这是我使用的,它的工作速度惊人的快。
public struct Matrix3
{
public readonly double a11, a12, a13;
public readonly double a21, a22, a23;
public readonly double a31, a32, a33;
...
public vec3 Multiply(vec3 rhs)
{
// y= A*x
// fill vector by element
return new vec3(
(a11*rhs.X+a12*rhs.Y+a13*rhs.Z),
(a21*rhs.X+a22*rhs.Y+a23*rhs.Z),
(a31*rhs.X+a32*rhs.Y+a33*rhs.Z));
}
public mat3 Multiply(mat3 rhs)
{
// Y = A*X
// fill matrix by row
return new mat3(
(a11*rhs.a11+a12*rhs.a21+a13*rhs.a31),
(a11*rhs.a12+a12*rhs.a22+a13*rhs.a32),
(a11*rhs.a13+a12*rhs.a23+a13*rhs.a33),
(a21*rhs.a11+a22*rhs.a21+a23*rhs.a31),
(a21*rhs.a12+a22*rhs.a22+a23*rhs.a32),
(a21*rhs.a13+a22*rhs.a23+a23*rhs.a33),
(a31*rhs.a11+a32*rhs.a21+a33*rhs.a31),
(a31*rhs.a12+a32*rhs.a22+a33*rhs.a32),
(a31*rhs.a13+a32*rhs.a23+a33*rhs.a33));
}
}
其中vec3
和mat3
是别名我自己Vector3
和Matrix3
结构存储的元素领域。类似的4个元素结构。我也编码它反转像这样:
public double Determinant()
{
return a11*(a22*a33-a23*a32)
+a12*(a23*a31-a21*a33)
+a13*(a21*a32-a22*a31);
}
/// <summary>
/// Solves the system of equations this*x=rhs for x
/// </summary>
public vec3 Solve(vec3 rhs)
{
double D=Determinant();
double ID=1/D;
return new vec3(
(((a22*a33-a23*a32)*rhs.X+(a13*a32-a12*a33)*rhs.Y+(a12*a23-a13*a22)*rhs.Z)*ID),
-(((a21*a33-a23*a31)*rhs.X+(a13*a31-a11*a33)*rhs.Y+(a11*a23-a13*a21)*rhs.Z)*ID),
(((a21*a32-a22*a31)*rhs.X+(a12*a31-a11*a32)*rhs.Y+(a11*a22-a12*a21)*rhs.Z)*ID));
}
/// <summary>
/// Solves the system of equations this*X = rhs for X
/// </summary>
public mat3 Solve(mat3 rhs)
{
double D=Determinant();
double ID=1/D;
return new mat3(
(((a22*a33-a23*a32)*rhs.a11+(a13*a32-a12*a33)*rhs.a21+(a12*a23-a13*a22)*rhs.a31)*ID),
(((a22*a33-a23*a32)*rhs.a12+(a13*a32-a12*a33)*rhs.a22+(a12*a23-a13*a22)*rhs.a32)*ID),
(((a22*a33-a23*a32)*rhs.a13+(a13*a32-a12*a33)*rhs.a23+(a12*a23-a13*a22)*rhs.a33)*ID),
-(((a21*a33-a23*a31)*rhs.a11+(a13*a31-a11*a33)*rhs.a21+(a11*a23-a13*a21)*rhs.a31)*ID),
-(((a21*a33-a23*a31)*rhs.a12+(a13*a31-a11*a33)*rhs.a22+(a11*a23-a13*a21)*rhs.a32)*ID),
-(((a21*a33-a23*a31)*rhs.a13+(a13*a31-a11*a33)*rhs.a23+(a11*a23-a13*a21)*rhs.a33)*ID),
(((a21*a32-a22*a31)*rhs.a11+(a12*a31-a11*a32)*rhs.a21+(a11*a22-a12*a21)*rhs.a31)*ID),
(((a21*a32-a22*a31)*rhs.a12+(a12*a31-a11*a32)*rhs.a22+(a11*a22-a12*a21)*rhs.a32)*ID),
(((a21*a32-a22*a31)*rhs.a13+(a12*a31-a11*a32)*rhs.a23+(a11*a22-a12*a21)*rhs.a33)*ID));
}
为什么不使用现有的Microsoft.Xna.Framework.Matrix结构? (http://msdn.microsoft.com/en-us/library/microsoft.xna.framework.matrix.aspx)它也有一个Multiply方法:http://msdn.microsoft。com/en-us/library/bb198134.aspx – pascalhein 2013-04-04 17:35:37
好点,之前没有注意到!检查一下,它会涉及一些相当大的语法变化,并且从double切换到float,以及向xna框架添加依赖项,但这绝对是需要考虑的事情。 – HugoRune 2013-04-04 17:40:20
相应的向量将是Vector2/Vector3/Vector4,您可以使用Vector3.Transform()作为矩阵向量(http://msdn.microsoft.com/en-us/) library/microsoft.xna.framework.vector3.transform.aspx) – pascalhein 2013-04-04 17:41:29