/// <summary>
/// 単調増加ベジエの場合にのみ使用可。X座標からY座標を得る
/// </summary>
/// <param name="X"></param>
/// <returns></returns>
public float GetYFromX(float X)
{
float ret = 0;
PointF p1 = BCPS[0].Second, p2 = BCPS[0].Second, p3 = BCPS[1].Second, p4 = BCPS[1].Second;
if (BCPS[0].ValidThird)
{
p2 = BCPS[0].Third;
}
if (BCPS[1].ValidFirst)
{
p3 = BCPS[1].First;
}
float s = 0, e = 1;
for (int i = 0; i < 20; i++)
{
float m = (s + e) / 2;
var bp = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref m);
if (bp.X < X)
{
e = m;
}
else
{
s = m;
}
ret = bp.Y;
}
return(ret);
}
/// <summary>
/// ベジエ曲線状に乗っているか調べる
/// </summary>
/// <param name="p1">頂点１</param>
/// <param name="p2">頂点２</param>
/// <param name="p3">頂点３</param>
/// <param name="p4">頂点４</param>
/// <param name="target">調べる対象</param>
/// <param name="outt">乗っていた時の割合(0~1)</param>
/// <returns></returns>
public static bool OnBezeier(PointF p1, PointF p2, PointF p3, PointF p4, PointF target, out float outt)
{
PointF lastbezierpoint, bezierpoint;
lastbezierpoint = p1;
outt = -1;
float best = float.MaxValue;
var count = BezierCaliculate.AboutBezeirCount(ref p1, ref p2, ref p3, ref p4);
for (int i = count; i >= 0; i--)
{
float t = (float)i / count;
bezierpoint = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t);
var temp = GetLength(new PointF(bezierpoint.X - target.X, bezierpoint.Y - target.Y));
if (temp < best)
{
best = temp;
outt = t;
}
lastbezierpoint = bezierpoint;
}
if (best <= 2)
{
return(true);
}
return(false);
}
/// <summary>
/// ４頂点からベジエ曲線上の位置を得る
/// </summary>
/// <param name="p1">頂点１</param>
/// <param name="p2">頂点２</param>
/// <param name="p3">頂点３</param>
/// <param name="p4">頂点４</param>
/// <returns></returns>
public static IEnumerable <PointF> GetPoints(PointF p1, PointF p2, PointF p3, PointF p4)
{
var count = BezierCaliculate.AboutBezeirCount(ref p1, ref p2, ref p3, ref p4);
for (int i = count; i >= 0; i--)
{
float t = (float)i / count;
yield return(BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t));
}
}
private static float GetBezeierLength(PointF p1, PointF p2, PointF p3, PointF p4)
{
PointF lastbezierpoint, bezierpoint;
lastbezierpoint = p1;
float sum = 0;
var count = BezierCaliculate.AboutBezeirCount(ref p1, ref p2, ref p3, ref p4);
if (count == 0)
{
return(0);
}
for (int i = count; i >= 0; i--)
{
float t = (float)i / count;
bezierpoint = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t);
sum += GetLength(new PointF(bezierpoint.X - lastbezierpoint.X, bezierpoint.Y - lastbezierpoint.Y));
lastbezierpoint = bezierpoint;
}
return(sum);
}
private static void GetBezeirSplitPoint(PointF p1, PointF p2, PointF p3, PointF p4, float length, out PointF pos, out PointF direction)
{
PointF lastbezierpoint, bezierpoint;
lastbezierpoint = p1;
pos = p1;
direction = new PointF(1, 0);
float sum = 0;
var count = BezierCaliculate.AboutBezeirCount(ref p1, ref p2, ref p3, ref p4);
for (int i = count; i >= 0; i--)
{
float t = (float)i / count;
bezierpoint = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t);
sum += GetLength(new PointF(bezierpoint.X - lastbezierpoint.X, bezierpoint.Y - lastbezierpoint.Y));
if (sum >= length)
{
pos = bezierpoint;
direction = GetNormalizePoint(new PointF(bezierpoint.X - lastbezierpoint.X, bezierpoint.Y - lastbezierpoint.Y));
if (direction.X == 0 && direction.Y == 0)
{
t = (float)(i - 1) / count;
lastbezierpoint = bezierpoint;
bezierpoint = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t);
direction = GetNormalizePoint(new PointF(bezierpoint.X - lastbezierpoint.X, bezierpoint.Y - lastbezierpoint.Y));
}
return;
}
lastbezierpoint = bezierpoint;
}
pos = p4;
direction = GetNormalizePoint(new PointF(p4.X - lastbezierpoint.X, p4.Y - lastbezierpoint.Y));
if (direction.X == 0 && direction.Y == 0)
{
float t = (float)1 / count;
bezierpoint = BezierCaliculate.GetBezeirPoint(ref p1, ref p2, ref p3, ref p4, ref t);
direction = GetNormalizePoint(new PointF(lastbezierpoint.X - bezierpoint.X, lastbezierpoint.Y - bezierpoint.Y));
}
}
