more mucking about with pendulum/harmonics

src/shimmers/sketches.cljs

@@ -170,6 +170,7 @@
    shimmers.sketches.pawns
    shimmers.sketches.periapsis
    shimmers.sketches.permutations-of-transfiguration
+   shimmers.sketches.pendulum-sway
    shimmers.sketches.phase-shifting
    shimmers.sketches.physarum
    shimmers.sketches.pixel-rings

src/shimmers/sketches/pendulum_sway.cljs

@@ -0,0 +1,49 @@
+(ns shimmers.sketches.pendulum-sway
+  (:require
+   [clojure.math :as math]
+   [shimmers.common.svg :as csvg :include-macros true]
+   [shimmers.common.ui.controls :as ctrl]
+   [shimmers.common.ui.svg :as usvg]
+   [shimmers.math.equations :as eq]
+   [shimmers.math.vector :as v]
+   [shimmers.sketch :as sketch :include-macros true]
+   [thi.ng.geom.circle :as gc]
+   [thi.ng.geom.vector :as gv]
+   [thi.ng.math.core :as tm]
+   [shimmers.math.deterministic-random :as dr]))
+
+(def width 800)
+(def height 600)
+(defn rv [x y]
+  (gv/vec2 (* width x) (* height y)))
+
+(defn plot [{:keys [p r]} lambda1 lambda2 dx dy]
+  (let [limit 90]
+    (for [t (range 0 (* limit eq/TAU) 0.05)]
+      (let [dampen1 (math/exp (* (- lambda1) t))
+            dampen2 (math/exp (* (- lambda2) t))]
+        (gc/circle (tm/+ p
+                         (tm/+ (gv/vec2 (* r dampen1 (math/cos (* dampen2 dx t)))
+                                        (* r dampen1 (math/sin (* dampen2 dy t))))
+                               (v/polar (* 0.04 r dampen2) (* math/PI t))))
+                   1.0)))))
+
+(defn scene [{:keys [scene-id]}]
+  (let [dx (+ (dr/random-int 1 4) (dr/random -0.01 0.01))
+        dy (+ (dr/random-int 1 4) (dr/random -0.01 0.01))]
+    (println dx dy)
+    (csvg/svg-timed
+      {:id scene-id
+       :width width
+       :height height
+       :stroke "black"
+       :fill "white"
+       :stroke-width 0.5}
+      (plot {:p (rv 0.5 0.5) :r (* 0.475 height)}
+            0.004 0.003 dx dy))))
+
+(sketch/definition pendulum-sway
+  {:created-at "2024-07-31"
+   :tags #{}
+   :type :svg}
+  (ctrl/mount (usvg/page sketch-args scene)))