raze/source/games/blood/src/gameutil.cpp
Christoph Oelckers f2d89b7609 - refactored actWallBounceVector as well
This completes the abstraction of velocity in Blood.
2022-10-15 10:15:20 +02:00

734 lines
20 KiB
C++

//-------------------------------------------------------------------------
/*
Copyright (C) 2010-2019 EDuke32 developers and contributors
Copyright (C) 2019 Nuke.YKT
This file is part of NBlood.
NBlood is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License version 2
as published by the Free Software Foundation.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
//-------------------------------------------------------------------------
#include "ns.h" // Must come before everything else!
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "build.h"
#include "blood.h"
BEGIN_BLD_NS
HitInfo gHitInfo;
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
bool CheckProximity(DBloodActor* actor, const DVector3& pos, sectortype* pSector, int nDist)
{
assert(actor != nullptr);
auto vec = pos - actor->spr.pos;
if (abs(vec.Z) >= nDist) return false;
if (vec.LengthSquared() >= nDist * nDist) return false;
double bottom, top;
GetActorExtents(actor, &top, &bottom);
if (cansee(actor->spr.pos, actor->sector(), pos, pSector))
return 1;
if (cansee(DVector3(actor->spr.pos.XY(), bottom), actor->sector(), pos, pSector))
return 1;
if (cansee(DVector3(actor->spr.pos.XY(), top), actor->sector(), pos, pSector))
return 1;
return 0;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
bool CheckProximityPoint(int nX1, int nY1, int nZ1, int nX2, int nY2, int nZ2, int nDist)
{
int oX = abs(nX2 - nX1) >> 4;
if (oX >= nDist)
return 0;
int oY = abs(nY2 - nY1) >> 4;
if (oY >= nDist)
return 0;
if (nZ2 != nZ1)
{
int oZ = abs(nZ2 - nZ1) >> 8;
if (oZ >= nDist)
return 0;
}
if (approxDist(oX, oY) >= nDist) return 0;
return 1;
}
//---------------------------------------------------------------------------
//
// Note: This function features some very bad math.
// It cannot be redone because some game functionality
// depends on the math being broken.
//
//---------------------------------------------------------------------------
bool CheckProximityWall(walltype* pWall, int x, int y, int nDist)
{
int x1 = pWall->wall_int_pos().X;
int y1 = pWall->wall_int_pos().Y;
int x2 = pWall->point2Wall()->wall_int_pos().X;
int y2 = pWall->point2Wall()->wall_int_pos().Y;
nDist <<= 4;
if (x1 < x2)
{
if (x <= x1 - nDist || x >= x2 + nDist)
{
return 0;
}
}
else
{
if (x <= x2 - nDist || x >= x1 + nDist)
{
return 0;
}
if (x1 == x2)
{
int px1 = x - x1;
int py1 = y - y1;
int px2 = x - x2;
int py2 = y - y2;
int dist1 = px1 * px1 + py1 * py1;
int dist2 = px2 * px2 + py2 * py2;
if (y1 < y2)
{
if (y <= y1 - nDist || y >= y2 + nDist)
{
return 0;
}
if (y < y1)
{
return dist1 < nDist* nDist;
}
if (y > y2)
{
return dist2 < nDist* nDist;
}
}
else
{
if (y <= y2 - nDist || y >= y1 + nDist)
{
return 0;
}
if (y < y2)
{
return dist2 < nDist* nDist;
}
if (y > y1)
{
return dist1 < nDist* nDist;
}
}
return 1;
}
}
if (y1 < y2)
{
if (y <= y1 - nDist || y >= y2 + nDist)
{
return 0;
}
}
else
{
if (y <= y2 - nDist || y >= y1 + nDist)
{
return 0;
}
if (y1 == y2)
{
int px1 = x - x1;
int py1 = y - y1;
int px2 = x - x2;
int py2 = y - y2;
int check1 = px1 * px1 + py1 * py1;
int check2 = px2 * px2 + py2 * py2;
if (x1 < x2)
{
if (x <= x1 - nDist || x >= x2 + nDist)
{
return 0;
}
if (x < x1)
{
return check1 < nDist* nDist;
}
if (x > x2)
{
return check2 < nDist* nDist;
}
}
else
{
if (x <= x2 - nDist || x >= x1 + nDist)
{
return 0;
}
if (x < x2)
{
return check2 < nDist* nDist;
}
if (x > x1)
{
return check1 < nDist* nDist;
}
}
}
}
int dx = x2 - x1;
int dy = y2 - y1;
int px = x - x2;
int py = y - y2;
int side = px * dx + dy * py;
if (side >= 0)
{
return px * px + py * py < nDist* nDist;
}
px = x - x1;
py = y - y1;
side = px * dx + dy * py;
if (side <= 0)
{
return px * px + py * py < nDist* nDist;
}
int check1 = px * dy - dx * py;
int check2 = dy * dy + dx * dx;
return check1 * check1 < check2* nDist* nDist;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
int GetWallAngle(walltype* pWall)
{
return getangle(pWall->delta());
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
bool IntersectRay(int wx, int wy, int wdx, int wdy, int x1, int y1, int z1, int x2, int y2, int z2, int* ix, int* iy, int* iz)
{
int dX = x1 - x2;
int dY = y1 - y2;
int dZ = z1 - z2;
int side = wdx * dY - wdy * dX;
int dX2 = x1 - wx;
int dY2 = y1 - wy;
int check1 = dX2 * dY - dY2 * dX;
int check2 = wdx * dY2 - wdy * dX2;
if (side >= 0)
{
if (!side)
return 0;
if (check1 < 0)
return 0;
if (check2 < 0 || check2 >= side)
return 0;
}
else
{
if (check1 > 0)
return 0;
if (check2 > 0 || check2 <= side)
return 0;
}
int nScale = DivScale(check2, side, 16);
*ix = x1 + MulScale(dX, nScale, 16);
*iy = y1 + MulScale(dY, nScale, 16);
*iz = z1 + MulScale(dZ, nScale, 16);
return 1;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
int HitScan(DBloodActor* actor, int z, int dx, int dy, int dz, unsigned int nMask, int nRange)
{
assert(actor != nullptr);
assert(dx != 0 || dy != 0);
gHitInfo.clearObj();
int x = actor->int_pos().X;
int y = actor->int_pos().Y;
auto bakCstat = actor->spr.cstat;
actor->spr.cstat &= ~CSTAT_SPRITE_BLOCK_HITSCAN;
if (nRange)
{
hitscangoal.X = x + MulScale(nRange << 4, Cos(actor->int_ang()), 30);
hitscangoal.Y = y + MulScale(nRange << 4, Sin(actor->int_ang()), 30);
}
else
{
hitscangoal.X = hitscangoal.Y = 0x1fffffff;
}
hitscan(vec3_t( x, y, z ), actor->sector(), { dx, dy, dz << 4 }, gHitInfo, nMask);
hitscangoal.X = hitscangoal.Y = 0x1fffffff;
actor->spr.cstat = bakCstat;
if (gHitInfo.actor() != nullptr)
return 3;
if (gHitInfo.hitWall != nullptr)
{
auto pWall = gHitInfo.hitWall;
if (!pWall->twoSided())
return 0;
int nZCeil, nZFloor;
getzsofslopeptr(pWall->nextSector(), gHitInfo.int_hitpos().X, gHitInfo.int_hitpos().Y, &nZCeil, &nZFloor);
if (gHitInfo.int_hitpos().Z <= nZCeil || gHitInfo.int_hitpos().Z >= nZFloor)
return 0;
return 4;
}
if (gHitInfo.hitSector != nullptr)
return 1 + (z < gHitInfo.int_hitpos().Z);
return -1;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
int VectorScan(DBloodActor* actor, int nOffset, int nZOffset, int dx, int dy, int dz, int nRange, int ac)
{
assert(actor != nullptr);
int nNum = 256;
gHitInfo.clearObj();
int x1 = actor->int_pos().X + MulScale(nOffset, Cos(actor->int_ang() + 512), 30);
int y1 = actor->int_pos().Y + MulScale(nOffset, Sin(actor->int_ang() + 512), 30);
int z1 = actor->int_pos().Z + nZOffset;
auto bakCstat = actor->spr.cstat;
actor->spr.cstat &= ~CSTAT_SPRITE_BLOCK_HITSCAN;
if (nRange)
{
hitscangoal.X = x1 + MulScale(nRange << 4, Cos(actor->int_ang()), 30);
hitscangoal.Y = y1 + MulScale(nRange << 4, Sin(actor->int_ang()), 30);
}
else
{
hitscangoal.X = hitscangoal.Y = 0x1fffffff;
}
vec3_t pos = { x1, y1, z1 };
hitscan(pos, actor->sector(), { dx, dy, dz << 4 }, gHitInfo, CLIPMASK1);
hitscangoal.X = hitscangoal.Y = 0x1ffffff;
actor->spr.cstat = bakCstat;
while (nNum--)
{
if (nRange && approxDist(gHitInfo.hitpos.XY() - actor->spr.pos.XY()) > nRange)
return -1;
auto other = gHitInfo.actor();
if (other != nullptr)
{
if ((other->spr.flags & 8) && !(ac & 1))
return 3;
if ((other->spr.cstat & CSTAT_SPRITE_ALIGNMENT_MASK) != 0)
return 3;
int nPicnum = other->spr.picnum;
if (tileWidth(nPicnum) == 0 || tileHeight(nPicnum) == 0)
return 3;
int height = (tileHeight(nPicnum) * other->spr.yrepeat) << 2;
int otherZ = other->int_pos().Z;
if (other->spr.cstat & CSTAT_SPRITE_YCENTER)
otherZ += height / 2;
int nTopOfs = tileTopOffset(nPicnum);
if (nTopOfs)
otherZ -= (nTopOfs * other->spr.yrepeat) << 2;
assert(height > 0);
int height2 = Scale(otherZ - gHitInfo.int_hitpos().Z, tileHeight(nPicnum), height);
if (!(other->spr.cstat & CSTAT_SPRITE_YFLIP))
height2 = tileHeight(nPicnum) - height2;
if (height2 >= 0 && height2 < tileHeight(nPicnum))
{
int width = (tileWidth(nPicnum) * other->spr.xrepeat) >> 2;
width = (width * 3) / 4;
int check1 = ((y1 - other->int_pos().Y) * dx - (x1 - other->int_pos().X) * dy) / ksqrt(dx * dx + dy * dy);
assert(width > 0);
int width2 = Scale(check1, tileWidth(nPicnum), width);
int nLeftOfs = tileLeftOffset(nPicnum);
width2 += nLeftOfs + tileWidth(nPicnum) / 2;
if (width2 >= 0 && width2 < tileWidth(nPicnum))
{
auto pData = tilePtr(nPicnum);
if (pData[width2 * tileHeight(nPicnum) + height2] != TRANSPARENT_INDEX)
return 3;
}
}
bakCstat = other->spr.cstat;
other->spr.cstat &= ~CSTAT_SPRITE_BLOCK_HITSCAN;
gHitInfo.clearObj();
pos = gHitInfo.int_hitpos(); // must make a copy!
hitscan(pos, other->sector(), { dx, dy, dz << 4 }, gHitInfo, CLIPMASK1);
other->spr.cstat = bakCstat;
continue;
}
if (gHitInfo.hitWall != nullptr)
{
walltype* pWall = gHitInfo.hitWall;
if (!pWall->twoSided())
return 0;
sectortype* pSector = gHitInfo.hitSector;
sectortype* pSectorNext = pWall->nextSector();
int nZCeil, nZFloor;
getzsofslopeptr(pWall->nextSector(), gHitInfo.int_hitpos().X, gHitInfo.int_hitpos().Y, &nZCeil, &nZFloor);
if (gHitInfo.int_hitpos().Z <= nZCeil)
return 0;
if (gHitInfo.int_hitpos().Z >= nZFloor)
{
if (!(pSector->floorstat & CSTAT_SECTOR_SKY) || !(pSectorNext->floorstat & CSTAT_SECTOR_SKY))
return 0;
return 2;
}
if (!(pWall->cstat & (CSTAT_WALL_MASKED | CSTAT_WALL_1WAY)))
return 0;
int nOfs;
if (pWall->cstat & CSTAT_WALL_ALIGN_BOTTOM)
nOfs = ClipHigh(pSector->int_floorz(), pSectorNext->int_floorz());
else
nOfs = ClipLow(pSector->int_ceilingz(), pSectorNext->int_ceilingz());
nOfs = (gHitInfo.int_hitpos().Z - nOfs) >> 8;
if (pWall->cstat & CSTAT_WALL_YFLIP)
nOfs = -nOfs;
int nPicnum = pWall->overpicnum;
int nSizX = tileWidth(nPicnum);
int nSizY = tileHeight(nPicnum);
if (!nSizX || !nSizY)
return 0;
nOfs = (nOfs * pWall->yrepeat) / 8;
nOfs += int((nSizY * pWall->ypan_) / 256);
int nLength = approxDist(pWall->pos - pWall->point2Wall()->pos);
int nHOffset;
if (pWall->cstat & CSTAT_WALL_XFLIP)
nHOffset = approxDist(gHitInfo.hitpos.XY() - pWall->point2Wall()->pos);
else
nHOffset = approxDist(gHitInfo.hitpos.XY() - pWall->pos);
nHOffset = pWall->xpan() + ((nHOffset * pWall->xrepeat) << 3) / nLength;
nHOffset %= nSizX;
nOfs %= nSizY;
auto pData = tilePtr(nPicnum);
int nPixel;
nPixel = nHOffset * nSizY + nOfs;
if (pData[nPixel] == TRANSPARENT_INDEX)
{
auto bakCstat1 = pWall->cstat;
pWall->cstat &= ~CSTAT_WALL_BLOCK_HITSCAN;
auto bakCstat2 = pWall->nextWall()->cstat;
pWall->nextWall()->cstat &= ~CSTAT_WALL_BLOCK_HITSCAN;
gHitInfo.clearObj();
pos = gHitInfo.int_hitpos();
hitscan(pos, pWall->nextSector(), { dx, dy, dz << 4 }, gHitInfo, CLIPMASK1);
pWall->cstat = bakCstat1;
pWall->nextWall()->cstat = bakCstat2;
continue;
}
return 4;
}
if (gHitInfo.hitSector != nullptr)
{
if (dz > 0)
{
auto upper = barrier_cast<DBloodActor*>(gHitInfo.hitSector->upperLink);
if (!upper) return 2;
auto link = upper->GetOwner();
gHitInfo.clearObj();
x1 = gHitInfo.int_hitpos().X + link->int_pos().X - upper->int_pos().X;
y1 = gHitInfo.int_hitpos().Y + link->int_pos().Y - upper->int_pos().Y;
z1 = gHitInfo.int_hitpos().Z + link->int_pos().Z - upper->int_pos().Z;
pos = { x1, y1, z1 };
hitscan(pos, link->sector(), { dx, dy, dz << 4 }, gHitInfo, CLIPMASK1);
continue;
}
else
{
auto lower = barrier_cast<DBloodActor*>(gHitInfo.hitSector->lowerLink);
if (!lower) return 1;
auto link = lower->GetOwner();
gHitInfo.clearObj();
x1 = gHitInfo.int_hitpos().X + link->int_pos().X - lower->int_pos().X;
y1 = gHitInfo.int_hitpos().Y + link->int_pos().Y - lower->int_pos().Y;
z1 = gHitInfo.int_hitpos().Z + link->int_pos().Z - lower->int_pos().Z;
pos = { x1, y1, z1 };
hitscan(pos, link->sector(), { dx, dy, dz << 4 }, gHitInfo, CLIPMASK1);
continue;
}
}
return -1;
}
return -1;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
void GetZRange(DBloodActor* actor, int* ceilZ, Collision* ceilColl, int* floorZ, Collision* floorColl, int nDist, unsigned int nMask, unsigned int nClipParallax)
{
assert(actor != nullptr);
Collision scratch;
auto bakCstat = actor->spr.cstat;
int32_t nTemp1;
actor->spr.cstat &= ~CSTAT_SPRITE_BLOCK_ALL;
getzrange(actor->int_pos(), actor->sector(), (int32_t*)ceilZ, *ceilColl, (int32_t*)floorZ, *floorColl, nDist, nMask);
if (floorColl->type == kHitSector)
{
auto pSector = floorColl->hitSector;
if ((nClipParallax & PARALLAXCLIP_FLOOR) == 0 && (pSector->floorstat & CSTAT_SECTOR_SKY))
*floorZ = 0x7fffffff;
if (pSector->hasX())
{
XSECTOR* pXSector = &pSector->xs();
*floorZ += pXSector->Depth << 10;
}
auto linkActor = barrier_cast<DBloodActor*>(pSector->upperLink);
if (linkActor)
{
auto linkOwner = linkActor->GetOwner();
vec3_t lpos = actor->int_pos() + linkOwner->int_pos() - linkActor->int_pos();
getzrange(lpos, linkOwner->sector(), &nTemp1, scratch, (int32_t*)floorZ, *floorColl, nDist, nMask);
*floorZ -= linkOwner->int_pos().Z - linkActor->int_pos().Z;
}
}
if (ceilColl->type == kHitSector)
{
auto pSector = ceilColl->hitSector;
if ((nClipParallax & PARALLAXCLIP_CEILING) == 0 && (pSector->ceilingstat & CSTAT_SECTOR_SKY))
*ceilZ = 0x80000000;
auto linkActor = barrier_cast<DBloodActor*>(pSector->lowerLink);
if (linkActor)
{
auto linkOwner = linkActor->GetOwner();
vec3_t lpos = actor->int_pos() + linkOwner->int_pos() - linkActor->int_pos();
getzrange(lpos, linkOwner->sector(), (int32_t*)ceilZ, *ceilColl, &nTemp1, scratch, nDist, nMask);
*ceilZ -= linkOwner->int_pos().Z - linkActor->int_pos().Z;
}
}
actor->spr.cstat = bakCstat;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
void GetZRangeAtXYZ(int x, int y, int z, sectortype* pSector, int* ceilZ, Collision* ceilColl, int* floorZ, Collision* floorColl, int nDist, unsigned int nMask, unsigned int nClipParallax)
{
Collision scratch;
int32_t nTemp1;
vec3_t lpos = { x, y, z };
getzrange(lpos, pSector, (int32_t*)ceilZ, *ceilColl, (int32_t*)floorZ, *floorColl, nDist, nMask);
if (floorColl->type == kHitSector)
{
auto pHitSect = floorColl->hitSector;
if ((nClipParallax & PARALLAXCLIP_FLOOR) == 0 && (pHitSect->floorstat & CSTAT_SECTOR_SKY))
*floorZ = 0x7fffffff;
if (pHitSect->hasX())
{
XSECTOR* pXSector = &pHitSect->xs();
*floorZ += pXSector->Depth << 10;
}
auto actor = barrier_cast<DBloodActor*>(pHitSect->upperLink);
if (actor)
{
auto link = actor->GetOwner();
vec3_t newpos = lpos + link->int_pos() - actor->int_pos();
getzrange(newpos, link->sector(), &nTemp1, scratch, (int32_t*)floorZ, *floorColl, nDist, nMask);
*floorZ -= link->int_pos().Z - actor->int_pos().Z;
}
}
if (ceilColl->type == kHitSector)
{
auto pHitSect = ceilColl->hitSector;
if ((nClipParallax & PARALLAXCLIP_CEILING) == 0 && (pHitSect->ceilingstat & CSTAT_SECTOR_SKY))
*ceilZ = 0x80000000;
auto actor = barrier_cast<DBloodActor*>(pHitSect->lowerLink);
if (actor)
{
auto link = actor->GetOwner();
vec3_t newpos = lpos + link->int_pos() - actor->int_pos();
getzrange(newpos, link->sector(), (int32_t*)ceilZ, *ceilColl, &nTemp1, scratch, nDist, nMask);
*ceilZ -= link->int_pos().Z - actor->int_pos().Z;
}
}
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
int GetDistToLine(int x1, int y1, int x2, int y2, int x3, int y3)
{
int check = (y1 - y3) * (x3 - x2);
int check2 = (x1 - x2) * (y3 - y2);
if (check2 > check)
return -1;
int v8 = DMulScale(x1 - x2, x3 - x2, y1 - y3, y3 - y2, 4);
int vv = DMulScale(x3 - x2, x3 - x2, y3 - y2, y3 - y2, 4);
int t1, t2;
if (v8 <= 0)
{
t1 = x2;
t2 = y2;
}
else if (vv > v8)
{
t1 = x2 + Scale(x3 - x2, v8, vv);
t2 = y2 + Scale(y3 - y2, v8, vv);
}
else
{
t1 = x3;
t2 = y3;
}
return approxDist(t1 - x1, t2 - y1);
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
void ClipMove(vec3_t& pos, sectortype** pSector, int xv, int yv, int wd, int cd, int fd, unsigned int nMask, CollisionBase& hit, int tracecount)
{
auto opos = pos;
sectortype* bakSect = *pSector;
clipmove(pos, &bakSect, xv << 14, yv << 14, wd, cd, fd, nMask, hit, tracecount);
if (bakSect == nullptr)
{
pos = opos;
}
else
{
*pSector = bakSect;
}
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
BitArray GetClosestSpriteSectors(sectortype* pSector, const DVector2& pos, int nDist, TArray<walltype*>* pWalls, bool newSectCheckMethod)
{
int x = pos.X * worldtoint;
int y = pos.Y * worldtoint;
// by default this function fails with sectors that linked with wide spans, or there was more than one link to the same sector. for example...
// E6M1: throwing TNT on the stone footpath while standing on the brown road will fail due to the start/end points of the span being too far away. it'll only do damage at one end of the road
// E1M2: throwing TNT at the double doors while standing on the train platform
// by setting newSectCheckMethod to true these issues will be resolved
BitArray sectorMap(sector.Size()); // this gets returned to the caller.
sectorMap.Zero();
sectorMap.Set(sectnum(pSector));
double nDist4sq = nDist * nDist; // (nDist * 16)^2 - * 16 to account for Build's 28.4 fixed point format.
BFSSectorSearch search(pSector);
while (auto pCurSector = search.GetNext())
{
for (auto& wal : wallsofsector(pCurSector))
{
if (!wal.twoSided()) continue;
const auto pNextSector = wal.nextSector();
bool withinRange = false;
if (!newSectCheckMethod) // original method
{
if (search.Check(pNextSector)) // if we've already checked this sector, skip. This is bad, therefore only in compat mode.
continue;
withinRange = CheckProximityWall(wal.point2Wall(), x, y, nDist);
}
else // new method using proper math and no bad shortcut.
{
double dist1 = SquareDistToWall(pos.X, pos.Y, &wal);
withinRange = dist1 <= nDist4sq;
}
if (withinRange) // if new sector is within range, add it to the processing queue
{
sectorMap.Set(sectnum(pNextSector));
search.Add(pNextSector);
if (pWalls && wal.hasX())
{
XWALL* pXWall = &wal.xw();
if (pXWall->triggerVector && !pXWall->isTriggered && !pXWall->state)
pWalls->Push(&wal);
}
}
}
}
return sectorMap;
}
//---------------------------------------------------------------------------
//
//
//
//---------------------------------------------------------------------------
int picWidth(int nPic, int repeat) {
return ClipLow((tileWidth(nPic) * repeat) << 2, 0);
}
int picHeight(int nPic, int repeat) {
return ClipLow((tileHeight(nPic) * repeat) << 2, 0);
}
END_BLD_NS