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se5a/matrix2d.cs

Created August 4, 2020 23:06
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2dMatrixMath
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matrix2d.cs
using System;
using System.Collections.Generic;
namespace Pulsar4X.Orbital
{
public class Matrix2d
{
double[] X = new double[3] { 1, 0, 0 };
double[] Y = new double[3] { 0, 1, 0};
double[] Z = new double[3] {0, 0, 1};
public static Matrix2d IDScale(double scaleX, double scaleY)
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { scaleX, 0, 0 },
Y = new double[3] { 0, scaleY, 0 },
Z = new double[3] {0, 0, 1}
};
return matrix;
}
public static Matrix2d IDTranslate(double translateX, double tranlsateY)
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { 1, 0, 0},
Y = new double[3] { 0, 1, 0 },
Z = new double[3] {translateX, tranlsateY, 1}
};
return matrix;
}
public static Matrix2d IDMirror(bool x, bool y)
{
Matrix2d matrix = new Matrix2d();
if (y)
matrix.X = new double[3] { -1, 0, 0 };
if (x)
matrix.Y = new double[3] { 0, -1, 0 };
return matrix;
}
public static Matrix2d IDRotate(double radians)
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { Math.Cos(radians), -Math.Sin(radians), 0 },
Y = new double[3] { Math.Sin(radians), Math.Cos(radians), 0 },
Z = new double[3] {0, 0, 1}
};
return matrix;
}
public static Matrix2d IDRotate90Deg()
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { 0, -1, 0 },
Y = new double[3] { 1, 0, 0 },
Z = new double[3] {0, 0, 1},
};
return matrix;
}
public static Matrix2d IDRotate180Deg()
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { -1, 0, 0 },
Y = new double[3] { 0, -1, 0 },
Z = new double[3] {0, 0, 1},
};
return matrix;
}
public static Matrix2d IDRotate270Deg()
{
Matrix2d matrix = new Matrix2d()
{
X = new double[3] { 0, 1, 0 },
Y = new double[3] { -1, 0, 0 },
Z = new double[3] {0, 0, 1},
};
return matrix;
}
public static Matrix2d operator *(Matrix2d matrixA, Matrix2d matrixB)
{
Matrix2d newMatrix = new Matrix2d();
newMatrix.X[0] = matrixA.X[0] * matrixB.X[0] + matrixA.X[1] * matrixB.Y[0] + matrixA.X[2] * matrixB.Z[0];
newMatrix.X[1] = matrixA.X[0] * matrixB.X[1] + matrixA.X[1] * matrixB.Y[1] + matrixA.X[2] * matrixB.Z[1];
newMatrix.X[2] = matrixA.X[0] * matrixB.X[2] + matrixA.X[1] * matrixB.Y[2] + matrixA.X[2] * matrixB.Z[2];
newMatrix.Y[0] = matrixA.Y[0] * matrixB.X[0] + matrixA.Y[1] * matrixB.Y[0] + matrixA.Y[2] * matrixB.Z[0];
newMatrix.Y[1] = matrixA.Y[0] * matrixB.X[1] + matrixA.Y[1] * matrixB.Y[1] + matrixA.Y[2] * matrixB.Z[1];
newMatrix.Y[2] = matrixA.Y[0] * matrixB.X[2] + matrixA.Y[1] * matrixB.Y[2] + matrixA.Y[2] * matrixB.Z[2];
newMatrix.Z[0] = matrixA.Z[0] * matrixB.X[0] + matrixA.Z[1] * matrixB.Y[0] + matrixA.Z[2] * matrixB.Z[0];
newMatrix.Z[1] = matrixA.Z[0] * matrixB.X[1] + matrixA.Z[1] * matrixB.Y[1] + matrixA.Z[2] * matrixB.Z[1];
newMatrix.Z[2] = matrixA.Z[0] * matrixB.X[2] + matrixA.Z[1] * matrixB.Y[2] + matrixA.Z[2] * matrixB.Z[2];
return newMatrix;
}
public Vector2 Transform(Vector2 point)
{
return Transform(point.X, point.Y);
}
public Vector2 Transform(double itemx, double itemy)
{
Vector2 newPoint = new Vector2();
//multiply a 2x2 matrix by a 2x1 matrix
double x;
x = X[0] * itemx;
x += X[1] * itemy;
x += X[2] * 1;
newPoint.X = x;
double y;
y = Y[0] * itemx;
y += Y[1] * itemy;
y += Y[2] * 1;
newPoint.Y = y;
return newPoint;
}
public Vector2[] Transform(ICollection<Vector2> points)
{
Vector2[] newPoints = new Vector2[points.Count];
int i = 0;
foreach (var item in points)
{
newPoints[i] = Transform(item);
i++;
}
return newPoints;
}
}
}
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