g_func.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

/*
Copyright (C) 1997-2001 Id Software, Inc.

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.

*/
#include "g_local.h"

/*
=========================================================

  PLATS

  movement options:

  linear
  smooth start, hard stop
  smooth start, smooth stop

  start
  end
  acceleration
  speed
  deceleration
  begin sound
  end sound
  target fired when reaching end
  wait at end

  object characteristics that use move segments
  ---------------------------------------------
  movetype_push, or movetype_stop
  action when touched
  action when blocked
  action when used
	disabled?
  auto trigger spawning


=========================================================
*/

#define PLAT_LOW_TRIGGER	1

#define	STATE_TOP			0
#define	STATE_BOTTOM		1
#define STATE_UP			2
#define STATE_DOWN			3

#define DOOR_START_OPEN		1
#define DOOR_REVERSE		2
#define DOOR_CRUSHER		4
#define DOOR_NOMONSTER		8
#define DOOR_TOGGLE			32
#define DOOR_X_AXIS			64
#define DOOR_Y_AXIS			128


//
// Support routines for movement (changes in origin using velocity)
//

void Move_Done (edict_t *ent)
{
	VectorClear (ent->velocity);
	ent->moveinfo.endfunc (ent);
}

void Move_Final (edict_t *ent)
{
	if (ent->moveinfo.remaining_distance == 0)
	{
		Move_Done (ent);
		return;
	}

	VectorScale (ent->moveinfo.dir, ent->moveinfo.remaining_distance / FRAMETIME, ent->velocity);

	ent->think = Move_Done;
	ent->nextthink = level.time + FRAMETIME;
}

void Move_Begin (edict_t *ent)
{
	float	frames;

	if ((ent->moveinfo.speed * FRAMETIME) >= ent->moveinfo.remaining_distance)
	{
		Move_Final (ent);
		return;
	}
	VectorScale (ent->moveinfo.dir, ent->moveinfo.speed, ent->velocity);
	frames = floor((ent->moveinfo.remaining_distance / ent->moveinfo.speed) / FRAMETIME);
	ent->moveinfo.remaining_distance -= frames * ent->moveinfo.speed * FRAMETIME;
	ent->nextthink = level.time + (frames * FRAMETIME);
	ent->think = Move_Final;
}

void Think_AccelMove (edict_t *ent);

void Move_Calc (edict_t *ent, vec3_t dest, void(*func)(edict_t*))
{
	VectorClear (ent->velocity);
	VectorSubtract (dest, ent->s.origin, ent->moveinfo.dir);
	ent->moveinfo.remaining_distance = VectorNormalize (ent->moveinfo.dir);
	ent->moveinfo.endfunc = func;

	if (ent->moveinfo.speed == ent->moveinfo.accel && ent->moveinfo.speed == ent->moveinfo.decel)
	{
		if (level.current_entity == ((ent->flags & FL_TEAMSLAVE) ? ent->teammaster : ent))
		{
			Move_Begin (ent);
		}
		else
		{
			ent->nextthink = level.time + FRAMETIME;
			ent->think = Move_Begin;
		}
	}
	else
	{
		// accelerative
		ent->moveinfo.current_speed = 0;
		ent->think = Think_AccelMove;
		ent->nextthink = level.time + FRAMETIME;
	}
}


//
// Support routines for angular movement (changes in angle using avelocity)
//

void AngleMove_Done (edict_t *ent)
{
	VectorClear (ent->avelocity);
	ent->moveinfo.endfunc (ent);
}

void AngleMove_Final (edict_t *ent)
{
	vec3_t	move;

	if (ent->moveinfo.state == STATE_UP)
		VectorSubtract (ent->moveinfo.end_angles, ent->s.angles, move);
	else
		VectorSubtract (ent->moveinfo.start_angles, ent->s.angles, move);

	if (VectorCompare (move, vec3_origin))
	{
		AngleMove_Done (ent);
		return;
	}

	VectorScale (move, 1.0/FRAMETIME, ent->avelocity);

	ent->think = AngleMove_Done;
	ent->nextthink = level.time + FRAMETIME;
}

void AngleMove_Begin (edict_t *ent)
{
	vec3_t	destdelta;
	float	len;
	float	traveltime;
	float	frames;

	// set destdelta to the vector needed to move
	if (ent->moveinfo.state == STATE_UP)
		VectorSubtract (ent->moveinfo.end_angles, ent->s.angles, destdelta);
	else
		VectorSubtract (ent->moveinfo.start_angles, ent->s.angles, destdelta);
	
	// calculate length of vector
	len = VectorLength (destdelta);
	
	// divide by speed to get time to reach dest
	traveltime = len / ent->moveinfo.speed;

	if (traveltime < FRAMETIME)
	{
		AngleMove_Final (ent);
		return;
	}

	frames = floor(traveltime / FRAMETIME);

	// scale the destdelta vector by the time spent traveling to get velocity
	VectorScale (destdelta, 1.0 / traveltime, ent->avelocity);

	// set nextthink to trigger a think when dest is reached
	ent->nextthink = level.time + frames * FRAMETIME;
	ent->think = AngleMove_Final;
}

void AngleMove_Calc (edict_t *ent, void(*func)(edict_t*))
{
	VectorClear (ent->avelocity);
	ent->moveinfo.endfunc = func;
	if (level.current_entity == ((ent->flags & FL_TEAMSLAVE) ? ent->teammaster : ent))
	{
		AngleMove_Begin (ent);
	}
	else
	{
		ent->nextthink = level.time + FRAMETIME;
		ent->think = AngleMove_Begin;
	}
}


/*
==============
Think_AccelMove

The team has completed a frame of movement, so
change the speed for the next frame
==============
*/
#define AccelerationDistance(target, rate)	(target * ((target / rate) + 1) / 2)

void plat_CalcAcceleratedMove(moveinfo_t *moveinfo)
{
	float	accel_dist;
	float	decel_dist;

	moveinfo->move_speed = moveinfo->speed;

	if (moveinfo->remaining_distance < moveinfo->accel)
	{
		moveinfo->current_speed = moveinfo->remaining_distance;
		return;
	}

	accel_dist = AccelerationDistance (moveinfo->speed, moveinfo->accel);
	decel_dist = AccelerationDistance (moveinfo->speed, moveinfo->decel);

	if ((moveinfo->remaining_distance - accel_dist - decel_dist) < 0)
	{
		float	f;

		f = (moveinfo->accel + moveinfo->decel) / (moveinfo->accel * moveinfo->decel);
		moveinfo->move_speed = (-2 + sqrt(4 - 4 * f * (-2 * moveinfo->remaining_distance))) / (2 * f);
		decel_dist = AccelerationDistance (moveinfo->move_speed, moveinfo->decel);
	}

	moveinfo->decel_distance = decel_dist;
};

void plat_Accelerate (moveinfo_t *moveinfo)
{
	// are we decelerating?
	if (moveinfo->remaining_distance <= moveinfo->decel_distance)
	{
		if (moveinfo->remaining_distance < moveinfo->decel_distance)
		{
			if (moveinfo->next_speed)
			{
				moveinfo->current_speed = moveinfo->next_speed;
				moveinfo->next_speed = 0;
				return;
			}
			if (moveinfo->current_speed > moveinfo->decel)
				moveinfo->current_speed -= moveinfo->decel;
		}
		return;
	}

	// are we at full speed and need to start decelerating during this move?
	if (moveinfo->current_speed == moveinfo->move_speed)
		if ((moveinfo->remaining_distance - moveinfo->current_speed) < moveinfo->decel_distance)
		{
			float	p1_distance;
			float	p2_distance;
			float	distance;

			p1_distance = moveinfo->remaining_distance - moveinfo->decel_distance;
			p2_distance = moveinfo->move_speed * (1.0 - (p1_distance / moveinfo->move_speed));
			distance = p1_distance + p2_distance;
			moveinfo->current_speed = moveinfo->move_speed;
			moveinfo->next_speed = moveinfo->move_speed - moveinfo->decel * (p2_distance / distance);
			return;
		}

	// are we accelerating?
	if (moveinfo->current_speed < moveinfo->speed)
	{
		float	old_speed;
		float	p1_distance;
		float	p1_speed;
		float	p2_distance;
		float	distance;

		old_speed = moveinfo->current_speed;

		// figure simple acceleration up to move_speed
		moveinfo->current_speed += moveinfo->accel;
		if (moveinfo->current_speed > moveinfo->speed)
			moveinfo->current_speed = moveinfo->speed;

		// are we accelerating throughout this entire move?
		if ((moveinfo->remaining_distance - moveinfo->current_speed) >= moveinfo->decel_distance)
			return;

		// during this move we will accelrate from current_speed to move_speed
		// and cross over the decel_distance; figure the average speed for the
		// entire move
		p1_distance = moveinfo->remaining_distance - moveinfo->decel_distance;
		p1_speed = (old_speed + moveinfo->move_speed) / 2.0;
		p2_distance = moveinfo->move_speed * (1.0 - (p1_distance / p1_speed));
		distance = p1_distance + p2_distance;
		moveinfo->current_speed = (p1_speed * (p1_distance / distance)) + (moveinfo->move_speed * (p2_distance / distance));
		moveinfo->next_speed = moveinfo->move_speed - moveinfo->decel * (p2_distance / distance);
		return;
	}

	// we are at constant velocity (move_speed)
	return;
};

void Think_AccelMove (edict_t *ent)
{
	ent->moveinfo.remaining_distance -= ent->moveinfo.current_speed;

	if (ent->moveinfo.current_speed == 0)		// starting or blocked
		plat_CalcAcceleratedMove(&ent->moveinfo);

	plat_Accelerate (&ent->moveinfo);

	// will the entire move complete on next frame?
	if (ent->moveinfo.remaining_distance <= ent->moveinfo.current_speed)
	{
		Move_Final (ent);
		return;
	}

	VectorScale (ent->moveinfo.dir, ent->moveinfo.current_speed*10, ent->velocity);
	ent->nextthink = level.time + FRAMETIME;
	ent->think = Think_AccelMove;
}


void plat_go_down (edict_t *ent);

void plat_hit_top (edict_t *ent)
{
	if (!(ent->flags & FL_TEAMSLAVE))
	{
		if (ent->moveinfo.sound_end)
			gi.sound (ent, CHAN_NO_PHS_ADD+CHAN_VOICE, ent->moveinfo.sound_end, 1, ATTN_STATIC, 0);
		ent->s.sound = 0;
	}
	ent->moveinfo.state = STATE_TOP;

	ent->think = plat_go_down;
	ent->nextthink = level.time + 3;
}

void plat_hit_bottom (edict_t *ent)
{
	if (!(ent->flags & FL_TEAMSLAVE))
	{
		if (ent->moveinfo.sound_end)
			gi.sound (ent, CHAN_NO_PHS_ADD+CHAN_VOICE, ent->moveinfo.sound_end, 1, ATTN_STATIC, 0);
		ent->s.sound = 0;
	}
	ent->moveinfo.state = STATE_BOTTOM;
}

void plat_go_down (edict_t *ent)
{
	if (!(ent->flags & FL_TEAMSLAVE))
	{
		if (ent->moveinfo.sound_start)
			gi.sound (ent, CHAN_NO_PHS_ADD+CHAN_VOICE, ent->moveinfo.sound_start, 1, ATTN_STATIC, 0);
		ent->s.sound = ent->moveinfo.sound_middle;
	}
	ent->moveinfo.state = STATE_DOWN;
	Move_Calc (ent, ent->moveinfo.end_origin, plat_hit_bottom);
}

void plat_go_up (edict_t *ent)
{
	if (!(ent->flags & FL_TEAMSLAVE))
	{
		if (ent->moveinfo.sound_start)
			gi.sound (ent, CHAN_NO_PHS_ADD+CHAN_VOICE, ent->moveinfo.sound_start, 1, ATTN_STATIC, 0);
		ent->s.sound = ent->moveinfo.sound_middle;
	}
	ent->moveinfo.state = STATE_UP;
	Move_Calc (ent, ent->moveinfo.start_origin, plat_hit_top);
}

void plat_blocked (edict_t *self, edict_t *other)
{
	if (!(other->svflags & SVF_MONSTER) && (!other->client) )
	{
		// give it a chance to go away on it's own terms (like gibs)
		T_Damage (other, self, self, vec3_origin, other->s.origin, vec3_origin, 100000, 1, 0, MOD_CRUSH);
		// if it's still there, nuke it
		if (other)
			BecomeExplosion1 (other);
		return;
	}

	T_Damage (other, self, self, vec3_origin, other->s.origin, vec3_origin, self->dmg, 1, 0, MOD_CRUSH);

	if (self->moveinfo.state == STATE_UP)
		plat_go_down (self);
	else if (self->moveinfo.state == STATE_DOWN)
		plat_go_up (self);
}


void Use_Plat (edict_t *ent, edict_t *other, edict_t *activator)
{ 
	if (ent->think)
		return;		// already down
	plat_go_down (ent);
}


void Touch_Plat_Center (edict_t *ent, edict_t *other, cplane_t *plane, csurface_t *surf)
{
	if (!other->client)
		return;
		
	if (other->health <= 0)
		return;

	ent = ent->enemy;	// now point at the plat, not the trigger
	if (ent->moveinfo.state == STATE_BOTTOM)
		plat_go_up (ent);
	else if (ent->moveinfo.state == STATE_TOP)
		ent->nextthink = level.time + 1;	// the player is still on the plat, so delay going down
}

void plat_spawn_inside_trigger (edict_t *ent)
{
	edict_t	*trigger;
	vec3_t	tmin, tmax;

//
// middle trigger
//	
	trigger = G_Spawn();
	trigger->touch = Touch_Plat_Center;
	trigger->movetype = MOVETYPE_NONE;
	trigger->solid = SOLID_TRIGGER;
	trigger->enemy = ent;
	
	tmin[0] = ent->mins[0] + 25;
	tmin[1] = ent->mins[1] + 25;
	tmin[2] = ent->mins[2];

	tmax[0] = ent->maxs[0] - 25;
	tmax[1] = ent->maxs[1] - 25;
	tmax[2] = ent->maxs[2] + 8;

	tmin[2] = tmax[2] - (ent->pos1[2] - ent->pos2[2] + st.lip);

	if (ent->spawnflags & PLAT_LOW_TRIGGER)
		tmax[2] = tmin[2] + 8;
	
	if (tmax[0] - tmin[0] <= 0)
	{
		tmin[0] = (ent->mins[0] + ent->maxs[0]) *0.5;
		tmax[0] = tmin[0] + 1;
	}
	if (tmax[1] - tmin[1] <= 0)
	{
		tmin[1] = (ent->mins[1] + ent->maxs[1]) *0.5;
		tmax[1] = tmin[1] + 1;
	}
	
	VectorCopy (tmin, trigger->mins);
	VectorCopy (tmax, trigger->maxs);

	gi.linkentity (trigger);
}


/*QUAKED func_plat (0 .5 .8) ? PLAT_LOW_TRIGGER
speed	default 150

Plats are always drawn in the extended position, so they will light correctly.

If the plat is the target of another trigger or button, it will start out disabled in the extended position until it is trigger, when it will lower and become a normal plat.

"speed"	overrides default 200.
"accel" overrides default 500
"lip"	overrides default 8 pixel lip

If the "height" key is set, that will determine the amount the plat moves, instead of being implicitly determoveinfoned by the model's height.

Set "sounds" to one of the following:
1) base fast
2) chain slow
*/