/// <summary>
/// Матрица вращения вокруг определённой оси.
/// Учительский rot_axis
/// </summary>
private static double[,] AxleRotationMatrix(Point firstAxlePoint, Point secondAxlePoint, double angle)
{
/* Здесь происходят некие вещи, так называемые "тёмное программирование".
* Этот участок кода оптимизирован учителем до упора, и структуризировать его особого смысла нету.
* В связи с этим были изменены только названия переменных и методов.
*/
double a, b, c, d, length;
double[,] m = new double[4, 4];
double[,] mr1 = new double[4, 4];
double[,] mr2 = new double[4, 4];
double[,] axleRotationMatrixResult = new double[4, 4];
a = secondAxlePoint.X - firstAxlePoint.X;
b = secondAxlePoint.Y - firstAxlePoint.Y;
c = secondAxlePoint.Z - firstAxlePoint.Z;
length = Math.Sqrt(Math.Pow(a, 2) + Math.Pow(b, 2) + Math.Pow(c, 2));
a = a / length; b = b / length; c = c / length;
d = Math.Sqrt(Math.Pow(b, 2) + Math.Pow(c, 2));
if (d > 0.0000001)
{
double crd = (c / d);
double brd = (b / d);
{
mr1 = MovementMatrix(firstAxlePoint.GetNegative());
m = NewMatrix();
m[1, 1] = crd; m[1, 2] = brd; //nondefault x rotation
m[2, 1] = -brd; m[2, 2] = crd;
mr2 = MultiplyMatrix(mr1, m);
m = NewMatrix();
m[0, 0] = d; m[0, 2] = a; //nondefault y rotation
m[2, 0] = -a; m[2, 2] = d;
mr1 = MultiplyMatrix(mr2, m);
m = DefaultZRotationMatrix(angle); //default z rotation
mr2 = MultiplyMatrix(mr1, m);
m = NewMatrix();
m[0, 0] = d; m[0, 2] = -a; //nondefault y rotation reverse
m[2, 0] = a; m[2, 2] = d;
mr1 = MultiplyMatrix(mr2, m);
m = NewMatrix();
m[1, 1] = crd; m[1, 2] = -brd; // nondefault x rotation reverse
m[2, 1] = brd; m[2, 2] = crd;
mr2 = MultiplyMatrix(mr1, m);
m = MovementMatrix(firstAxlePoint);
axleRotationMatrixResult = MultiplyMatrix(mr2, m);
}
}
else
{
mr1 = MovementMatrix(firstAxlePoint.GetNegative());
m = DefaultXRotationMatrix(angle);
mr2 = MultiplyMatrix(mr1, m);
m = MovementMatrix(firstAxlePoint);
axleRotationMatrixResult = MultiplyMatrix(mr2, m);
}
return axleRotationMatrixResult;
}
/// <summary>
/// Матрица увеличения относительно точки.
/// </summary>
public static Matrix Scaling(double scale,Point scalePoint)
{
var centerBindingMatrix = MovementMatrix(scalePoint.GetNegative());
var scalingMatrix = DefaultScalingMatrix(scale);
var positionReturningMatrix = MovementMatrix(scalePoint);
scalingMatrix = MultiplyMatrix(centerBindingMatrix, scalingMatrix);
scalingMatrix = MultiplyMatrix(scalingMatrix, positionReturningMatrix);
var scalingMatrixResult = new Matrix()
{
type = MatrixType.Scaling,
matrix = scalingMatrix
};
return scalingMatrixResult;
}