firstFreeIndex--;
         *theSpark = gSparks[firstFreeIndex];
      }
      else
      {
      theSpark->ttl -= dT;
      theSpark->pos += theSpark->vel * dT;
      if(theSpark->ttl > 1)
         theSpark->alpha = 1;
      else
         theSpark->alpha = theSpark->ttl;
         i++;
      }
   }
   for(TeleporterEffect **walk = &teleporterEffects; *walk; )
   {
      TeleporterEffect *temp = *walk;
      temp->time += dT * 1000;
      if(temp->time > Teleporter::TeleportInExpandTime)
      {
         *walk = temp->nextEffect;
         delete temp;
      }
      else
         walk = &(temp->nextEffect);
   }
}

void render(U32 renderPass)
{
   // the teleporter effects should render under the ships and such
   if(renderPass == 0)
   {
      for(TeleporterEffect *walk = teleporterEffects; walk; walk = walk->nextEffect)
      {
         F32 radius = walk->time / F32(Teleporter::TeleportInExpandTime);
         F32 alpha = 1.0;
         if(radius > 0.5)
            alpha = (1 - radius) / 0.5;
         renderTeleporter(walk->pos, walk->type, false, Teleporter::TeleportInExpandTime - walk->time, radius, Teleporter::TeleportInRadius, alpha);
      }
   }
   else if(renderPass == 1)
   {
      glPointSize( 2.0f );
      glEnable(GL_BLEND);
      
      glEnableClientState(GL_COLOR_ARRAY);
      glEnableClientState(GL_VERTEX_ARRAY);

      glVertexPointer(2, GL_FLOAT, sizeof(Spark), &gSparks[0].pos);
      glColorPointer(4, GL_FLOAT , sizeof(Spark), &gSparks[0].color);
      
      glDrawArrays(GL_POINTS, 0, firstFreeIndex);

      glDisableClientState(GL_COLOR_ARRAY);
      glDisableClientState(GL_VERTEX_ARRAY);

      glDisable(GL_BLEND);
   }
}

void emitExplosion(Point pos, F32 size, Color *colorArray, U32 numColors)
{
   for(U32 i = 0; i < (250.0 * size); i++)
   {

      F32 th = Random::readF() * 2 * 3.14;
      F32 f = (Random::readF() * 2 - 1) * 400 * size;
      U32 colorIndex = Random::readI() % numColors;

      emitSpark(pos, Point(cos(th)*f, sin(th)*f), colorArray[colorIndex], Random::readF()*size + 2*size);
   }
}

void emitBurst(Point pos, Point scale, Color color1, Color color2)
{
   F32 size = 1;

   for(U32 i = 0; i < (250.0 * size); i++)
   {

      F32 th = Random::readF() * 2 * 3.14;
      F32 f = (Random::readF() * 0.1 + 0.9) * 200 * size;
      F32 t = Random::readF();

      Color r;

      r.interp(t, color1, color2);

      emitSpark(
         pos + Point(cos(th)*scale.x, sin(th)*scale.y),
         Point(cos(th)*scale.x*f, sin(th)*scale.y*f),
         r,
         Random::readF() * scale.len() * 3 + scale.len()
      );
   }
}

};

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

FXTrail::FXTrail(U32 dropFrequency, U32 len)
{
   mDropFreq = dropFrequency;
   mLength   = len;
   registerTrail();
}

FXTrail::~FXTrail()
{
   unregisterTrail();
}

void FXTrail::update(Point pos, bool boosted, bool invisible)
{
   if(mNodes.size() < mLength)
   {
      TrailNode t;
      t.pos = pos;
      t.ttl = mDropFreq;
      t.boosted = boosted;
      t.invisible = invisible;

      mNodes.push_front(t);
   }
   else
   {
      mNodes[0].pos = pos;
      if(invisible)
         mNodes[0].invisible = true;      
      else if(boosted)
         mNodes[0].boosted = true;
   }
}

void FXTrail::tick(U32 dT)
{
   if(mNodes.size() == 0)
      return;

   mNodes.last().ttl -= dT;
   if(mNodes.last().ttl <= 0)
      mNodes.pop_back();
}

void FXTrail::render()
{
   glBegin(GL_LINE_STRIP);

   for(S32 i=0; i<mNodes.size(); i++)
   {
      F32 t = ((F32)i/(F32)mNodes.size());

      if(mNodes[i].invisible)
         glColor4f(0.f,0.f,0.f,0.f);
      else if(mNodes[i].boosted)
         glColor4f(1.f - t, 1.f - t, 0.f, 1.f-t);
      else
         glColor4f(1.f - 2*t, 1.f - 2*t, 1.f, 0.7f-0.7*t);

      glVertex2f(mNodes[i].pos.x, mNodes[i].pos.y);
   }

   glEnd();
}

void FXTrail::reset()
{
   mNodes.clear();
}

Point FXTrail::getLastPos()
{
   if(mNodes.size())
   {
      return mNodes[0].pos;
   }
   else
      return Point(0,0);
}

FXTrail * FXTrail::mHead = NULL;

void FXTrail::registerTrail()
{
  FXTrail *n = mHead;
  mHead = this;
  mNext = n;
}

void FXTrail::unregisterTrail()
{
   // Find ourselves in the list (lame O(n) solution)
   FXTrail *w = mHead, *p = NULL;
   while(w)
   {
      if(w == this)
      {
         if(p)
         {
            p->mNext = w->mNext;
         }
         else
         {
            mHead = w->mNext;
         }
      }
      p = w;
      w = w->mNext;
   }
}

void FXTrail::renderTrails()
{
   glEnable(GL_BLEND);

   FXTrail *w = mHead;
   while(w)
   {
      w->render();
      w = w->mNext;
   }

   glDisable(GL_BLEND);
}

};