// just for rotation
public Matrix2x2 Inverse()
{
Vector2 newOne = new Vector2(mLast[1], -mFirst[1]);
Vector2 newTwo = new Vector2(-mLast[0], mFirst[0]);
float rdet = 1.0f / Det();
Matrix2x2 inv = new Matrix2x2(newOne * rdet, newTwo * rdet);
return(inv);
}
public static Matrix2x2 CreateMatrix2D(Vector2 from, Vector2 to)
{
float degree = VectorAngleVector(from, to);
Vector2 oneRow;
Vector2 twoRow;
CreateMatrix2D(degree, out oneRow, out twoRow);
Matrix2x2 res = new Matrix2x2(oneRow, twoRow);
return(res);
}
public static Matrix2x2 CreateMatrix2D(float degree, Vector2 center)
{
Vector2 oneRow;
Vector2 twoRow;
CreateMatrix2D(degree, out oneRow, out twoRow);
Matrix2x2 res = new Matrix2x2(oneRow, twoRow);
res.Translate = center;
return(res);
}
public static List <Vector2> CalculateCircle(float angle, float r, Vector2 center)
{
List <Vector2> cir = new List <Vector2>();
Matrix2x2 mat2 = MatrixUtils.CreateMatrix2D(angle, center);
mat2.Scale = Vector2.one * r;
Vector2 start = new Vector2(0, 1);
int count = (int)(360.0f / angle);
for (int i = 0; i < count; ++i)
{
Vector2 next = mat2.Rotate(start);
start = next.normalized;
cir.Add(start * r + center);
}
return(cir);
}