2. Basics - understanding Graphics System

Analysis 2.1 graphics system - introduction to the function and structure diagram of the system

1. Functions of the computer graphics system

   Calculation stored interactive input output

2. Composition of computer graphics system

   Hardware : a display device a graphical input device storage media graphics output device (graphics display subsystem)

   Software : Game -> Game Engine -> graphics standards (OpenGL or DirectX) -> Graphics Driver [-> GPU -> memory] (hardware)

3. Graphics Hardware

   • Input device: perforated paper, a light pen, a mouse, data Yi (four stages)

   • The display device: CRT display, a liquid crystal display, 3D display

   • Output devices: a printer / plotter

   • Graphics display subsystem

Data from 2.2 to perforated paper coating: an input device

1. Enter the four stages of device development

   Perforated paper -> light pen (open stage interactive graphics) -> Mouse (GUI) -> Data clothing (multi-channel, multi-media intelligent human-computer interaction stage)

2. Dynamic VR aware device

   • Three mouse

     • The virtual space of six degrees of freedom:

       Freedom of movement along the X, Y, Z three orthogonal coordinate axes, and rotational degrees of freedom about three coordinates

   • Data Glove

     • Core: a motion capture member

   • Data clothing

     • Motion capture data Yi: Let the VR system to recognize the body movement designed input device

     • Sensory feedback data garment: the tactile and other sensory output

   • Force feedback device

2.3 CRT basic principles

1. A cathode ray tube

   • The CRT (Cathode Ray Tube) is a vacuum device, which uses an electromagnetic field of high-speed, through the electron beam is focused, deflected to different positions of the screen surface of the bombardment of a fluorescent screen material and produce a visible pattern

   • Structure:

     ① electron gun: the Z-axis direction generated proceeds bombardment fine screen eBook

     • The electron beam is required: sufficient strength; size, the presence or absence should be controlled; well focused

     ② deflection system: magnetic deflection / electric deflection

     ③ screen: the glass coated with a phosphor made of a bottom wall

     • Phosphor requirements: high emission efficiency; Suitable afterglow time; long life

2. A color cathode ray tube

   • Trichromatic principle - red, yellow, blue (RGB)

   • Typical: Three Trinitron Color CRT

   • Color book issues:

     • Each switch can control the electron gun: 2 * 2 * 2 = 8

     • Each electron gun n different strength: n * n * n

     • Each electron gun to control the intensity of 256 kinds: 256 * 256 * 256 = 2 24 [True Color System]

3. scanning method

   • Then scanned graphical display

     • Random scan (Random-Scan): unsuitable for complex images

   • Raster scan graphics display

     • Working principle: controlling the electron beam according to a certain sequential scanning grating pattern, and the character, the image signal is controlled by the Z-axis to form a highlight.

     • Related concepts:

       ① refresh rate: the number of times per second refresh

       ② horizontal scan

       ③ horizontal retrace (blanking)

       ④ vertical retrace (blanking)

     • Progressive scan and interlaced

       Interlaced scanning: scans the even-numbered rows, odd-numbered scanning lines and then

     • Disadvantages:

       ① need to scan conversion

       ② will produce aliasing

The basic principle of a flat panel display 2.4

1. Flat panel displays

   • Features: thin, power-saving (low power consumption), low radiation, no flicker, no interference

   • classification:

     • Emission: self-luminous, a light emitting medium itself (the LED, plasma display)

     • Non-emissive type: passive light, medium itself does not emit light (liquid crystal display)

2. LCD Monitor

   • Color display principle: Each pixel has three sub-pixels (RGB)

   • Viewing angle: left and right sides of the visual angle and the largest

3. Plasma display

   • Since the light emitting Plasma Display Panel (PDP) using a gas discharge principle to realize display technology

4. LED display

   • Liquid-Emitting Diode (LED) light emitting diode display

   • Pixel location diodes arranged in a matrix form to display

   • Advantages: wide high brightness, high efficiency, long life, viewing angle ......

2.5 popular 3D display device

1. Earlier three-dimensional display

   • Near the far smaller big

2. Three-dimensional display principle

   • Principle of stereo vision of the human eye

   • 3D animation or film principle: two cameras, with 3D glasses

3. Three-dimensional display apparatus

   • Three-dimensional glasses: color 3D glasses, polarized 3D glasses, shutter 3D glasses

   • HMD: two small displays, display of two different eyes

   • Glasses box: split-screen display

4. Autostereoscopic display

   • Based on the parallax barrier is a liquid crystal display technology

   • Gas projection technology

   • Direction: the naked eye, holographic, interactive

2.6 display subsystem

1. Graphic Display Subsystem

   • The graphic display processor (video)

     • (Display main chip / graphics processor) GPU: good numerical matrix operations, compute-intensive tasks more advantages

2. Related concepts

   • Pixel: Each unit is a matrix of pixels

   • Resolution: horizontal display resolution = number of pixels * vertical number of pixels

     • Depending on: the spot size; frame buffer size (resolution frame buffer capacity = * color bit plane)

   • Color lookup table: palette storage is a one-dimensional linear color table is composed of a high-speed random access memory