// theta is in degrees
public static GraphicsMatrix GetRotationMatrix(double thetaX, double thetaY, double thetaZ)
{
double c = Math.PI / 180;
double radX = c * thetaX;
double radY = c * thetaY;
double radZ = c * thetaZ;
GraphicsMatrix x = new GraphicsMatrix(new double[4, 4] {
{ 1, 0, 0, 0 },
{ 0, Math.Cos(radX), Math.Sin(radX), 0 },
{ 0, -1 * Math.Sin(radX), Math.Cos(radX), 0 },
{ 0, 0, 0, 1 }
});
GraphicsMatrix y = new GraphicsMatrix(new double [4, 4] {
{ Math.Cos(radY), 0, Math.Sin(radY), 0 },
{ 0, 1, 0, 0 },
{ -1 * Math.Sin(radY), 0, Math.Cos(radY), 0 },
{ 0, 0, 0, 1 }
});
GraphicsMatrix z = new GraphicsMatrix(new double[4, 4] {
{ Math.Cos(radZ), Math.Sin(radZ), 0, 0 },
{ -1 * Math.Sin(radZ), Math.Cos(radZ), 0, 0 },
{ 0, 0, 1, 0 },
{ 0, 0, 0, 1 }
});
y.Multiply(x);
z.Multiply(x);
return(x);
}
/* static methods */
public static GraphicsMatrix GetIdentity(int dimensions)
{
double[,] matrixOut = new double[dimensions, dimensions];
int i;
for (i = 0; i < dimensions; i++)
{
matrixOut[i, i] = 1;
}
GraphicsMatrix gmOut = new GraphicsMatrix(matrixOut);
return(gmOut);
}
public void Multiply(GraphicsMatrix matrix)
{
// the product
double[,] matrixOut = new double[4, matrix.Cols];
int row, col, index;
for (row = 0; row < 4; row++)
{
for (col = 0; col < matrix.Cols; col++)
{
double sum = 0;
for (index = 0; index < this.Cols; index++)
{
sum += this.Matrix[row, index] * matrix.Matrix[index, col];
}
matrixOut[row, col] = sum;
}
}
matrix.Matrix = matrixOut;
}
public void Rotate(double x, double y, double z, GraphicsMatrix rotationMatrix)
{
this.Translate(-x, -y, -z);
this.Rotate(rotationMatrix);
this.Translate(x, y, z);
}
public void Rotate(double thetaX, double thetaY, double thetaZ)
{
GraphicsMatrix rotationMatrix = GraphicsMatrix.GetRotationMatrix(thetaX, thetaY, thetaZ);
this.Rotate(rotationMatrix);
}
public void Rotate(GraphicsMatrix rotationMatrix)
{
rotationMatrix.Multiply(this);
}