Last active
August 29, 2015 14:06
-
-
Save rm-hull/1be4335002213cce2999 to your computer and use it in GitHub Desktop.
Old-skool plasma effect, flogged to death in the early 90's demo scene - the plasma is basically a function on 2D space created by adding together a few sinusoids. By combining different types of sines and adding a time component the illusion of motion is achieved.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
(ns big-bang.examples.plasma | |
(:require | |
[big-bang.core :refer [big-bang]] | |
[enchilada :refer [ctx canvas canvas-size]] | |
[jayq.core :refer [show]])) | |
(def initial-state | |
(let [block-size 15 | |
[width height] (map #(quot % block-size) (canvas-size))] | |
{:t 1 :block-size block-size :w width :h height})) | |
(defn update-state [event world-state] | |
(update-in world-state [:n] inc)) | |
(defn render [{:keys [n block-size w h] :as world-state}] | |
(let [m (* n 4)] | |
(doseq [y (range h) | |
:let [y' (* y block-size)] | |
x (range w) | |
:let [x' (* x block-size) | |
s (Math/sin (* x 10)) | |
; RGB color components | |
r (Math/floor (* 255 (+ (Math/cos (/ (+ x y n s) 20)) | |
(Math/cos (/ (+ x y m) 10))))) | |
g (Math/floor (* 255 (+ (Math/sin (/ (+ x y m s) 20)) | |
(Math/cos (/ (+ x x n) 10))))) | |
b (Math/floor (* 255 (+ (Math/cos (/ (+ x (Math/cos (/ y (+ x m))) (Math/sin (* y 10))) 20)) | |
(Math/cos (/ (+ x x n) 20)))))]] | |
(set! (.-fillStyle ctx) (str "rgba(" r "," g "," b ",0.3)")) | |
(. ctx (fillRect x' y' block-size block-size))) | |
ctx)) | |
(show canvas) | |
(big-bang | |
:initial-state initial-state | |
:on-tick update-state | |
:to-draw render) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment