Computer Science 455 Instructor: R. P. Burton Fourth Quiz October 24-25, 2005 Name _________________________________________Score ____________/34 1.The (standard) keyboard is still a remarkably efficient input device due largely to the fact that the initial designers placed the keys so as to maximize typing efficiency. a. true b. false (b) 2.A mouse which does not sense faithfully its movement across a surface generally is not useful as an input device. a. true b. false (b) 3.An input device which does not move in response to force exerted by the user generally is not useful as an input device a. true b. false (b) 4.Wires embedded in a tablet (such as the Rand tablet) must use codes consisting of at least _____ bit(s) if the 1024 left-to-right and the 1024 top-to-bottom wires are to be distinguished. a. 1 b. 10 c. 1024 d. 2048 (a) 5.Given two times tx and ty associated with a two-dimensional acoustic tablet, a unique location is determined. a. true b. false (b) 6.To convert a 2D acoustic tablet to a 3D acoustic tablet, the third microphone is placed a. perpendicular to the other two b. parallel to one of the other two c. (either (a) or (b) will work) d. (neither (a) nor (b) will work) (c) 7.What is the locus of points equidistant from a point microphone (as used with a tablet)? a. a line b. a circle c. a sphere (c) 8.The Lincoln wand used one _____ and ______. a. sound source, three microphones b. sound source, four microphones c. microphone, three sound sources d. microphone, four sound sources (b) 9.The locus of points equidistant from one of the "sensors" in the Utah wand was a. a point b. a line c. a plane d. a circle e. a sphere (e) 10.As used with the Twinklebox, a single LED determined a _______ containing a point of interest. a. line b. plane c. volume d. sphere (b) 11.Touch-panels use ______ techniques. a. optical b. acoustic c. electrical d. (all of the above) (d) 12.Light pens were so named because they a. were light weight in comparison to other input devices of the times (in fact, a recent version is called the "UltraLite") b. emitted light c. detected light d. were capable of writing directly on the screen (c) 13.When used with a raster device, a light pen is essentially a. a pick device b. a locator device (b) 14.A "stroke device" is an example of a ______ device. a. logical b. physical (a) 15.Pick the best statement: a. Any of the physical devices discussed in class can be used to model any of the logical devices discussed in class. b. Any of the logical devices discussed in class can be modeled by any of the physical devices discussed in class. c. (both (a) and (b)) (c) 16.How is the ink in an inkjet printer directed? a. by a mechanically-aimed nozzle b. by an electric field c. by spraying the ink through a "shadow mask" d. by scanning the entire page in raster fashion, turning the (otherwise undirected) ink jet on and off depending on the position of the nozzle relative to the page (b) 17.A mechanical plotter with a stylus that has no means of depositing pigment is effectively useless. a. true b. false (b) 18.Suppose chairs, tables, and bookshelves are defined in master coordinates. Suppose the scene consists of several office buildings, each with several floors, each with several offices, each with some number of chairs, tables and bookshelves. The coordinate system of the scene is "world coordinates." A segment of the world is presented on the screen in "device coordinates." Floors tend to be identical from office building to office building. Offices are placed similarly on floors. What is the coordinate system where a "floor" or an "office" is defined? a. master b. world c. normalized d. device e. (none of the above) (a) 19.What is the primary basis for graphics standards? a. scientific principles b. conformity for the sake of neatness c. portability d. perpetuate the employment of the administrators e. perpetuation of traditions (c) 20.Which of the following situations is least desirable? a. posted and painted b. posted and not painted c. not posted and painted d. not posted and not painted e. (all are equivalently desirable) (c) 21.Which likely requires the most data at the master coordinate level? a. a flat hierarchy b. a tall hierarchy (a) 22.Of the following, the most important aspect of a GUI is a. appearance b. "current" (i..e. the latest GUI components and features) c. ease of use (c) 23. Which is more desireable? A GUI which a. essentially disappears by drawing the user into the application b. presents the user with the most current GUI components, indicating clearly that it is "up to date" (a) 24. It is not possible to clip in master coordinates, since the symbols defined in master coordinates typically overlap at the origin of master coordinates. a. true b. false (b) 25. If it were possible to clip in master coordinates, a separate (inverse) transformation would be needed for every instance in the scene. a. true b. false (a) 26.Which of the following is least efficient (or impossible)? Clipping in _______ coordinates. a. master b. world c. device (b) 27. All of the following are applicable to "picking" any one of several overlapping elements of the scene EXCEPT a. simply pointing b. highlighting in sequence c. "hot points" d. bounding box e. identifying the kinds of elements with which the user has been interacting (a) 28.A program can be expected to relate to a graphical input devices can be in _____. a. Request mode b. Sample mode c. Event mode d. (any of the above modes) (d) 29.Sufficient information with which to produce on-line character recognition software for a tablet device (for a CS 455 student already familiar with coding for the tablet device) anticipates a. part of a class discussion b. an entire class discussion c. an entire week of class discussion d. an entire course (a) 30.Which of the following produces the least satisfactory rubber lines? (If a technique doesn't work, it's entirely unsatisfactory. If it's slow or if it produces a potentially displeasing line or if it obliterates part of the scene, it's unsatisfactory) a. XORing b. Re-scan-convert the entire scene after each movement of the rubber line c. Provide a separate (higher priority) frame buffer for the rubber line d. Simply redraw the line into the frame buffer in its new position after each movement of the rubber line (d) 31.A programmer wishes to produce an image of a Klein bottle. Likely he will produce the data a. analytically b. synthetically (b) 32.Human motion (for presentation using computer graphics) is provided by ____ techniques a. analytic b. synthetic c. both (a) and (b) (c) 33.In general, a viewer with only monocular vision is able to "see" only two dimensions (rather than three). a. true b. false (b) 34.When a shape is drawn using darker and lighter lines, the ______ lines should be used for the lines farther away. a. darker b. lighter c. (not everyone sees darker as closer or darker as farther away) (c)