BrightSign BrightScript 2 Reference Guide - Manual (Page 54)

54
Appendix
– Example Script - Snake
The following code will run on any BrightSign and uses GPIO buttons 1,2,3,4 for
controls.
REM
REM The game of Snake
REM demonstrates BrightScript programming concepts
REM June 22, 2008
REM
REM Every BrightScript program must have a single Main()
REM
Sub Main()
game_board=newGameBoard()
While true
game_board.SetSnake(newSnake(game_board.StartX(), game_board.StartY()))
game_board.Draw()
game_board.EventLoop()
if game_board.GameOver() then ExitWhile
End While
End Sub
REM *******************************************************
REM *******************************************************
REM *************** *********************
REM *************** GAME BOARD OBJECT *********************
REM *************** *********************
REM *******************************************************
REM *******************************************************
REM
REM An example BrightScript constructor. "newGameBoard()" is regular Function of module scope
REM BrightScript Objects are "dynamic" and created at runtime. They have no "class".
REM The object container is a Roku Object of type roAssocitiveArray (AA).
REM The AA is used to hold member data and member functions.
REM
Function newGameBoard() As Object
game_board=CreateObject( "roAssociativeArray" ) ' Create a Roku Object of type/class
roAssociativeArray
game_board.Init=gbInit ' Add an entry to the AA of type roBrSub with value
gbDraw (a sub defined in this module)
game_board.Draw=gbDraw
game_board.SetSnake=gbSetSnake
game_board.EventLoop=gbEventLoop
game_board.GameOver=gbGameOver
game_board.StartX=gbStartX
game_board.StartY=gbStartY
game_board.Init()
' Call the Init member function (which is
gbInit)
return game_board
End Function
REM
REM gbInit() is a member function of the game_board BrightScript Object.
REM When it is called, the "this" pointer "m" is set to the appropriate instance by
REM the BrightScript bytecode interpreter
REM