func FromXAxisAngle(angle float32) T {
	angle *= 0.5
	return T{math.Sin(angle), 0, 0, math.Cos(angle)}
}
FromXAxisAngle returns a quaternion representing a rotation around the x axis.
package quaternion
import (
	"fmt"
	math "github.com/ungerik/go3d/fmath"
	"github.com/ungerik/go3d/vec3"
	"github.com/ungerik/go3d/vec4"
)
var (
	Zero = T{}
	Ident = T{0, 0, 0, 1}
)
type T [4]float32
func FromAxisAngle(axis *vec3.T, angle float32) T {
	angle *= 0.5
	sin := math.Sin(angle)
	q := T{axis[0] * sin, axis[1] * sin, axis[2] * sin, math.Cos(angle)}
	return q.Normalized()
}