Render Part D Assignment

In this studio we will evolve our code from Render_Part_C_Assignment to leverage mixins.

Continue editing files in the render/assignment directory.

Background

Investigate Ruby Modules, specifically the module and include keywords.

Warning

Do NOT use the include keyword in Ruby as you would typically in C or C++.
Be sure to include within the intended class or module definition.
If you include at the top-level, it will mixin to Object!
This may or may not rip a hole in the universe.

Code to Implement

Composite

file:	src/main/ruby/render/assignment/composite.rb
module:	Composite
methods:	initialize_components() push_component(component) each_component() calculate_local_bounds()

module Composite should define methods initialize_components, push_component, and each_component as well as mixin the Enumerable module.

initialize_components

add an instance variable with a suitable name to store an array of components

NOTE: initialize_components() must be private.

push_component

push a component onto your array instance variable.

each_component

if a block is given, yield for each component in your array instance variable.

otherwise use to_enum to return a new Enumerator of the components.

Note: be sure to invoke to_enum with the symbol of the method :each_component and not invoke the method by mistake.

calculate_local_bounds

Similar to the bounds calculations on CompositeTransform and Scene from Part C.

Mixin Enumerable

to add a number of useful methods, include the Enumerable module and

Alias each

use alias_method to alias an :each method to the :each_component method.

CompositeTransform

Be sure to add:

require_relative 'composite'

Mixin your Composite module to the CompositeTransform class.

include Composite

Be sure to invoke initialize_components from the constructor and clean up existing code. For example bounds calculation can now use map.

Scene

Be sure to add:

require_relative 'composite'

Mixin your Composite module to the Scene class.

include Composite

Be sure to invoke initialize_components from the constructor and clean up existing code. For example bounds calculation can now use map.

Testing Your Solution

Unit Test

Complete

file:

src/test/ruby/drawings/preliminary/part_d/*.rb

UnitTest

note: ensure that you have removed all printing to receive credit for any assignment.