4D Simplex noise example

Author: monkstone

processing_app/basics/math/noise4_tap.rb

@@ -0,0 +1,75 @@
+#!/usr/bin/env jruby
+require 'propane'
+
+Coord = Struct.new(:mx, :my, :mz, :az, :al)
+
+class ForD < Propane::App
+  attr_reader :half_w, :half_h, :radius, :spin_x, :spin, :coords
+
+  def settings
+    size(480, 480, P3D)
+  end
+
+  def setup
+    sketch_title '4D Simplex Noise Test'
+    background(0)
+    stroke(255)
+    fill(32, 255, 64)
+    noise_mode(Propane::SIMPLEX)
+    @half_w = width * 0.5
+    @half_h = height * 0.5
+    @radius = height * 0.4
+    @spin_x = 0.0
+    @spin = 0.0
+
+    angle = ((1.0 + Math.sqrt(5)) / 2.0 - 1) * TWO_PI # Fibonacci distribution
+    @coords = (0..2_000).map do |i|
+      inc = Math.asin(i / 1_000.0 - 1.0) # inclination
+      az = angle * i # azimuth
+      # Too lazy to do this the right way... precalculating both the angles and the coordinates
+      Coord.new.tap do |coord|
+        push_matrix
+        rotate_y(az)
+        rotate_z(inc)
+        translate(radius, 0, 0)
+        coord.mx = model_x(0, 0, 0) * 0.007
+        coord.my = model_y(0, 0, 0) * 0.007
+        coord.mz = modelZ(0, 0, 0) * 0.007
+        coord.az = az
+        coord.al = inc
+        pop_matrix
+      end
+    end
+  end
+
+  def draw
+    background(0)
+    @spin -= (mouse_x - pmouse_x) * 0.0001 if mouse_pressed?
+    @spin_x += spin
+    @spin *= 0.98
+    push_matrix
+    translate(half_w, half_h, -0)
+    rotate_y(-spin_x)
+    coords.each do |ci|
+      push_matrix
+      rotate_y(ci.az)
+      rotate_z(ci.al)
+      translate(radius, 0, 0)
+      dst = (modelZ(0, 0, 0) + half_h) / 2 + 32
+      stroke(dst, dst * 0.5, dst * 0.25)
+      #  4D Simplex noise(x, y, z, time)
+      ang = noise(ci.mx, ci.my, ci.mz, frame_count * 0.007) * TWO_PI
+      rotate_x(ang)
+      line(0, 0, 0, 0, 15, 0)
+      translate(0, 15, 0)
+      rotate_x(-10)
+      line(0, 0, 0, 0, 4, 0)
+      rotate_x(20)
+      line(0, 0, 0, 0, 4, 0)
+      pop_matrix
+    end
+    pop_matrix
+  end
+end
+
+ForD.new