flesh out readme

Author: monkstone

README.md

@@ -13,6 +13,28 @@ to run
 math_demo
 ```
 
+### Now you've installed propane! Get more examples to try:-
+
+```bash
+propane --install samples
+```
+The samples get copied to `~/propane_samples`, NB: depends on `wget`. for a simple demo of circumcircle math see `~/propane_samples/processing_app/library/vecmath/vec2d/circumcircle_sketch.rb` or to  run samples as a demo:-
+```bash
+cd ~/propane_samples
+rake
+# Some sketches require opengl which doesn't get installed on windows.
+# For other libraries see below
+```
+Or to run individual sketches `cd` to directory and:-
+```bash
+jruby sketch_name.rb
+```
+Or explore using `atom` editor and use `script` plugin to run (NB: make sure the file type is `Ruby` or `JRubyArt`, sketches wont run with type as `Ruby on Rails`) also make sure `jruby` is on your `path`.
+
+### Propane documentation
+
+[Propane web-site](https://ruby-processing.github.io/propane/)
+
 ### Scope for improvement
 
 In theory we should be able to use nmatrix (jruby version) in the matrix calculation, possibly on the gpu https://groups.google.com/forum/#!topic/sciruby-dev/CIC0EuTRNAk

lib/math_demo/t_points.rb

@@ -2,7 +2,7 @@
 require 'forwardable'
 MAX_POINT = 3
 # A collection of a maximum of 3 points in the processing world
-# includes a collinearity test using Vec2D
+# includes a collinearity test using Vec2D positions
 class TrianglePoints
   extend Forwardable
   def_delegators(:@points, :each, :map, :size, :shift, :clear, :[])
@@ -20,8 +20,8 @@ def <<(pt)
   end
 
   def collinear?
-    pos1 = positions[1]
-    full? ? (positions[0] - pos1).cross(pos1 - positions[2]).zero? : false
+    first, second, third = positions
+    full? ? (first - second).cross(second - third).zero? : false
   end
 
   # returns positions as an array of Vec2D

lib/math_demo/triangle_point.rb

@@ -2,15 +2,14 @@
 # particle and triangle point
 class TPoint
   include Propane::Proxy
-  attr_reader :pos, :vel, :accel, :xbound, :ybound
+  attr_reader :pos, :vel, :accel, :bounds
   # attr_reader :width, :height # uncomment for testing
 
   def initialize(position)
     @pos = position
     @vel = Vec2D.new
     @accel = Vec2D.random
-    @xbound = Boundary.new(0, width)
-    @ybound = Boundary.new(0, height)
+    @bounds = [Boundary.new(0, width), Boundary.new(0, height)]
   end
 
   def direction(acc)
@@ -33,8 +32,8 @@ def update
   private
 
   def check_bounds
-    @vel.x *= -1 if xbound.exclude? pos.x
-    @vel.y *= -1 if ybound.exclude? pos.y
+    @vel.x *= -1 if bounds[0].exclude? pos.x
+    @vel.y *= -1 if bounds[1].exclude? pos.y
   end
 end