CODE:

#ifndef SPLINE_H
#define SPLINE_H

/*!
 * @brief	2次元座標用3次スプライン関数の計算用クラス
 *
 * @sec	使い方	
 *			1.コンストラクタで座標と個数をセット、もしくは SetPos() と SetCount() で座標と個数をセットする
 *			2.Setup() 関数を使用して移動速度を元に時間を設定する
 *			3.GetNowInfo() 関数で現在の座標と向きを取得する
 *			4.Step() 関数で次の位置へ移動する
 *			5. 3.と4.を繰り返し、 Step() 関数が false を返したら終端
 *			6.Reset() 関数で最初の位置へ戻る
 */
template
class Spline2D
{
	float h[MAX];
	float b[MAX];
	float d[MAX];
	float g[MAX];
	float u[MAX];
	float r[MAX+1];

	float t[MAX+1];
	float x[MAX+1];
	float y[MAX+1];

	unsigned int	count;
	unsigned int	step;
	float			unit;

	float xp, yp;
	float xn, yn;
	float dir;

	void spline( unsigned int st, float& x, float& y )
	{
		float tm = st * unit;
		x = spline(count, t, this->x, tm);
		y = spline(count, t, this->y, tm);
	}

	float spline( int n, const float* x, const float* y, float x1 )
	{
		int i = -1, j, k;
		float fRes, fQ, fS, fX;

		for (j = 1;j  1) ? i : 1;
		r[0]   = 0.0f;
		r[n]   = 0.0f;
		r[n-1] = u[n-1];
		for (j = n-2;j >= k;--j)
		{
			r[j] = u[j] - g[j] * r[j+1];
		}
		fX = x1 - x[i];
		fQ = (y[i+1] - y[i]) / h[i] - h[i] * (r[i+1] + 2.0f * r[i]) / 3.0f;
		fS = (r[i+1] - r[i]) / (3.0f * h[i]);
		fRes = y[i] + fX * (fQ + fX * (r[i] + fS * fX));

		return fRes;
	}
public:
	Spline2D( const float* (&pos)[2], unsigned int n ) : count(n), step(0)
	{
		if (count > MAX) { count = MAX - 1; }
	}
	Spline2D( unsigned int n ) : count(n), step(0)
	{
		if (count > MAX) { count = MAX - 1; }
	}
	Spline2D( void ) : count(MAX), step(0)
	{
	}

	unsigned int GetCount( void )const{ return count; }
	float GetPosX( unsigned int i )const{ return x[i]; }
	float GetPosY( unsigned int i )const{ return y[i]; }
	float GetPosT( unsigned int i )const{ return t[i]; }

	void SetPos( unsigned int i, float x, float y ) { this->x[i] = x; this->y[i] = y; }
	void SetCount( unsigned int n )
	{
		if (count > MAX) { count = MAX - 1; }
	}

	void Setup( float scale, float unit )
	{
		float tm = 0.0f;
		t[0] = 0.0f;

		for (unsigned int i = 1;i unit = unit;
		Reset();
	}

	void Reset()
	{
		spline(0, xp, yp);
		spline(1, xn, yn);
		step = 1;

		dir = atan2f(yn - yp, xn - xp);
	}

	bool Step()
	{
		float tm = (step + 1) * unit;

		xp = xn;
		yp = yn;
		if (tm dir;
	}
};

#endif // SPLINE_H