pmove.c

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

// see if standing on something solid	
	point[0] = pml.origin[0];
	point[1] = pml.origin[1];
	point[2] = pml.origin[2] - 0.25;
	if (pml.velocity[2] > 180) //!!ZOID changed from 100 to 180 (ramp accel)
	{
		pm->s.pm_flags &= ~PMF_ON_GROUND;
		pm->groundentity = NULL;
	}
	else
	{
		trace = pm->trace (pml.origin, pm->mins, pm->maxs, point);
		pml.groundplane = trace.plane;
		pml.groundsurface = trace.surface;
		pml.groundcontents = trace.contents;

		if (!trace.ent || (trace.plane.normal[2] < 0.7 && !trace.startsolid) )
		{
			pm->groundentity = NULL;
			pm->s.pm_flags &= ~PMF_ON_GROUND;
		}
		else
		{
			pm->groundentity = trace.ent;

			// hitting solid ground will end a waterjump
			if (pm->s.pm_flags & PMF_TIME_WATERJUMP)
			{
				pm->s.pm_flags &= ~(PMF_TIME_WATERJUMP | PMF_TIME_LAND | PMF_TIME_TELEPORT);
				pm->s.pm_time = 0;
			}

			if (! (pm->s.pm_flags & PMF_ON_GROUND) )
			{	// just hit the ground
				pm->s.pm_flags |= PMF_ON_GROUND;
				// don't do landing time if we were just going down a slope
				if (pml.velocity[2] < -200)
				{
					pm->s.pm_flags |= PMF_TIME_LAND;
					// don't allow another jump for a little while
					if (pml.velocity[2] < -400)
						pm->s.pm_time = 25;	
					else
						pm->s.pm_time = 18;
				}
			}
		}

#if 0
		if (trace.fraction < 1.0 && trace.ent && pml.velocity[2] < 0)
			pml.velocity[2] = 0;
#endif

		if (pm->numtouch < MAXTOUCH && trace.ent)
		{
			pm->touchents[pm->numtouch] = trace.ent;
			pm->numtouch++;
		}
	}

//
// get waterlevel, accounting for ducking
//
	pm->waterlevel = 0;
	pm->watertype = 0;

	sample2 = pm->viewheight - pm->mins[2];
	sample1 = sample2 / 2;

	point[2] = pml.origin[2] + pm->mins[2] + 1;	
	cont = pm->pointcontents (point);

	if (cont & MASK_WATER)
	{
		pm->watertype = cont;
		pm->waterlevel = 1;
		point[2] = pml.origin[2] + pm->mins[2] + sample1;
		cont = pm->pointcontents (point);
		if (cont & MASK_WATER)
		{
			pm->waterlevel = 2;
			point[2] = pml.origin[2] + pm->mins[2] + sample2;
			cont = pm->pointcontents (point);
			if (cont & MASK_WATER)
				pm->waterlevel = 3;
		}
	}

}


/*
=============
PM_CheckJump
=============
*/
void PM_CheckJump (void)
{
	if (pm->s.pm_flags & PMF_TIME_LAND)
	{	// hasn't been long enough since landing to jump again
		return;
	}

	if (pm->cmd.upmove < 10)
	{	// not holding jump
		pm->s.pm_flags &= ~PMF_JUMP_HELD;
		return;
	}

	// must wait for jump to be released
	if (pm->s.pm_flags & PMF_JUMP_HELD)
		return;

	if (pm->s.pm_type == PM_DEAD)
		return;

	if (pm->waterlevel >= 2)
	{	// swimming, not jumping
		pm->groundentity = NULL;

		if (pml.velocity[2] <= -300)
			return;

		if (pm->watertype == CONTENTS_WATER)
			pml.velocity[2] = 100;
		else if (pm->watertype == CONTENTS_SLIME)
			pml.velocity[2] = 80;
		else
			pml.velocity[2] = 50;
		return;
	}

	if (pm->groundentity == NULL)
		return;		// in air, so no effect

	pm->s.pm_flags |= PMF_JUMP_HELD;

	pm->groundentity = NULL;
	pml.velocity[2] += 270;
	if (pml.velocity[2] < 270)
		pml.velocity[2] = 270;
}


/*
=============
PM_CheckSpecialMovement
=============
*/
void PM_CheckSpecialMovement (void)
{
	vec3_t	spot;
	int		cont;
	vec3_t	flatforward;
	trace_t	trace;

	if (pm->s.pm_time)
		return;

	pml.ladder = false;

	// check for ladder
	flatforward[0] = pml.forward[0];
	flatforward[1] = pml.forward[1];
	flatforward[2] = 0;
	VectorNormalize (flatforward);

	VectorMA (pml.origin, 1, flatforward, spot);
	trace = pm->trace (pml.origin, pm->mins, pm->maxs, spot);
	if ((trace.fraction < 1) && (trace.contents & CONTENTS_LADDER))
		pml.ladder = true;

	// check for water jump
	if (pm->waterlevel != 2)
		return;

	VectorMA (pml.origin, 30, flatforward, spot);
	spot[2] += 4;
	cont = pm->pointcontents (spot);
	if (!(cont & CONTENTS_SOLID))
		return;

	spot[2] += 16;
	cont = pm->pointcontents (spot);
	if (cont)
		return;
	// jump out of water
	VectorScale (flatforward, 50, pml.velocity);
	pml.velocity[2] = 350;

	pm->s.pm_flags |= PMF_TIME_WATERJUMP;
	pm->s.pm_time = 255;
}


/*
===============
PM_FlyMove
===============
*/
void PM_FlyMove (qboolean doclip)
{
	float	speed, drop, friction, control, newspeed;
	float	currentspeed, addspeed, accelspeed;
	int			i;
	vec3_t		wishvel;
	float		fmove, smove;
	vec3_t		wishdir;
	float		wishspeed;
	vec3_t		end;
	trace_t	trace;

	pm->viewheight = 22;

	// friction

	speed = VectorLength (pml.velocity);
	if (speed < 1)
	{
		VectorCopy (vec3_origin, pml.velocity);
	}
	else
	{
		drop = 0;

		friction = pm_friction*1.5;	// extra friction
		control = speed < pm_stopspeed ? pm_stopspeed : speed;
		drop += control*friction*pml.frametime;

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

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

	// accelerate
	fmove = pm->cmd.forwardmove;
	smove = pm->cmd.sidemove;
	
	VectorNormalize (pml.forward);
	VectorNormalize (pml.right);

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

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

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


	currentspeed = DotProduct(pml.velocity, wishdir);
	addspeed = wishspeed - currentspeed;
	if (addspeed <= 0)
		return;
	accelspeed = pm_accelerate*pml.frametime*wishspeed;
	if (accelspeed > addspeed)
		accelspeed = addspeed;
	
	for (i=0 ; i<3 ; i++)
		pml.velocity[i] += accelspeed*wishdir[i];	

	if (doclip) {
		for (i=0 ; i<3 ; i++)
			end[i] = pml.origin[i] + pml.frametime * pml.velocity[i];

		trace = pm->trace (pml.origin, pm->mins, pm->maxs, end);

		VectorCopy (trace.endpos, pml.origin);
	} else {
		// move
		VectorMA (pml.origin, pml.frametime, pml.velocity, pml.origin);
	}
}


/*
==============
PM_CheckDuck

Sets mins, maxs, and pm->viewheight
==============
*/
void PM_CheckDuck (void)
{
	trace_t	trace;

	pm->mins[0] = -16;
	pm->mins[1] = -16;

	pm->maxs[0] = 16;
	pm->maxs[1] = 16;

	if (pm->s.pm_type == PM_GIB)
	{
		pm->mins[2] = 0;
		pm->maxs[2] = 16;
		pm->viewheight = 8;
		return;
	}

	pm->mins[2] = -24;

	if (pm->s.pm_type == PM_DEAD)
	{
		pm->s.pm_flags |= PMF_DUCKED;
	}
	else if (pm->cmd.upmove < 0 && (pm->s.pm_flags & PMF_ON_GROUND) )
	{	// duck
		pm->s.pm_flags |= PMF_DUCKED;
	}
	else
	{	// stand up if possible
		if (pm->s.pm_flags & PMF_DUCKED)
		{
			// try to stand up
			pm->maxs[2] = 32;
			trace = pm->trace (pml.origin, pm->mins, pm->maxs, pml.origin);
			if (!trace.allsolid)
				pm->s.pm_flags &= ~PMF_DUCKED;
		}
	}

	if (pm->s.pm_flags & PMF_DUCKED)
	{
		pm->maxs[2] = 4;
		pm->viewheight = -2;
	}
	else
	{
		pm->maxs[2] = 32;
		pm->viewheight = 22;
	}
}


/*
==============
PM_DeadMove
==============
*/
void PM_DeadMove (void)
{
	float	forward;

	if (!pm->groundentity)
		return;

	// extra friction

	forward = VectorLength (pml.velocity);
	forward -= 20;
	if (forward <= 0)
	{
		VectorClear (pml.velocity);
	}
	else
	{
		VectorNormalize (pml.velocity);
		VectorScale (pml.velocity, forward, pml.velocity);
	}
}


qboolean	PM_GoodPosition (void)
{
	trace_t	trace;
	vec3_t	origin, end;
	int		i;

	if (pm->s.pm_type == PM_SPECTATOR)
		return true;

	for (i=0 ; i<3 ; i++)
		origin[i] = end[i] = pm->s.origin[i]*0.125;
	trace = pm->trace (origin, pm->mins, pm->maxs, end);

	return !trace.allsolid;
}

/*
================
PM_SnapPosition

On exit, the origin will have a value that is pre-quantized to the 0.125
precision of the network channel and in a valid position.
================
*/
void PM_SnapPosition (void)
{
	int		sign[3];
	int		i, j, bits;
	short	base[3];
	// try all single bits first
	static int jitterbits[8] = {0,4,1,2,3,5,6,7};

	// snap velocity to eigths
	for (i=0 ; i<3 ; i++)
		pm->s.velocity[i] = (int)(pml.velocity[i]*8);

	for (i=0 ; i<3 ; i++)
	{
		if (pml.origin[i] >= 0)
			sign[i] = 1;
		else 
			sign[i] = -1;
		pm->s.origin[i] = (int)(pml.origin[i]*8);
		if (pm->s.origin[i]*0.125 == pml.origin[i])
			sign[i] = 0;
	}
	VectorCopy (pm->s.origin, base);

	// try all combinations
	for (j=0 ; j<8 ; j++)
	{
		bits = jitterbits[j];
		VectorCopy (base, pm->s.origin);
		for (i=0 ; i<3 ; i++)
			if (bits & (1<<i) )
				pm->s.origin[i] += sign[i];

		if (PM_GoodPosition ())
			return;
	}

	// go back to the last position
	VectorCopy (pml.previous_origin, pm->s.origin);
//	Com_DPrintf ("using previous_origin\n");
}

#if 0
//NO LONGER USED
/*
================
PM_InitialSnapPosition

================
*/
void PM_InitialSnapPosition (void)
{
	int		x, y, z;
	short	base[3];

	VectorCopy (pm->s.origin, base);

	for (z=1 ; z>=-1 ; z--)
	{
		pm->s.origin[2] = base[2] + z;
		for (y=1 ; y>=-1 ; y--)
		{
			pm->s.origin[1] = base[1] + y;
			for (x=1 ; x>=-1 ; x--)
			{
				pm->s.origin[0] = base[0] + x;
				if (PM_GoodPosition ())
				{
					pml.origin[0] = pm->s.origin[0]*0.125;
					pml.origin[1] = pm->s.origin[1]*0.125;
					pml.origin[2] = pm->s.origin[2]*0.125;
					VectorCopy (pm->s.origin, pml.previous_origin);
					return;
				}
			}
		}
	}

	Com_DPrintf ("Bad InitialSnapPosition\n");
}
#else
/*
================
PM_InitialSnapPosition

================
*/
void PM_InitialSnapPosition(void)
{
	int        x, y, z;
	short      base[3];
	static int offset[3] = { 0, -1, 1 };

	VectorCopy (pm->s.origin, base);

	for ( z = 0; z < 3; z++ ) {
		pm->s.origin[2] = base[2] + offset[ z ];
		for ( y = 0; y < 3; y++ ) {
			pm->s.origin[1] = base[1] + offset[ y ];
			for ( x = 0; x < 3; x++ ) {
				pm->s.origin[0] = base[0] + offset[ x ];
				if (PM_GoodPosition ()) {
					pml.origin[0] = pm->s.origin[0]*0.125;
					pml.origin[1] = pm->s.origin[1]*0.125;
					pml.origin[2] = pm->s.origin[2]*0.125;
					VectorCopy (pm->s.origin, pml.previous_origin);
					return;
				}
			}
		}
	}

	Com_DPrintf ("Bad InitialSnapPosition\n");
}

#endif

/*
================
PM_ClampAngles

================
*/
void PM_ClampAngles (void)
{
	short	temp;
	int		i;

	if (pm->s.pm_flags & PMF_TIME_TELEPORT)
	{
		pm->viewangles[YAW] = SHORT2ANGLE(pm->cmd.angles[YAW] + pm->s.delta_angles[YAW]);
		pm->viewangles[PITCH] = 0;
		pm->viewangles[ROLL] = 0;
	}
	else
	{
		// circularly clamp the angles with deltas
		for (i=0 ; i<3 ; i++)
		{
			temp = pm->cmd.angles[i] + pm->s.delta_angles[i];
			pm->viewangles[i] = SHORT2ANGLE(temp);
		}

		// don't let the player look up or down more than 90 degrees
		if (pm->viewangles[PITCH] > 89 && pm->viewangles[PITCH] < 180)
			pm->viewangles[PITCH] = 89;
		else if (pm->viewangles[PITCH] < 271 && pm->viewangles[PITCH] >= 180)
			pm->viewangles[PITCH] = 271;
	}
	AngleVectors (pm->viewangles, pml.forward, pml.right, pml.up);
}

/*
================
Pmove

Can be called by either the server or the client
================
*/
void Pmove (pmove_t *pmove)
{
	pm = pmove;

	// clear results
	pm->numtouch = 0;
	VectorClear (pm->viewangles);
	pm->viewheight = 0;
	pm->groundentity = 0;
	pm->watertype = 0;
	pm->waterlevel = 0;

	// clear all pmove local vars
	memset (&pml, 0, sizeof(pml));

	// convert origin and velocity to float values
	pml.origin[0] = pm->s.origin[0]*0.125;
	pml.origin[1] = pm->s.origin[1]*0.125;
	pml.origin[2] = pm->s.origin[2]*0.125;

	pml.velocity[0] = pm->s.velocity[0]*0.125;
	pml.velocity[1] = pm->s.velocity[1]*0.125;
	pml.velocity[2] = pm->s.velocity[2]*0.125;

	// save old org in case we get stuck
	VectorCopy (pm->s.origin, pml.previous_origin);

	pml.frametime = pm->cmd.msec * 0.001;

	PM_ClampAngles ();

	if (pm->s.pm_type == PM_SPECTATOR)
	{
		PM_FlyMove (false);
		PM_SnapPosition ();
		return;
	}

	if (pm->s.pm_type >= PM_DEAD)
	{
		pm->cmd.forwardmove = 0;
		pm->cmd.sidemove = 0;
		pm->cmd.upmove = 0;
	}

	if (pm->s.pm_type == PM_FREEZE)
		return;		// no movement at all

	// set mins, maxs, and viewheight
	PM_CheckDuck ();

	if (pm->snapinitial)
		PM_InitialSnapPosition ();

	// set groundentity, watertype, and waterlevel
	PM_CatagorizePosition ();

	if (pm->s.pm_type == PM_DEAD)
		PM_DeadMove ();

	PM_CheckSpecialMovement ();

	// drop timing counter
	if (pm->s.pm_time)
	{
		int		msec;

		msec = pm->cmd.msec >> 3;
		if (!msec)
			msec = 1;
		if ( msec >= pm->s.pm_time) 
		{
			pm->s.pm_flags &= ~(PMF_TIME_WATERJUMP | PMF_TIME_LAND | PMF_TIME_TELEPORT);
			pm->s.pm_time = 0;
		}
		else
			pm->s.pm_time -= msec;
	}

	if (pm->s.pm_flags & PMF_TIME_TELEPORT)
	{	// teleport pause stays exactly in place
	}
	else if (pm->s.pm_flags & PMF_TIME_WATERJUMP)
	{	// waterjump has no control, but falls
		pml.velocity[2] -= pm->s.gravity * pml.frametime;
		if (pml.velocity[2] < 0)
		{	// cancel as soon as we are falling down again
			pm->s.pm_flags &= ~(PMF_TIME_WATERJUMP | PMF_TIME_LAND | PMF_TIME_TELEPORT);
			pm->s.pm_time = 0;
		}

		PM_StepSlideMove ();
	}
	else
	{
		PM_CheckJump ();

		PM_Friction ();

		if (pm->waterlevel >= 2)
			PM_WaterMove ();
		else {
			vec3_t	angles;

			VectorCopy(pm->viewangles, angles);
			if (angles[PITCH] > 180)
				angles[PITCH] = angles[PITCH] - 360;
			angles[PITCH] /= 3;

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

			PM_AirMove ();
		}
	}

	// set groundentity, watertype, and waterlevel for final spot
	PM_CatagorizePosition ();

	PM_SnapPosition ();
}