Overview

Version 1 - An Hourglass

Add an x and y axis to the image:

Version 2 - Change the View

In this version, try to figure out values for the gluLookAt calls for the following two views:

View 1	View 2

Don't go crazy if you can't reproduce the exact images – as long as you give me something more than a blank screen, you're OK.

(In the first, I've changed the up direction; in the second, I've changed the position of the eye and center).

Version 3 - Add Some Color

• Use the following colors:

Version 4 - Specify Vertices Using Vectors (Arrays)

• Same image as in version 3, but now:
  • Introduce a Point2 (analogous to Point3 in version 4 of the cube)
  • Introduce a typedef named Color3 and use it to define various color variables (e.g. yellow) which can then be used in glColor3fv calls (i.e., replace the previous glColor3f with glColor3fv calls).
  • Only 5 vertices need to be specfied (for the hourglass-- the axes require their own).

Version 5 - Turn it into an Array of Vertices

• Again, the same image as in version 4, but now:
  • Have three arrays of Point2:
    • hourglass - contains the vertices for the hourglass
    • xAxis, yAxis - contains the vertices for the x and y axes respectively

Version 6 - Specify Window Size and Position

Version 7 - Change the Clipping Area

• Use gluOrtho2D (not glOrtho) to modify the clipping area.
• The hourglass itself is 1 unit hight by 1 unit wide (since we're using vertices +/-0.5 in both the x and y directions)
• Remember, the default volumne is a 2x2x2 cube (only the x and y count now, though — why?)

create three images (in separate programs):

Just larger than the hourglass	Double the default in the x and y direction	Double the size of the default clipping area

Version 8 - Triangles (Polygons)

• Use a single GL_TRIANGLES glBegin/glEnd section to create the hourglass as a pair of triangles

  

• Same image, but this time use GL_POLYGON (you won't be able to do it in a single glBegin/glEnd)

Version 10 - Rendering Order

• We're going to be drawing circles-- look at (and copy) the code in the ParaCircle files-- you can find them in the Sphere subdirectory of the Chapter 2 files (at the bottom of the Chapter 2 notes).
• No hidden line removal in 2D, but the order in which the shapes are specified does make a difference (similarly in 3D, the last shape to modify a particular point in space is the one that persists).
• Here are the three views to reproduce:

Outlined circle in front	Filled circle behind	Confused filled circle

• For the filled circle, you can either use a triangle fan (as in one of the ParaCircle examples), or (probably more efficient), use a polygon (same basic code, different glBegin parameter).

Version 11 - Parameterizing the Image

• No change to the image-- just introduce a (float) variable base that is the width of the base (and top) of the hourglass.

  

Version 12 - Handling Window Resizing by Adjusting the Clipping Area/Rectangle

• Add a resizing callback function
• Use gluOrtho2D (rather than glOrtho since you're in 2 dimensions.
• Don't forget, you still need to specify a viewport

  

Version 13 - Handling Window Resizing by Adjusting the Viewport

• Add a resizing callback function
• Use gluOrtho2D (rather than glOrtho since you're in 2 dimensions.

  

Version 14 - Do Something Original

• No picture-- that's why they call it original! :)

What and How to Submit

• Please do NOT submit anything until you have finished the entire assignment.
• The files:
  • There should be a single parent directory named Assignment02
  • Each part of the assignment should reside in its own directory, Part** beneath a single directory where ** is 01, 02, 03, .., 07, etc
• zip or otherwise compress all files into a single compressed file, maintaining path information
• email me the resulting compressed file, using the subject *** CIS 3620 *** Assignment 02 SUBMISSION. Please do not use a different subject heading
• If you need help, email me with the subject heading *** CIS 3620 *** Assignment 02 HELP.
• When submitting all asking for help, please make sure you attach ALL files necessary to build and run your submission.