gzdoom/src/portal.cpp

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#include "portal.h"
#include "p_local.h"
#include "p_lnspec.h"
#include "r_bsp.h"
#include "r_segs.h"
#include "c_cvars.h"
#include "m_bbox.h"
#include "p_tags.h"
#include "farchive.h"
// simulation recurions maximum
CVAR(Int, sv_portal_recursions, 4, CVAR_ARCHIVE|CVAR_SERVERINFO)
TArray<FLinePortal> linePortals;
FArchive &operator<< (FArchive &arc, FLinePortal &port)
{
arc << port.mOrigin
<< port.mDestination
<< port.mXDisplacement
<< port.mYDisplacement
<< port.mType
<< port.mFlags
<< port.mDefFlags
<< port.mAlign;
return arc;
}
void P_SpawnLinePortal(line_t* line)
{
// portal destination is special argument #0
line_t* dst = NULL;
if (line->args[2] >= PORTT_VISUAL && line->args[2] <= PORTT_LINKED)
{
if (line->args[0] > 0)
{
int linenum = -1;
for (int i = 0; i < numlines; i++)
{
if (&lines[i] == line)
continue;
if (tagManager.LineHasID(&lines[i], line->args[0]))
{
dst = &lines[i];
break;
}
}
}
line->portalindex = linePortals.Reserve(1);
FLinePortal *port = &linePortals.Last();
memset(port, 0, sizeof(FLinePortal));
port->mOrigin = line;
port->mDestination = dst;
port->mType = BYTE(line->args[2]); // range check is done above.
port->mAlign = BYTE(line->args[3] >= PORG_ABSOLUTE && line->args[3] <= PORG_CEILING ? line->args[3] : PORG_ABSOLUTE);
if (port->mDestination != NULL)
{
port->mDefFlags = port->mType == PORTT_VISUAL ? PORTF_VISIBLE : port->mType == PORTT_TELEPORT ? PORTF_TYPETELEPORT : PORTF_TYPEINTERACTIVE;
}
}
else if (line->args[2] == PORTT_LINKEDEE && line->args[0] == 0)
{
// EE-style portals require that the first line ID is identical and the first arg of the two linked linedefs are 0 and 1 respectively.
int mytag = tagManager.GetFirstLineID(line);
for (int i = 0; i < numlines; i++)
{
if (tagManager.GetFirstLineID(&lines[i]) == mytag && lines[i].args[0] == 1)
{
line->portalindex = linePortals.Reserve(1);
FLinePortal *port = &linePortals.Last();
memset(port, 0, sizeof(FLinePortal));
port->mOrigin = line;
port->mDestination = &lines[i];
port->mType = PORTT_LINKED;
port->mAlign = PORG_ABSOLUTE;
port->mDefFlags = PORTF_TYPEINTERACTIVE;
}
}
}
else
{
// undefined type
return;
}
}
void P_UpdatePortal(FLinePortal *port)
{
if (port->mDestination == NULL)
{
// Portal has no destination: switch it off
port->mFlags = 0;
}
else if (port->mDestination->getPortalDestination() != port->mOrigin)
{
//portal doesn't link back. This will be a simple teleporter portal.
port->mFlags = port->mDefFlags & ~PORTF_INTERACTIVE;
if (port->mType == PORTT_LINKED)
{
// this is illegal. Demote the type to TELEPORT
port->mType = PORTT_TELEPORT;
port->mDefFlags &= ~PORTF_INTERACTIVE;
}
}
else
{
port->mFlags = port->mDefFlags;
}
}
void P_FinalizePortals()
{
for (unsigned i = 0; i < linePortals.Size(); i++)
{
FLinePortal * port = &linePortals[i];
P_UpdatePortal(port);
}
}
// [ZZ] lots of floats here to avoid overflowing a lot
bool P_IntersectLines(fixed_t o1x, fixed_t o1y, fixed_t p1x, fixed_t p1y,
fixed_t o2x, fixed_t o2y, fixed_t p2x, fixed_t p2y,
fixed_t& rx, fixed_t& ry)
{
double xx = FIXED2DBL(o2x) - FIXED2DBL(o1x);
double xy = FIXED2DBL(o2y) - FIXED2DBL(o1y);
double d1x = FIXED2DBL(p1x) - FIXED2DBL(o1x);
double d1y = FIXED2DBL(p1y) - FIXED2DBL(o1y);
if (d1x > d1y)
{
d1y = d1y / d1x * 32767.0f;
d1x = 32767.0;
}
else
{
d1x = d1x / d1y * 32767.0f;
d1y = 32767.0;
}
double d2x = FIXED2DBL(p2x) - FIXED2DBL(o2x);
double d2y = FIXED2DBL(p2y) - FIXED2DBL(o2y);
double cross = d1x*d2y - d1y*d2x;
if (fabs(cross) < 1e-8)
return false;
double t1 = (xx * d2y - xy * d2x)/cross;
rx = o1x + FLOAT2FIXED(d1x * t1);
ry = o1y + FLOAT2FIXED(d1y * t1);
return true;
}
inline int P_PointOnLineSideExplicit (fixed_t x, fixed_t y, fixed_t x1, fixed_t y1, fixed_t x2, fixed_t y2)
{
return DMulScale32 (y-y1, x2-x1, x1-x, y2-y1) > 0;
}
bool P_ClipLineToPortal(line_t* line, line_t* portal, fixed_t viewx, fixed_t viewy, bool partial, bool samebehind)
{
// check if this line is between portal and the viewer. clip away if it is.
bool behind1 = !!P_PointOnLineSidePrecise(line->v1->x, line->v1->y, portal);
bool behind2 = !!P_PointOnLineSidePrecise(line->v2->x, line->v2->y, portal);
// [ZZ] update 16.12.2014: if a vertex equals to one of portal's vertices, it's treated as being behind the portal.
// this is required in order to clip away diagonal lines around the portal (example: 1-sided triangle shape with a mirror on it's side)
if ((line->v1->x == portal->v1->x && line->v1->y == portal->v1->y) ||
(line->v1->x == portal->v2->x && line->v1->y == portal->v2->y))
behind1 = samebehind;
if ((line->v2->x == portal->v1->x && line->v2->y == portal->v1->y) ||
(line->v2->x == portal->v2->x && line->v2->y == portal->v2->y))
behind2 = samebehind;
if (behind1 && behind2)
{
// line is behind the portal plane. now check if it's in front of two view plane borders (i.e. if it will get in the way of rendering)
fixed_t dummyx, dummyy;
bool infront1 = P_IntersectLines(line->v1->x, line->v1->y, line->v2->x, line->v2->y, viewx, viewy, portal->v1->x, portal->v1->y, dummyx, dummyy);
bool infront2 = P_IntersectLines(line->v1->x, line->v1->y, line->v2->x, line->v2->y, viewx, viewy, portal->v2->x, portal->v2->y, dummyx, dummyy);
if (infront1 && infront2)
return true;
}
return false;
}
void P_TranslatePortalXY(line_t* src, line_t* dst, fixed_t& x, fixed_t& y)
{
if (!src || !dst)
return;
fixed_t nposx, nposy; // offsets from line
// Get the angle between the two linedefs, for rotating
// orientation and velocity. Rotate 180 degrees, and flip
// the position across the exit linedef, if reversed.
angle_t angle =
R_PointToAngle2(0, 0, dst->dx, dst->dy) -
R_PointToAngle2(0, 0, src->dx, src->dy);
angle += ANGLE_180;
// Sine, cosine of angle adjustment
fixed_t s = finesine[angle>>ANGLETOFINESHIFT];
fixed_t c = finecosine[angle>>ANGLETOFINESHIFT];
fixed_t tx, ty;
nposx = x - src->v1->x;
nposy = y - src->v1->y;
// Rotate position along normal to match exit linedef
tx = FixedMul(nposx, c) - FixedMul(nposy, s);
ty = FixedMul(nposy, c) + FixedMul(nposx, s);
tx += dst->v2->x;
ty += dst->v2->y;
x = tx;
y = ty;
}
void P_TranslatePortalVXVY(line_t* src, line_t* dst, fixed_t& vx, fixed_t& vy)
{
angle_t angle =
R_PointToAngle2(0, 0, dst->dx, dst->dy) -
R_PointToAngle2(0, 0, src->dx, src->dy);
angle += ANGLE_180;
// Sine, cosine of angle adjustment
fixed_t s = finesine[angle>>ANGLETOFINESHIFT];
fixed_t c = finecosine[angle>>ANGLETOFINESHIFT];
fixed_t orig_velx = vx;
fixed_t orig_vely = vy;
vx = FixedMul(orig_velx, c) - FixedMul(orig_vely, s);
vy = FixedMul(orig_vely, c) + FixedMul(orig_velx, s);
}
void P_TranslatePortalAngle(line_t* src, line_t* dst, angle_t& angle)
{
if (!src || !dst)
return;
// Get the angle between the two linedefs, for rotating
// orientation and velocity. Rotate 180 degrees, and flip
// the position across the exit linedef, if reversed.
angle_t xangle =
R_PointToAngle2(0, 0, dst->dx, dst->dy) -
R_PointToAngle2(0, 0, src->dx, src->dy);
xangle += ANGLE_180;
angle += xangle;
}
void P_TranslatePortalZ(line_t* src, line_t* dst, fixed_t& z)
{
// args[2] = 0 - no adjustment
// args[2] = 1 - adjust by floor difference
// args[2] = 2 - adjust by ceiling difference
switch (src->getPortalAlignment())
{
case PORG_FLOOR:
z = z - src->frontsector->floorplane.ZatPoint(src->v1->x, src->v1->y) + dst->frontsector->floorplane.ZatPoint(dst->v2->x, dst->v2->y);
return;
case PORG_CEILING:
z = z - src->frontsector->ceilingplane.ZatPoint(src->v1->x, src->v1->y) + dst->frontsector->ceilingplane.ZatPoint(dst->v2->x, dst->v2->y);
return;
default:
return;
}
}
// calculate shortest distance from a point (x,y) to a linedef
fixed_t P_PointLineDistance(line_t* line, fixed_t x, fixed_t y)
{
angle_t angle = R_PointToAngle2(0, 0, line->dx, line->dy);
angle += ANGLE_180;
fixed_t dx = line->v1->x - x;
fixed_t dy = line->v1->y - y;
fixed_t s = finesine[angle>>ANGLETOFINESHIFT];
fixed_t c = finecosine[angle>>ANGLETOFINESHIFT];
fixed_t d2x = FixedMul(dx, c) - FixedMul(dy, s);
return abs(d2x);
}
void P_NormalizeVXVY(fixed_t& vx, fixed_t& vy)
{
double _vx = FIXED2DBL(vx);
double _vy = FIXED2DBL(vy);
double len = sqrt(_vx*_vx+_vy*_vy);
vx = FLOAT2FIXED(_vx/len);
vy = FLOAT2FIXED(_vy/len);
}
// portal tracer code
PortalTracer::PortalTracer(fixed_t startx, fixed_t starty, fixed_t endx, fixed_t endy)
{
this->startx = startx;
this->starty = starty;
this->endx = endx;
this->endy = endy;
intx = endx;
inty = endy;
intxIn = intx;
intyIn = inty;
z = 0;
angle = 0;
depth = 0;
frac = 0;
in = NULL;
out = NULL;
vx = 0;
vy = 0;
}
bool PortalTracer::TraceStep()
{
if (depth > sv_portal_recursions)
return false;
this->in = NULL;
this->out = NULL;
this->vx = 0;
this->vy = 0;
int oDepth = depth;
fixed_t dirx = endx-startx;
fixed_t diry = endy-starty;
P_NormalizeVXVY(dirx, diry);
dirx = 0;
diry = 0;
FPathTraverse it(startx-dirx, starty-diry, endx+dirx, endy+diry, PT_ADDLINES | PT_COMPATIBLE);
intercept_t *in;
while ((in = it.Next()))
{
line_t* li;
if (in->isaline)
{
li = in->d.line;
if (li->isLinePortal())
{
if (P_PointOnLineSide(startx-dirx, starty-diry, li))
continue; // we're at the back side of this line
line_t* out = li->getPortalDestination();
this->in = li;
this->out = out;
// we only know that we crossed it, but we also need to know WHERE we crossed it
fixed_t vx = it.Trace().dx;
fixed_t vy = it.Trace().dy;
fixed_t x = it.Trace().x + FixedMul(vx, in->frac);
fixed_t y = it.Trace().y + FixedMul(vy, in->frac);
P_NormalizeVXVY(vx, vy);
this->vx = vx;
this->vy = vy;
// teleport our trace
if (!out->backsector)
{
intx = x + vx;
inty = y + vy;
}
else
{
intx = x - vx;
inty = y - vy;
}
//P_TranslateCoordinatesAndAngle(li, out, startx, starty, noangle);
//P_TranslateCoordinatesAndAngle(li, out, endx, endy, angle);
//if (hdeltaZ)
// P_TranslateZ(li, out, deltaZ);
//P_TranslateCoordinatesAndAngle(li, out, vx, vy, noangle);
P_TranslatePortalXY(li, out, startx, starty);
P_TranslatePortalVXVY(li, out, this->vx, this->vy);
intxIn = intx;
intyIn = inty;
P_TranslatePortalXY(li, out, intx, inty);
P_TranslatePortalXY(li, out, endx, endy);
P_TranslatePortalAngle(li, out, angle);
P_TranslatePortalZ(li, out, z);
frac += in->frac;
depth++;
break; // breaks to outer loop
}
if (!(li->flags & ML_TWOSIDED) || (li->flags & ML_BLOCKEVERYTHING))
return false; // stop tracing, 2D blocking line
}
}
//Printf("returning %d; vx = %.2f; vy = %.2f\n", (oDepth != depth), FIXED2DBL(this->vx), FIXED2DBL(this->vy));
return (oDepth != depth); // if a portal has been found, return false
}