rpgxef/code/game/bg_slidemove.c
2012-10-17 16:26:50 +02:00

317 lines
8 KiB
C

// Copyright (C) 1999-2000 Id Software, Inc.
//
// bg_slidemove.c -- part of bg_pmove functionality
#include "q_shared.h"
#include "bg_public.h"
#include "bg_local.h"
/*
input: origin, velocity, bounds, groundPlane, trace function
output: origin, velocity, impacts, stairup boolean
*/
/*
==================
PM_SlideMove
==================
*/
/**
* Returns qtrue if the velocity was clipped in some way
*/
#define MAX_CLIP_PLANES 5
qboolean PM_SlideMove( qboolean gravity ) {
int bumpcount, numbumps;
vec3_t dir;
float d;
int numplanes;
vec3_t planes[MAX_CLIP_PLANES];
vec3_t primal_velocity;
vec3_t clipVelocity;
int i, j, k;
trace_t trace;
vec3_t end;
float time_left;
float into;
vec3_t endVelocity;
vec3_t endClipVelocity;
playerState_t *ps = pm->ps;
numbumps = 4;
VectorCopy (ps->velocity, primal_velocity);
if ( gravity ) {
VectorCopy( ps->velocity, endVelocity );
endVelocity[2] -= ps->gravity * pml.frametime;
ps->velocity[2] = ( ps->velocity[2] + endVelocity[2] ) * 0.5;
primal_velocity[2] = endVelocity[2];
if ( pml.groundPlane ) {
// slide along the ground plane
PM_ClipVelocity (ps->velocity, pml.groundTrace.plane.normal,
ps->velocity, OVERCLIP );
}
}
time_left = pml.frametime;
// never turn against the ground plane
if ( pml.groundPlane ) {
numplanes = 1;
VectorCopy( pml.groundTrace.plane.normal, planes[0] );
} else {
numplanes = 0;
}
// never turn against original velocity
VectorNormalize2( ps->velocity, planes[numplanes] );
numplanes++;
for ( bumpcount=0 ; bumpcount < numbumps ; bumpcount++ ) {
// calculate position we are trying to move to
VectorMA( ps->origin, time_left, ps->velocity, end );
// see if we can make it there
pm->trace ( &trace, ps->origin, pm->mins, pm->maxs, end, ps->clientNum, pm->tracemask);
if (trace.allsolid) {
// entity is completely trapped in another solid
ps->velocity[2] = 0; // don't build up falling damage, but allow sideways acceleration
return qtrue;
}
if (trace.fraction > 0) {
// actually covered some distance
VectorCopy (trace.endpos, ps->origin);
}
if (trace.fraction == 1) {
break; // moved the entire distance
}
// save entity for contact
PM_AddTouchEnt( trace.entityNum );
time_left -= time_left * trace.fraction;
if (numplanes >= MAX_CLIP_PLANES) {
// this shouldn't really happen
VectorClear( ps->velocity );
return qtrue;
}
//
// if this is the same plane we hit before, nudge velocity
// out along it, which fixes some epsilon issues with
// non-axial planes
//
for ( i = 0 ; i < numplanes ; i++ ) {
if ( DotProduct( trace.plane.normal, planes[i] ) > 0.99 ) {
VectorAdd( trace.plane.normal, ps->velocity, ps->velocity );
break;
}
}
if ( i < numplanes ) {
continue;
}
VectorCopy (trace.plane.normal, planes[numplanes]);
numplanes++;
//
// modify velocity so it parallels all of the clip planes
//
// find a plane that it enters
for ( i = 0 ; i < numplanes ; i++ ) {
into = DotProduct( ps->velocity, planes[i] );
if ( into >= 0.1 ) {
continue; // move doesn't interact with the plane
}
// see how hard we are hitting things
if ( -into > pml.impactSpeed ) {
pml.impactSpeed = -into;
}
// slide along the plane
PM_ClipVelocity (ps->velocity, planes[i], clipVelocity, OVERCLIP );
// slide along the plane
PM_ClipVelocity (endVelocity, planes[i], endClipVelocity, OVERCLIP );
// see if there is a second plane that the new move enters
for ( j = 0 ; j < numplanes ; j++ ) {
if ( j == i ) {
continue;
}
if ( DotProduct( clipVelocity, planes[j] ) >= 0.1 ) {
continue; // move doesn't interact with the plane
}
// try clipping the move to the plane
PM_ClipVelocity( clipVelocity, planes[j], clipVelocity, OVERCLIP );
PM_ClipVelocity( endClipVelocity, planes[j], endClipVelocity, OVERCLIP );
// see if it goes back into the first clip plane
if ( DotProduct( clipVelocity, planes[i] ) >= 0 ) {
continue;
}
// slide the original velocity along the crease
CrossProduct (planes[i], planes[j], dir);
VectorNormalize( dir );
d = DotProduct( dir, ps->velocity );
VectorScale( dir, d, clipVelocity );
CrossProduct (planes[i], planes[j], dir);
VectorNormalize( dir );
d = DotProduct( dir, endVelocity );
VectorScale( dir, d, endClipVelocity );
// see if there is a third plane the the new move enters
for ( k = 0 ; k < numplanes ; k++ ) {
if ( k == i || k == j ) {
continue;
}
if ( DotProduct( clipVelocity, planes[k] ) >= 0.1 ) {
continue; // move doesn't interact with the plane
}
// stop dead at a tripple plane interaction
VectorClear( ps->velocity );
return qtrue;
}
}
// if we have fixed all interactions, try another move
VectorCopy( clipVelocity, ps->velocity );
VectorCopy( endClipVelocity, endVelocity );
break;
}
}
if ( gravity ) {
VectorCopy( endVelocity, ps->velocity );
}
// don't change velocity if in a timer (FIXME: is this correct?)
if ( ps->pm_time ) {
VectorCopy( primal_velocity, ps->velocity );
}
return ( bumpcount != 0 );
}
/*
==================
PM_StepSlideMove
==================
*/
void PM_StepSlideMove( qboolean gravity ) {
vec3_t start_o, start_v;
vec3_t down_o, down_v;
vec3_t slideMove, stepUpMove;
trace_t trace;
vec3_t up, down;
playerState_t *ps = pm->ps;
VectorCopy (ps->origin, start_o);
VectorCopy (ps->velocity, start_v);
if ( PM_SlideMove( gravity ) == 0 ) {
return; // we got exactly where we wanted to go first try
}
VectorCopy(start_o, down);
down[2] -= STEPSIZE;
pm->trace (&trace, start_o, pm->mins, pm->maxs, down, ps->clientNum, pm->tracemask);
VectorSet(up, 0, 0, 1);
// never step up when you still have up velocity
if ( ps->velocity[2] > 0 && (trace.fraction == 1.0 ||
DotProduct(trace.plane.normal, up) < 0.7)) {
return;
}
VectorCopy (ps->origin, down_o);
VectorCopy (ps->velocity, down_v);
VectorCopy (start_o, up);
up[2] += STEPSIZE;
// test the player position if they were a stepheight higher
pm->trace (&trace, up, pm->mins, pm->maxs, up, ps->clientNum, pm->tracemask);
if ( trace.allsolid ) {
if ( pm->debugLevel ) {
Com_Printf("%i:bend can't step\n", c_pmove);
}
return; // can't step up
}
// try slidemove from this position
VectorCopy (up, ps->origin);
VectorCopy (start_v, ps->velocity);
PM_SlideMove( gravity );
//compare the initial slidemove and this slidemove from a step up position
VectorSubtract( down_o, start_o, slideMove );
VectorSubtract( trace.endpos, ps->origin, stepUpMove );
if ( fabs(stepUpMove[0]) < 0.1 && fabs(stepUpMove[1]) < 0.1 && VectorLengthSquared( slideMove ) > VectorLengthSquared( stepUpMove ) )
{
//slideMove was better, use it
VectorCopy (down_o, ps->origin);
VectorCopy (down_v, ps->velocity);
}
else
{
// push down the final amount
VectorCopy (ps->origin, down);
down[2] -= STEPSIZE;
pm->trace (&trace, ps->origin, pm->mins, pm->maxs, down, ps->clientNum, pm->tracemask);
if ( !trace.allsolid ) {
VectorCopy (trace.endpos, ps->origin);
}
if ( trace.fraction < 1.0 ) {
PM_ClipVelocity( ps->velocity, trace.plane.normal, ps->velocity, OVERCLIP );
}
}
#if 0
// if the down trace can trace back to the original position directly, don't step
pm->trace( &trace, ps->origin, pm->mins, pm->maxs, start_o, ps->clientNum, pm->tracemask);
if ( trace.fraction == 1.0 ) {
// use the original move
VectorCopy (down_o, ps->origin);
VectorCopy (down_v, ps->velocity);
if ( pm->debugLevel ) {
Com_Printf("%i:bend\n", c_pmove);
}
} else
#endif
{
// use the step move
float delta;
delta = ps->origin[2] - start_o[2];
if ( delta > 2 ) {
if ( delta < 7 ) {
PM_AddEvent( EV_STEP_4 );
} else if ( delta < 11 ) {
PM_AddEvent( EV_STEP_8 );
} else if ( delta < 15 ) {
PM_AddEvent( EV_STEP_12 );
} else {
PM_AddEvent( EV_STEP_16 );
}
}
if ( pm->debugLevel ) {
Com_Printf("%i:stepped\n", c_pmove);
}
}
}