chapt 7

Author: monkstone

chapter_07/01_defining_a_function.rb

@@ -1,22 +1,17 @@
-require 'ruby-processing'
+# Strictly there are only bound and unbound methods in ruby
+# "setup, draw and draw_black_circle" are all bound to a Sketch object
 
-class DefiningAFunction < Processing::App
+def setup
+  size 200, 200
+end
+
+def draw
 
-  def setup
-  
-  end
-  
-  def draw
-  
-  end
-  
-  # This example defines a function, but it is
-  # not called.  So nothing happens.
-  def draw_black_circle
-    fill 0
-    ellipse 50, 50, 20, 20
-  end
-  
 end
 
-DefiningAFunction.new :title => "Defining A Function", :width => 200, :height => 200
+# This example defines a function, but it is
+# not called.  So nothing happens.
+def draw_black_circle
+  fill 0
+  ellipse 50, 50, 20, 20
+end

chapter_07/02_calling_a_function.rb

@@ -1,22 +1,21 @@
-require 'ruby-processing'
+# Many languages distinguish between functions, which have no associated object, 
+# and methods, which are invoked on a receiver object. Strictly in ruby there are 
+# no functions, they are either bound or unbound methods.
+# all the below are bound methods (bound to an object of the Sketch class)
 
-class CallingAFunction < Processing::App
+def setup
+  size 100, 100
+  smooth 4
+  draw_black_circle
+end
+
+def draw
+  background 255
+  draw_black_circle
+end
 
-  def setup
-    smooth
-    draw_black_circle
-  end
-  
-  def draw
-    background 255
-    draw_black_circle
-  end
-  
-  def draw_black_circle
-    fill 0
-    ellipse 50, 50, 20, 20
-  end
-  
+def draw_black_circle
+  fill 0
+  ellipse 50, 50, 20, 20
 end
 
-CallingAFunction.new :title => "Calling A Function", :width => 100, :height => 100

chapter_07/03_bouncing_ball_with_functions.rb

@@ -1,49 +1,45 @@
-require 'ruby-processing'
-
-class BouncingBallWithFunctions < Processing::App
-
-  def setup
-    # Declare variables
-    @x = 1
-    @speed = 1
-    smooth
-  end
-  
-  def draw
-    background 255
-    # Instead of writing out all the code about the ball 
-    # in draw, we simply call three functions. How do 
-    # we know the names of these functions? We made them up!
-    move
-    bounce
-    display
-  end
-  
-  # Where should functions be placed?
-  # You can define your functions anywhere in the code outside of setup and draw.
-  # However, the convention is to place your function definitions below draw.
-
-  # A function to move the ball
-  def move
-    # Change the x location by speed
-    @x += @speed
-  end
-
-  # A function to bounce the ball
-  def bounce
-    # If we’ve reached an edge, reverse speed
-    # (0..width) is a Ruby range, representing the numbers from 0 to width (aka 200).
-    # You can ask a range if it includes another number or not.
-    @speed *= -1 unless (0..width).include? @x
-  end
-
-  # A function to display the ball
-  def display
-    stroke 0
-    fill 175
-    ellipse @x, 100, 32, 32
-  end
-  
+
+
+def setup
+  size 200, 200
+  @x = 1
+  @speed = 1
+  smooth
+end
+
+def draw
+  background 255
+  # Instead of writing out all the code about the ball 
+  # in draw, we simply call three methods. How do 
+  # we know the names of these methods? We made them up!
+  move
+  bounce
+  display
+end
+
+# Where should methods be placed?
+# You can define your methods anywhere in the code outside of setup and draw.
+# However, the convention is to place your method definitions below draw.
+# These methods all get wrapped in the Sketch class at runtime.
+
+# A method to move the ball
+def move
+  # Change the x location by speed
+  @x += @speed
+end
+
+# A method to bounce the ball
+def bounce
+  # If we’ve reached an edge, reverse speed
+  # (0..width) is a Ruby range, representing the numbers from 0 to width (aka 200).
+  # You can ask a range if it includes another number or not.
+  @speed *= -1 unless (0..width).include? @x
+end
+
+# A method to display the ball
+def display
+  stroke 0
+  fill 175
+  ellipse @x, 100, 32, 32
 end
 
-BouncingBallWithFunctions.new :title => "Bouncing Ball With Functions", :width => 200, :height => 200

chapter_07/04_function_returns_distance.rb

@@ -1,48 +1,43 @@
-require 'ruby-processing'
 
-class FunctionReturnsDistance < Processing::App
 
-  def setup
+def setup
+  size 200, 200
+end
+
+def draw
+  background 0
+  stroke 0
 
-  end
+  # Set up width/2-1 and height/2-1 variables, for convenience.
+  w1, h1 = width/2-1, height/2-1
 
-  def draw
-    background 0
-    stroke 0
-    
-    # Set up width/2-1 and height/2-1 variables, for convenience.
-    w1, h1 = width/2-1, height/2-1
-    
-    # Top left square
-    # Our distance function is used to calculate a brightness value
-    # for each quadrant. We could use the built-in function dist 
-    # instead, but we are learning how to write our own functions.
-    fill distance(0, 0, mouse_x ,mouse_y)
-    rect 0, 0, w1, h1
-    
-    # Top right square
-    fill distance(width, 0, mouse_x, mouse_y)
-    rect width/2, 0, w1, h1
-    
-    # Bottom left square
-    fill distance(0, height, mouse_x, mouse_y)
-    rect 0, height/2, w1, h1
-    
-    # Bottom right square
-    fill distance(width, height, mouse_x, mouse_y)
-    rect width/2, height/2, w1, h1
+  # Top left square
+  # Our distance method is used to calculate a brightness value
+  # for each quadrant. We could use the built-in method dist 
+  # instead, but we are learning how to write our own methods.
+  fill distance(0, 0, mouse_x ,mouse_y)
+  rect 0, 0, w1, h1
 
-  end
+  # Top right square
+  fill distance(width, 0, mouse_x, mouse_y)
+  rect width/2, 0, w1, h1
 
-  # Defining the distance method.
-  # In Ruby we don't have to write "return", because Ruby implicitly
-  # returns the last thing that was evaluated from any method.
-  def distance x1, y1, x2, y2
-    dx = x1 - x2
-    dy = y1 - y2
-    sqrt(dx*dx + dy*dy)
-  end
+  # Bottom left square
+  fill distance(0, height, mouse_x, mouse_y)
+  rect 0, height/2, w1, h1
 
+  # Bottom right square
+  fill distance(width, height, mouse_x, mouse_y)
+  rect width/2, height/2, w1, h1
+
+end
+
+# Defining the distance method.
+# In Ruby we don't have to write "return", because Ruby implicitly
+# returns the last thing that was evaluated from any method.
+def distance x1, y1, x2, y2
+  dx = x1 - x2
+  dy = y1 - y2
+  sqrt(dx*dx + dy*dy)
 end
 
-FunctionReturnsDistance.new :title => "Function Returns Distance", :width => 200, :height => 200

chapter_07/05_zoog_with_functions.rb

@@ -1,71 +1,66 @@
-require 'ruby-processing'
 
-class ZoogWithFunctions < Processing::App
+def setup
+  size 200, 200
+  @x, @y = 100, 100
+  @w, @h = 60, 60
+  @eye_size = 16
+  @speed = 1
+  ellipse_mode CENTER 
+  rect_mode CENTER
+  stroke 0
+  smooth 4
+end
 
-  def setup
-    @x, @y = 100, 100
-    @w, @h = 60, 60
-    @eye_size = 16
-    @speed = 1
-    ellipse_mode CENTER 
-    rect_mode CENTER
-    stroke 0
-    smooth
-  end
+def draw
+  background 255 # Draw a black background
 
-  def draw
-    background 255 # Draw a black background
-    
-    # mouse_x position determines speed factor for moveZoog function
-    factor = constrain mouse_x/10, 0, 5
-    
-    # The code for changing the variables associated with Zoog and 
-    # displaying Zoog is moved outside of draw and into functions
-    # called here. The functions are given arguments, such as 
-    # "Jiggle Zoog by the following factor" and "draw Zoog with 
-    # the following eye color".
-    jiggle_zoog factor
-    
-    # pass in a color to the draw_zoog function for eye color
-    d = dist(@x, @y, mouse_x, mouse_y)
-    c = color(d)
-    draw_zoog c
-  end
+  # mouse_x position determines speed factor for moveZoog function
+  factor = constrain mouse_x/10, 0, 5
 
-  def jiggle_zoog speed
-    # Change the x and y location of Zoog randomly
-    @x = @x + random(-1, 1) * speed
-    @y = @y + random(-1, 1) * speed
-    # Constrain Zoog to window
-    @x = constrain @x, 0, width
-    @y = constrain @y, 0, height
-  end
+  # The code for changing the variables associated with Zoog and 
+  # displaying Zoog is moved outside of draw and into methods
+  # called here. The methods are given arguments, such as 
+  # "Jiggle Zoog by the following factor" and "draw Zoog with 
+  # the following eye color".
+  jiggle_zoog factor
 
-  def draw_zoog eye_color
-    # Arms are incorporated into Zoog's design with a times loop.
-    6.times do |i|
-      y = i * 10 + @y + 5
-      line @x-@w/3, y, @x+@w/3, y
-    end
+  # pass in a color to the draw_zoog function for eye color
+  d = dist(@x, @y, mouse_x, mouse_y)
+  c = color(d)
+  draw_zoog c
+end
 
-    # Draw Zoog's body
-    fill 175 
-    rect @x, @y, @w/6, @h*2 
+def jiggle_zoog speed
+  # Change the x and y location of Zoog randomly
+  @x = @x + random(-1, 1) * speed
+  @y = @y + random(-1, 1) * speed
+  # Constrain Zoog to window
+  @x = constrain @x, 0, width
+  @y = constrain @y, 0, height
+end
 
-    # Draw Zoog's head
-    fill 255 
-    ellipse @x, @y-@h/2, @w, @h 
+def draw_zoog eye_color
+  # Arms are incorporated into Zoog's design with a times loop.
+  6.times do |i|
+    y = i * 10 + @y + 5
+    line @x-@w/3, y, @x+@w/3, y
+  end
 
-    # Draw Zoog's eyes
-    fill eye_color
-    ellipse @x-@w/3+1, @y-@h/2, @eye_size, @eye_size*2 
-    ellipse @x+@w/3-1, @y-@h/2, @eye_size, @eye_size*2 
+  # Draw Zoog's body
+  fill 175 
+  rect @x, @y, @w/6, @h*2 
 
-    # Draw Zoog's legs
-    line @x-@w/12, @y+@h, @x-@w/4, @y+@h+10 
-    line @x+@w/12, @y+@h, @x+@w/4, @y+@h+10
-  end
-  
+  # Draw Zoog's head
+  fill 255 
+  ellipse @x, @y-@h/2, @w, @h 
+
+  # Draw Zoog's eyes
+  fill eye_color
+  ellipse @x-@w/3+1, @y-@h/2, @eye_size, @eye_size*2 
+  ellipse @x+@w/3-1, @y-@h/2, @eye_size, @eye_size*2 
+
+  # Draw Zoog's legs
+  line @x-@w/12, @y+@h, @x-@w/4, @y+@h+10 
+  line @x+@w/12, @y+@h, @x+@w/4, @y+@h+10
 end
 
-ZoogWithFunctions.new :title => "Zoog With Functions", :width => 200, :height => 200