2-D Graphics

• hardware
• line drawing
• graphics primitives
• attributes (e.g., color, style) and the graphics primitives they apply to
• polygon/filling
• 2D transformations
• animation
• interactive graphics

Types of questions

1. Terminology: For example: jaggies, pixel, refreshing, filling, frame buffer, odd-parity test/inside-outside test, clipping or world window, viewport. scan conversion, coherence, animation

2. Scan Conversion:
   • The Basic Incremental Algorithm vs the Bresenham's Line Algorithm
   • Issues in Line Drawing
   • Circle drawing

3. Hardware: raster
   • how save an image (where, what form)
   • how refresh image

4. Filling
   • What is the name of the underlying principle/test for polygon filling?
   • What does the underlying principle/test say?
   • How is the underlying principle/test used in the implementation of polygon filling in your text?
   • How does the polygon fill algorithm work?
   • Should rectangles be treated as polygons? Pros and cons

5. Clipping
   • Sutherland_Hodgman vs Cohen_Sutherland algorithm
   • Understand the algorithms (outcodes or region code in CS, 4 cases in SH)
   • What role does convex or rectangular clipping regions play?

6. Transformations: Scale, Rotate, Translate, Shearing, clipping/world window to Viewport (View transformation)
   • What are the transformation equations/matrices for scale, rotate (clockwise vs counterclockwise), and translate?
   • Be able to apply transformations.
   • Why matrices/composite matrices?
   • Does it matter in which order you apply the transformations?
   • How to scale or rotate item about a point (x, y) that is not the origin.
   • What transformations must be performed to go from clipping/world window to viewport? what are the translation and scale factor values?
   • What coordinate systems are used to specify points for the clipping/world window and viewport?

7. Animation
   • Techniques and their affects
   • Issues

8. Interactive Graphics
   • Input Primitives: choice, pick, string, valuator, locator
     • What kind of info is returned
     • Example devices
   • Interactive techniques: Inking, rubberbanding, dragging, grids, constraints
     • Be able to describe the technique
     • What kind of logical devices are required to implement
   • The whys and hows of feedback in interactive graphics
   • Event driven programming model (how it's done in GLUT for OpenGL), including the purposes of the event processing loop, the event queue and the individual glut callback functions:
     • glutDisplayFunc
     • glutReshapeFunc
     • glutKeyboardFunc
     • glutMouseFunc
     • glutMotionFunc
     • glutPassiveMotionFunc
     • glutIdleFunc