British Computer Society May 2005

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British Computer SocietyMay 2005

• Video Game Programming Using The PlayStation2
  Games Console
• Dr Henry S Fortuna
• School of Computing and Creative Technologies
• University of Abertay Dundee
• E-mail h.s.fortuna_at_abertay.ac.uk
• Web www.hsfortuna.pwp.blueyonder.co.uk

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My Background

• First Degree in Electrical and Electronic
  Engineering
• PhD in Semiconductor Physics
• Taught Electronics/Microprocessors
• Always interested in playing computer games
• Always interested in computer programming/graphics
  
• Joined Games Technology Course team at Abertay
• Got involved with Sony Computers Entertainment
• Now lead Games Technology course developments

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Presentation Contents

• Games programming why bother?
• Short historical context
• Components of a Video Game? (video)
• Internal structure of PlayStation2
• Development Environment
• Programming techniques
• What students do/think
• Examples of student work

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The UK Games Industry 2004

• UK Software sales were 934m in 2000
• 1.34 Billion in 2004 even though no new
  consoles
• GTA San Andreas
• fasting selling game of all time
• 1 million units in 9 days 1.75M in the year
• 5 titles sold more than 600,000 (double platinum)
• Xbox greatest growth, PS2 greatest volume (640
  M)
• Electronic Arts had 9 titles in top 20
• Top 40 8 sports, 10 film and TV based

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First Video Game (1961)

• MIT student Steve Russell creates Spacewar
• Digital PDP-1 Minicomputer

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Nolan Bushnell Pong 1972
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Space Invaders (1978)
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Other Key Developments

• Atari 400 (1978)
• Commodore 64 (1983)
• Nintendo Entertainment System (1985)
• Sega Master System (1986)
• Nintendo Gameboy (1989)
• Sega 16-bit Genisis (1989)
• Atari Lynx Handheld (1989)
• Nintendo SNES (1991)
• Sega CD (1992)
• Sony Playstation (1995)
• Nintendo N64 (1996)
• Sony Net Yaroze (1997)
• Sega Dreamcast (1999)
• Sony PlayStation2 (2000)
• Microsoft Xbox (2001)
• Nintendo GameCube (2001)
• Sony PlayStation2 Linux Kit (2002)

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Next-Generation Consoles

• Sony PlayStation 3
• Cell Processor (8 Core?)
• Xbox 360
• 3xIBM PowerPC 3.2Ghz cores
• ATI 500MHz graphics processor
• Nintendo Revolution
• Lots of handheld devices

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Components of a Video Game

• (show video)

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Components of a Video Game

• 3D graphics
• User interaction
• Sound effects and music
• 3D models
• 2D textures
• Animation
• Game and level design
• Immersion, excitement, alternate reality

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PlayStation Net Yaroze (1997)(Official
hobbyist Game Development)

• Host-target Development
• Net Yaroze games dev libraries
• No access to hardware
• Sub-optimal Performance

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PlayStation2 Games Console
European Launch November 2000
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Professional Development EnvironmentThe TOOL

• Use the Linux-based tools that come with the TOOL

• Use third party dev tools such as CodeWarrior or
  SN systems

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PlayStation2 Linux Kit May 2002

• USB keyboard mouse
• 10/100 Ethernet Adapter
• 40GB Hard Disk
• DVDs
• Linux operating system
• Hardware Manuals
• Development Tools
• Example Applications

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Development Configuration(Several Options)

• Host/Target
• Native

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Development Tools

• GNU gcc and g compilers
• GNU gdb debugger!
• Vector Command Line Pre-processor
• Vector Unit assembler
• Visual Vector Unit Debugger
• Development can be done offline with Visual
  Studio

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Development Environment
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Graphics Transformation Pipeline

• Transforms vertices from model or local space to
  2D screen space for rasterisation

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PS2 Graphics Architecture
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PS2 Specific Pipeline

• Transformation Matrices built by CPU
• Matrices and untransformed vertex data sent to
  VU1
• VU1 performs vertex transformation, clipping,
  lighting, view port scaling.
• Transformed data sent to GS.
• GS performs texturing and rasterisation.
• All above (3 processes) can run in parallel !!

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Organisation of Memory

• Dynamic buffer contains data that changes from
  frame to frame, e.g. transformed data,
  transformation matrices.
• Two dynamic buffers needed to exploit parallelism
  of PS2
• One buffer is being compiled by the CPU whilst
  the other is being sent for rendering.
• Utilises Parallelism of PS2

Swap Every Frame
Written by CPU
Read by DMAC
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The Game Loop

• while(Game_Running)
• Fire() // Start data transfer
• GetUserInput() //
• DoGameLogic() // AI, Physics, Logic.
• // Following code ONLY puts render data into
  memory
• BeginScene() // Clear frame buffer
• SetStaticData() // textures, 3d models etc
• SetDynamicData() // Matrices, TL, etc.
• EndScene() // Wait for previous frame to
  render

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VU Overview
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Architecture of VU1

• 16k data memory, address in qwords (128-bit)
• 16k program memory, address in dwords (64-bit)
• 32 x 128-bit floating point registers
• 16 x 16-bit integer registers (newbie killer!)
• Two execution units (upper and lower)
• Special registers (ACC, I, Q, R, P)
• Dual stream assembly language (.vsm file)
• VU assembler provided by Sony (ee-dvp-as)
• Latency, scheduling, pairing, issues.

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Typical vsm assembly (dual stream)

• NOP
  lq VF06,7(VI02)
  
• mulax ACC,VF02,VF06x
  iaddiu VI01,VI01,0x00000001
• madday ACC,VF03,VF06y
  iaddiu VI02,VI02,0x00000002
  
• maddaz ACC,VF04,VF06z
  NOP
  
• maddw VF06,VF05,VF06w
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• mulaw.xyz ACC,VF01,VF00w
  div Q,VF00w,VF06w
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  
• mulq.xyz VF06,VF06,Q
  waitq
  
• NOP
  NOP
  
• NOP
  NOP
  
• NOP
  NOP
  

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Typical VCL(Single Stream)

• loop
• lq Vert, StartVert(iVertPtr)
• MatrixMultiplyVertex Vert, fTransform, Vert
• div q, vf00w, Vertw
• mul.xyz Vert, Vert, q
• mula.xyz acc, fScales, vf00w
• madd.xyz Vert, Vert, fScales
• ftoi4.xyz Vert, Vert

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What is the PS2 used for?

• Introduced in year 2
• Introduce console development topics
• 2D graphics, frame buffers, graphics packets,
  graphics processors, memory management, console
  architecture.
• Further Develop programming skills
• C concepts in a games context, Sprite classes
  etc., structure of a games program, creating a 2D
  game.

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What is the PS2 used for?

• Continued in Year 3
• Introduce 3D console development topics
• 3D graphics, 3D console architecture, Vector
  Units, Parallel processing, vertex
  transformation, clipping, lighting.
• Further develop programming skills
• Further C concepts in a games context, High
  level 3D graphics engine design, Low level vertex
  processing.

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What is the kit used for?

• Students choose to use the kit for
• Group project work
• Honours project work
• Other initiatives such as Dare To Be Digital

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Evaluation

• Games Employers Value Console Skills
• Steep learning curve for students
• In-house development framework needed
• Similarities to Pro-development
• Motivational for students
• Introduces Linux Linux development tool chain

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Student View of the Kit

• Some Hate it
• Some are indifferent
• But most LOVE it

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Example Applications
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Example Applications
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Example Applications
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Example Applications
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Student Work

• (Video)
• (Example Applications)

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Questions?

• Development framework and tutorials at
• http//www.hsfortuna.pwp.blueyonder.co.uk/
• (Dr Henry S Fortuna)

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Development Environment

• Libps2dev (May 2002)
• Bundled with kit on DVDs
• Examples and some documentation
• Some hardware features emulated
• Sub optimal performance
• SPS2 project (November 2002)
• Available on playstation2-linux.com
• Full access to graphics hardware
• Similar experience to Pro-Development
• Comparable performance to Pro-Development