Game Engine

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Game Engine

• EECS150 Spring2006
• Lab Lecture 10
• Guang Yang

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Project Status
Check Point 1 N64 Controller Interface
Check Point 2 NTSC Video
VideoRAM
VideoRAM
Check Point 3 Chipcon RF Transceiver
Check Point 4 Game Engine
Block Diagram of the Design
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Checkpoint 4

• Basic Requirements
• 2-player wireless Tron
• Being able to find an opponent and start playing
• Display the game and scores
• Extra Credits
• There is a list of features in cp4 doc
• Feel free to add extra features. Talk to TAs
  about extra credits BEFORE you do it.

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First thing first

• 100 Freedom
• 0 Freedom

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Game Setup

• Game Board Setup

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Game Board (1)

• Internal game board representation
• It is in the engine. You can decide.
• One possible way
• Use RAM to store the board data
• See the reference RAM implementation in cp4 zip
  file

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Game Board (2)

• For each point on the board, use 2 bits to
  represent its status

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Wireless Tron?? Two main phases

• In channel 0
• Initialize the board
• Find an opponent
• Select another channel for playing the game
• Go there

Initialization Phase

• In channel 115
• Maintain a GameIndex
• Send your position and GameIndex
• Receive those from your opponent
• Update the game
• Game over. Go back to Initialization phase

Game Playing Phase
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Initialization Phase
Send Acknowledge with (random) ch115
Receive an Invitation
Listen to Channel 0 for 1 sec
Timeout
Timeout
Timeout
Listen to Channel 0 for 1 sec
Send Invitation
Listen to Channel 0 for 1 sec
Receive an Acknowledge
Send Confirmation Save ch
Receive a Confirmation
Player1
Player2
Change to new channel
Wait 1 sec
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Initialization Phase

• Packet formats standardize the 32-bit payload.
  You need to decide the proper source address and
  destination address.

• where N is the channel number ranging from 1 to
  15.

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Wireless Communication

• !!! UNRELIABLE !!!
• You must add redundancy to make it reliable
• Send every packet multiple times. We start with
  packetRepeatTimes 3. You can experiment later
  on to find out the optimal value.

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Administrative Info (1)

• Checkpoint 3 due in the week after spring break
  in lab
• 50 off one week later
• Plan out a design for checkpoint 4
• No design review, but should be useful for
  project writeup
• Considering extra credit? Plan for it
• Design consideration
• Time allocation

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Administrative Info (2)

• Project grade breakdown
• Checkpoint 1 10
• Checkpoint 2 15
• Checkpoint 3 30
• Checkpoint 4 / Final Checkoff 30
• Report 15

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Administrative Info (3)

• Extra credit
• Up to 20 of total project grade
• Due at the same time as your CP4 check-off
• (either early or standard check-off)
• Not eligible unless you complete all previous
  required project work.
• (Single student groups can submit the blackboxes
  we gave you.)

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Game Playing Phase

• Parameters
• Packet repetition times
• packetRepeatTimes 3
• Car moving speed
• speed 10 pixel/second
• You could try different values later
• To synchronize the moves of both players,
  introduce a GameIndex. It starts from 0, and
  increment after moving one pixel ahead

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Game Playing Phase
GameIndex does not match
Check Game Status for the New Positions
GameIndex matches
Start Game
Receive Position Update Packets
Both alive
You need to arbitrate
Make the move Increment GameIndex
GameIndex0 Set init position
At least one dies
No valid packet received in one second
Send Position Update Packets
End Game. Update Score
Start button pressed on N64
Init Phase
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Game Playing Phase

• Packet Format

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VideoRAM

• You are free to choose any implementation
• For your reference, in our implementation, we
  have dedicated groups of signals for Read/Write
  car positions, and for Write characters on the
  screen
• Refer to the Checkpoint assignment for detailed
  port information

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Extra Credit

• Some extra credit options
• EARLY CHECKOFF (5)
• Week of 4/10 to 4/14
• Multiplayer (gt4) game (7)
• For this one, you need to modify communication
  protocols and/or packet formats
• Audio (5)
• Viewpoints (5)
• Finite wall (like snake) (3)
• Check webpage for more options
• Up to 20

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Project Tips (1)

• Design
• Get used to debugging
• An unverified module is useless
• Refer to lab4 and lab5
• Start from SIMULATION
• Testing
• Multiple boards, different addresses, different
  orderings, etc.

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Project Tips (2)

• Requirements
• Finish these first
• Make sure it works well
• Shouldnt depend on a certain N64 controller
• Should work on multiple boards
• Extra Credit
• Finish early, its worth 5
• Keep your required version separate
• Dont touch it while you work on extra credit!

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Project Writeup

• Includes
• Block diagrams
• Bubble-and-arc diagrams
• Comments
• NO SCHEMATICS (Theyre too detailed)
• Use your design reviews!
• Documentation helps you debug
• Also makes it easier for us to help you
• More details will be posted later

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• Enjoy your spring break
• and/or
• Wireless Tron