Render Part A Assignment

OpenGL

glBegin

glVertex2f

glEnd

glColor3f

glEnable

glPushMatrix

glTranslatef

glRotatef

glPopMatrix

glMap1f

glRasterPos2f

glPixelZoom

glDrawPixels

glClearColor

GLUT

glutBitmapCharacter

Code to Investigate

Cavalcade of Graphics

ruby/examples/cavalcade_of_graphics.rb

Code to Implement

Components

Each of the renderable components has its own file in the ruby/render/assignment directory.

Equilateral Triangle

wikipedia

The triangle should be equilateral, rendered with its the origin at the center of mass.

Your constructor should accept a half_side_length parameter.

The height of the triangle should be side_length * sqrt(3)/2

The center of mass is one third from the bottom.

So, the bottom left point A's x coordinate should be -half_side_length and its y coordinate should be -1/3 height.

Rectangle

Ellipse

Note: to produce the reference image the code below was used:

    slice_count = 32
    delta_theta = (2*Math::PI) /slice_count

Chord

Note: to produce the reference image the code below was used:

    slice_count = 32
    delta_theta = (@theta_z-@theta_a) / slice_count

Note: a Chord with 32 slices will have 33 points.

Image

Text

Bézier Curve

Point2

To support Bézier curves you will want to implement Point in point2.rb. You may wish to use Ruby's convenient Struct construct.

You should be able to construct a Point2 with an x and a y and be able to access those values.

Component

Quadratic (Second Order) Curve:
Quadratic (Third Order) Curve:
Fourth Order Curve:

Testing Your Solution

Visual Comparison

file to run:

src/main/ruby/render/part_a/part_a_test_snapshots_web_page_generator.rb

Unit Test

file:

src/test/ruby/render/part_a/part_a_unit_test.rb

UnitTest

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