How should I draw a path from points

[lihui guo]

There is a macro `path`:

(def star 

  (path [] 

    (move-to 0 20) (line-to 5 5) 

    (line-to 20 0) (line-to 5 -5)

    (line-to 0 -20) (line-to -5 -5)

    (line-to -20 0) (line-to -5 5)

    (line-to 0 20)))

But when I has some points, How should I do?

(def points [[0 20] [20 20] [20 0] [0 0]])
(dean my-path [points]
  ?)

Because `path` is a macro, so I only use java interop to implementation it. How did I do without using java interop?

[abacus]

You would like to (move-to ... the first point, right?

And then you would like to (line-to ... each additional point?

I think you will need (first points),  (rest points),  and a loop.  The fundamental loop is (loop...) and it would definitely suffice, but (doseq...) would be easier.  See https://clojure.github.io/clojure/clojure.core-api.html#clojure.core/doseq

[lihui guo]

but move-to, line-to is not function. So I only use java interop:

(let [p (path [])]
  (.moveTo p 0, 0)
  (doseq [[x y] points]
    (.lineTo p x y)))

在 2019年1月9日星期三 UTC+8下午6:36:15，abacus写道：