gzdoom-gles/src/p_trace.cpp
Christoph Oelckers e016a66dc0 - Fixed: When I changed the scaling of textures to full fixed point precision
I forgot to change the call that draws the automap marker numbers.
- Fixed: The chaingun-flash-checking code always checked the first player,
  not the calling one.
- Fixed: Hitscan traces didn't hit actors when entering from above or below


SVN r551 (trunk)
2007-09-27 14:08:45 +00:00

423 lines
11 KiB
C++

/*
** p_trace.cpp
** Generalized trace function, like most 3D games have
**
**---------------------------------------------------------------------------
** Copyright 1998-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/
#include "p_trace.h"
#include "p_local.h"
#include "i_system.h"
static fixed_t StartZ;
static fixed_t Vx, Vy, Vz;
static DWORD ActorMask, WallMask;
static AActor *IgnoreThis;
static FTraceResults *Results;
static sector_t *CurSector;
static fixed_t MaxDist;
static fixed_t EnterDist;
static bool (*TraceCallback)(FTraceResults &res);
static DWORD TraceFlags;
static bool PTR_TraceIterator (intercept_t *);
static bool CheckSectorPlane (const sector_t *sector, bool checkFloor);
static bool EditTraceResult (DWORD flags, FTraceResults &res);
bool Trace (fixed_t x, fixed_t y, fixed_t z, sector_t *sector,
fixed_t vx, fixed_t vy, fixed_t vz, fixed_t maxDist,
DWORD actorMask, DWORD wallMask, AActor *ignore,
FTraceResults &res,
DWORD flags, bool (*callback)(FTraceResults &res))
{
int ptflags;
ptflags = actorMask ? PT_ADDLINES|PT_ADDTHINGS : PT_ADDLINES;
StartZ = z;
Vx = vx;
Vy = vy;
Vz = vz;
ActorMask = actorMask;
WallMask = wallMask;
IgnoreThis = ignore;
CurSector = sector;
MaxDist = maxDist;
EnterDist = 0;
TraceCallback = callback;
TraceFlags = flags;
res.CrossedWater = NULL;
Results = &res;
res.HitType = TRACE_HitNone;
if (P_PathTraverse (x, y, x + FixedMul (vx, maxDist), y + FixedMul (vy, maxDist),
ptflags, PTR_TraceIterator))
{ // check for intersection with floor/ceiling
res.Sector = CurSector;
if (CheckSectorPlane (CurSector, true))
{
res.HitType = TRACE_HitFloor;
if (res.CrossedWater == NULL &&
CurSector->heightsec != NULL &&
CurSector->heightsec->floorplane.ZatPoint (res.X, res.Y) >= res.Z)
{
res.CrossedWater = CurSector;
}
}
else if (CheckSectorPlane (CurSector, false))
{
res.HitType = TRACE_HitCeiling;
}
}
if (res.HitType != TRACE_HitNone)
{
if (flags)
{
return EditTraceResult (flags, res);
}
else
{
return true;
}
}
else
{
res.HitType = TRACE_HitNone;
res.X = x + FixedMul (vx, maxDist);
res.Y = y + FixedMul (vy, maxDist);
res.Z = z + FixedMul (vz, maxDist);
res.Distance = maxDist;
res.Fraction = FRACUNIT;
return false;
}
}
static bool PTR_TraceIterator (intercept_t *in)
{
fixed_t hitx, hity, hitz;
fixed_t dist;
if (in->isaline)
{
int lineside;
sector_t *entersector;
dist = FixedMul (MaxDist, in->frac);
hitx = trace.x + FixedMul (Vx, dist);
hity = trace.y + FixedMul (Vy, dist);
hitz = StartZ + FixedMul (Vz, dist);
fixed_t ff, fc, bf = 0, bc = 0;
if (in->d.line->frontsector == CurSector)
{
lineside = 0;
}
else if (in->d.line->backsector == CurSector)
{
lineside = 1;
}
else
{ // Dammit. Why does Doom have to allow non-closed sectors?
if (in->d.line->backsector == NULL)
{
lineside = 0;
CurSector = in->d.line->frontsector;
}
else
{
lineside = P_PointOnLineSide (trace.x, trace.y, in->d.line);
CurSector = lineside ? in->d.line->backsector : in->d.line->frontsector;
}
}
if (!(in->d.line->flags & ML_TWOSIDED))
{
entersector = NULL;
}
else
{
entersector = (lineside == 0) ? in->d.line->backsector : in->d.line->frontsector;
// For backwards compatibility: Ignore lines with the same sector on both sides.
// This is the way Doom.exe did it and some WADs (e.g. Alien Vendetta MAP15 need it.
if (i_compatflags & COMPATF_TRACE && in->d.line->backsector == in->d.line->frontsector)
{
return true;
}
}
ff = CurSector->floorplane.ZatPoint (hitx, hity);
fc = CurSector->ceilingplane.ZatPoint (hitx, hity);
if (entersector != NULL)
{
bf = entersector->floorplane.ZatPoint (hitx, hity);
bc = entersector->ceilingplane.ZatPoint (hitx, hity);
}
if (Results->CrossedWater == NULL &&
CurSector->heightsec &&
!(CurSector->MoreFlags & SECF_IGNOREHEIGHTSEC) &&
//CurSector->heightsec->waterzone &&
hitz <= CurSector->heightsec->floorplane.ZatPoint (hitx, hity))
{
// hit crossed a water plane
Results->CrossedWater = CurSector;
}
if (hitz <= ff)
{ // hit floor in front of wall
Results->HitType = TRACE_HitFloor;
}
else if (hitz >= fc)
{ // hit ceiling in front of wall
Results->HitType = TRACE_HitCeiling;
}
else if (entersector == NULL ||
hitz <= bf || hitz >= bc ||
in->d.line->flags & WallMask)
{ // hit the wall
Results->HitType = TRACE_HitWall;
Results->Tier =
entersector == NULL ? TIER_Middle :
hitz <= bf ? TIER_Lower :
hitz >= bc ? TIER_Upper : TIER_Middle;
if (TraceFlags & TRACE_Impact)
{
P_ActivateLine (in->d.line, IgnoreThis, lineside, SPAC_IMPACT);
}
}
else
{ // made it past the wall
Results->HitType = TRACE_HitNone;
if (TraceFlags & TRACE_PCross)
{
P_ActivateLine (in->d.line, IgnoreThis, lineside, SPAC_PCROSS);
}
if (TraceFlags & TRACE_Impact)
{ // This is incorrect for "impact", but Hexen did this, so
// we need to as well, for compatibility
P_ActivateLine (in->d.line, IgnoreThis, lineside, SPAC_IMPACT);
}
}
if (Results->HitType != TRACE_HitNone)
{
// We hit something, so figure out where exactly
Results->Sector = CurSector;
if (Results->HitType != TRACE_HitWall &&
!CheckSectorPlane (CurSector, Results->HitType == TRACE_HitFloor))
{ // trace is parallel to the plane (or right on it)
if (entersector == NULL)
{
Results->HitType = TRACE_HitWall;
Results->Tier = TIER_Middle;
}
else
{
if (hitz <= bf || hitz >= bc)
{
Results->HitType = TRACE_HitWall;
Results->Tier =
hitz <= bf ? TIER_Lower :
hitz >= bc ? TIER_Upper : TIER_Middle;
}
else
{
Results->HitType = TRACE_HitNone;
}
}
if (Results->HitType == TRACE_HitWall && TraceFlags & TRACE_Impact)
{
P_ActivateLine (in->d.line, IgnoreThis, lineside, SPAC_IMPACT);
}
}
if (Results->HitType == TRACE_HitWall)
{
Results->X = hitx;
Results->Y = hity;
Results->Z = hitz;
Results->Distance = dist;
Results->Fraction = in->frac;
Results->Line = in->d.line;
Results->Side = lineside;
}
}
if (Results->HitType == TRACE_HitNone)
{
CurSector = entersector;
EnterDist = dist;
return true;
}
if (TraceCallback != NULL)
{
return TraceCallback (*Results);
}
else
{
return false;
}
}
// Encountered an actor
if (!(in->d.thing->flags & ActorMask) ||
in->d.thing == IgnoreThis)
{
return true;
}
dist = FixedMul (MaxDist, in->frac);
hitx = trace.x + FixedMul (Vx, dist);
hity = trace.y + FixedMul (Vy, dist);
hitz = StartZ + FixedMul (Vz, dist);
if (hitz > in->d.thing->z + in->d.thing->height)
{ // trace enters above actor
if (Vz >= 0) return true; // Going up: can't hit
// Does it hit the top of the actor?
dist = StartZ - (in->d.thing->z + in->d.thing->height);
if (dist > MaxDist) return true;
in->frac = FixedDiv(dist, MaxDist);
hitx = trace.x + FixedMul (Vx, dist);
hity = trace.y + FixedMul (Vy, dist);
hitz = StartZ + FixedMul (Vz, dist);
}
else if (hitz < in->d.thing->z)
{ // trace enters below actor
if (Vz <= 0) return true; // Going down: can't hit
// Does it hit the bottom of the actor?
dist = in->d.thing->z - StartZ;
if (dist > MaxDist) return true;
in->frac = FixedDiv(dist, MaxDist);
hitx = trace.x + FixedMul (Vx, dist);
hity = trace.y + FixedMul (Vy, dist);
hitz = StartZ + FixedMul (Vz, dist);
}
Results->HitType = TRACE_HitActor;
Results->X = hitx;
Results->Y = hity;
Results->Z = hitz;
Results->Distance = dist;
Results->Fraction = in->frac;
Results->Actor = in->d.thing;
if (TraceCallback != NULL)
{
return TraceCallback (*Results);
}
else
{
return false;
}
}
static bool CheckSectorPlane (const sector_t *sector, bool checkFloor)
{
secplane_t plane;
if (checkFloor)
{
plane = sector->floorplane;
}
else
{
plane = sector->ceilingplane;
}
fixed_t den = TMulScale16 (plane.a, Vx, plane.b, Vy, plane.c, Vz);
if (den != 0)
{
fixed_t num = TMulScale16 (plane.a, trace.x,
plane.b, trace.y,
plane.c, StartZ) + plane.d;
fixed_t hitdist = FixedDiv (-num, den);
if (hitdist > EnterDist && hitdist < MaxDist)
{
Results->X = trace.x + FixedMul (Vx, hitdist);
Results->Y = trace.y + FixedMul (Vy, hitdist);
Results->Z = StartZ + FixedMul (Vz, hitdist);
Results->Distance = hitdist;
Results->Fraction = FixedDiv (hitdist, MaxDist);
return true;
}
}
return false;
}
static bool EditTraceResult (DWORD flags, FTraceResults &res)
{
if (flags & TRACE_NoSky)
{ // Throw away sky hits
if (res.HitType == TRACE_HitFloor)
{
if (res.Sector->floorpic == skyflatnum)
{
res.HitType = TRACE_HitNone;
return false;
}
}
else if (res.HitType == TRACE_HitCeiling)
{
if (res.Sector->ceilingpic == skyflatnum)
{
res.HitType = TRACE_HitNone;
return false;
}
}
else if (res.HitType == TRACE_HitWall)
{
if (res.Tier == TIER_Upper &&
res.Line->frontsector->ceilingpic == skyflatnum &&
res.Line->backsector->ceilingpic == skyflatnum)
{
res.HitType = TRACE_HitNone;
return false;
}
}
}
return true;
}