Render Part B Assignment

In this assignment we will evolve our code from Render (Part A) to leverage class hierarchies.

Continue editing files in the drawings/core directory.

In this studio, we will have parameters for which explicitly passed arguments are not required (for convenience and backwards compatibility). We will prefer keyword arguments over optional arguments.

Code To Use

Graphics

push_affine_transform

pop_affine_transform

apply_translation

color=

clear

Code to Implement

Transform

file:	src/main/ruby/drawings/transform.rb
class:	Transform
superclass:	Object
methods:	initialize(x,y) x() x=() y() y=() render()

Add accesors for x and y.

Transform's constructor should take x and y parameters and store them in instance variables.

It should define a render method which preserves the current affine transformation, translates by x and y, passes the untransformed_render message to itself (a.k.a. invokes a method on itself), and restores the model view transformation.

All subclasses must implement a private untransformed_render method.

Image

file:	src/main/ruby/drawings/image.rb
class:	Image
superclass:	Transform
methods to evolve:	initialize(path, x: 0, y: 0)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'transform'

Add keyword parameters for x: 0 and y: 0 and invoke your superclass with these parameters.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

ColorTransform

file:	src/main/ruby/drawings/color_transform.rb
class:	ColorTransform
superclass:	Transform
methods:	initialize(x,y,color) color() color=() render()

Add an accessor for color.

ColorTransform's constructor should take x, y, and color parameters. x and y should be passed to the superclass and color should be stored in an instance variable.

NOTE: Override render. Be sure to change the color (unless it is nil) before invoking your superclass.

NOTE: invoke the nil? method to check for nil.

Text

file:	src/main/ruby/drawings/text.rb
class:	Text
superclass:	ColorTransform
methods to evolve:	initialize(text, font, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

Ellipse

file:	src/main/ruby/drawings/ellipse.rb
class:	Ellipse
superclass:	ColorTransform
methods to evolve:	initialize(x_radius, y_radius, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

EquilateralTriangle

file:	src/main/ruby/drawings/equilateral_triangle.rb
class:	EquilateralTriangle
superclass:	ColorTransform
methods to evolve:	initialize(half_side_length, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

BezierCurve

file:	src/main/ruby/drawings/bezier_curve.rb
class:	BezierCurve
superclass:	ColorTransform
methods to evolve:	initialize(control_points, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

CircularSegment

file:	src/main/ruby/drawings/circular_segment.rb
class:	CircularSegment
superclass:	ColorTransform
methods to evolve:	initialize(x_radius, y_radius, theta_a, theta_z, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

Rectangle

file:	src/main/ruby/drawings/rectangle.rb
class:	Rectangle
superclass:	ColorTransform
methods to evolve:	initialize(half_width, half_height, x: 0, y: 0, color: nil)
methods to add:	untransformed_render()
methods to remove:	render()

You will evolve your code from from Part A

be sure to add the following line above your class:

require_relative 'color_transform'

Add keyword parameters for x: 0, y: 0, and color: nil to the constructor and pass them to the superclass.

NOTE: Be sure to not override render. Implement the untransformed_render method instead.

NOTE: untransformed_render() must be private.

CompositeTransform

file:	src/main/ruby/drawings/composite_transform.rb
class:	CompositeTransform
superclass:	Transform
methods:	initialize(x: 0, y: 0) components push_component(component) untransformed_render()

Instances of CompositeTransform will act like a group of objects. When it moves all of its child components will move with it. When it is drawn, each of its child components will be drawn.

Add a reader for components.

Add a push_component method which accepts a component which will later be rendered.

The untransformed_render method should render each pushed component.

NOTE: untransformed_render() must be private.

NOTE: sometimes when constructing objects we need to initialize instance variables that are not necessarily passed in as arguments. this is one of those times.

Scene

file:	src/main/ruby/drawings/scene.rb
class:	Scene
superclass:	Object
methods:	initialize(background_color: Color::BLACK) background_color() background_color=() components() push_component(component) render()

Add an accessor for background_color and a reader for components.

Scene's constructor should take a keyword parameter background_color: Color.new(0,0,0) and store it in an instance variable.

Add a push_component method which accepts a component which will later be rendered.

The render method should clear

the color buffer once before proceeding to render each pushed component.

Testing Your Solution

Unit Test

file:

src/test/ruby/drawings/core/relatively_fast/part_b/*.rb

UnitTest

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

file:

src/test/ruby/drawings/core/relatively_slow/part_b/*.rb

UnitTest

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

Backwards Compatibility

file:

src/test/ruby/drawings/core/relatively_fast/part_a/*.rb

UnitTest

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

Visual Comparison

file to run:

src/test/ruby/drawings/core/snapshots/part_b_components_snapshots_web_page_generator.rb

file to run:

src/test/ruby/drawings/core/snapshots/part_b_composites_snapshots_web_page_generator.rb