Straws::Straws( const std::deque<CGPoint> &i_path, int W )
{
_straws.resize( i_path.size() );
auto straw = _straws.begin();
auto p1 = i_path.end() - W;
auto p2 = i_path.begin() + W;
for ( int i = 0; i < W; ++i )
{
*straw = squareLength( *p1 - *p2 );
++straw;
++p1;
++p2;
}
p1 = i_path.begin();
for ( ; p2 != i_path.end(); ++p1, ++p2 )
{
*straw = squareLength( *p1 - *p2 );
++straw;
}
p2 = i_path.begin();
for ( int i = 0; i < W; ++i )
{
*straw = squareLength( *p1 - *p2 );
++straw;
++p1;
++p2;
}
}
bool isStraightLine( T first, T last, CGFloat i_error2 )
{
CGPoint v = *first;
CGPoint w = *(last-1);
CGPoint wMinusV = w - v;
const CGFloat l2 = squareLength( wMinusV ); // i.e. |w-v|^2 - avoid a sqrt
if ( l2 == 0 )
{
// v == w
assert( false );
}
else
{
for ( auto it = first + 1; it != (last-1); ++it )
{
const CGPoint &p( *it );
CGFloat t = ((p - v) * wMinusV) / l2;
if ( t < 0.0 )
{
// Beyond the 'v' end of the segment
if ( squareLength( v - p ) > i_error2 )
return false;
}
else if ( t > 1.0 )
{
// Beyond the 'w' end of the segment
if ( squareLength( w - p ) > i_error2 )
return false;
}
else
{
CGPoint projection = v + (t * wMinusV); // Projection falls on the segment
if ( squareLength( projection - p ) > i_error2 )
return false;
}
}
}
return true;
}
//------------------------------------------------------------------------------
/// 値の表すベクトル (x, y) の長さを計算します。
///
/// @return ベクトルの長さ。
float Vec2::length()const
{
return Math::Sqrt(squareLength());
}
float ofxVec4f::lengthSquared() const {
return squareLength();
}
float
length(const Vector<N, T>& vect)
{
return std::sqrt(squareLength(vect));
}