mycelium

Author: monkstone

external_library/gem/pbox2d/lib/particle_system.rb

@@ -2,8 +2,8 @@
 
 module Runnable
   def run
-    reject! { |item| item.done }
-    each { |item| item.display }
+    reject!(&:done)
+    each(&:display)
   end
 end
 
@@ -14,15 +14,15 @@ class ParticleSystem
   def_delegator(:@particles, :empty?, :dead?)
 
   attr_reader :x, :y
-  
+
   def initialize(bd, num, x, y)
     @particles = []          # Initialize the Array
-    @x, @y = x, y            # Store the origin point  
+    @x, @y = x, y            # Store the origin point
     num.times do
       self << Particle.new(bd, x, y)
     end
   end
-  
+
   def add_particles(bd, n)
     n.times do
       self << Particle.new(bd, x, y)
@@ -37,9 +37,9 @@ class Particle
   include Processing::Proxy
   TRAIL_SIZE = 6
   # We need to keep track of a Body
-  
+
   attr_reader :trail, :body, :box2d
-  
+
   # Constructor
   def initialize(b2d, x, y)
     @box2d = b2d
@@ -49,12 +49,12 @@ def initialize(b2d, x, y)
     # This way we have collisions, but they don't overwhelm the system
     make_body(x, y, 0.2)
   end
-  
+
   # This function removes the particle from the box2d world
   def kill_body
     box2d.destroy_body(body)
   end
-  
+
   # Is the particle ready for deletion?
   def done
     # Let's find the screen position of the particle
@@ -64,7 +64,7 @@ def done
     kill_body
     true
   end
-  
+
   # Drawing the box
   def display
     # We look at each body and get its screen position
@@ -84,7 +84,7 @@ def display
     end
     end_shape
   end
-  
+
   # This function adds the rectangle to the box2d world
   def make_body(x, y, r)
     # Define and create the body

external_library/gem/toxiclibs/library/branch/branch.rb

@@ -0,0 +1,71 @@
+require 'forwardable'
+
+# Here we use our own Vec2D class, until we create a path as an array of TVec2D
+# toxis Vec2D. Required to use the ToxicLibsSupport lineStrip2D method.
+# further we can and should use power of ruby to make Branch enumerable and
+# Forwardable to define which enumerable methods we want to use
+class Branch
+  include Enumerable
+  extend Forwardable
+  def_delegators(:@children, :<<, :each, :length)
+  # variance angle for growth direction per time step
+  THETA = Math::PI / 6
+  # max segments per branch
+  MAX_LEN = 100
+  # max recursion limit
+  MAX_GEN = 3
+  # branch chance per time step
+  BRANCH_CHANCE = 0.05
+  # branch angle variance
+  BRANCH_THETA = Math::PI / 3
+  attr_reader :position, :dir, :path, :children, :xbound, :speed, :ybound, :app
+
+  def initialize(app, pos, dir, speed)
+    @app = app
+    @position = pos
+    @dir = dir
+    @speed = speed
+    @path = []
+    @children = []
+    @xbound = Boundary.new(0, app.width)
+    @ybound = Boundary.new(0, app.height)
+    path << TVec2D.new(pos.x, pos.y)
+  end
+
+  def run
+    grow
+    display
+  end
+
+  private
+
+  # Note use of both rotate! (changes original) rotate (returns a copy) of Vec2D
+  def grow
+    check_bounds(position + (dir * speed)) if path.length < MAX_LEN
+    @position += (dir * speed)
+    dir.rotate!(rand(-0.5..0.5) * THETA)
+    path << TVec2D.new(position.x, position.y)
+    if (length < MAX_GEN) && (rand < BRANCH_CHANCE)
+      branch_dir = dir.rotate(rand(-0.5..0.5) * BRANCH_THETA)
+      self << Branch.new(app, position.copy, branch_dir, speed * 0.99)
+    end
+    each(&:grow)
+  end
+
+  def display
+    app.gfx.lineStrip2D(path)
+    each(&:display)
+  end
+
+  def check_bounds(pos)
+    dir.x *= -1 if xbound.exclude? pos.x
+    dir.y *= -1 if ybound.exclude? pos.y
+  end
+end
+
+# we are looking for excluded values
+Boundary = Struct.new(:lower, :upper) do
+  def exclude?(val)
+    true unless (lower...upper).cover? val
+  end
+end

external_library/gem/toxiclibs/mycelium.rb

@@ -0,0 +1,33 @@
+require 'toxiclibs'
+
+# Simple recursive branching system inspired by mycelium growth
+#
+# The vanilla processing sketch was part of the SAC 2013 workshop project
+# (c) 2013 Karsten Schmidt
+# LGPLv3 licensed
+# translated to PiCrate by Martin Prout 2018
+
+load_library :branch
+
+attr_reader :gfx, :root
+
+def setup
+  @gfx = Gfx::ToxiclibsSupport.new(self)
+  @root = Branch.new(
+    self,
+    Vec2D.new(0, height / 2),
+    Vec2D.new(1, 0),
+    10.0
+  )
+end
+
+def draw
+  background(0)
+  stroke(255)
+  no_fill
+  root.run
+end
+
+def settings
+  full_screen
+end