public static XnaMatrix ToXna(this Matrix matrix)
{
return new XnaMatrix(
matrix.R1C1, matrix.R1C2, matrix.R1C3, matrix.R1C4,
matrix.R2C1, matrix.R2C2, matrix.R2C3, matrix.R2C4,
matrix.R3C1, matrix.R3C2, matrix.R3C3, matrix.R3C4,
matrix.R4C1, matrix.R4C2, matrix.R4C3, matrix.R4C4);
}