/*
 * $Header: /H2 Mission Pack/SV_MOVE.C 17    3/18/98 4:46p Mgummelt $
 */

// sv_move.c -- monster movement

#include "quakedef.h"

#define	STEPSIZE	18

/*
=============
SV_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;//These are never checked!!

qboolean SV_CheckBottom (edict_t *ent)
{//By this point, ent has been moved to it's new position after the
	//move, and adjusted for steps
	model_t		*model;
	vec3_t	mins, maxs, start, stop, check,size;
	trace_t	trace;
	hull_t	*wclip_hull;
	int		x, y;
	float	mid, bottom;
	float	save_hull;
	int		index;

	VectorAdd (ent->v.origin, ent->v.mins, mins);
	VectorAdd (ent->v.origin, ent->v.maxs, maxs);

/*//Make it use the clipping hull's size, not their bounding box...
	model = sv.models[ (int)sv.edicts->v.modelindex ];
	VectorSubtract (ent->v.maxs, ent->v.mins, size);
	if(ent->v.hull)
	{
		index = ent->v.hull-1;
		wclip_hull = &model->hulls[index];;
		if (!wclip_hull)  // Invalid hull
		{
			Con_Printf ("ERROR: hull %d is null.\n",wclip_hull);
			wclip_hull = &model->hulls[0];
		}
	}
	else  // Using the old way uses size to determine hull to use
	{
		if (size[0] < 3) // Point
			wclip_hull = &model->hulls[0];
		else if (size[0] <= 8)  // Pentacles
			wclip_hull = &model->hulls[4];
		else if (size[0] <= 32 && size[2] <= 28)  // Half Player
			wclip_hull = &model->hulls[3];
		else if (size[0] <= 32)  // Full Player
			wclip_hull = &model->hulls[1];
		else // Golumn
			wclip_hull = &model->hulls[5];
	}
	VectorAdd (ent->v.origin, wclip_hull->clip_mins, mins);
	VectorAdd (ent->v.origin, wclip_hull->clip_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<2 ; x++)
		for	(y=0 ; y<2 ; y++)
		{
			if(x)
				start[0] = maxs[0];
			else
				start[0] = mins[0];
			if(y)
				start[1] = maxs[1];
			else
				start[1] = mins[1];
//			start[0] = x ? maxs[0] : mins[0];
//			start[1] = y ? maxs[1] : mins[1];
			if (SV_PointContents (start) != CONTENTS_SOLID)
				goto realcheck;
		}

//	c_yes++;
	return true;		// we got out easy

realcheck:	// check it for real...
//	c_no++;

	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;
//do a trace from the bottom center of the ent down
//to 36 below the bottom center of the ent, using a point hull
//the "true" in this function is telling SV_Move to consider
//this ent's movement as MOVE_NOMONSTERS - means it will
//not clip against entities in this move
//NOTE: these don't check for trace_allsolid of trace_startsolid.
//Technically, these can't possibly be a valid result since
//the start point is in the ent, but what about imprecision?
	
	save_hull = ent->v.hull;//temp hack so it HullForEntity doesn't calculate the wrong offset
	ent->v.hull = 0;
	trace = SV_Move (start, vec3_origin, vec3_origin, stop, true, ent);
	ent->v.hull = save_hull;
	
/*	if((int)ent->v.flags&FL_MONSTER)
	{
		if(trace.allsolid)
			Con_DPrintf("Checkbottom midpoint check was all solid!!!\n");
		else if(trace.startsolid)
			Con_DPrintf("Checkbottom midpoint check started solid!!!\n");
	}
*/
	if (trace.fraction == 1.0)
		return false;
//trace did not reach full 36 below, so set mid and bottom
//to whatever distance it did get to below the ent's
//bottom centerpoint (start[2])
	mid = bottom = trace.endpos[2];

	// the corners must be within 16 of the midpoint	
	for	(x=0 ; x<2 ; x++)
		for	(y=0 ; y<2 ; y++)
		{//check 4 corners, in this order:
			//x = 0, y = 0 (NE)
			//x = 0, y = 1 (SE)
			//x = 1, y = 0 (NW)
			//x = 1, y = 1 (SW)
			if(x)
				start[0] = stop[0] = maxs[0];
			else
				start[0] = stop[0] = mins[0];
			if(y)
				start[1] = stop[1] = maxs[1];
			else
				start[1] = stop[1] = mins[1];
//			start[0] = stop[0] = x ? maxs[0] : mins[0];
//			start[1] = stop[1] = y ? maxs[1] : mins[1];
			
			//same check as above, just from the 4 corners down 36
			save_hull = ent->v.hull;//temp hack so it HullForEntity doesn't calculate the wrong offset
			ent->v.hull = 0;
			trace = SV_Move (start, vec3_origin, vec3_origin, stop, true, ent);
			ent->v.hull = save_hull;

/*			if((int)ent->v.flags&FL_MONSTER)
			{
				if(trace.allsolid)
					Con_DPrintf("Checkbottom (x=%d,y=%d) check was all solid!!!\n",x,y);
				else if(trace.startsolid)
					Con_DPrintf("Checkbottom (x=%d,y=%d) check started solid!!!\n",x,y);
			}*/
			//Hit a closer surface than did when checked center,
			//so set the "bottom" to the new, closer z height
			//we hit
			if (trace.fraction != 1.0 && trace.endpos[2] > bottom)
				bottom = trace.endpos[2];
			
			//one of the corners does not have a surface within
			//36 below it, or the surface it did hit is more than
			//54 below this corner.  This is a really stupid check,
			//because if it hits a surface more than 54 below the
			//ent,the trace_fraction will be 1
			if (trace.fraction == 1.0 || mid - trace.endpos[2] > STEPSIZE)
				return false;
		}

//	c_yes++;
	return true;
}


void set_move_trace(trace_t *trace)
{
	pr_global_struct->trace_allsolid = trace->allsolid;
	pr_global_struct->trace_startsolid = trace->startsolid;
	pr_global_struct->trace_fraction = trace->fraction;
	pr_global_struct->trace_inwater = trace->inwater;
	pr_global_struct->trace_inopen = trace->inopen;
	VectorCopy (trace->endpos, pr_global_struct->trace_endpos);
	VectorCopy (trace->plane.normal, pr_global_struct->trace_plane_normal);
	pr_global_struct->trace_plane_dist =  trace->plane.dist;	
	if (trace->ent)
		pr_global_struct->trace_ent = EDICT_TO_PROG(trace->ent);
	else
		pr_global_struct->trace_ent = EDICT_TO_PROG(sv.edicts);
}

/*
=============
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
=============
*/
qboolean SV_movestep (edict_t *ent, vec3_t move, qboolean relink, qboolean noenemy,
					  qboolean set_trace)
{
	float		dz;
	vec3_t		oldorg, neworg, end;
	trace_t		trace;
	int			i;
	edict_t		*enemy;

// try the move	
	VectorCopy (ent->v.origin, oldorg);
	VectorAdd (ent->v.origin, move, neworg);

// flying monsters don't step up, unless no_z turned on
	if ( ((int)ent->v.flags&(FL_SWIM|FL_FLY)) && !((int)ent->v.flags&FL_NOZ) && !((int)ent->v.flags&FL_HUNTFACE))
	{
	// try one move with vertical motion, then one without
		for (i=0 ; i<2 ; i++)
		{
			VectorAdd (ent->v.origin, move, neworg);
			if (!noenemy)
			{
				enemy = PROG_TO_EDICT(ent->v.enemy);
				if (i == 0 && enemy != sv.edicts)
				{
					if((int)ent->v.flags&FL_HUNTFACE)//Go for face
						dz = ent->v.origin[2] - PROG_TO_EDICT(ent->v.enemy)->v.origin[2] + PROG_TO_EDICT(ent->v.enemy)->v.view_ofs[2];
					else
						dz = ent->v.origin[2] - PROG_TO_EDICT(ent->v.enemy)->v.origin[2];

					if (dz > 40)
						neworg[2] -= 8;
					else if (dz < 30)
						neworg[2] += 8;
				}
			}

			if ( ((int)ent->v.flags & FL_SWIM) && SV_PointContents(neworg) == CONTENTS_EMPTY )
			{//Would end up out of water, don't do z move
				neworg[2]=ent->v.origin[2];
				trace = SV_Move (ent->v.origin, ent->v.mins, ent->v.maxs, neworg, false, ent);
				if (set_trace)
					set_move_trace(&trace);
				if(trace.fraction < 1||SV_PointContents(trace.endpos) == CONTENTS_EMPTY )
					return false;	// swim monster left water
			}
			else
			{
				trace = SV_Move (ent->v.origin, ent->v.mins, ent->v.maxs, neworg, false, ent);
				if (set_trace)
					set_move_trace(&trace);
			}
	
			if (trace.fraction == 1)
			{
				VectorCopy (trace.endpos, ent->v.origin);
				if (relink)
					SV_LinkEdict (ent, true);

				return true;
			}
			
			if (noenemy || enemy == sv.edicts)
				break;
		}
		
		return false;
	}

// push down from a step height above the wished position
	neworg[2] += STEPSIZE;
	VectorCopy (neworg, end);
	end[2] -= STEPSIZE*2;

	trace = SV_Move (neworg, ent->v.mins, ent->v.maxs, end, false, ent);

	if (set_trace)
		set_move_trace(&trace);

	if (trace.allsolid)
	{
		return false;
	}

	if (trace.startsolid)
	{
		neworg[2] -= STEPSIZE;
		trace = SV_Move (neworg, ent->v.mins, ent->v.maxs, end, false, ent);
		if (set_trace)
			set_move_trace(&trace);
		if (trace.allsolid || trace.startsolid)
		{
			return false;
		}
	}
	if (trace.fraction == 1)
	{
	// if monster had the ground pulled out, go ahead and fall
		if ( (int)ent->v.flags & FL_PARTIALGROUND )
		{
			VectorAdd (ent->v.origin, move, ent->v.origin);
			if (relink)
				SV_LinkEdict (ent, true);
			ent->v.flags = (int)ent->v.flags & ~FL_ONGROUND;
//	Con_Printf ("fall down\n"); 
			return true;
		}
	
		return false;		// walked off an edge
	}

// check point traces down for dangling corners
	VectorCopy (trace.endpos, ent->v.origin);
	
	if (!SV_CheckBottom (ent))
	{
		if ( (int)ent->v.flags & FL_PARTIALGROUND )
		{	// entity had floor mostly pulled out from underneath it
			// and is trying to correct
			if (relink)
				SV_LinkEdict (ent, true);
			return true;
		}
		VectorCopy (oldorg, ent->v.origin);

		return false;
	}

	if ( (int)ent->v.flags & FL_PARTIALGROUND )
	{
//		Con_Printf ("back on ground\n"); 
		ent->v.flags = (int)ent->v.flags & ~FL_PARTIALGROUND;
	}
	ent->v.groundentity = EDICT_TO_PROG(trace.ent);

// the move is ok
	if (relink)
		SV_LinkEdict (ent, true);
	return true;
}


//============================================================================

/*
======================
SV_StepDirection

Turns to the movement direction, and walks the current distance if
facing it.

======================
*/
void PF_changeyaw (void);
qboolean SV_StepDirection (edict_t *ent, float yaw, float dist)
{
	vec3_t		move, oldorigin;
	float		delta;
	qboolean    set_trace_plane;
	
	ent->v.ideal_yaw = yaw;
	PF_changeyaw();
	
	yaw = yaw*M_PI*2 / 360;
	move[0] = cos(yaw)*dist;
	move[1] = sin(yaw)*dist;
	move[2] = 0;//FIXME: Make wallcrawlers and flying monsters use this!

	VectorCopy (ent->v.origin, oldorigin);
	if((int)ent->v.flags & FL_SET_TRACE)
		set_trace_plane = true;
	else
		set_trace_plane = false;

	if (SV_movestep (ent, move, false, false, set_trace_plane))
	{
		delta = ent->v.angles[YAW] - ent->v.ideal_yaw;
		if (delta > 45 && delta < 315)
		{		// not turned far enough, so don't take the step
			VectorCopy (oldorigin, ent->v.origin);
		}
		SV_LinkEdict (ent, true);
		return true;
	}
	SV_LinkEdict (ent, true);
		
	return false;
}

/*
======================
SV_FixCheckBottom

======================
*/
void SV_FixCheckBottom (edict_t *ent)
{
//	Con_Printf ("SV_FixCheckBottom\n");
	
	ent->v.flags = (int)ent->v.flags | FL_PARTIALGROUND;
}



/*
================
SV_NewChaseDir

================
*/
#define	DI_NODIR	-1
void SV_NewChaseDir (edict_t *actor, edict_t *enemy, float dist)
{
	float		deltax,deltay,deltaz;
	float			d[3];
	float		tdir, olddir, turnaround;

	olddir = anglemod( (int)(actor->v.ideal_yaw/45)*45 );
	turnaround = anglemod(olddir - 180);

	deltax = enemy->v.origin[0] - actor->v.origin[0];
	deltay = enemy->v.origin[1] - actor->v.origin[1];

	if((int)actor->v.flags&FL_FLY)//Pentacles
		deltaz = enemy->v.origin[2] + enemy->v.view_ofs[2] - actor->v.origin[2];
	else
		deltaz = enemy->v.origin[2] - actor->v.origin[2];

	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;

/*	if (deltaz < -10)//Below
		d[0]= ;
	else if (deltaz>10)//above
		d[0]= ;
	else
		d[0]= 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))//If north/sounth diff is greater than east/west diff?!!
	{
		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->v.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 (!SV_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->v.absmin[i] > ent->v.absmax[i] + dist)
			return false;
		if (goal->v.absmax[i] < ent->v.absmin[i] - dist)
			return false;
	}
	return true;
}

/*
======================
SV_MoveToGoal

======================
*/
void SV_MoveToGoal (void)
{
	edict_t		*ent, *goal;
	float		dist;
#ifdef QUAKE2
	edict_t		*enemy;
#endif
	
	ent = PROG_TO_EDICT(pr_global_struct->self);//Entity moving
	goal = PROG_TO_EDICT(ent->v.goalentity);//it's goalentity
	dist = G_FLOAT(OFS_PARM0);//how far to move

//Reset trace_plane_normal
	VectorCopy(vec3_origin,pr_global_struct->trace_plane_normal);
	if ( !( (int)ent->v.flags & (FL_ONGROUND|FL_FLY|FL_SWIM) ) )
	{//If not onground, flying, or swimming, return 0
		G_FLOAT(OFS_RETURN) = 0;
		return;
	}

// if the next step hits the enemy, return immediately
#ifdef QUAKE2
	enemy = PROG_TO_EDICT(ent->v.enemy);//Convert a progs entity to an edict?
	if (enemy != sv.edicts &&  SV_CloseEnough (ent, enemy, dist) )//If edict is not world and 2 edicts close enough to touch if dist is moved
#else
	if ( PROG_TO_EDICT(ent->v.enemy) != sv.edicts &&  SV_CloseEnough (ent, goal, dist) )
#endif
	{
		G_FLOAT(OFS_RETURN) = 0;
		return;
	}

// bump around...
	if (!SV_StepDirection (ent, ent->v.ideal_yaw, dist))//If can't go in a direction (including step check) or 30% chance...
	{
		SV_NewChaseDir (ent, goal, dist);//Find a new direction to go in instead
		G_FLOAT(OFS_RETURN) = 0;
	}
	else
	{
		if ((rand()&3)==1)
		{
			SV_NewChaseDir (ent, goal, dist);//Find a new direction to go in instead
		}
		G_FLOAT(OFS_RETURN) = 1;
	}
	return;
}

/*
 * $Log: /H2 Mission Pack/SV_MOVE.C $
 * 
 * 17    3/18/98 4:46p Mgummelt
 * 
 * 16    3/16/98 6:38a Mgummelt
 * 
 * 15    3/14/98 5:13p Mgummelt
 * 
 * 14    3/13/98 1:51p Mgummelt
 * Fixed friction_change entity to work,  made checkbottom use the hull
 * mins/maxs for it's checks, not the bounding box's.
 * 
 * 13    3/13/98 12:02p Jmonroe
 * more fixes for hullforent
 * 
 * 12    3/13/98 5:01a Mgummelt
 * May have finally fixed that damn monster stair-stepping problem...
 * 
 * 11    3/06/98 12:14p Jweier
 * 
 * 10    3/04/98 4:24p Jweier
 * 
 * 9     2/03/98 10:56a Mgummelt
 * 
 * 8     2/02/98 10:28a Mgummelt
 * 
 * 7     1/22/98 5:52p Mgummelt
 * 
 * 6     1/22/98 5:01p Mgummelt
 * 
 * 5     1/14/98 7:44p Mgummelt
 * 
 * 4     5/07/97 11:13a Rjohnson
 * Added a new field to the movement routines to allow setting of the
 * traceline info
 * 
 * 3     2/18/97 4:33p Rjohnson
 * Id Updates
 * 
 * 2     11/26/96 4:10p Rjohnson
 * Added sv_movestep to the quake c external functions.  Modified the
 * routine so that it can ignore enemy positions.
 */