/// <summary>
/// 构造函数
/// </summary>
/// <param name="pt1">局部编录坐标控制点1</param>
/// <param name="pt2">局部编录坐标控制点2</param>
/// <param name="pt3">局部编录坐标控制点3</param>
public M3(sg_Vector3 pt1, sg_Vector3 pt2, sg_Vector3 pt3, double xOffset = 0.0, double yOffset = 0.0)
{
sg_Vector3 v12 = pt2 - pt1;
sg_Vector3 v13 = pt3 - pt1;
if (v12.isParallel(v13))
{
}
else
{
}
sg_Vector3 newZ = new sg_Vector3(0, 0, 1);
sg_Vector3 newX = pt2 - pt1;
sg_Vector3 YR1 = pt3 - pt1;
sg_Vector3 newY = newZ.crossMul(newX);
double angle = Math.Abs(YR1.getInterAngle(newY)); // 两向量夹角
if (angle > 90)
{
newY.reverse();
}
sg_Vector3 nLocalXoY = v12.crossMul(v13); // 局部编录面法向量
sg_Vector3 nGeodeticXoY = new sg_Vector3(0, 0, 1); // 大地坐标XoY面法向量
sg_Vector3 nx = nLocalXoY.isParallel(nGeodeticXoY)
? new sg_Vector3(1, 0, 0)
: nLocalXoY.crossMul(nGeodeticXoY);
sg_Vector3 ny = nLocalXoY.isParallel(nGeodeticXoY)
? new sg_Vector3(0, 1, 0)
: nLocalXoY.crossMul(nx);
sg_Vector3 nz = nx.crossMul(ny);
sg_Vector3 origin = new sg_Vector3(pt1.x + xOffset, pt1.y + yOffset, pt1.z);
this.mTrans = new sg_Transformation(nz, nx, ny, origin);
IsValid = true;
}
/// <summary>
/// 判断点集是否共线
/// </summary>
/// <param name="pts">点集</param>
/// <returns></returns>
public static bool IsPtsCollinear(sg_Vector3[] pts)
{
int iCount = pts.Length;
// 若点集中的点数小于3个，判定共线
if (iCount < 3)
{
return(true);
}
// 获取第一个非零辅助向量
sg_Vector3 v1 = pts[1] - pts[0];
if (v1.isZero())
{
for (int i = 2; i < iCount; ++i)
{
v1 = pts[i] - pts[0];
if (!v1.isZero())
{
break;
}
}
}
// 获取第二个非零辅助向量
for (int j = 1; j < iCount; ++j)
{
var v2 = pts[j] - pts[0];
if (v2.isZero())
{
continue;
}
// 若两个非零辅助向量不平行，则判定不共线
if (!v1.isParallel(v2))
{
return(false);
}
}
// 若两个非零辅助向量始终平行，则判定共线
return(true);
}
