ref: 38de7eaca1fa15e005bc0065adc7019dfaedae38
dir: /sv_move.c/
#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.
=============
*/
bool SV_CheckBottom (edict_t *ent)
{
vec3_t mins, maxs, start, stop;
trace_t trace;
int x, y;
float mid, bottom;
VectorAdd (ent->v.origin, ent->v.mins, mins);
VectorAdd (ent->v.origin, ent->v.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<=1 ; x++)
for (y=0 ; y<=1 ; y++)
{
start[0] = x ? maxs[0] : mins[0];
start[1] = y ? maxs[1] : mins[1];
if (SV_PointContents (start) != CONTENTS_SOLID)
goto realcheck;
}
return true; // we got out easy
realcheck:
// check it for real...
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;
trace = SV_Move (start, vec3_origin, vec3_origin, stop, true, ent);
if (trace.fraction == 1.0)
return false;
mid = bottom = trace.endpos[2];
// the corners must be within 16 of the midpoint
for (x=0 ; x<=1 ; x++)
for (y=0 ; y<=1 ; y++)
{
start[0] = stop[0] = x ? maxs[0] : mins[0];
start[1] = stop[1] = y ? maxs[1] : mins[1];
trace = SV_Move (start, vec3_origin, vec3_origin, stop, true, ent);
if (trace.fraction != 1.0 && trace.endpos[2] > bottom)
bottom = trace.endpos[2];
if (trace.fraction == 1.0 || mid - trace.endpos[2] > STEPSIZE)
return false;
}
return true;
}
/*
=============
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
sv.pr->global_struct->trace_normal is set to the normal of the blocking wall
=============
*/
bool SV_movestep (edict_t *ent, vec3_t move, bool relink)
{
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
if ( (int)ent->v.flags & (FL_SWIM | FL_FLY) )
{
// try one move with vertical motion, then one without
for (i=0 ; i<2 ; i++)
{
VectorAdd (ent->v.origin, move, neworg);
enemy = PROG_TO_EDICT(sv.pr, ent->v.enemy);
if (i == 0 && enemy != sv.pr->edicts)
{
dz = ent->v.origin[2] - PROG_TO_EDICT(sv.pr, ent->v.enemy)->v.origin[2];
if (dz > 40)
neworg[2] -= 8;
else if (dz < 30)
neworg[2] += 8;
}
trace = SV_Move (ent->v.origin, ent->v.mins, ent->v.maxs, neworg, false, ent);
if (trace.fraction == 1)
{
if ( ((int)ent->v.flags & FL_SWIM) && SV_PointContents(trace.endpos) == CONTENTS_EMPTY )
return false; // swim monster left water
VectorCopy (trace.endpos, ent->v.origin);
if (relink)
SV_LinkEdict (ent, true);
return true;
}
if (enemy == sv.pr->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 (trace.allsolid)
return false;
if (trace.startsolid)
{
neworg[2] -= STEPSIZE;
trace = SV_Move (neworg, ent->v.mins, ent->v.maxs, end, false, ent);
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(sv.pr, 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.
======================
*/
bool
SV_StepDirection(edict_t *ent, float yaw, float dist)
{
vec3_t move, oldorigin;
float delta;
ent->v.ideal_yaw = yaw;
PF_changeyaw(sv.pr);
yaw = yaw*M_PI*2 / 360;
move[0] = cosf(yaw)*dist;
move[1] = sinf(yaw)*dist;
move[2] = 0;
VectorCopy (ent->v.origin, oldorigin);
if (SV_movestep (ent, move, false))
{
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
======================
*/
static 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;
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 (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;
// 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) || fabs(deltay)>fabs(deltax))
{
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);
}