(ns space-sim.vec2
  (:require [clojure.math :as math]))

(defn zero
  []
  [0. 0.])

(defn add
  [v1 v2]
  (mapv + v1 v2))

(defn scale
  [v & scalars]
  (mapv #(* (apply * scalars) %) v))

(defn len2
  [v]
  (apply + (map #(* % %) v)))

(defn len
  [v]
  (math/sqrt (len2 v)))

(defn normalize
  [v]
  (let [length (len v)]
    (mapv #(/ % length) v)))

(defn dot
  [v1 v2]
  (apply + (map * v1 v2)))