/* Emacs style mode select   -*- C++ -*-
 *-----------------------------------------------------------------------------
 *
 *
 *  PrBoom a Doom port merged with LxDoom and LSDLDoom
 *  based on BOOM, a modified and improved DOOM engine
 *  Copyright (C) 1999 by
 *  id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
 *  Copyright (C) 1999-2000 by
 *  Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
 *
 *  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.
 *
 *  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.
 *
 * DESCRIPTION:
 *  Action routines for lighting thinkers
 *  Spawn sector based lighting effects.
 *  Handle lighting linedef types
 *
 *-----------------------------------------------------------------------------*/

#include "doomstat.h" //jff 5/18/98
#include "doomdef.h"
#include "m_random.h"
#include "r_main.h"
#include "p_spec.h"
#include "p_tick.h"

//////////////////////////////////////////////////////////
//
// Lighting action routines, called once per tick
//
//////////////////////////////////////////////////////////

//
// T_FireFlicker()
//
// Firelight flicker action routine, called once per tick
//
// Passed a fireflicker_t structure containing light levels and timing
// Returns nothing
//
void T_FireFlicker (fireflicker_t* flick)
{
   int amount;

   if (--flick->count)
      return;

   amount = (P_Random(pr_lights)&3)*16;

   if (flick->sector->lightlevel - amount < flick->minlight)
      flick->sector->lightlevel = flick->minlight;
   else
      flick->sector->lightlevel = flick->maxlight - amount;

   flick->count = 4;
}

//
// T_LightFlash()
//
// Broken light flashing action routine, called once per tick
//
// Passed a lightflash_t structure containing light levels and timing
// Returns nothing
//
void T_LightFlash (lightflash_t* flash)
{
   if (--flash->count)
      return;

   if (flash->sector->lightlevel == flash->maxlight)
   {
      flash-> sector->lightlevel = flash->minlight;
      flash->count = (P_Random(pr_lights)&flash->mintime)+1;
   }
   else
   {
      flash-> sector->lightlevel = flash->maxlight;
      flash->count = (P_Random(pr_lights)&flash->maxtime)+1;
   }

}

//
// T_StrobeFlash()
//
// Strobe light flashing action routine, called once per tick
//
// Passed a strobe_t structure containing light levels and timing
// Returns nothing
//
void T_StrobeFlash (strobe_t*   flash)
{
   if (--flash->count)
      return;

   if (flash->sector->lightlevel == flash->minlight)
   {
      flash-> sector->lightlevel = flash->maxlight;
      flash->count = flash->brighttime;
   }
   else
   {
      flash-> sector->lightlevel = flash->minlight;
      flash->count =flash->darktime;
   }
}

//
// T_Glow()
//
// Glowing light action routine, called once per tick
//
// Passed a glow_t structure containing light levels and timing
// Returns nothing
//

void T_Glow(glow_t* g)
{
   switch(g->direction)
   {
   case -1:
      // light dims
      g->sector->lightlevel -= GLOWSPEED;
      if (g->sector->lightlevel <= g->minlight)
      {
         g->sector->lightlevel += GLOWSPEED;
         g->direction = 1;
      }
      break;

   case 1:
      // light brightens
      g->sector->lightlevel += GLOWSPEED;
      if (g->sector->lightlevel >= g->maxlight)
      {
         g->sector->lightlevel -= GLOWSPEED;
         g->direction = -1;
      }
      break;
   }
}

//////////////////////////////////////////////////////////
//
// Sector lighting type spawners
//
// After the map has been loaded, each sector is scanned
// for specials that spawn thinkers
//
//////////////////////////////////////////////////////////

//
// P_SpawnFireFlicker()
//
// Spawns a fire flicker lighting thinker
//
// Passed the sector that spawned the thinker
// Returns nothing
//
void P_SpawnFireFlicker (sector_t*  sector)
{
   fireflicker_t*  flick;

   // Note that we are resetting sector attributes.
   // Nothing special about it during gameplay.
   sector->special &= ~31; //jff 3/14/98 clear non-generalized sector type

   flick = Z_Malloc ( sizeof(*flick), PU_LEVSPEC, 0);

   P_AddThinker (&flick->thinker);

   flick->thinker.function = T_FireFlicker;
   flick->sector = sector;
   flick->maxlight = sector->lightlevel;
   flick->minlight = P_FindMinSurroundingLight(sector,sector->lightlevel)+16;
   flick->count = 4;
}

//
// P_SpawnLightFlash()
//
// Spawns a broken light flash lighting thinker
//
// Passed the sector that spawned the thinker
// Returns nothing
//
void P_SpawnLightFlash (sector_t* sector)
{
   lightflash_t* flash;

   // nothing special about it during gameplay
   sector->special &= ~31; //jff 3/14/98 clear non-generalized sector type

   flash = Z_Malloc ( sizeof(*flash), PU_LEVSPEC, 0);

   P_AddThinker (&flash->thinker);

   flash->thinker.function = T_LightFlash;
   flash->sector = sector;
   flash->maxlight = sector->lightlevel;

   flash->minlight = P_FindMinSurroundingLight(sector,sector->lightlevel);
   flash->maxtime = 64;
   flash->mintime = 7;
   flash->count = (P_Random(pr_lights)&flash->maxtime)+1;
}

//
// P_SpawnStrobeFlash
//
// Spawns a blinking light thinker
//
// Passed the sector that spawned the thinker, speed of blinking
// and whether blinking is to by syncrhonous with other sectors
//
// Returns nothing
//
void P_SpawnStrobeFlash
( sector_t* sector,
  int   fastOrSlow,
  int   inSync )
{
   strobe_t* flash;

   flash = Z_Malloc ( sizeof(*flash), PU_LEVSPEC, 0);

   P_AddThinker (&flash->thinker);

   flash->sector = sector;
   flash->darktime = fastOrSlow;
   flash->brighttime = STROBEBRIGHT;
   flash->thinker.function = T_StrobeFlash;
   flash->maxlight = sector->lightlevel;
   flash->minlight = P_FindMinSurroundingLight(sector, sector->lightlevel);

   if (flash->minlight == flash->maxlight)
      flash->minlight = 0;

   // nothing special about it during gameplay
   sector->special &= ~31; //jff 3/14/98 clear non-generalized sector type

   if (!inSync)
      flash->count = (P_Random(pr_lights)&7)+1;
   else
      flash->count = 1;
}

//
// P_SpawnGlowingLight()
//
// Spawns a glowing light (smooth oscillation from min to max) thinker
//
// Passed the sector that spawned the thinker
// Returns nothing
//
void P_SpawnGlowingLight(sector_t*  sector)
{
   glow_t* g;

   g = Z_Malloc( sizeof(*g), PU_LEVSPEC, 0);

   P_AddThinker(&g->thinker);

   g->sector = sector;
   g->minlight = P_FindMinSurroundingLight(sector,sector->lightlevel);
   g->maxlight = sector->lightlevel;
   g->thinker.function = T_Glow;
   g->direction = -1;

   sector->special &= ~31; //jff 3/14/98 clear non-generalized sector type
}

//////////////////////////////////////////////////////////
//
// Linedef lighting function handlers
//
//////////////////////////////////////////////////////////

//
// EV_StartLightStrobing()
//
// Start strobing lights (usually from a trigger)
//
// Passed the line that activated the strobing
// Returns true
//
// jff 2/12/98 added int return value, fixed return
//
int EV_StartLightStrobing(line_t* line)
{
   int   secnum;
   sector_t* sec;

   secnum = -1;
   // start lights strobing in all sectors tagged same as line
   while ((secnum = P_FindSectorFromLineTag(line,secnum)) >= 0)
   {
      sec = &sectors[secnum];
      // if already doing a lighting function, don't start a second
      if (P_SectorActive(lighting_special,sec)) //jff 2/22/98
         continue;

      P_SpawnStrobeFlash (sec,SLOWDARK, 0);
   }
   return 1;
}

//
// EV_TurnTagLightsOff()
//
// Turn line's tagged sector's lights to min adjacent neighbor level
//
// Passed the line that activated the lights being turned off
// Returns true
//
// jff 2/12/98 added int return value, fixed return
//
int EV_TurnTagLightsOff(line_t* line)
{
   int j;

   // search sectors for those with same tag as activating line

   // killough 10/98: replaced inefficient search with fast search
   for (j = -1; (j = P_FindSectorFromLineTag(line,j)) >= 0;)
   {
      sector_t *sector = sectors + j, *tsec;
      int i, min = sector->lightlevel;
      // find min neighbor light level
      for (i = 0;i < sector->linecount; i++)
         if ((tsec = getNextSector(sector->lines[i], sector)) &&
               tsec->lightlevel < min)
            min = tsec->lightlevel;
      sector->lightlevel = min;
   }
   return 1;
}

//
// EV_LightTurnOn()
//
// Turn sectors tagged to line lights on to specified or max neighbor level
//
// Passed the activating line, and a level to set the light to
// If level passed is 0, the maximum neighbor lighting is used
// Returns true
//
// jff 2/12/98 added int return value, fixed return
//
int EV_LightTurnOn(line_t *line, int bright)
{
   int i;

   // search all sectors for ones with same tag as activating line

   // killough 10/98: replace inefficient search with fast search
   for (i = -1; (i = P_FindSectorFromLineTag(line,i)) >= 0;)
   {
      sector_t *temp, *sector = sectors+i;
      int j, tbright = bright; //jff 5/17/98 search for maximum PER sector

      // bright = 0 means to search for highest light level surrounding sector

      if (!bright)
         for (j = 0;j < sector->linecount; j++)
            if ((temp = getNextSector(sector->lines[j],sector)) &&
                  temp->lightlevel > tbright)
               tbright = temp->lightlevel;

      sector->lightlevel = tbright;

      //jff 5/17/98 unless compatibility optioned
      //then maximum near ANY tagged sector
      if (comp[comp_model])
         bright = tbright;
   }
   return 1;
}

/* killough 10/98:
 *
 * EV_LightTurnOnPartway()
 *
 * Turn sectors tagged to line lights on to specified or max neighbor level
 *
 * Passed the activating line, and a light level fraction between 0 and 1.
 * Sets the light to min on 0, max on 1, and interpolates in-between.
 * Used for doors with gradual lighting effects.
 *
 * Returns true
 */

int EV_LightTurnOnPartway(line_t *line, fixed_t level)
{
   int i;

   if (level < 0)          // clip at extremes
      level = 0;
   if (level > FRACUNIT)
      level = FRACUNIT;

   // search all sectors for ones with same tag as activating line
   for (i = -1; (i = P_FindSectorFromLineTag(line,i)) >= 0;)
   {
      sector_t *temp, *sector = sectors+i;
      int j, bright = 0, min = sector->lightlevel;

      for (j = 0; j < sector->linecount; j++)
         if ((temp = getNextSector(sector->lines[j],sector)))
         {
            if (temp->lightlevel > bright)
               bright = temp->lightlevel;
            if (temp->lightlevel < min)
               min = temp->lightlevel;
         }

      sector->lightlevel =   // Set level in-between extremes
         (level * bright + (FRACUNIT-level) * min) >> FRACBITS;
   }
   return 1;
}