EsenthalEngine/Engine/Source/Math/Shapes/Cone.cpp

/******************************************************************************/
#include "stdafx.h"
namespace EE{
/******************************************************************************/
Flt Cone::area()C
{
   Flt min, max; MinMax(r_low, r_high, min, max);
   if(min==  0)return PI *max*(max + Dist(max, h));
   if(min==max)return PI2*max*(max + h);
   Flt h0=h*min/(max-min);
   return PI*(max*(max + Dist(max, h0+h))
             +min*(min - Dist(min, h0  )));
}
Flt Cone::volume()C
{
   Flt min, max; MinMax(r_low, r_high, min, max);
   if(min==  0)return PI_3*max*max*h;
   if(min==max)return PI  *max*max*h;
   Flt h0=h*min/(max-min);
   return PI_3*(max*max*(h0+h) - min*min*h0);
}
Cone& Cone::operator*=(Flt f)
{
   r_low *=f;
   r_high*=f;
   h     *=f;
   pos   *=f;
   return T;
}
Cone& Cone::operator/=(Flt f)
{
   r_low /=f;
   r_high/=f;
   h     /=f;
   pos   /=f;
   return T;
}
Cone& Cone::operator*=(C Matrix3 &m)
{
   Flt   s=m.maxScale();
   pos   *=m;
   up    *=m;
   h     *=up.normalize();
   r_low *=s;
   r_high*=s;
   return T;
}
Cone& Cone::operator*=(C Matrix &m)
{
   Flt   s=m.maxScale();
   pos   *=m;
   up    *=m.orn();
   h     *=up.normalize();
   r_low *=s;
   r_high*=s;
   return T;
}
/******************************************************************************/
void Cone::draw(C Color &color, Bool fill, Int resolution)C
{
   if(resolution<0)resolution=24;else if(resolution<3)resolution=3;
   Matrix3 matrix; matrix.setUp(up); matrix.y*=h;
   Vec     prev0=pos+         r_low *matrix.x,
           prev1=pos+matrix.y+r_high*matrix.x;

   VI.color(color);
   REP(resolution)
   {
      Flt c, s; CosSin(c, s, (PI2*i)/resolution);
      Vec next0=pos+         (c*r_low )*matrix.x+(s*r_low )*matrix.z,
          next1=pos+matrix.y+(c*r_high)*matrix.x+(s*r_high)*matrix.z;
      if(fill)VI.quad(next1, prev1, prev0, next0);else
      {
         VI.line(next1, prev1);
         VI.line(next0, next1);
         VI.line(next0, prev0);
      }
      prev0=next0;
      prev1=next1;
   }
   VI.end();
}
/******************************************************************************/
Bool Cuts(C Vec &point, C Cone &cone)
{
   if(cone.h>0)
   {
      Flt z=DistPointPlane(point, cone.pos, cone.up);
      if( z>=0 && z<=cone.h)
      {
         Vec    on_line=cone.pos+cone.up*z;
         Flt    dist2  =Dist2(point, on_line),
                r2     =Sqr  (Lerp(cone.r_low, cone.r_high, z/cone.h));
         return dist2<=r2;
      }
   }
   return false;
}
/******************************************************************************/
}
/******************************************************************************/