Interaction DevicesUser CommunicationPointing Device TasksDirect vs IndirectComparisonSpeech TechnologyDiscrete Word RecognitionWhen should you use it?Speech Store and ForwardWhen to use computer generated speech?Display TechnologiesVideo Display FeaturesImage TechnologiesHardcopy DevicesColorColor Display ProblemsColor Description SchemesRGB ModelSlide 19Slide 20CMY ModelSlide 22Slide 23CMY ConversionsRGB to YIQHSV ModelSlide 27Using Color Effectively - 1Using Color Effectively - 2Direct-InputSlide 31InputLaMothe ExampleKeyboard Global DeclarationsGame_Init( )Game_Shutdown( )Game_Main( )MouseSlide 39Mouse Global DeclarationsSlide 41Slide 42Slide 43Slide 44Slide 45Slide 46Game PadsJoysticksUsing Joysticks & Game PadsSlide 50Joystick Global DeclarationsDI_Enum_Joysticks( )Slide 53Slide 54Slide 55Slide 56Slide 57Slide 58Slide 59Force FeedbackSlide 6101/14/19 1Interaction DevicesCIS 577Bruce R. MaximUM-Dearborn01/14/19 2User Communication•Keyboard remains the user’s primary input device•Most GUI systems expect pointing devices as well–Light pen (direct)–Touch screen (direct)–Mouse –Trackball –Joystick –Graphics tablet –Touch pad –Foot controls (novel)–Gloves (novel)–Eye movement detectors (novel)01/14/19 3Pointing Device Tasks•Selection •Positioning objects •Orienting objects on screen •Path tracing •Quantify •Text entry/editing (not easily done)01/14/19 4Direct vs Indirect•Light pens and touch screens allow the fastest user responses, but are the least accurate (finger vs pixel level resolution)•Graphics tablets with a stylus allows good resolution and long periods of use without switching to the key board (with good software design – often menu driven)01/14/19 5Comparison•Keyboard–Fast control, require memorization and recall•Mouse–Best choice for pointing to objects in arbitrary positions, can be as fast as pointing with a finger•Joystick–Poor cursor control devices, actually slower than mouse (only use where they are game realistic)01/14/19 6Speech Technology•Discrete word recognition •Continuous speech recognition •Speech store and forward •Speech generation01/14/19 7Discrete Word Recognition•90 to 98% reliability for small vocabulary •Usually requires speaker dependent training •Most people would rather type than dictate01/14/19 8When should you use it?•Speakers hands are busy •Mobility required •Speakers eyes are occupied •Harsh or cramped conditions prevent use of key board01/14/19 9Speech Store and Forward•Voice mail type technology •Video games •Low cost •Resource intensive01/14/19 10When to use computer generated speech?•Message is simple •Message is short •Message will not be referred to later •Message deals with events in time •Message requires immediate response •Visual communications channels are overloaded •Environment lighting is bad •User must move around •User subjected to high G forces or lack of oxygen01/14/19 11Display Technologies•CRT –raster scan cathode ray tube•LCD–flicker free, lightweight, limited viewing angles•Plasma–early touch screens•LED–some resolution limitations•Projectors–room lighting and resolution restrictions01/14/19 12Video Display Features •Rapid operation •Reasonable size (24 by 80 or 66 by 166 chars)•Reasonable resolution (768 by 1024 minimum)•Quiet operation •No waste paper •Low cost (< $100)•Reliable •Good for highlighting •Good for graphics and animation01/14/19 13Image Technologies•Scanners (< $100)•Digital cameras (< $200)•Digital video (< $200)•12 inch video disk •CD ROM (600 MB data, 1 hour music)•DVD (3 GB data, 2 hours video)•Motion Capture01/14/19 14Hardcopy Devices•Printers –ink jet, laser, thermal, dot matrix•Plotters–seem to be vanishing (slow, high resolution)•Photographic printers–ink jet technology, special paper01/14/19 15Color•Can soothe or strike the eye •Adds accents to an uninteresting display •Facilitates subtle discriminations in complex displays •Emphasizes the logical organization of information •Draws attention to warnings •Can evoke strong emotional reactions of joy, excitement, fear, or anger01/14/19 16Color Display Problems•Colors can't be represented perfectly on digital computer systems•People don’t have the same perceptions of colors•Color blindness•Eye fatigue can be caused by using bad color combinations01/14/19 17Color Description Schemes•Computer Industry Approach (RBG)–Red, Green, Blue (0 – 255), additive model•Ink jet Approach (CMY or CMYK)–Cyan, Magenta, Yellow, subtractive model•Broadcast TV (YIQ)–Y = luminence, I, Q = chromacity•Psychological Dimensions (HSB or HSV) –Brightness (amount of light energy)–Hue (predominant wave length)–Saturation (color purity)RGB ModelRGB ModelRGB Model•Note that for the "complementary" colors the sum of the values equals white light (1, 1, 1). •For example:red (1, 0, 0) + cyan (0, 1, 1) = white (1, 1, 1)green (0, 1, 0) + magenta (1, 0, 1) = white (1, 1, 1)blue (0, 0, 1) + yellow (1, 1, 0) = white (1, 1, 1)CMY ModelCMY ModelCMY Model•Cyan = Green + Blue, so light reflected from a cyan pigment has no red component, i.e., the red is absorbed (or subtracted) by cyan.•Magenta subtracts Green•Yellow subtracts Blue. •Printers usually use four colors: Cyan, Yellow, Magenta and Black.•Cyan, Yellow, and Magenta together produce a dark gray rather than a true Black.CMY Conversions•RGB to CMYC = 1 – RM = 1 – GY = 1 – B •CMY to RGBR = 1 – CG = 1 – MB = 1 – Y •For printing (CKYK)K = min(C,M,Y)C = C – KM = M – KY = Y – K•Where K = BlackRGB to YIQ|Y| |0.299 0.587 0.114| |R||I| = |0.596 -0.275 –0.321| * |G||Q | |0.212 –0.528 0.311| |B|•For YIQ to RGB use inverse matrixHSV ModelHSV Model•Pure Red is H=0, S = 1, V = 1•White is S = 0, V = 1 (H is irrelevant)•Black is V = 0 (both H and S are irrelevant)•Adding white is done by decreasing S and leaving V unchanged•Changing shades is done by decreasing V and keeping S unchanged•Create tones by decreasing both S and VUsing Color Effectively - 1•Limit total number of colors•Recognize power of color to speed up or slow down a task•Ensure color coding supports user task•Have color coding appear with minimal user effort•Place color coding under user control•Design for good monochrome display first•Use color to help formatting01/14/19 29Using Color