jeremy-website/cljs/jeremy_website/sketches/tree.cljs

125 lines
5.5 KiB
Clojure

(ns jeremy-website.sketches.tree
(:require [jeremy-website.l-system :as l-system :include-macros true]
[quil.core :as q]
[quil.middleware :as m]))
(defn degrees->radians [deg]
(* deg (/ js/Math.PI 180)))
;; The tree branch object
;; A branch has a coordinate, a list of segments and a map of child branches
;; A segment has an x1, y1, x2, y2
;; The child branch map's keys are the segment index at which the
;; child branch originates, and the values are the child branch itself
(defn l-system-tree
[{:keys [segment-length initial-angle initial-x initial-y l-system]}]
(let [make-tree
(fn make-tree [segment-length x y angle symbols branch idx]
(let [[symbol & rest-symbols] symbols]
(condp = symbol
nil [branch rest-symbols]
"F" (let [new-x (+ x (* segment-length
(js/Math.cos (degrees->radians angle))))
new-y (+ y (* (- segment-length)
(js/Math.sin (degrees->radians angle))))
branch (assoc branch
:segments
(conj (:segments branch)
{:x1 x
:y1 y
:x2 new-x
:y2 new-y}))]
(recur segment-length new-x new-y angle rest-symbols branch (inc idx)))
"+" (recur segment-length x y (+ angle 25) rest-symbols branch idx)
"-" (recur segment-length x y (- angle 25) rest-symbols branch idx)
"*" (recur segment-length x y (+ angle 20) rest-symbols branch idx)
"/" (recur segment-length x y (- angle 20) rest-symbols branch idx)
">" (recur segment-length x y (+ angle 15) rest-symbols branch idx)
"<" (recur segment-length x y (- angle 15) rest-symbols branch idx)
"[" (let [[new-branch rest-symbols] (make-tree segment-length
x
y
angle
rest-symbols
{:x x
:y y
:segments []
:children {}}
0)
branch (assoc-in branch [:children idx] new-branch)]
(recur segment-length x y angle rest-symbols branch idx))
"]" [branch rest-symbols] ;; stop processing current branch and pop to parent call
(recur segment-length x y angle rest-symbols branch idx))))]
(first (make-tree segment-length
initial-x
initial-y
initial-angle
(:state l-system)
{:x initial-x
:y initial-y
:segments []
:children {}}
0))))
(defn setup []
;; Hue goes from 0-360, saturation/brightness from 0-100
(q/color-mode :hsb 360 100 100)
(q/frame-rate 60)
(q/random-seed (or (-> (js/URLSearchParams. js/window.location.search)
(.get "seed"))
(.now js/Date)))
(let [l-system (-> (l-system/instantiate {:axiom "X"
:rules (l-system/rules
"X(0.4)" -> "F+[[X]-X]-F[-FX]+X"
"X(0.4)" -> "F*[[X]/X]/F[/FX]*X"
"X(0.2)" -> "F>[[X]<X]<F[<FX]>X"
"F" -> "FF")
:random-fn (partial q/random 1)})
((apply comp (repeat 6 l-system/step))))
tree (l-system-tree {:initial-angle (- 90 25)
:segment-length 6
:initial-x (* (q/width) 0.1)
:initial-y (* (q/height) 0.95)
:l-system l-system})]
{:tree tree
:current-branches [{:branch tree
:i 0}]
:drawn-branches []
:to-draw []
:drawing []
:drawn []}))
(defn update-state [state]
(let [drawn (concat (mapcat :segments (:drawn-branches state))
(mapcat #(let [i (:i %)
segs (get-in % [:branch :segments])]
(subvec segs i))
(:current-branches state)))]
(assoc state
:drawn drawn)))
{:drawing [{:x1 10 :y1 15 :x2 20 :y2 25 :lerp 0.4}]
:drawn []
:to-draw []}
(defn draw [{:keys [drawing drawn to-draw]}]
(q/background 0 0 100)
(q/fill 0 0 0)
(doseq [{:keys [x1 y1 x2 y2]} drawn]
(q/line x1 y1 x2 y2))
(doseq [{:keys [x1 y1 x2 y2 lerp]} drawing]
(let [x2 (q/lerp x1 x2 lerp)
y2 (q/lerp y1 y2 lerp)]
(q/line x1 y1 x2 y2))))
(defn sketch
[{:keys [host size]}]
(q/sketch
:host host
:middleware [m/fun-mode]
:size size
:setup setup
:update update-state
:draw draw))