/****************************************************************************/
/*                                                                          */
/*    project    : CGF                  (c) 1999 William van der Sterren    */
/*                               parts  (c) 1998 id software                */
/*                                                                          */
/*      file     : cgf_sfx_glass.cpp  "special effects for glass entities"  */
/*      author(s): William van der Sterren                                  */
/*      version  : 0.5                                                      */
/*                                                                          */
/*      date (last revision):  Jun 12, 99                                   */
/*      date (creation)     :  Jun 04, 99                                   */
/*                                                                          */
/*                                                                          */
/*      revision history                                                    */
/*      -- date ---- | -- revision ---------------------- | -- revisor --   */
/*      Jun 12, 1999 | fixed knife slash breaks glass     | William         */
/*      Jun 08, 1999 | improved fragment limit            | William         */
/*                                                                          */
/******* http://www.botepidemic.com/aid/cgf for CGF for Action Quake2 *******/

#ifdef __cplusplus
  // VC++, for CGF
  #include <cmath> // prevent problems between C and STL
  extern "C"
  {
  #include "g_local.h"
  #include "cgf_sfx_glass.h"
  }
#else
  // C, for other AQ2 variants
  #include "g_local.h"
  #include "cgf_sfx_glass.h"
#endif


// cvar for breaking glass
static cvar_t  *breakableglass     = 0;

// cvar for max glass fragment count
static cvar_t  *glassfragmentlimit = 0;

static int      glassfragmentcount = 0;


// additional functions - Q2 expects C calling convention
#ifdef __cplusplus
extern "C"
{
#endif

void CGF_SFX_TouchGlass(edict_t *self, edict_t *other, cplane_t *plane, csurface_t *surf);
// called whenever an entity hits the trigger spawned for the glass

void CGF_SFX_EmitGlass (edict_t* aGlassPane, edict_t* anInflictor, vec3_t   aPoint);
// emits glass fragments from aPoint, to show effects of firing thru window

void CGF_SFX_BreakGlass(edict_t* aGlassPane, edict_t* anOther, edict_t* anAttacker, 
                        int      aDamage,    vec3_t   aPoint,  vec_t    aPaneDestructDelay
                       );
// breaks glass

void CGF_SFX_InstallBreakableGlass(edict_t* aGlassPane);
// when working on a glass pane for the first time, just install trigger
// when working on a glass pane again (after a game ended), move
// glass back to original location

void CGF_SFX_HideBreakableGlass(edict_t* aGlassPane);
// after being broken, the pane cannot be removed as it is needed in
// subsequent missions/games, so hide it at about z = -1000

void CGF_SFX_ApplyGlassFragmentLimit(const char* aClassName);
// updates glassfragmentcount and removes oldest glass fragement if
// necessary to meet limit

void CGF_SFX_MiscGlassUse(edict_t *self, edict_t *other, edict_t *activator);
// catches use from unforeseen objects (weapons, debris,
// etc. touching the window)

void CGF_SFX_MiscGlassDie(edict_t *self, edict_t *inflictor, edict_t *attacker, int damage, vec3_t point);
// catches die calls caused by unforeseen objects (weapons, debris,
// etc. damaging the window)

void CGF_SFX_GlassThrowDebris (edict_t *self, char *modelname, float speed, vec3_t origin);
// variant of id software's ThrowDebris, now numbering the entity (for later removal)

extern // from a_game.c
edict_t *FindEdictByClassnum (char *classname, int classnum);

// declaration from g_misc.c
extern // from g_misc.c
void debris_die (edict_t *self, edict_t *inflictor, edict_t *attacker, int damage, vec3_t point);

#ifdef __cplusplus
}
#endif



void CGF_SFX_InstallGlassSupport()
{
  breakableglass     = gi.cvar("breakableglass", "0", 0);
  glassfragmentlimit = gi.cvar("glassfragmentlimit", "30", 0);
}


int  CGF_SFX_IsBreakableGlassEnabled()
{
  // returns whether breakable glass is enabled (cvar) and allowed (dm mode)
  return breakableglass->value;
}  



void CGF_SFX_TestBreakableGlassAndRemoveIfNot_Think(edict_t* aPossibleGlassEntity)
{
  // at level.time == 0.1 the entity has been introduced in the game,
  // and we can use gi.pointcontents and gi.trace to check the entity
  vec3_t   origin;
  int      breakingglass;
  trace_t  trace;

  // test for cvar
  if (!CGF_SFX_IsBreakableGlassEnabled())
    {
      G_FreeEdict(aPossibleGlassEntity);
      return;
    }

  VectorAdd(aPossibleGlassEntity->absmax, aPossibleGlassEntity->absmin, origin);
  VectorScale(origin, 0.5, origin);

  // detect glass (does not work for complex shapes,
  // for example, the glass window near the satellite
  // dish at Q2 base3
  breakingglass = (gi.pointcontents(origin) & CONTENTS_TRANSLUCENT);

  if (!breakingglass)
    {
      // test for complex brushes that happen to be
      // hollow in their origin (for instance, the
      // window at Q2 base3, near the satellite dish
      trace = gi.trace(origin, vec3_origin, vec3_origin, aPossibleGlassEntity->absmax, 0, 
                       MASK_PLAYERSOLID
                      );
      breakingglass = ((trace.ent == aPossibleGlassEntity) &&
                       (trace.contents & CONTENTS_TRANSLUCENT)
                      );
      trace = gi.trace(origin, vec3_origin, vec3_origin, aPossibleGlassEntity->absmin, 0, 
                       MASK_PLAYERSOLID
                      );
      breakingglass = ((breakingglass) ||
                       ((trace.ent == aPossibleGlassEntity) &&
                        (trace.contents & CONTENTS_TRANSLUCENT)
                       )
                      );
    }
 
  if (!breakingglass)
    {
      // do remove other func_explosives
		  G_FreeEdict (aPossibleGlassEntity);
		  return;
    }

  // discovered some glass - now make store the origin
  // we need that after hiding the glass
  VectorCopy(aPossibleGlassEntity->s.origin, aPossibleGlassEntity->pos1);  // IMPORTANT!

  // make a backup of the health in light_level
  aPossibleGlassEntity->light_level = aPossibleGlassEntity->health;

  // install the glass
  CGF_SFX_InstallBreakableGlass(aPossibleGlassEntity);
}



void CGF_SFX_InstallBreakableGlass(edict_t* aGlassPane)
{
  // when working on a glass pane for the first time, just install trigger
  // when working on a glass pane again (after a game ended), move
  // glass back to original location
  edict_t* trigger;
  vec3_t   maxs;
  vec3_t   mins;

  // reset origin based on aGlassPane->pos1
  VectorCopy(aGlassPane->pos1, aGlassPane->s.origin);

  // reset health based on aGlassPane->light_level
  aGlassPane->health     = aGlassPane->light_level;

  // replace die and use functions by glass specific ones
  aGlassPane->die = CGF_SFX_MiscGlassDie;
  aGlassPane->use = CGF_SFX_MiscGlassUse;

  // reset some pane attributes
	aGlassPane->takedamage = DAMAGE_YES;
	aGlassPane->solid      = SOLID_BSP;
	aGlassPane->movetype   = MOVETYPE_FLYMISSILE;  
    // for other movetypes, cannot move pane to hidden location and back

  // try to establish size
  VectorCopy(aGlassPane->maxs, maxs);
  VectorCopy(aGlassPane->mins, mins);

  // set up trigger, similar to triggers for doors
  // but with a smaller box
	mins[0] -= 24;
	mins[1] -= 24;
	mins[2] -= 24;
	maxs[0] += 24;
	maxs[1] += 24;
	maxs[2] += 24;

  // adjust some settings
	trigger            = G_Spawn ();
  trigger->classname = "breakableglass_trigger";
	VectorCopy (mins, trigger->mins);
	VectorCopy (maxs, trigger->maxs);
	trigger->owner     = aGlassPane;
	trigger->solid     = SOLID_TRIGGER;
	trigger->movetype  = MOVETYPE_NONE;
	trigger->touch     = CGF_SFX_TouchGlass;
	gi.linkentity (trigger);
}


void CGF_SFX_ShootBreakableGlass(edict_t* aGlassPane, 
                                 edict_t* anAttacker,
                                 /*trace_t**/ void* tr,
                                 int      mod
                                )
{
  // process gunshots thru glass
  edict_t* trigger;
  int      destruct;

  // depending on mod, destroy window or emit fragments
  switch (mod)
  {
    // break for ap, shotgun, handcannon, and kick, destory window
    case MOD_M3      :
    case MOD_HC      :
    case MOD_SNIPER  :
    case MOD_KICK    :
    case MOD_GRENADE :
    case MOD_G_SPLASH:
    case MOD_HANDGRENADE:         
    case MOD_HG_SPLASH:
    case MOD_KNIFE   : // slash damage
                       destruct = true;
                       break;
    default          :         
                       destruct = (rand() % 3 == 0);
                       break;
  };

  if (destruct)
    {
      // break glass (and hurt if doing kick)
      CGF_SFX_BreakGlass(aGlassPane, anAttacker, 0, aGlassPane->health, vec3_origin, FRAMETIME);
      if (mod == MOD_KICK)
        {
          vec3_t bloodorigin;
          vec3_t dir;
          vec3_t normal;
          VectorAdd(aGlassPane->absmax, aGlassPane->absmin, bloodorigin);
          VectorScale(bloodorigin, 0.5, bloodorigin);
          VectorSubtract(bloodorigin, anAttacker->s.origin, dir);
          VectorNormalize(dir);
          VectorMA(anAttacker->s.origin, 32.0, dir, bloodorigin);
          VectorSet(normal, 0, 0, -1);
          T_Damage(anAttacker, aGlassPane, anAttacker, dir, bloodorigin, normal, 15.0, 0, 0, MOD_BREAKINGGLASS);
        }

      // remove corresponding trigger
      trigger = 0;
      while (trigger = G_Find(trigger, FOFS(classname), "breakableglass_trigger"))
        {
          if (trigger->owner == aGlassPane)
            {
              // remove it
              G_FreeEdict(trigger);
              // only one to be found
              break;
            }
        }
    }
  else
    {
      // add decal (if not grenade)
      if (   (mod != MOD_HANDGRENADE) 
          && (mod != MOD_HG_SPLASH)
          && (mod != MOD_GRENADE) 
          && (mod != MOD_G_SPLASH)
         )
        {
          AddDecal(anAttacker, (trace_t*) tr);
        }
      // and emit glass
      CGF_SFX_EmitGlass(aGlassPane, anAttacker, ((trace_t*) tr)->endpos);
    }
}


void CGF_SFX_TouchGlass(edict_t *self, edict_t *other, cplane_t *plane, csurface_t *surf)
{
  // called whenever an entity hits the trigger spawned for the glass

  vec3_t   origin;
  vec3_t   normal;
  vec3_t   spot;
  trace_t  trace;
  edict_t* glass;
  vec3_t   velocity;
  vec_t    speed;
  vec_t    projected_speed;
  int      is_hgrenade;
  int      is_knife;

  is_hgrenade = is_knife = false;

  // ignore non-clients-non-grenade-non-knife
  if (!other->client)
    {
      is_knife = (0 == Q_stricmp("weapon_knife", other->classname));
      if (!is_knife)
        {
          is_hgrenade = (0 == Q_stricmp("hgrenade", other->classname)); 
        }

      if ((!is_knife) && (!is_hgrenade))
        return;
      if (is_knife)
        goto knife_and_grenade_handling;
    }

  // test whether other really hits the glass - deal with
  // the special case that other hits some boundary close to the border of the glass pane
  //
  //
  //             ....trigger.......
  //      +++++++++              +++++++++++
  //             .+---glass------+.
  //       wall  .+--------------+.wall
  //      +++++++++              +++++++++++
  //       ----->..................
  //    wrong    ^            ^
  //             |            |
  //            wrong        ok 
  //
  glass = self->owner;
  // hack - set glass' movetype to MOVETYPE_PUSH as it is not
  // moving as long as the trigger is active
  glass->movetype = MOVETYPE_PUSH;

  VectorAdd(glass->absmax, glass->absmin, origin);
  VectorScale(origin, 0.5, origin);

  // other needs to be able to trace to glass origin
  trace = gi.trace(other->s.origin, vec3_origin, vec3_origin, origin, other, 
                   MASK_PLAYERSOLID
                  );
  if (trace.ent != glass)
    return;

  // we can reach the glass origin, so we have the normal of
  // the glass plane
  VectorCopy(trace.plane.normal, normal);

  // we need to check if client is not running into wall next
  // to the glass (the trigger stretches into the wall)
  VectorScale(normal, -1000.0, spot);
  VectorAdd(spot, other->s.origin, spot);
  // line between other->s.origin and spot (perpendicular to glass
  // surface should not hit wall but glass instead
  trace = gi.trace(other->s.origin, vec3_origin, vec3_origin, spot, other, 
                   MASK_PLAYERSOLID
                  );
  if (trace.ent != glass)
    return;

  // now, we check if the client's speed perpendicular to
  // the glass plane, exceeds the required 175
  // (speed should be < -200, as the plane's normal
  // points towards the client
  VectorCopy(other->velocity, velocity);
  speed           = VectorNormalize(velocity);
  projected_speed = speed * DotProduct(velocity, normal);

  // bump projected speed for grenades - they should break
  // the window more easily
  if (is_hgrenade)
    projected_speed *= 1.5;

  // if hitting the glass with sufficient speed (project < -175),
  // being jumpkicked (speed > 700, project < -5) break the window 
  if (!((projected_speed < -175.0) ||
        ((projected_speed < -5) && (speed > 700))
       )
     )
    goto knife_and_grenade_handling;

  // break glass
  CGF_SFX_BreakGlass(glass, other, other, glass->health, vec3_origin, 3.0 * FRAMETIME);
  // glass can take care of itself, but the trigger isn't needed anymore
	G_FreeEdict (self);

  /* not needed
  // reduce momentum of the client (he just broke the window
  // so he should lose speed. in addition, it doesn't feel
  // right if he overtakes the glass fragments
  //  VectorScale(normal, 200.0, velocity);
  //  VectorAdd(other->velocity, velocity, other->velocity);
  */

  // make sure client takes damage
  T_Damage(other, glass, other, normal, other->s.origin, normal, 15.0, 0, 0, MOD_BREAKINGGLASS);
  return;

  // goto label
  knife_and_grenade_handling:
    // if knife or grenade, bounce them
    if ((is_knife) || (is_hgrenade))
      {
        // change clipmask to bounce of glass
        other->clipmask = MASK_SOLID;
      }
}


void CGF_SFX_BreakGlass(edict_t* aGlassPane, edict_t* anInflictor, edict_t* anAttacker, 
                        int      aDamage,    vec3_t   aPoint,      vec_t    aPaneDestructDelay
                       )
{
  // based on func_explode, but with lotsa subtle differences
	vec3_t	origin;
	vec3_t	old_origin;
	vec3_t	chunkorigin;
	vec3_t	size;
	int		count;
	int		mass;

	// bmodel origins are (0 0 0), we need to adjust that here
  VectorCopy(aGlassPane->s.origin, old_origin);
	VectorScale (aGlassPane->size, 0.5, size);
	VectorAdd (aGlassPane->absmin, size, origin);
	VectorCopy (origin, aGlassPane->s.origin);

	aGlassPane->takedamage = DAMAGE_NO;

	VectorSubtract (aGlassPane->s.origin, anInflictor->s.origin, aGlassPane->velocity);
	VectorNormalize (aGlassPane->velocity);
  // use speed 250 instead of 150 for funkier glass spray
	VectorScale (aGlassPane->velocity, 250.0, aGlassPane->velocity);

	// start chunks towards the center
	VectorScale (size, 0.75, size);

	mass = aGlassPane->mass;
	if (!mass)
		mass = 75;

	// big chunks
	if (mass >= 100)
	{
		count = mass / 100;
		if (count > 8)
			count = 8;
		while(count--)
		{
      CGF_SFX_ApplyGlassFragmentLimit("debris");
			chunkorigin[0] = origin[0] + crandom() * size[0];
			chunkorigin[1] = origin[1] + crandom() * size[1];
			chunkorigin[2] = origin[2] + crandom() * size[2];
			CGF_SFX_GlassThrowDebris (aGlassPane, "models/objects/debris1/tris.md2", 1, chunkorigin);
		}
	}

	// small chunks
	count = mass / 25;
	if (count > 16)
		count = 16;
	while(count--)
	{
    CGF_SFX_ApplyGlassFragmentLimit("debris");
		chunkorigin[0] = origin[0] + crandom() * size[0];
		chunkorigin[1] = origin[1] + crandom() * size[1];
		chunkorigin[2] = origin[2] + crandom() * size[2];
		CGF_SFX_GlassThrowDebris (aGlassPane, "models/objects/debris2/tris.md2", 2, chunkorigin);
	}

  // clear velocity, reset origin (that has been abused in ThrowDebris)
  VectorClear(aGlassPane->velocity);
  VectorCopy (old_origin, aGlassPane->s.origin);

  if (anAttacker)
    {
      // jumping thru
    	G_UseTargets (aGlassPane, anAttacker);
    }
  else
    {
      // firing thru - the pane has no direct attacker to hurt,
      // but G_UseTargets expects one. So make it a DIY
    	G_UseTargets (aGlassPane, aGlassPane);
    }

  // have glass plane be visible for two more frames, 
  // and have it self-destruct then
  // meanwhile, make sure the player can move thru
  aGlassPane->solid     = SOLID_NOT;
  aGlassPane->think     = CGF_SFX_HideBreakableGlass;
  aGlassPane->nextthink = level.time + aPaneDestructDelay;
}



void CGF_SFX_EmitGlass (edict_t* aGlassPane, edict_t* anInflictor, vec3_t   aPoint)
{
  // based on func_explode, but with lotsa subtle differences
	vec3_t	old_origin;
	vec3_t	chunkorigin;
	vec3_t	size;
	int		count;

	// bmodel origins are (0 0 0), we need to adjust that here
  VectorCopy(aGlassPane->s.origin, old_origin);
	VectorCopy (aPoint, aGlassPane->s.origin);

	VectorSubtract (aGlassPane->s.origin, anInflictor->s.origin, aGlassPane->velocity);
	VectorNormalize (aGlassPane->velocity);
  // use speed 250 instead of 150 for funkier glass spray
	VectorScale (aGlassPane->velocity, 250.0, aGlassPane->velocity);

	// start chunks towards the center
	VectorScale (aGlassPane->size, 0.25, size);

  count = 4;
	while(count--)
	{
    CGF_SFX_ApplyGlassFragmentLimit("debris");
		chunkorigin[0] = aPoint[0] + crandom() * size[0];
		chunkorigin[1] = aPoint[1] + crandom() * size[1];
		chunkorigin[2] = aPoint[2] + crandom() * size[2];
		CGF_SFX_GlassThrowDebris (aGlassPane, "models/objects/debris2/tris.md2", 2, chunkorigin);
	}

  // clear velocity, reset origin (that has been abused in ThrowDebris)
  VectorClear(aGlassPane->velocity);
  VectorCopy (old_origin, aGlassPane->s.origin);

  // firing thru - the pane has no direct attacker to hurt,
  // but G_UseTargets expects one. So make it a DIY
  G_UseTargets (aGlassPane, aGlassPane);
}



void CGF_SFX_HideBreakableGlass(edict_t* aGlassPane)
{
  // remove all attached decals
  edict_t* decal;
  decal = 0;
  while (decal = G_Find(decal, FOFS(classname), "decal"))
    {
      if (decal->owner == aGlassPane)
        {
          // make it goaway in the next frame
          decal->nextthink = level.time + FRAMETIME;
        }
    }
  
  while (decal = G_Find(decal, FOFS(classname), "splat"))
    {
      if (decal->owner == aGlassPane)
        {
          // make it goaway in the next frame
          decal->nextthink = level.time + FRAMETIME;
        }
    }
  
  // after being broken, the pane cannot be freed as it is needed in
  // subsequent missions/games, so hide it at about z = -1000 lower
 	aGlassPane->movetype = MOVETYPE_FLYMISSILE;
  VectorCopy(aGlassPane->s.origin, aGlassPane->pos1);
  aGlassPane->s.origin[2] -=1000.0;
}



void CGF_SFX_AttachDecalToGlass(edict_t* aGlassPane, edict_t* aDecal)
{
  // just set aDecal's owner to be the glass pane
  aDecal->owner = aGlassPane;
}



void CGF_SFX_RebuildAllBrokenGlass()
{
  // iterate over all func_explosives
  edict_t* glass;
  glass = 0;
  while (glass = G_Find(glass, FOFS(classname), "func_explosive"))
    {
      // glass is broken if solid != SOLID_BSP
      if (glass->solid != SOLID_BSP)
        {
          CGF_SFX_InstallBreakableGlass(glass);
        }
    }
}



void CGF_SFX_ApplyGlassFragmentLimit(const char* aClassName)
{
  edict_t* oldfragment;

  glassfragmentcount++;
  if (glassfragmentcount > glassfragmentlimit->value)
    glassfragmentcount = 1;
  
  // remove fragment with corresponding number if any
  oldfragment = FindEdictByClassnum((char*) aClassName, glassfragmentcount);

  if (oldfragment)
    {
      // oldfragment->nextthink = level.time + FRAMETIME;
      G_FreeEdict(oldfragment);
    }
}



void CGF_SFX_MiscGlassUse(edict_t *self, edict_t *other, edict_t *activator)
{
  #ifdef _DEBUG
  const char* classname;
  classname = other->classname;
  #endif
}



void CGF_SFX_MiscGlassDie(edict_t *self, edict_t *inflictor, edict_t *attacker, int damage, vec3_t point)
{
  #ifdef _DEBUG
  const char* classname;
  classname = inflictor->classname;
  #endif
}



static vec_t previous_throw_time = 0;
static int   this_throw_count    = 0;

void CGF_SFX_GlassThrowDebris (edict_t *self, char *modelname, float speed, vec3_t origin)
{
  // based on ThrowDebris from id software - now returns debris created
  edict_t *chunk;
  vec3_t  v;

  if (level.time != previous_throw_time)
    {
      previous_throw_time = level.time;
      this_throw_count    = 0;
    }
  else
    {
      this_throw_count++;
      if (this_throw_count > glassfragmentlimit->value)
          return;
    }

  chunk = G_Spawn();
  VectorCopy (origin, chunk->s.origin);
  gi.setmodel (chunk, modelname);
  v[0] = 100 * crandom();
  v[1] = 100 * crandom();
  v[2] = 100 + 100 * crandom();
  VectorMA (self->velocity, speed, v, chunk->velocity);
  chunk->movetype = MOVETYPE_BOUNCE;
  chunk->solid = SOLID_NOT;
  chunk->avelocity[0] = random()*600;
  chunk->avelocity[1] = random()*600;
  chunk->avelocity[2] = random()*600;
  chunk->think = G_FreeEdict;
  chunk->nextthink = level.time + 5 + random()*5;
  chunk->s.frame = 0;
  chunk->flags = 0;
  chunk->classname = "debris";
  chunk->takedamage = DAMAGE_YES;
  chunk->die = debris_die;
  gi.linkentity (chunk);

  // number chunk
  chunk->classnum = glassfragmentcount;
}