bg_pmove.c

3D 游戏界的大牛人 John Carmack 终于放出了 Q3 的源代码

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code 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.

Quake III Arena source code 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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
//
// bg_pmove.c -- both games player movement code
// takes a playerstate and a usercmd as input and returns a modifed playerstate

#include "q_shared.h"
#include "bg_public.h"
#include "bg_local.h"

pmove_t		*pm;
pml_t		pml;

// movement parameters
float	pm_stopspeed = 100.0f;
float	pm_duckScale = 0.25f;
float	pm_swimScale = 0.50f;
float	pm_wadeScale = 0.70f;

float	pm_accelerate = 10.0f;
float	pm_airaccelerate = 1.0f;
float	pm_wateraccelerate = 4.0f;
float	pm_flyaccelerate = 8.0f;

float	pm_friction = 6.0f;
float	pm_waterfriction = 1.0f;
float	pm_flightfriction = 3.0f;
float	pm_spectatorfriction = 5.0f;

int		c_pmove = 0;


/*
===============
PM_AddEvent

===============
*/
void PM_AddEvent( int newEvent ) {
	BG_AddPredictableEventToPlayerstate( newEvent, 0, pm->ps );
}

/*
===============
PM_AddTouchEnt
===============
*/
void PM_AddTouchEnt( int entityNum ) {
	int		i;

	if ( entityNum == ENTITYNUM_WORLD ) {
		return;
	}
	if ( pm->numtouch == MAXTOUCH ) {
		return;
	}

	// see if it is already added
	for ( i = 0 ; i < pm->numtouch ; i++ ) {
		if ( pm->touchents[ i ] == entityNum ) {
			return;
		}
	}

	// add it
	pm->touchents[pm->numtouch] = entityNum;
	pm->numtouch++;
}

/*
===================
PM_StartTorsoAnim
===================
*/
static void PM_StartTorsoAnim( int anim ) {
	if ( pm->ps->pm_type >= PM_DEAD ) {
		return;
	}
	pm->ps->torsoAnim = ( ( pm->ps->torsoAnim & ANIM_TOGGLEBIT ) ^ ANIM_TOGGLEBIT )
		| anim;
}
static void PM_StartLegsAnim( int anim ) {
	if ( pm->ps->pm_type >= PM_DEAD ) {
		return;
	}
	if ( pm->ps->legsTimer > 0 ) {
		return;		// a high priority animation is running
	}
	pm->ps->legsAnim = ( ( pm->ps->legsAnim & ANIM_TOGGLEBIT ) ^ ANIM_TOGGLEBIT )
		| anim;
}

static void PM_ContinueLegsAnim( int anim ) {
	if ( ( pm->ps->legsAnim & ~ANIM_TOGGLEBIT ) == anim ) {
		return;
	}
	if ( pm->ps->legsTimer > 0 ) {
		return;		// a high priority animation is running
	}
	PM_StartLegsAnim( anim );
}

static void PM_ContinueTorsoAnim( int anim ) {
	if ( ( pm->ps->torsoAnim & ~ANIM_TOGGLEBIT ) == anim ) {
		return;
	}
	if ( pm->ps->torsoTimer > 0 ) {
		return;		// a high priority animation is running
	}
	PM_StartTorsoAnim( anim );
}

static void PM_ForceLegsAnim( int anim ) {
	pm->ps->legsTimer = 0;
	PM_StartLegsAnim( anim );
}


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

Slide off of the impacting surface
==================
*/
void PM_ClipVelocity( vec3_t in, vec3_t normal, vec3_t out, float overbounce ) {
	float	backoff;
	float	change;
	int		i;
	
	backoff = DotProduct (in, normal);
	
	if ( backoff < 0 ) {
		backoff *= overbounce;
	} else {
		backoff /= overbounce;
	}

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


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

Handles both ground friction and water friction
==================
*/
static void PM_Friction( void ) {
	vec3_t	vec;
	float	*vel;
	float	speed, newspeed, control;
	float	drop;
	
	vel = pm->ps->velocity;
	
	VectorCopy( vel, vec );
	if ( pml.walking ) {
		vec[2] = 0;	// ignore slope movement
	}

	speed = VectorLength(vec);
	if (speed < 1) {
		vel[0] = 0;
		vel[1] = 0;		// allow sinking underwater
		// FIXME: still have z friction underwater?
		return;
	}

	drop = 0;

	// apply ground friction
	if ( pm->waterlevel <= 1 ) {
		if ( pml.walking && !(pml.groundTrace.surfaceFlags & SURF_SLICK) ) {
			// if getting knocked back, no friction
			if ( ! (pm->ps->pm_flags & PMF_TIME_KNOCKBACK) ) {
				control = speed < pm_stopspeed ? pm_stopspeed : speed;
				drop += control*pm_friction*pml.frametime;
			}
		}
	}

	// apply water friction even if just wading
	if ( pm->waterlevel ) {
		drop += speed*pm_waterfriction*pm->waterlevel*pml.frametime;
	}

	// apply flying friction
	if ( pm->ps->powerups[PW_FLIGHT]) {
		drop += speed*pm_flightfriction*pml.frametime;
	}

	if ( pm->ps->pm_type == PM_SPECTATOR) {
		drop += speed*pm_spectatorfriction*pml.frametime;
	}

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

	vel[0] = vel[0] * newspeed;
	vel[1] = vel[1] * newspeed;
	vel[2] = vel[2] * newspeed;
}


/*
==============
PM_Accelerate

Handles user intended acceleration
==============
*/
static void PM_Accelerate( vec3_t wishdir, float wishspeed, float accel ) {
#if 1
	// q2 style
	int			i;
	float		addspeed, accelspeed, currentspeed;

	currentspeed = DotProduct (pm->ps->velocity, wishdir);
	addspeed = wishspeed - currentspeed;
	if (addspeed <= 0) {
		return;
	}
	accelspeed = accel*pml.frametime*wishspeed;
	if (accelspeed > addspeed) {
		accelspeed = addspeed;
	}
	
	for (i=0 ; i<3 ; i++) {
		pm->ps->velocity[i] += accelspeed*wishdir[i];	
	}
#else
	// proper way (avoids strafe jump maxspeed bug), but feels bad
	vec3_t		wishVelocity;
	vec3_t		pushDir;
	float		pushLen;
	float		canPush;

	VectorScale( wishdir, wishspeed, wishVelocity );
	VectorSubtract( wishVelocity, pm->ps->velocity, pushDir );
	pushLen = VectorNormalize( pushDir );

	canPush = accel*pml.frametime*wishspeed;
	if (canPush > pushLen) {
		canPush = pushLen;
	}

	VectorMA( pm->ps->velocity, canPush, pushDir, pm->ps->velocity );
#endif
}



/*
============
PM_CmdScale

Returns the scale factor to apply to cmd movements
This allows the clients to use axial -127 to 127 values for all directions
without getting a sqrt(2) distortion in speed.
============
*/
static float PM_CmdScale( usercmd_t *cmd ) {
	int		max;
	float	total;
	float	scale;

	max = abs( cmd->forwardmove );
	if ( abs( cmd->rightmove ) > max ) {
		max = abs( cmd->rightmove );
	}
	if ( abs( cmd->upmove ) > max ) {
		max = abs( cmd->upmove );
	}
	if ( !max ) {
		return 0;
	}

	total = sqrt( cmd->forwardmove * cmd->forwardmove
		+ cmd->rightmove * cmd->rightmove + cmd->upmove * cmd->upmove );
	scale = (float)pm->ps->speed * max / ( 127.0 * total );

	return scale;
}


/*
================
PM_SetMovementDir

Determine the rotation of the legs reletive
to the facing dir
================
*/
static void PM_SetMovementDir( void ) {
	if ( pm->cmd.forwardmove || pm->cmd.rightmove ) {
		if ( pm->cmd.rightmove == 0 && pm->cmd.forwardmove > 0 ) {
			pm->ps->movementDir = 0;
		} else if ( pm->cmd.rightmove < 0 && pm->cmd.forwardmove > 0 ) {
			pm->ps->movementDir = 1;
		} else if ( pm->cmd.rightmove < 0 && pm->cmd.forwardmove == 0 ) {
			pm->ps->movementDir = 2;
		} else if ( pm->cmd.rightmove < 0 && pm->cmd.forwardmove < 0 ) {
			pm->ps->movementDir = 3;
		} else if ( pm->cmd.rightmove == 0 && pm->cmd.forwardmove < 0 ) {
			pm->ps->movementDir = 4;
		} else if ( pm->cmd.rightmove > 0 && pm->cmd.forwardmove < 0 ) {
			pm->ps->movementDir = 5;
		} else if ( pm->cmd.rightmove > 0 && pm->cmd.forwardmove == 0 ) {
			pm->ps->movementDir = 6;
		} else if ( pm->cmd.rightmove > 0 && pm->cmd.forwardmove > 0 ) {
			pm->ps->movementDir = 7;
		}
	} else {
		// if they aren't actively going directly sideways,
		// change the animation to the diagonal so they
		// don't stop too crooked
		if ( pm->ps->movementDir == 2 ) {
			pm->ps->movementDir = 1;
		} else if ( pm->ps->movementDir == 6 ) {
			pm->ps->movementDir = 7;
		} 
	}
}


/*
=============
PM_CheckJump
=============
*/
static qboolean PM_CheckJump( void ) {
	if ( pm->ps->pm_flags & PMF_RESPAWNED ) {
		return qfalse;		// don't allow jump until all buttons are up
	}

	if ( pm->cmd.upmove < 10 ) {
		// not holding jump
		return qfalse;
	}

	// must wait for jump to be released
	if ( pm->ps->pm_flags & PMF_JUMP_HELD ) {
		// clear upmove so cmdscale doesn't lower running speed
		pm->cmd.upmove = 0;
		return qfalse;
	}

	pml.groundPlane = qfalse;		// jumping away
	pml.walking = qfalse;
	pm->ps->pm_flags |= PMF_JUMP_HELD;

	pm->ps->groundEntityNum = ENTITYNUM_NONE;
	pm->ps->velocity[2] = JUMP_VELOCITY;
	PM_AddEvent( EV_JUMP );

	if ( pm->cmd.forwardmove >= 0 ) {
		PM_ForceLegsAnim( LEGS_JUMP );
		pm->ps->pm_flags &= ~PMF_BACKWARDS_JUMP;
	} else {
		PM_ForceLegsAnim( LEGS_JUMPB );
		pm->ps->pm_flags |= PMF_BACKWARDS_JUMP;
	}

	return qtrue;
}

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

	if (pm->ps->pm_time) {
		return qfalse;
	}

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

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

	VectorMA (pm->ps->origin, 30, flatforward, spot);
	spot[2] += 4;
	cont = pm->pointcontents (spot, pm->ps->clientNum );
	if ( !(cont & CONTENTS_SOLID) ) {
		return qfalse;
	}

	spot[2] += 16;
	cont = pm->pointcontents (spot, pm->ps->clientNum );
	if ( cont ) {
		return qfalse;
	}

	// jump out of water
	VectorScale (pml.forward, 200, pm->ps->velocity);
	pm->ps->velocity[2] = 350;

	pm->ps->pm_flags |= PMF_TIME_WATERJUMP;
	pm->ps->pm_time = 2000;

	return qtrue;
}

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


/*
===================
PM_WaterJumpMove

Flying out of the water
===================
*/
static void PM_WaterJumpMove( void ) {
	// waterjump has no control, but falls

	PM_StepSlideMove( qtrue );

	pm->ps->velocity[2] -= pm->ps->gravity * pml.frametime;
	if (pm->ps->velocity[2] < 0) {
		// cancel as soon as we are falling down again
		pm->ps->pm_flags &= ~PMF_ALL_TIMES;
		pm->ps->pm_time = 0;
	}
}

/*
===================
PM_WaterMove

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

	if ( PM_CheckWaterJump() ) {
		PM_WaterJumpMove();
		return;
	}
#if 0
	// jump = head for surface
	if ( pm->cmd.upmove >= 10 ) {
		if (pm->ps->velocity[2] > -300) {
			if ( pm->watertype == CONTENTS_WATER ) {
				pm->ps->velocity[2] = 100;
			} else if (pm->watertype == CONTENTS_SLIME) {
				pm->ps->velocity[2] = 80;
			} else {
				pm->ps->velocity[2] = 50;
			}
		}
	}
#endif
	PM_Friction ();

	scale = PM_CmdScale( &pm->cmd );
	//
	// user intentions
	//
	if ( !scale ) {
		wishvel[0] = 0;
		wishvel[1] = 0;
		wishvel[2] = -60;		// sink towards bottom
	} else {
		for (i=0 ; i<3 ; i++)
			wishvel[i] = scale * pml.forward[i]*pm->cmd.forwardmove + scale * pml.right[i]*pm->cmd.rightmove;

		wishvel[2] += scale * pm->cmd.upmove;
	}

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

	if ( wishspeed > pm->ps->speed * pm_swimScale ) {
		wishspeed = pm->ps->speed * pm_swimScale;