detectCollision method

@override void detectCollision(Shape shape1, Shape shape2, ContactManifold manifold)

Detect collision of the shapes provided

Implementation

@override
void detectCollision(Shape shape1,Shape shape2,ContactManifold manifold ) {
  final Vector3 n = this.n;
  final Vector3 p = this.p;
  final Vector3 cc = this.cc;

  Plane pn;
  Box b;

  flip = shape1 is Plane;

  if(!flip){
    pn = shape2 as Plane;
    b = shape1 as Box;
  }
  else{
    pn = shape1 as Plane;
    b = shape2 as Box;
  }

  final D = b.dimentions;
  final double hw = b.halfWidth;
  final double hh = b.halfHeight;
  final double hd = b.halfDepth;
  double len;
  int overlap = 0;

  dix.setValues( D[0], D[1], D[2] );
  diy.setValues( D[3], D[4], D[5] );
  diz.setValues( D[6], D[7], D[8] );

  n.sub2( b.position, pn.position );

  n.x *= pn.normal.x;//+ rad;
  n.y *= pn.normal.y;
  n.z *= pn.normal.z;//+ rad;

  cc.setValues(
    Math.dotVectors( dix, n ),
    Math.dotVectors( diy, n ),
    Math.dotVectors( diz, n )
  );

  if( cc.x > hw ){
    cc.x = hw;
  }
  else if( cc.x < -hw ){
    cc.x = -hw;
  }
  else{
    overlap = 1;
  }

  if( cc.y > hh ){
    cc.y = hh;
  }
  else if( cc.y < -hh ){
    cc.y = -hh;
  }
  else{
    overlap |= 2;
  }

  if( cc.z > hd ){
    cc.z = hd;
  }
  else if( cc.z < -hd ){
    cc.z = -hd;
  }
  else{
    overlap |= 4;
  }

  if(overlap == 7){
    // center of sphere is in the box
    n.setValues(
      cc.x < 0 ? hw + cc.x : hw - cc.x,
      cc.y < 0 ? hh + cc.y : hh - cc.y,
      cc.z < 0 ? hd + cc.z : hd - cc.z
    );

    if( n.x < n.y ){
      if( n.x < n.z ){
        len = n.x - hw;
        if( cc.x < 0 ){
          cc.x = -hw;
          n.setFrom( dix );
        }
        else{
          cc.x = hw;
          n.sub( dix );
        }
      }
      else{
        len = n.z - hd;
        if( cc.z < 0 ){
          cc.z = -hd;
          n.setFrom( diz );
        }
        else{
          cc.z = hd;
          n.sub( diz );
        }
      }
    }
    else{
      if( n.y < n.z ){
        len = n.y - hh;
        if( cc.y < 0 ){
          cc.y = -hh;
          n.setFrom( diy );
        }
        else{
          cc.y = hh;
          n.sub( diy );
        }
      }
      else{
        len = n.z - hd;
        if( cc.z < 0 ){
          cc.z = -hd;
          n.setFrom( diz );
        }
        else{
          cc.z = hd;
          n.sub( diz );
        }
      }
    }

    p..setFrom( pn.position )..addScaled( n, 1 );
    manifold.addPointVec( p, n, len, flip );
  }
}