Quake-2

m_move.c (11476B)

---

 /*
 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.
 
 */
 // m_move.c -- monster movement
 
 #include "g_local.h"
 
 #define	STEPSIZE	18
 
 /*
 =============
 M_CheckBottom
 
 Returns false if any part of the bottom of the entity is off an edge that
 is not a staircase.
 
 =============
 */
 int c_yes, c_no;
 
 qboolean M_CheckBottom (edict_t *ent)
 {
 	vec3_t	mins, maxs, start, stop;
 	trace_t	trace;
 	int		x, y;
 	float	mid, bottom;
 	
 	VectorAdd (ent->s.origin, ent->mins, mins);
 	VectorAdd (ent->s.origin, ent->maxs, maxs);
 
 // if all of the points under the corners are solid world, don't bother
 // with the tougher checks
 // the corners must be within 16 of the midpoint
 	start[2] = mins[2] - 1;
 	for	(x=0 ; x<=1 ; x++)
 		for	(y=0 ; y<=1 ; y++)
 		{
 			start[0] = x ? maxs[0] : mins[0];
 			start[1] = y ? maxs[1] : mins[1];
 			if (gi.pointcontents (start) != CONTENTS_SOLID)
 				goto realcheck;
 		}
 
 	c_yes++;
 	return true;		// we got out easy
 
 realcheck:
 	c_no++;
 //
 // check it for real...
 //
 	start[2] = mins[2];
 	
 // the midpoint must be within 16 of the bottom
 	start[0] = stop[0] = (mins[0] + maxs[0])*0.5;
 	start[1] = stop[1] = (mins[1] + maxs[1])*0.5;
 	stop[2] = start[2] - 2*STEPSIZE;
 	trace = gi.trace (start, vec3_origin, vec3_origin, stop, ent, MASK_MONSTERSOLID);
 
 	if (trace.fraction == 1.0)
 		return false;
 	mid = bottom = trace.endpos[2];
 	
 // the corners must be within 16 of the midpoint	
 	for	(x=0 ; x<=1 ; x++)
 		for	(y=0 ; y<=1 ; y++)
 		{
 			start[0] = stop[0] = x ? maxs[0] : mins[0];
 			start[1] = stop[1] = y ? maxs[1] : mins[1];
 			
 			trace = gi.trace (start, vec3_origin, vec3_origin, stop, ent, MASK_MONSTERSOLID);
 			
 			if (trace.fraction != 1.0 && trace.endpos[2] > bottom)
 				bottom = trace.endpos[2];
 			if (trace.fraction == 1.0 || mid - trace.endpos[2] > STEPSIZE)
 				return false;
 		}
 
 	c_yes++;
 	return true;
 }
 
 
 /*
 =============
 SV_movestep
 
 Called by monster program code.
 The move will be adjusted for slopes and stairs, but if the move isn't
 possible, no move is done, false is returned, and
 pr_global_struct->trace_normal is set to the normal of the blocking wall
 =============
 */
 //FIXME since we need to test end position contents here, can we avoid doing
 //it again later in catagorize position?
 qboolean SV_movestep (edict_t *ent, vec3_t move, qboolean relink)
 {
 	float		dz;
 	vec3_t		oldorg, neworg, end;
 	trace_t		trace;
 	int			i;
 	float		stepsize;
 	vec3_t		test;
 	int			contents;
 
 // try the move	
 	VectorCopy (ent->s.origin, oldorg);
 	VectorAdd (ent->s.origin, move, neworg);
 
 // flying monsters don't step up
 	if ( ent->flags & (FL_SWIM | FL_FLY) )
 	{
 	// try one move with vertical motion, then one without
 		for (i=0 ; i<2 ; i++)
 		{
 			VectorAdd (ent->s.origin, move, neworg);
 			if (i == 0 && ent->enemy)
 			{
 				if (!ent->goalentity)
 					ent->goalentity = ent->enemy;
 				dz = ent->s.origin[2] - ent->goalentity->s.origin[2];
 				if (ent->goalentity->client)
 				{
 					if (dz > 40)
 						neworg[2] -= 8;
 					if (!((ent->flags & FL_SWIM) && (ent->waterlevel < 2)))
 						if (dz < 30)
 							neworg[2] += 8;
 				}
 				else
 				{
 					if (dz > 8)
 						neworg[2] -= 8;
 					else if (dz > 0)
 						neworg[2] -= dz;
 					else if (dz < -8)
 						neworg[2] += 8;
 					else
 						neworg[2] += dz;
 				}
 			}
 			trace = gi.trace (ent->s.origin, ent->mins, ent->maxs, neworg, ent, MASK_MONSTERSOLID);
 	
 			// fly monsters don't enter water voluntarily
 			if (ent->flags & FL_FLY)
 			{
 				if (!ent->waterlevel)
 				{
 					test[0] = trace.endpos[0];
 					test[1] = trace.endpos[1];
 					test[2] = trace.endpos[2] + ent->mins[2] + 1;
 					contents = gi.pointcontents(test);
 					if (contents & MASK_WATER)
 						return false;
 				}
 			}
 
 			// swim monsters don't exit water voluntarily
 			if (ent->flags & FL_SWIM)
 			{
 				if (ent->waterlevel < 2)
 				{
 					test[0] = trace.endpos[0];
 					test[1] = trace.endpos[1];
 					test[2] = trace.endpos[2] + ent->mins[2] + 1;
 					contents = gi.pointcontents(test);
 					if (!(contents & MASK_WATER))
 						return false;
 				}
 			}
 
 			if (trace.fraction == 1)
 			{
 				VectorCopy (trace.endpos, ent->s.origin);
 				if (relink)
 				{
 					gi.linkentity (ent);
 					G_TouchTriggers (ent);
 				}
 				return true;
 			}
 			
 			if (!ent->enemy)
 				break;
 		}
 		
 		return false;
 	}
 
 // push down from a step height above the wished position
 	if (!(ent->monsterinfo.aiflags & AI_NOSTEP))
 		stepsize = STEPSIZE;
 	else
 		stepsize = 1;
 
 	neworg[2] += stepsize;
 	VectorCopy (neworg, end);
 	end[2] -= stepsize*2;
 
 	trace = gi.trace (neworg, ent->mins, ent->maxs, end, ent, MASK_MONSTERSOLID);
 
 	if (trace.allsolid)
 		return false;
 
 	if (trace.startsolid)
 	{
 		neworg[2] -= stepsize;
 		trace = gi.trace (neworg, ent->mins, ent->maxs, end, ent, MASK_MONSTERSOLID);
 		if (trace.allsolid || trace.startsolid)
 			return false;
 	}
 
 
 	// don't go in to water
 	if (ent->waterlevel == 0)
 	{
 		test[0] = trace.endpos[0];
 		test[1] = trace.endpos[1];
 		test[2] = trace.endpos[2] + ent->mins[2] + 1;	
 		contents = gi.pointcontents(test);
 
 		if (contents & MASK_WATER)
 			return false;
 	}
 
 	if (trace.fraction == 1)
 	{
 	// if monster had the ground pulled out, go ahead and fall
 		if ( ent->flags & FL_PARTIALGROUND )
 		{
 			VectorAdd (ent->s.origin, move, ent->s.origin);
 			if (relink)
 			{
 				gi.linkentity (ent);
 				G_TouchTriggers (ent);
 			}
 			ent->groundentity = NULL;
 			return true;
 		}
 	
 		return false;		// walked off an edge
 	}
 
 // check point traces down for dangling corners
 	VectorCopy (trace.endpos, ent->s.origin);
 	
 	if (!M_CheckBottom (ent))
 	{
 		if ( ent->flags & FL_PARTIALGROUND )
 		{	// entity had floor mostly pulled out from underneath it
 			// and is trying to correct
 			if (relink)
 			{
 				gi.linkentity (ent);
 				G_TouchTriggers (ent);
 			}
 			return true;
 		}
 		VectorCopy (oldorg, ent->s.origin);
 		return false;
 	}
 
 	if ( ent->flags & FL_PARTIALGROUND )
 	{
 		ent->flags &= ~FL_PARTIALGROUND;
 	}
 	ent->groundentity = trace.ent;
 	ent->groundentity_linkcount = trace.ent->linkcount;
 
 // the move is ok
 	if (relink)
 	{
 		gi.linkentity (ent);
 		G_TouchTriggers (ent);
 	}
 	return true;
 }
 
 
 //============================================================================
 
 /*
 ===============
 M_ChangeYaw
 
 ===============
 */
 void M_ChangeYaw (edict_t *ent)
 {
 	float	ideal;
 	float	current;
 	float	move;
 	float	speed;
 	
 	current = anglemod(ent->s.angles[YAW]);
 	ideal = ent->ideal_yaw;
 
 	if (current == ideal)
 		return;
 
 	move = ideal - current;
 	speed = ent->yaw_speed;
 	if (ideal > current)
 	{
 		if (move >= 180)
 			move = move - 360;
 	}
 	else
 	{
 		if (move <= -180)
 			move = move + 360;
 	}
 	if (move > 0)
 	{
 		if (move > speed)
 			move = speed;
 	}
 	else
 	{
 		if (move < -speed)
 			move = -speed;
 	}
 	
 	ent->s.angles[YAW] = anglemod (current + move);
 }
 
 
 /*
 ======================
 SV_StepDirection
 
 Turns to the movement direction, and walks the current distance if
 facing it.
 
 ======================
 */
 qboolean SV_StepDirection (edict_t *ent, float yaw, float dist)
 {
 	vec3_t		move, oldorigin;
 	float		delta;
 	
 	ent->ideal_yaw = yaw;
 	M_ChangeYaw (ent);
 	
 	yaw = yaw*M_PI*2 / 360;
 	move[0] = cos(yaw)*dist;
 	move[1] = sin(yaw)*dist;
 	move[2] = 0;
 
 	VectorCopy (ent->s.origin, oldorigin);
 	if (SV_movestep (ent, move, false))
 	{
 		delta = ent->s.angles[YAW] - ent->ideal_yaw;
 		if (delta > 45 && delta < 315)
 		{		// not turned far enough, so don't take the step
 			VectorCopy (oldorigin, ent->s.origin);
 		}
 		gi.linkentity (ent);
 		G_TouchTriggers (ent);
 		return true;
 	}
 	gi.linkentity (ent);
 	G_TouchTriggers (ent);
 	return false;
 }
 
 /*
 ======================
 SV_FixCheckBottom
 
 ======================
 */
 void SV_FixCheckBottom (edict_t *ent)
 {
 	ent->flags |= FL_PARTIALGROUND;
 }
 
 
 
 /*
 ================
 SV_NewChaseDir
 
 ================
 */
 #define	DI_NODIR	-1
 void SV_NewChaseDir (edict_t *actor, edict_t *enemy, float dist)
 {
 	float	deltax,deltay;
 	float	d[3];
 	float	tdir, olddir, turnaround;
 
 	//FIXME: how did we get here with no enemy
 	if (!enemy)
 		return;
 
 	olddir = anglemod( (int)(actor->ideal_yaw/45)*45 );
 	turnaround = anglemod(olddir - 180);
 
 	deltax = enemy->s.origin[0] - actor->s.origin[0];
 	deltay = enemy->s.origin[1] - actor->s.origin[1];
 	if (deltax>10)
 		d[1]= 0;
 	else if (deltax<-10)
 		d[1]= 180;
 	else
 		d[1]= DI_NODIR;
 	if (deltay<-10)
 		d[2]= 270;
 	else if (deltay>10)
 		d[2]= 90;
 	else
 		d[2]= DI_NODIR;
 
 // try direct route
 	if (d[1] != DI_NODIR && d[2] != DI_NODIR)
 	{
 		if (d[1] == 0)
 			tdir = d[2] == 90 ? 45 : 315;
 		else
 			tdir = d[2] == 90 ? 135 : 215;
 			
 		if (tdir != turnaround && SV_StepDirection(actor, tdir, dist))
 			return;
 	}
 
 // try other directions
 	if ( ((rand()&3) & 1) ||  abs(deltay)>abs(deltax))
 	{
 		tdir=d[1];
 		d[1]=d[2];
 		d[2]=tdir;
 	}
 
 	if (d[1]!=DI_NODIR && d[1]!=turnaround 
 	&& SV_StepDirection(actor, d[1], dist))
 			return;
 
 	if (d[2]!=DI_NODIR && d[2]!=turnaround
 	&& SV_StepDirection(actor, d[2], dist))
 			return;
 
 /* there is no direct path to the player, so pick another direction */
 
 	if (olddir!=DI_NODIR && SV_StepDirection(actor, olddir, dist))
 			return;
 
 	if (rand()&1) 	/*randomly determine direction of search*/
 	{
 		for (tdir=0 ; tdir<=315 ; tdir += 45)
 			if (tdir!=turnaround && SV_StepDirection(actor, tdir, dist) )
 					return;
 	}
 	else
 	{
 		for (tdir=315 ; tdir >=0 ; tdir -= 45)
 			if (tdir!=turnaround && SV_StepDirection(actor, tdir, dist) )
 					return;
 	}
 
 	if (turnaround != DI_NODIR && SV_StepDirection(actor, turnaround, dist) )
 			return;
 
 	actor->ideal_yaw = olddir;		// can't move
 
 // if a bridge was pulled out from underneath a monster, it may not have
 // a valid standing position at all
 
 	if (!M_CheckBottom (actor))
 		SV_FixCheckBottom (actor);
 }
 
 /*
 ======================
 SV_CloseEnough
 
 ======================
 */
 qboolean SV_CloseEnough (edict_t *ent, edict_t *goal, float dist)
 {
 	int		i;
 	
 	for (i=0 ; i<3 ; i++)
 	{
 		if (goal->absmin[i] > ent->absmax[i] + dist)
 			return false;
 		if (goal->absmax[i] < ent->absmin[i] - dist)
 			return false;
 	}
 	return true;
 }
 
 
 /*
 ======================
 M_MoveToGoal
 ======================
 */
 void M_MoveToGoal (edict_t *ent, float dist)
 {
 	edict_t		*goal;
 	
 	goal = ent->goalentity;
 
 	if (!ent->groundentity && !(ent->flags & (FL_FLY|FL_SWIM)))
 		return;
 
 // if the next step hits the enemy, return immediately
 	if (ent->enemy &&  SV_CloseEnough (ent, ent->enemy, dist) )
 		return;
 
 // bump around...
 	if ( (rand()&3)==1 || !SV_StepDirection (ent, ent->ideal_yaw, dist))
 	{
 		if (ent->inuse)
 			SV_NewChaseDir (ent, goal, dist);
 	}
 }
 
 
 /*
 ===============
 M_walkmove
 ===============
 */
 qboolean M_walkmove (edict_t *ent, float yaw, float dist)
 {
 	vec3_t	move;
 	
 	if (!ent->groundentity && !(ent->flags & (FL_FLY|FL_SWIM)))
 		return false;
 
 	yaw = yaw*M_PI*2 / 360;
 	
 	move[0] = cos(yaw)*dist;
 	move[1] = sin(yaw)*dist;
 	move[2] = 0;
 
 	return SV_movestep(ent, move, true);
 }