Function dot

src/main/java/field/utility/KotlinExtensions.kt:134–134

infix fun Vec3.dot(v: Vec3) = this.dot(v)
infix fun Vec4.dot(v: Vec4) = this.dot(v)

fun Vec2.invoke(x : Double? = null, y : Double? = null) : Vec2 {
    val v = Vec2(this)
    if (x!=null)