khanat-opennel-code/code/nel/src/misc/plane.cpp

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// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010 Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#include "stdmisc.h"
#include "nel/misc/plane.h"
#include "nel/misc/uv.h"
#ifdef DEBUG_NEW
#define new DEBUG_NEW
#endif
namespace NLMISC
{
//============================================================
void CPlane::make(const CVector &normal, const CVector &p)
{
CVector v= normal.normed();
a= v.x;
b= v.y;
c= v.z;
d=-(v*p); // d=- (ax+by+cz).
}
void CPlane::make(const CVector &p0, const CVector &p1, const CVector &p2)
{
CVector v;
v=(p1-p0)^(p2-p1);
make(v,p1);
}
//============================================================
bool CPlane::clipSegmentBack(CVector &p0, CVector &p1) const
{
float d0,d1,decal;
CVector proj;
d0= (*this)*p0;
d1= (*this)*p1;
if(d0<0 && d1<0)
return true;
if(d0>=0 && d1>=0)
return false;
// Clip line.
decal= (0-d0) / (d1-d0);
proj= p0+ (p1-p0)*decal;
if(d0>=0)
p0=proj;
else
p1=proj;
return true;
}
bool CPlane::clipSegmentFront(CVector &p0, CVector &p1) const
{
float d0,d1,decal;
CVector proj;
d0= (*this)*p0;
d1= (*this)*p1;
if(d0>=0 && d1>=0)
return true;
if(d0<0 && d1<0)
return false;
// Clip line.
decal= (0-d0) / (d1-d0);
proj= p0+ (p1-p0)*decal;
if(d0<0)
p0=proj;
else
p1=proj;
return true;
}
//============================================================
sint CPlane::clipPolygonBack(CVector in[], CVector out[], sint nIn) const
{
sint nOut=0,s,p,i;
if(nIn<=2) return 0;
s=nIn-1;
for (i=0;i<nIn;i++)
{
p=i;
if ( (*this)*in[p] < 0 )
{
if ( (*this)*in[s] >= 0 )
out[nOut++]= intersect(in[s],in[p]);
out[nOut++]=in[p];
}
else
{
if ( (*this)*in[s] < 0 )
out[nOut++]= intersect(in[s],in[p]);
}
s=p;
}
return nOut;
}
//============================================================
sint CPlane::clipPolygonBack(const CVector in[], const CUV inUV[], CVector out[], CUV outUV[], sint nIn) const
{
sint nOut=0,s,p,i;
if(nIn<=2) return 0;
s=nIn-1;
for (i=0;i<nIn;i++)
{
p=i;
float dp3Curr = (*this)*in[p];
float dp3Prev = (*this)*in[s];
if ( dp3Curr < 0 )
{
if (dp3Prev >= 0 )
{
float lambda = favoid0((float) ((double) dp3Prev / ((double) dp3Prev - (double) dp3Curr)));
out[nOut] = blend(in[s], in[p], lambda);
outUV[nOut++] = blend(inUV[s], inUV[p], lambda);
}
out[nOut]=in[p];
outUV[nOut++]=inUV[p];
}
else
{
if (dp3Prev < 0 )
{
float lambda = favoid0((float) ((double) dp3Prev / ((double) dp3Prev - (double) dp3Curr)));
out[nOut] = blend(in[s], in[p], lambda);
outUV[nOut++] = blend(inUV[s], inUV[p], lambda);
}
}
s=p;
}
return nOut;
}
//============================================================
sint CPlane::clipPolygonFront(CVector in[], CVector out[], sint nIn) const
{
sint nOut=0,s,p,i;
if(nIn<=2) return 0;
s=nIn-1;
for (i=0;i<nIn;i++)
{
p=i;
if ( (*this)*in[p] > 0 )
{
if ( (*this)*in[s] <= 0 )
out[nOut++]= intersect(in[s],in[p]);
out[nOut++]=in[p];
}
else
{
if ( (*this)*in[s] > 0 )
out[nOut++]= intersect(in[s],in[p]);
}
s=p;
}
return nOut;
}
//============================================================
CPlane CPlane::inverted() const
{
return CPlane(-a, -b, -c, -d);
}
//============================================================
void CPlane::invert()
{
a = -a;
b = -b;
c = -c;
d = -d;
}
}