public Matrix4X4 RotateX(float angle)
{
float s = Math.Sin(angle);
float c = Math.Cos(angle);
// Cache the matrix values (makes for huge speed increases!)
float a10 = Elements[4], a11 = Elements[5], a12 = Elements[6], a13 = Elements[7];
float a20 = Elements[8], a21 = Elements[9], a22 = Elements[10], a23 = Elements[11];
// Perform axis-specific matrix multiplication
Elements[4] = a10*c + a20*s;
Elements[5] = a11 * c + a21 * s;
Elements[6] = a12 * c + a22 * s;
Elements[7] = a13 * c + a23 * s;
Elements[8] = a10 * -s + a20 * c;
Elements[9] = a11 * -s + a21 * c;
Elements[10] = a12 * -s + a22 * c;
Elements[11] = a13 * -s + a23 * c;
return this;
}
