fteqw/engine/common/pmove.c

/*
Copyright (C) 1996-1997 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 "quakedef.h"

extern float pm_stepheight;

movevars_t		movevars;
playermove_t	pmove;

float		frametime;

vec3_t		forward, right, up;

vec3_t	player_mins = {-16, -16, -24};
vec3_t	player_maxs = {16, 16, 32};


void PM_Init (void)
{
	PM_InitBoxHull();
}

#define	MIN_STEP_NORMAL	0.7		// roughly 45 degrees

#define pm_flyfriction 4

#define	STOP_EPSILON	0.1
#define BLOCKED_FLOOR	1
#define BLOCKED_STEP	2
#define BLOCKED_OTHER	4
#define BLOCKED_ANY		7

/*
==================
PM_ClipVelocity

Slide off of the impacting object
returns the blocked flags (1 = floor, 2 = step / wall)
==================
*/

int PM_ClipVelocity (vec3_t in, vec3_t normal, vec3_t out, float overbounce)
{
	float	backoff;
	float	change;
	int		i, blocked;

	blocked = 0;
	if (normal[2] > 0)
		blocked |= BLOCKED_FLOOR;		// floor
	if (!normal[2])
		blocked |= BLOCKED_STEP;		// step

	backoff = DotProduct (in, normal) * overbounce;

	for (i=0 ; i<3 ; i++)
	{
		change = normal[i]*backoff;
		out[i] = in[i] - change;
		if (out[i] > -STOP_EPSILON && out[i] < STOP_EPSILON)
			out[i] = 0;
	}

	return blocked;
}


/*
============
PM_SlideMove

The basic solid body movement clip that slides along multiple planes
============
*/
#define	MAX_CLIP_PLANES	5

int PM_SlideMove (void)
{
	int			bumpcount, numbumps;
	vec3_t		dir;
	float		d;
	int			numplanes;
	vec3_t		planes[MAX_CLIP_PLANES];
	vec3_t		primal_velocity, original_velocity;
	int			i, j;
	trace_t		trace;
	vec3_t		end;
	float		time_left;
	int			blocked;

	numbumps = 4;

	blocked = 0;
	VectorCopy (pmove.velocity, original_velocity);
	VectorCopy (pmove.velocity, primal_velocity);
	numplanes = 0;

	time_left = frametime;

	for (bumpcount=0 ; bumpcount<numbumps ; bumpcount++)
	{
		for (i=0 ; i<3 ; i++)
			end[i] = pmove.origin[i] + time_left * pmove.velocity[i];

		trace = PM_PlayerTrace (pmove.origin, end);

		if (trace.startsolid || trace.allsolid)
		{	// entity is trapped in another solid
			VectorClear (pmove.velocity);
			return 3;
		}

		if (trace.fraction > 0)
		{	// actually covered some distance
			VectorCopy (trace.endpos, pmove.origin);
			numplanes = 0;
		}

		if (trace.fraction == 1)
			 break;		// moved the entire distance

		// save entity for contact
		if (pmove.numtouch < MAX_PHYSENTS)
		{
			pmove.touchindex[pmove.numtouch] = trace.entnum;
			pmove.numtouch++;
		}

		if (trace.plane.normal[2] >= MIN_STEP_NORMAL)
			blocked |= BLOCKED_FLOOR;
		else if (!trace.plane.normal[2])
			blocked |= BLOCKED_STEP;
		else
			blocked |= BLOCKED_OTHER;

		time_left -= time_left * trace.fraction;

	// cliped to another plane
		if (numplanes >= MAX_CLIP_PLANES)
		{	// this shouldn't really happen
			VectorClear (pmove.velocity);
			break;
		}

		VectorCopy (trace.plane.normal, planes[numplanes]);
		numplanes++;

//
// modify original_velocity so it parallels all of the clip planes
//
		for (i=0 ; i<numplanes ; i++)
		{
			if (movevars.walljump == 2)	//just bounce off!
			{	//pinball
				PM_ClipVelocity (original_velocity, planes[i], pmove.velocity, 2);
				return blocked;
			}
			//regular run at a wall and jump off
			if (movevars.walljump && planes[i][2] != 1	//not on floors
				&& Length(pmove.velocity)>200 && pmove.cmd.buttons & 2 && !pmove.jump_held && !pmove.waterjumptime)
			{
				PM_ClipVelocity (original_velocity, planes[i], pmove.velocity, 2);
				if (pmove.velocity[2] < 270)
					pmove.velocity[2] = 270;
				pmove.jump_msec = pmove.cmd.msec;
				pmove.jump_held = true;
				pmove.waterjumptime = 0;
				return blocked;
			}
			PM_ClipVelocity (original_velocity, planes[i], pmove.velocity, 1);
			for (j=0 ; j<numplanes ; j++)
				if (j != i)
				{
					if (DotProduct (pmove.velocity, planes[j]) < 0)
						break;	// not ok
				}
			if (j == numplanes)
				break;
		}

		if (i != numplanes)
		{	// go along this plane
		}
		else
		{	// go along the crease
			if (numplanes != 2)
			{
				VectorClear (pmove.velocity);
				break;
			}
			CrossProduct (planes[0], planes[1], dir);
			d = DotProduct (dir, pmove.velocity);
			VectorScale (dir, d, pmove.velocity);
		}

//
// if velocity is against the original velocity, stop dead
// to avoid tiny occilations in sloping corners
//
		if (DotProduct (pmove.velocity, primal_velocity) <= 0)
		{
			VectorClear (pmove.velocity);
			break;
		}
	}

	if (pmove.waterjumptime)
	{
		VectorCopy (primal_velocity, pmove.velocity);
	}
	return blocked;
}

/*
=============
PM_StepSlideMove

Each intersection will try to step over the obstruction instead of
sliding along it.
=============
*/
void PM_StepSlideMove (void)
{
	vec3_t	dest;
	trace_t	trace;
	vec3_t	original, originalvel, down, up, downvel;
	float	downdist, updist;
	int		blocked;

	// try sliding forward both on ground and up 16 pixels
	// take the move that goes farthest
	VectorCopy (pmove.origin, original);
	VectorCopy (pmove.velocity, originalvel);

	blocked = PM_SlideMove ();

	if (!blocked)
		return;		// moved the entire distance

	VectorCopy (pmove.origin, down);
	VectorCopy (pmove.velocity, downvel);

	VectorCopy (original, pmove.origin);
	VectorCopy (originalvel, pmove.velocity);

// move up a stair height
	VectorCopy (pmove.origin, dest);
	dest[2] += pm_stepheight;
	trace = PM_PlayerTrace (pmove.origin, dest);
	if (!trace.startsolid && !trace.allsolid)
	{
		VectorCopy (trace.endpos, pmove.origin);
	}

	PM_SlideMove ();

// press down the stepheight
	VectorCopy (pmove.origin, dest);
	dest[2] -= pm_stepheight;
	trace = PM_PlayerTrace (pmove.origin, dest);
	if (trace.fraction != 1 && trace.plane.normal[2] < MIN_STEP_NORMAL)
		goto usedown;
	if (!trace.startsolid && !trace.allsolid)
	{
		VectorCopy (trace.endpos, pmove.origin);
	}

	if (pmove.origin[2] < original[2])
		goto usedown;

	VectorCopy (pmove.origin, up);

	// decide which one went farther
	downdist = (down[0] - original[0])*(down[0] - original[0])
		+ (down[1] - original[1])*(down[1] - original[1]);
	updist = (up[0] - original[0])*(up[0] - original[0])
		+ (up[1] - original[1])*(up[1] - original[1]);

	if (downdist >= updist)
	{
usedown:
		VectorCopy (down, pmove.origin);
		VectorCopy (downvel, pmove.velocity);
		return;
	}

	// copy z value from slide move
	pmove.velocity[2] = downvel[2];

	if (!pmove.onground && pmove.waterlevel < 2 && (blocked & BLOCKED_STEP)) {
		float scale;
		// in pm_airstep mode, walking up a 16 unit high step
		// will kill 16% of horizontal velocity
		scale = 1 - 0.01*(pmove.origin[2] - original[2]);
		pmove.velocity[0] *= scale;
		pmove.velocity[1] *= scale;
	}
}



/*
==================
PM_Friction

Handles both ground friction and water friction
==================
*/
void PM_Friction (void)
{
	float	speed, newspeed, control;
	float	friction;
	float	drop;
	vec3_t	start, stop;
	trace_t	trace;

	if (pmove.waterjumptime)
		return;

	speed = Length(pmove.velocity);
	if (speed < 1)
	{
		pmove.velocity[0] = 0;
		pmove.velocity[1] = 0;
		if (pmove.pm_type == PM_FLY)
			pmove.velocity[2] = 0;
		return;
	}

	if (pmove.waterlevel >= 2)
		// apply water friction, even if in fly mode
		drop = speed*movevars.waterfriction*pmove.waterlevel*frametime;
	else if (pmove.pm_type == PM_FLY) {
		// apply flymode friction
		drop = speed * pm_flyfriction * frametime;
	}
	else if (pmove.onground) {
		// apply ground friction
		friction = movevars.friction;

		// if the leading edge is over a dropoff, increase friction
		start[0] = stop[0] = pmove.origin[0] + pmove.velocity[0]/speed*16;
		start[1] = stop[1] = pmove.origin[1] + pmove.velocity[1]/speed*16;
		start[2] = pmove.origin[2] + player_mins[2];
		stop[2] = start[2] - 34;
		trace = PM_PlayerTrace (start, stop);
		if (trace.fraction == 1)
			friction *= 2;

		control = speed < movevars.stopspeed ? movevars.stopspeed : speed;
		drop = control*friction*frametime;
	}
	else if (pmove.onladder)
	{
		control = speed < movevars.stopspeed ? movevars.stopspeed : speed;
		drop = control*movevars.friction*frametime*6;
	}
	else
		return;		// in air, no friction

// scale the velocity
	newspeed = speed - drop;
	if (newspeed < 0)
		newspeed = 0;

	VectorScale (pmove.velocity, newspeed / speed, pmove.velocity);
}


/*
==============
PM_Accelerate
==============
*/
void PM_Accelerate (vec3_t wishdir, float wishspeed, float accel)
{
	int			i;
	float		addspeed, accelspeed, currentspeed;

	if (pmove.pm_type == PM_DEAD)
		return;
	if (pmove.waterjumptime)
		return;

	currentspeed = DotProduct (pmove.velocity, wishdir);
	addspeed = wishspeed - currentspeed;
	if (addspeed <= 0)
		return;
	accelspeed = accel*frametime*wishspeed;
	if (accelspeed > addspeed)
		accelspeed = addspeed;

	for (i=0 ; i<3 ; i++)
		pmove.velocity[i] += accelspeed*wishdir[i];
}

void PM_AirAccelerate (vec3_t wishdir, float wishspeed, float accel)
{
	int			i;
	float		addspeed, accelspeed, currentspeed, wishspd = wishspeed;
	float		originalspeed, newspeed, speedcap;

	if (pmove.pm_type == PM_DEAD)
		return;
	if (pmove.waterjumptime)
		return;

	if (movevars.bunnyspeedcap > 0)
	{
		originalspeed = sqrt(pmove.velocity[0]*pmove.velocity[0] +
						pmove.velocity[1]*pmove.velocity[1]);
	}
	else
		originalspeed = 0;	//shh compiler.

	if (wishspd > 30)
		wishspd = 30;
	currentspeed = DotProduct (pmove.velocity, wishdir);
	addspeed = wishspd - currentspeed;
	if (addspeed <= 0)
		return;
	accelspeed = accel * wishspeed * frametime;
	if (accelspeed > addspeed)
		accelspeed = addspeed;

	for (i=0 ; i<3 ; i++)
		pmove.velocity[i] += accelspeed*wishdir[i];

	if (movevars.bunnyspeedcap > 0)
	{
		newspeed = sqrt(pmove.velocity[0]*pmove.velocity[0] +
					pmove.velocity[1]*pmove.velocity[1]);
		if (newspeed > originalspeed)
		{
			speedcap = movevars.maxspeed * movevars.bunnyspeedcap;
			if (newspeed > speedcap)
			{
				if (originalspeed < speedcap)
					originalspeed = speedcap;
				pmove.velocity[0] *= originalspeed / newspeed;
				pmove.velocity[1] *= originalspeed / newspeed;
			}
		}
	}
}



/*
===================
PM_WaterMove
===================
*/
void PM_WaterMove (void)
{
	int		i;
	vec3_t	wishvel;
	float	wishspeed;
	vec3_t	wishdir;

//
// user intentions
//
	for (i=0 ; i<3 ; i++)
		wishvel[i] = forward[i]*pmove.cmd.forwardmove + right[i]*pmove.cmd.sidemove;

	if (pmove.pm_type != PM_FLY && !pmove.cmd.forwardmove && !pmove.cmd.sidemove && !pmove.cmd.upmove)
		wishvel[2] -= 60;		// drift towards bottom
	else
		wishvel[2] += pmove.cmd.upmove;

	VectorCopy (wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);

	if (wishspeed > movevars.maxspeed) {
		VectorScale (wishvel, movevars.maxspeed/wishspeed, wishvel);
		wishspeed = movevars.maxspeed;
	}
	wishspeed *= 0.7;

//
// water acceleration
//
	PM_Accelerate (wishdir, wishspeed, movevars.wateraccelerate);

	PM_StepSlideMove ();
}


/*
*/
void PM_FlyMove ()
{
	int		i;
	vec3_t	wishvel;
	float	wishspeed;
	vec3_t	wishdir;

	for (i=0 ; i<3 ; i++)
		wishvel[i] = forward[i]*pmove.cmd.forwardmove + right[i]*pmove.cmd.sidemove;

	wishvel[2] += pmove.cmd.upmove;

	VectorCopy (wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);

	if (wishspeed > movevars.maxspeed) {
		VectorScale (wishvel, movevars.maxspeed/wishspeed, wishvel);
		wishspeed = movevars.maxspeed;
	}

	PM_Accelerate (wishdir, wishspeed, movevars.accelerate);

	PM_StepSlideMove ();
}

void PM_LadderMove (void)
{
	int		i;
	vec3_t	wishvel;
	float	wishspeed;
	vec3_t	wishdir;
	vec3_t	start, dest;
	trace_t	trace;

//
// user intentions
//
	for (i=0 ; i<3 ; i++)
		wishvel[i] = forward[i]*pmove.cmd.forwardmove + right[i]*pmove.cmd.sidemove + up[i]*pmove.cmd.upmove;

	if (wishvel[2] > 100 || wishvel[2] < -100)	//large up/down move
		wishvel[2]*=10;

	if (pmove.cmd.buttons & 2)
		wishvel[2]+=100;

	VectorCopy (wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);

	if (wishspeed > movevars.maxspeed)
	{
		VectorScale (wishvel, movevars.maxspeed/wishspeed, wishvel);
		wishspeed = movevars.maxspeed;
	}

	PM_Accelerate (wishdir, wishspeed, movevars.wateraccelerate);

// assume it is a stair or a slope, so press down from stepheight above
	VectorMA (pmove.origin, frametime, pmove.velocity, dest);
	VectorCopy (dest, start);
	start[2] += pm_stepheight + 1;
	trace = PM_PlayerTrace (start, dest);
	if (!trace.startsolid && !trace.allsolid)	// FIXME: check steep slope?
	{	// walked up the step
		VectorCopy (trace.endpos, pmove.origin);
		return;
	}

	PM_FlyMove ();

}

/*
===================
PM_AirMove

===================
*/
void PM_AirMove (void)
{
	int			i;
	vec3_t		wishvel;
	float		fmove, smove;
	vec3_t		wishdir;
	float		wishspeed;

	fmove = pmove.cmd.forwardmove;
	smove = pmove.cmd.sidemove;

	forward[2] = 0;
	right[2] = 0;
	VectorNormalize (forward);
	VectorNormalize (right);

	for (i=0 ; i<2 ; i++)
		wishvel[i] = forward[i]*fmove + right[i]*smove;
	wishvel[2] = 0;

	VectorCopy (wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);

//
// clamp to server defined max speed
//
	if (wishspeed > movevars.maxspeed)
	{
		VectorScale (wishvel, movevars.maxspeed/wishspeed, wishvel);
		wishspeed = movevars.maxspeed;
	}

	if (pmove.onground)
	{
		if (pmove.velocity[2] > 0 || !movevars.slidefix)
			pmove.velocity[2] = 0;
		PM_Accelerate (wishdir, wishspeed, movevars.accelerate);
		pmove.velocity[2] -= movevars.entgravity * movevars.gravity * frametime;

		if (!pmove.velocity[0] && !pmove.velocity[1] && !movevars.slidyslopes)
		{
			pmove.velocity[2] = 0;
			return;
		}
		else if (!movevars.slidefix && !movevars.slidyslopes)
			pmove.velocity[2] = 0;

		PM_StepSlideMove ();
	}
	else
	{	// not on ground, so little effect on velocity
		PM_AirAccelerate (wishdir, wishspeed, movevars.accelerate);
//		PM_Accelerate (wishdir, wishspeed, movevars.airaccelerate);

		// add gravity
		pmove.velocity[2] -= movevars.entgravity * movevars.gravity * frametime;

		if (movevars.airstep)
			PM_StepSlideMove ();
		else
			PM_SlideMove ();
	}
}


cplane_t	groundplane;

/*
=============
PM_CategorizePosition
=============
*/
void PM_CategorizePosition (void)
{
	vec3_t		point;
	int			cont;
	trace_t		trace;

// if the player hull point one unit down is solid, the player
// is on ground

// see if standing on something solid
	point[0] = pmove.origin[0];
	point[1] = pmove.origin[1];
	point[2] = pmove.origin[2] - 1;
	trace.startsolid = trace.allsolid = true;
	VectorClear(trace.endpos);
	if (pmove.velocity[2] > 180)
	{
		pmove.onground = false;
	}
	else
	{
		trace = PM_PlayerTrace (pmove.origin, point);
		if (trace.fraction == 1 || trace.plane.normal[2] < MIN_STEP_NORMAL)
			pmove.onground = false;
		else
		{
			pmove.onground = true;
			pmove.groundent = trace.entnum;
			groundplane = trace.plane;
			pmove.waterjumptime = 0;
		}

		// standing on an entity other than the world
		if (trace.entnum > 0)
		{
			if (pmove.numtouch < MAX_PHYSENTS) {
				pmove.touchindex[pmove.numtouch] = trace.entnum;
				pmove.numtouch++;
			}
		}
	}

//
// get waterlevel
//
	pmove.waterlevel = 0;
	pmove.watertype = FTECONTENTS_EMPTY;

	point[2] = pmove.origin[2] + player_mins[2] + 1;
	cont = PM_PointContents (point);

	if (cont & FTECONTENTS_FLUID)
	{
		pmove.watertype = cont;
		pmove.waterlevel = 1;
		point[2] = pmove.origin[2] + (player_mins[2] + player_maxs[2])*0.5;
		cont = PM_PointContents (point);
		if (cont & FTECONTENTS_FLUID)
		{
			pmove.waterlevel = 2;
			point[2] = pmove.origin[2] + player_mins[2]+24+DEFAULT_VIEWHEIGHT;
			cont = PM_PointContents (point);
			if (cont & FTECONTENTS_FLUID)
				pmove.waterlevel = 3;
		}
	}

	//are we on a ladder?
#ifdef Q2BSPS
	if (pmove.physents[0].model->fromgame == fg_quake3)
	{
		trace_t t;
		vec3_t flatforward, fwd1;

		flatforward[0] = forward[0];
		flatforward[1] = forward[1];
		flatforward[2] = 0;
		VectorNormalize (flatforward);

		VectorMA (pmove.origin, 24, flatforward, fwd1);

		t = CM_BoxTrace(pmove.physents[0].model, pmove.origin, fwd1, player_mins, player_maxs, MASK_PLAYERSOLID);
		if (t.surface->flags & Q3SURF_LADDER)
		{
			pmove.onladder = true;
			pmove.onground = false;	// too steep
		}
	}
	if (cont & FTECONTENTS_LADDER && pmove.physents[0].model->fromgame == fg_quake2)
	{
		trace_t t;
		vec3_t flatforward, fwd1;

		flatforward[0] = forward[0];
		flatforward[1] = forward[1];
		flatforward[2] = 0;
		VectorNormalize (flatforward);

		VectorMA (pmove.origin, 24, flatforward, fwd1);

		//if we hit a wall when going forwards and we are in a ladder region, then we are on a ladder.
		if (pmove.physents[0].model->fromgame == fg_quake2)
		{
			t = CM_BoxTrace(pmove.physents[0].model, pmove.origin, fwd1, player_mins, player_maxs, MASK_PLAYERSOLID);
			if (t.fraction < 1)
			{
				pmove.onladder = true;
				pmove.onground = false;	// too steep
			}
		}
	}
#endif

	if (pmove.onground && pmove.pm_type != PM_FLY && pmove.waterlevel < 3)
	{
		// snap to ground so that we can't jump higher than we're supposed to
		if (!trace.startsolid && !trace.allsolid)
			VectorCopy (trace.endpos, pmove.origin);
	}
}


/*
=============
PM_CheckJump
=============
*/
void PM_CheckJump (void)
{
	if (pmove.pm_type == PM_FLY)
		return;

	if (pmove.pm_type == PM_DEAD)
	{
		pmove.jump_held = true;	// don't jump on respawn
		return;
	}

	if (!(pmove.cmd.buttons & BUTTON_JUMP))
	{
		pmove.jump_held = false;
		return;
	}

	if (pmove.waterjumptime)
		return;

	if (pmove.waterlevel >= 2)
	{	// swimming, not jumping
		pmove.onground = false;

		if (pmove.watertype == FTECONTENTS_WATER)
			pmove.velocity[2] = 100;
		else if (pmove.watertype == FTECONTENTS_SLIME)
			pmove.velocity[2] = 80;
		else
			pmove.velocity[2] = 50;
		return;
	}

	if (!pmove.onground)
		return;		// in air, so no effect

	if (pmove.jump_held && !pmove.jump_msec)
		return;		// don't pogo stick

	// check for jump bug
	// groundplane normal was set in the call to PM_CategorizePosition
	if (pmove.velocity[2] < 0 &&
		DotProduct(pmove.velocity, groundplane.normal) < -0.1)
	{
		// pmove.velocity is pointing into the ground, clip it
		PM_ClipVelocity (pmove.velocity, groundplane.normal, pmove.velocity, 1);
	}

	pmove.onground = false;
	pmove.velocity[2] += 270;

	if (movevars.ktjump > 0)
	{
		if (movevars.ktjump > 1)
			movevars.ktjump = 1;
		if (pmove.velocity[2] < 270)
			pmove.velocity[2] = pmove.velocity[2] * (1 - movevars.ktjump)
				+ 270 * movevars.ktjump;
	}

	pmove.jump_held = true;		// don't jump again until released

	pmove.jump_msec = pmove.cmd.msec;
}

/*
=============
PM_CheckWaterJump
=============
*/
void PM_CheckWaterJump (void)
{
	vec3_t	spot;
	int		cont;
	vec3_t	flatforward;

	if (pmove.waterjumptime>0)
		return;

	// don't hop out if we just jumped in
	if (pmove.velocity[2] < -180)
		return;

	// see if near an edge
	flatforward[0] = forward[0];
	flatforward[1] = forward[1];
	flatforward[2] = 0;
	VectorNormalize (flatforward);

	VectorMA (pmove.origin, 24, flatforward, spot);
	spot[2] += 8 + 24+player_mins[2];	//hexen2 fix. calculated from the normal bottom of bbox
	cont = PM_PointContents (spot);
	if (!(cont & FTECONTENTS_SOLID))
		return;
	spot[2] += 24;
	cont = PM_PointContents (spot);
	if (cont != FTECONTENTS_EMPTY)
		return;
	// jump out of water
	VectorScale (flatforward, 50, pmove.velocity);
	pmove.velocity[2] = 310;
	pmove.waterjumptime = 2;	// safety net
	pmove.jump_held = true;		// don't jump again until released
}

/*
=================
PM_NudgePosition

If pmove.origin is in a solid position,
try nudging slightly on all axis to
allow for the cut precision of the net coordinates
=================
*/
void PM_NudgePosition (void)
{
	vec3_t	base;
	int		x, y, z;
	int		i;
	static int	sign[3] = {0, -1, 1};

	VectorCopy (pmove.origin, base);

	for (i=0 ; i<3 ; i++)
		pmove.origin[i] = ((int)(pmove.origin[i]*8)) * 0.125;

	for (z=0 ; z<=2 ; z++)
	{
		for (x=0 ; x<=2 ; x++)
		{
			for (y=0 ; y<=2 ; y++)
			{
				pmove.origin[0] = base[0] + (sign[x] * 1.0/8);
				pmove.origin[1] = base[1] + (sign[y] * 1.0/8);
				pmove.origin[2] = base[2] + (sign[z] * 1.0/8);
				if (PM_TestPlayerPosition (pmove.origin))
					return;
			}
		}
	}
	VectorCopy (base, pmove.origin);
//	Com_DPrintf ("NudgePosition: stuck\n");
}

/*
===============
PM_SpectatorMove
===============
*/
void PM_SpectatorMove (void)
{
	float	speed, drop, friction, control, newspeed;
	float	currentspeed, addspeed, accelspeed;
	int			i;
	vec3_t		wishvel;
	float		fmove, smove;
	vec3_t		wishdir;
	float		wishspeed;

	// friction

	speed = Length (pmove.velocity);
	if (speed < 1)
	{
		VectorClear (pmove.velocity);
	}
	else
	{
		drop = 0;

		friction = movevars.friction*1.5;	// extra friction
		control = speed < movevars.stopspeed ? movevars.stopspeed : speed;
		drop += control*friction*frametime;

		// scale the velocity
		newspeed = speed - drop;
		if (newspeed < 0)
			newspeed = 0;
		newspeed /= speed;

		VectorScale (pmove.velocity, newspeed, pmove.velocity);
	}

	// accelerate
	fmove = pmove.cmd.forwardmove;
	smove = pmove.cmd.sidemove;

	VectorNormalize (forward);
	VectorNormalize (right);

	for (i=0 ; i<3 ; i++)
		wishvel[i] = forward[i]*fmove + right[i]*smove;
	wishvel[2] += pmove.cmd.upmove;

	VectorCopy (wishvel, wishdir);
	wishspeed = VectorNormalize(wishdir);

	//
	// clamp to server defined max speed
	//
	if (wishspeed > movevars.spectatormaxspeed)
	{
		VectorScale (wishvel, movevars.spectatormaxspeed/wishspeed, wishvel);
		wishspeed = movevars.spectatormaxspeed;
	}

	currentspeed = DotProduct(pmove.velocity, wishdir);
	addspeed = wishspeed - currentspeed;

	// Buggy QW spectator mode, kept for compatibility
	if (pmove.pm_type == PM_OLD_SPECTATOR)
	{
		if (addspeed <= 0)
			return;
	}

	if (addspeed > 0) {
		accelspeed = movevars.accelerate*frametime*wishspeed;
		if (accelspeed > addspeed)
			accelspeed = addspeed;

		for (i=0 ; i<3 ; i++)
			pmove.velocity[i] += accelspeed*wishdir[i];
	}

	// move
	VectorMA (pmove.origin, frametime, pmove.velocity, pmove.origin);
}

/*
=============
PM_PlayerMove

Returns with origin, angles, and velocity modified in place.

Numtouch and touchindex[] will be set if any of the physents
were contacted during the move.
=============
*/
void PM_PlayerMove (float gamespeed)
{
	frametime = pmove.cmd.msec * 0.001*gamespeed;
	pmove.numtouch = 0;

	if (pmove.pm_type == PM_NONE || pmove.pm_type == PM_FREEZE) {
		PM_CategorizePosition ();
		return;
	}

	// take angles directly from command
	pmove.angles[0] = SHORT2ANGLE(pmove.cmd.angles[0]);
	pmove.angles[1] = SHORT2ANGLE(pmove.cmd.angles[1]);
	pmove.angles[2] = SHORT2ANGLE(pmove.cmd.angles[2]);

	AngleVectors (pmove.angles, forward, right, up);

	if (pmove.pm_type == PM_SPECTATOR || pmove.pm_type == PM_OLD_SPECTATOR)
	{
		PM_SpectatorMove ();
		pmove.onground = false;
		return;
	}

	PM_NudgePosition ();

	// set onground, watertype, and waterlevel
	PM_CategorizePosition ();

	if (pmove.waterlevel == 2 && pmove.pm_type != PM_FLY)
		PM_CheckWaterJump ();

	if (pmove.velocity[2] < 0 || pmove.pm_type == PM_DEAD)
		pmove.waterjumptime = 0;

	if (pmove.waterjumptime)
	{
		pmove.waterjumptime -= frametime;
		if (pmove.waterjumptime < 0)
			pmove.waterjumptime = 0;
	}

	if (pmove.jump_msec)
	{
		pmove.jump_msec += pmove.cmd.msec;
		if (pmove.jump_msec > 50)
			pmove.jump_msec = 0;
	}

	PM_CheckJump ();

	PM_Friction ();

	if (pmove.waterlevel >= 2)
		PM_WaterMove ();
	else if (pmove.pm_type == PM_FLY)
		PM_FlyMove ();
	else if (pmove.onladder)
		PM_LadderMove ();
	else
		PM_AirMove ();

	// set onground, watertype, and waterlevel for final spot
	PM_CategorizePosition ();

	// this is to make sure landing sound is not played twice
	// and falling damage is calculated correctly
	if (pmove.onground && pmove.velocity[2] < -300
		&& DotProduct(pmove.velocity, groundplane.normal) < -0.1)
	{
		PM_ClipVelocity (pmove.velocity, groundplane.normal, pmove.velocity, 1);
	}
}