this is the first assignment in chapter 2.

Some answers of qustions in P.82,P.83


2-1) List the operating characteristics for the following display technologies: raster refresh systems, vector refresh systems, plasma panels, and LCDs.
1)Raster Refresh system: in which the electronic beam makes the screen a number of lines, and draw each one and this is called (scan lines) and the picture is refreshed every interval of time from the refresh buffer " frame buffer".

It's characteristics.

a)The pixels in the screen aren't related. b)Fast in loading image. c)when magnifying, the quality of the screen decreases.

2)Vector Refresh system: a)The pixels in the screen are related by function ex: function of lines. b)slow in loading because t need some processing in its function. c)when magnifying the quality of the image is increase.

3)Plasma panels: a)new technology (10/1/2005). b)the screen is divided into little small cells. c)have high resolution although the screen size may be small.


2-2) List some applications appropriate for each of the display technologies in Exercise 2-1.



2-3) determine the resolution (pixels per centimeter) in the x and y directions for the video monitor in use on your system. Determine the aspect ratio, and explain how relative proportions of objects can be maintained on your system.


The Aspect ration is: 800 / number of lines.


2-4) Consider three different raster systems with resolutions of 640 by 480 ,1280 by 1024, and 2560 by 2048. what size frame buffer (in bytes ) is needed for each of these systems to store 12 bits per pixel? How much storage is required for each system if 24 bits per pixel are to be stored?
The answer: a) (640*480*12) / 8 b)(1280*1024*12) / 8 c)(2560*2048*12) / 8 we can replace 12 with 24.


2-5) suppose an RGB raster system is to be designed using an 8 inch by 10 inch screen with a resolution of 100 pixels per inch in each direction. If we want to store 6 bits per pixel in the frame buffer, how much storage (in bytes) do we need for the frame buffer?
(800*10000*6) / 8 byte


2-6)how long would it take to load a 640 by 480 frame buffer with 12 bits per pixel, if 10^5 bits can be transferred per second? How long would it take to load a 24- bit per pixel frame buffer with a resolution of 1280 by 1024 using this same transfer rate?
640*480*12=100000x. after solution x= 3686400 / 100000=36.864 seconds.


2-7) suppose we have a computer with 32 bits per word and a transfer rate of 1 mip (one million instructions per second). How long would it take to fill the frame buffer of a 300 dpi(dot per inch) laser printer with a page size of 8 inches by 11 inches?


2-8) Consider two raster systems with resolution of 640 by 480 and 1280 by 1024.how many pixels could be accessed per second in each of these systems by a display controller that refreshes the screen at a rate of 60 frames per second? What is the access time per pixel in each system?
60*640*480=18432000 pixels. 60*1024*1280=78643200 pixels.


2-9) suppose we have a video monitor with a display area that measures 12 inches across and 9.6 inches high. If the resolution is 1280 by 1024 and the aspect ration is 1, what is the diameter of each screen point?


2-10) How much time is spent scanning across each row of pixels during screen refresh on a raster system with a resolution of 1280 by 1024 and a refresh rate of 60k frames per second?


2-11) Consider a no interlaced raster monitor with a resolution of n by m(m scan lines and n pixels per scan line), a refresh rate of r frames per second ,a horizontal retrace time of t(horiz), and a vertical retrace time of t(vert) .what is the fraction of the total refresh time per frame spent in retrace of the electron beam?


2-12) what is the fraction of the total refresh time per frame spent in retrace of the electron beam for a no interlaced raster system with a resolution of 1280 by 1024, a refresh rate of 60 hz, a horizontal retrace time of 5 microseconds, and a vertical retrace time of 500 microseconds?


2-13) Assuming that a certain full-color (24-bit-per-pixel)RCB raster system has a 512 by 512 frame buffer, how many distinct color choices (intensity levels) would we have available? How many different colors could we display at any one time?


2-14) Compare the advantages and disadvantages of a three-dimension monitor using a varifocal mirror to those of a stereoscopic system.


2-15) List the different input and output components that are typically used with virtual reality systems. Also ,explain how users interact with a virtual scene displayed with different output devices , such as two dimensional and stereoscopic monitors.


2-16) Explain how virtual reality systems can be used in design applications. What are some other applications for virtual reality systems?


2-17) List some applications for large-screen displays.


2-18) Explain the differences between a general graphics system designed for a programmer and one designed for a specific application, such as architectural design.
General graphics system: This is the system that provides a library functions that help programmer in designing his displaying using some programming language as C++ and Java. One of these General graphics systems is OpenGL (graphics library).
Special graphics system: This system help user who hasn't experience in programming to create shapes and views by simple interface consist of buttons and menu (For example : Photo Shop )


2-19) Explain the differences between the OpenGL core library, the OpenGL utility , and the OpenGL utility Toolkit.
OpenGL core :This library function provide programmer functions that help him in constructing primitives shapes, geometric transformation and attributes
OpenGL Utility :
This library function provide programmer functions that help him in constructing complex shapes and quadric shapes. It provides other advanced operations such as processing
OpenGL Utility Toolkit :
This library function provides functions that Implement the interacting with screen window.


2-20) What command could we use to set the color of an OpenGL display window to light gray? What command would we use to set the color of the display window to black ?
glClearColor (0.4, 0.4, 0.4, 0.0); // set the displayed
glClearColor (0.0, 0.0, 0.0, 0.0); // set the displayed window color black


2-21) List the statements needed to set up an OpenGL display window whose lower-right corner is at pixel position (200,200), with a window width of 100 pixels and a height of 75 pixels.
glutCreatWindow ("My Window");
glutInitWindowPosition();
glutInitWindowSize(100,75);


2-22) Explain what is meant by the term" OpenGL display callback function"
. Its answer in the last paragraph in section 2.9. But I can not understand it.
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