2D Control Method Woes... - GameCreators Forum

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The Boy Chris

22

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Joined: 13th May 2004

Location: Liverpool - UK

Posted: 13th May 2004 15:01

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Hello everyone,

I've had a bash at creating a 2D GTA-1 style control method - UpKey() moves player forward, LeftKey() rotates avatar left, etc...

At the moment I'm just working on the algorythm to get the numbers correct, then I'm going to enter the sprite code. However, I can't seem to get my numbers to rotate correctly. Can anyone see what I'm doing wrong?

Thanks

Chris

REM // This is the setup phase for variables and any other startup neccessities.
sync rate 60
sync on
backdrop on

REM // Set up system variables
UpdateLoop  = 0
DrawLoop = 1
EndGame  = 0

REM // Set up the screen...
f_ScreenX# = Screen Width()
f_ScreenY# = Screen Height()

REM // Set up some constants
g_Pi# = 3.1415927

REM // Set up player values
iMaxNumPlayers = 8
DIM g_PlayerX(iMaxNumPlayers)
DIM g_PlayerY(iMaxNumPlayers)
DIM g_PlayerSpeed(iMaxNumPlayers)
DIM g_PlayerDirection(iMaxNumPlayers)
g_CurrentPlayer = 0
g_MaxSpeed = 4
g_MinSpeed = 0

g_PlayerX(g_CurrentPlayer) = f_ScreenX# / 2
g_PlayerY(g_CurrentPlayer) = f_ScreenY# / 2

REM // This is the beginning of the game loop.
Repeat

REM // This is the update loop.
   IF UpdateLoop = 0

Repeat

IF RightKey()=1
          g_PlayerDirection(g_CurrentPlayer) = g_Playerdirection(g_CurrentPlayer) + (g_Pi#/100.0)
          Print "Right key pressed!"
      ENDIF

IF LeftKey()=1
          g_PlayerDirection(g_CurrentPlayer) = g_Playerdirection(g_CurrentPlayer) - (g_Pi#/100.0)
          Print "Left key pressed!"
      ENDIF

IF UpKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) <= g_MaxSpeed
          g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + 1
          Print "Up key pressed!"
      ENDIF

IF DownKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
          g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) - 1
          Print "Down key pressed!"
      ENDIF

g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) + (g_PlayerSpeed(g_CurrentPlayer) * sin(g_PlayerDirection(g_CurrentPlayer)))
      g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) + (g_PlayerSpeed(g_CurrentPlayer) * cos(g_PlayerDirection(g_CurrentPlayer)))

UpdateLoop = 1
      DrawLoop = 0
      Until UpdateLoop = 1

ENDIF

REM // This is the draw loop.
   IF DrawLoop = 0

Repeat

box g_PlayerX(g_CurrentPlayer),g_PlayerY(g_CurrentPlayer),g_PlayerX(g_CurrentPlayer) + 20,g_PlayerY(g_CurrentPlayer) + 20
      Print g_PlayerX(g_CurrentPlayer)
      Print g_PlayerY(g_CurrentPlayer)
      Print g_PlayerSpeed(g_CurrentPlayer)
      Print g_PlayerDirection(g_CurrentPlayer)

sync
      DrawLoop = 1
      UpdateLoop = 0
      Until DrawLoop = 1

ENDIF

REM // This is the end of the game loop.
Until EndGame = 1

+ Code Snippet

REM // This is the setup phase for variables and any other startup neccessities.
sync rate 60
sync on
backdrop on

REM // Set up system variables
UpdateLoop  = 0
DrawLoop = 1
EndGame  = 0

REM // Set up the screen...
f_ScreenX# = Screen Width()
f_ScreenY# = Screen Height()

REM // Set up some constants
g_Pi# = 3.1415927

REM // Set up player values
iMaxNumPlayers = 8
DIM g_PlayerX(iMaxNumPlayers)
DIM g_PlayerY(iMaxNumPlayers)
DIM g_PlayerSpeed(iMaxNumPlayers)
DIM g_PlayerDirection(iMaxNumPlayers)
g_CurrentPlayer = 0
g_MaxSpeed = 4
g_MinSpeed = 0

g_PlayerX(g_CurrentPlayer) = f_ScreenX# / 2
g_PlayerY(g_CurrentPlayer) = f_ScreenY# / 2

REM // This is the beginning of the game loop.
Repeat

   REM // This is the update loop.
   IF UpdateLoop = 0

      Repeat

      IF RightKey()=1
          g_PlayerDirection(g_CurrentPlayer) = g_Playerdirection(g_CurrentPlayer) + (g_Pi#/100.0)
          Print "Right key pressed!"
      ENDIF

      IF LeftKey()=1
          g_PlayerDirection(g_CurrentPlayer) = g_Playerdirection(g_CurrentPlayer) - (g_Pi#/100.0)
          Print "Left key pressed!"
      ENDIF

      IF UpKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) <= g_MaxSpeed
          g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + 1
          Print "Up key pressed!"
      ENDIF

      IF DownKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
          g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) - 1
          Print "Down key pressed!"
      ENDIF

      g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) + (g_PlayerSpeed(g_CurrentPlayer) * sin(g_PlayerDirection(g_CurrentPlayer)))
      g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) + (g_PlayerSpeed(g_CurrentPlayer) * cos(g_PlayerDirection(g_CurrentPlayer)))

      UpdateLoop = 1
      DrawLoop = 0
      Until UpdateLoop = 1

   ENDIF

   REM // This is the draw loop.
   IF DrawLoop = 0

      Repeat

      box g_PlayerX(g_CurrentPlayer),g_PlayerY(g_CurrentPlayer),g_PlayerX(g_CurrentPlayer) + 20,g_PlayerY(g_CurrentPlayer) + 20
      Print g_PlayerX(g_CurrentPlayer)
      Print g_PlayerY(g_CurrentPlayer)
      Print g_PlayerSpeed(g_CurrentPlayer)
      Print g_PlayerDirection(g_CurrentPlayer)

      sync
      DrawLoop = 1
      UpdateLoop = 0
      Until DrawLoop = 1

   ENDIF

REM // This is the end of the game loop.
Until EndGame = 1

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The Boy Chris

22

Years of Service

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Joined: 13th May 2004

Location: Liverpool - UK

Posted: 13th May 2004 15:20

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Oh, and I have DB-Pro by the way.

Thanks

http://www.bizarrecreations.com

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Lampton Worm

23

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Joined: 4th Sep 2002

Location: United Kingdom

Posted: 13th May 2004 15:24

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Hi,

Wouldn't it be easier to use a sprite from the start, and the commands rotate sprite and move sprite?

e.g. (untested)...

`Codestart
sync on:sync rate 40
load image "player.bmp",1
sprite 1,screen width()/2,screen height()/2,1
do
if upkey()=1 then move sprite 1,1
if downkey()=1 then move sprite 1,0-1
if leftkey()=1 then rotate sprite 1,wrapvalue(sprite angle(1)+3)
if rightkey()=1 then rotate sprite 1,wrapvalue(sprite angle(1)-3)
sync
loop
`Codeend

etc.

Not sure if that is what you're trying to achieve?

Hope it helps,
Cheers.

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The Boy Chris

22

Years of Service

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Joined: 13th May 2004

Location: Liverpool - UK

Posted: 13th May 2004 15:32

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I'm doing it this way because it'll make it easier when I need to work out collision, acceleration and other stuff later on. The way you desribed is accurate, but there is no Update/Render loop to it, therefore I can't work out everything before I draw the screen (which I will need to do...)

Chris

http://www.bizarrecreations.com

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Lampton Worm

23

Years of Service

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Joined: 4th Sep 2002

Location: United Kingdom

Posted: 13th May 2004 15:35

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Hi,

You could use the (limited) built in sprite collision detection, if you only need box collision.

Also you can track the sprite size and coords easily enough...just use PlayerX=sprite x(1) etc.

For acceleration you'd just calculate the velocity and apply it to the move sprite command.

I'm sure you way will work a treat when its fixed, just thinking that DBP provides these commands to make life easier

Cheers.

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The Boy Chris

22

Years of Service

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Joined: 13th May 2004

Location: Liverpool - UK

Posted: 13th May 2004 15:52 Edited at: 13th May 2004 15:52

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Nevermind, thanks for the info

I'm going to try what you said and look into the stuff DBP does automatically.

In the meantime I gave up and resigned myself to 8 directional movement. Ahhh well...]

Chris

REM // This is the setup phase for variables and any other startup neccessities.
sync rate 60
sync on
backdrop on

REM // Set up system variables
UpdateLoop  = 0
DrawLoop = 1
EndGame  = 0

REM // Set up the screen...
f_ScreenX# = Screen Width()
f_ScreenY# = Screen Height()

REM // Set up some constants
g_Pi# = 3.1415927

REM // Set up player values
iMaxNumPlayers = 8

SetUpPlayerArrays()

REM // Set up some values we can work from...
g_CurrentPlayer = 0
g_MaxSpeed = 4
g_MinSpeed = 0
g_PlayerX(g_CurrentPlayer) = f_ScreenX# / 2
g_PlayerY(g_CurrentPlayer) = f_ScreenY# / 2
g_PlayerAcceleration(g_CurrentPlayer) = 1

REM // This is the beginning of the game loop.
Repeat

REM // This is the update loop.
   IF UpdateLoop = 0

Repeat

IF RightKey()=1
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) + g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

IF LeftKey()=1
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) - g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

IF UpKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) <= g_MaxSpeed
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) - g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

IF DownKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) + g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

UpdateLoop = 1
      DrawLoop = 0
      Until UpdateLoop = 1

ENDIF

REM // This is the draw loop.
   IF DrawLoop = 0

Repeat
      box g_PlayerX(g_CurrentPlayer),g_PlayerY(g_CurrentPlayer),g_PlayerX(g_CurrentPlayer) + 20,g_PlayerY(g_CurrentPlayer) + 20

sync
      DrawLoop = 1
      UpdateLoop = 0
      Until DrawLoop = 1

ENDIF

REM // This is the end of the game loop.
Until EndGame = 1

Function SetUpPlayerArrays()
DIM g_PlayerX(iMaxNumPlayers)
DIM g_PlayerY(iMaxNumPlayers)
DIM g_PlayerSpeed(iMaxNumPlayers)
DIM g_PlayerAcceleration(iMaxNumPlayers)
DIM g_PlayerDirection(iMaxNumPlayers)
DIM g_PlayerVehicle(iMaxNumPlayers)
EndFunction

+ Code Snippet

REM // This is the setup phase for variables and any other startup neccessities.
sync rate 60
sync on
backdrop on

REM // Set up system variables
UpdateLoop  = 0
DrawLoop = 1
EndGame  = 0

REM // Set up the screen...
f_ScreenX# = Screen Width()
f_ScreenY# = Screen Height()

REM // Set up some constants
g_Pi# = 3.1415927

REM // Set up player values
iMaxNumPlayers = 8

SetUpPlayerArrays()

REM // Set up some values we can work from...
g_CurrentPlayer = 0
g_MaxSpeed = 4
g_MinSpeed = 0
g_PlayerX(g_CurrentPlayer) = f_ScreenX# / 2
g_PlayerY(g_CurrentPlayer) = f_ScreenY# / 2
g_PlayerAcceleration(g_CurrentPlayer) = 1

REM // This is the beginning of the game loop.
Repeat

   REM // This is the update loop.
   IF UpdateLoop = 0

      Repeat

      IF RightKey()=1
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) + g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

      IF LeftKey()=1
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerX(g_CurrentPlayer) = g_PlayerX(g_CurrentPlayer) - g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

      IF UpKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) <= g_MaxSpeed
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) - g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

      IF DownKey()=1 AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
         IF g_PlayerSpeed(g_CurrentPlayer) < g_MaxSpeed AND g_PlayerSpeed(g_CurrentPlayer) >= g_MinSpeed
            g_PlayerSpeed(g_CurrentPlayer) = g_PlayerSpeed(g_CurrentPlayer) + g_PlayerAcceleration(g_CurrentPlayer)
         ENDIF
         g_PlayerY(g_CurrentPlayer) = g_PlayerY(g_CurrentPlayer) + g_PlayerSpeed(g_CurrentPlayer)
      ENDIF

      UpdateLoop = 1
      DrawLoop = 0
      Until UpdateLoop = 1

   ENDIF

   REM // This is the draw loop.
   IF DrawLoop = 0

      Repeat
      box g_PlayerX(g_CurrentPlayer),g_PlayerY(g_CurrentPlayer),g_PlayerX(g_CurrentPlayer) + 20,g_PlayerY(g_CurrentPlayer) + 20

      sync
      DrawLoop = 1
      UpdateLoop = 0
      Until DrawLoop = 1

   ENDIF

REM // This is the end of the game loop.
Until EndGame = 1

Function SetUpPlayerArrays()
DIM g_PlayerX(iMaxNumPlayers)
DIM g_PlayerY(iMaxNumPlayers)
DIM g_PlayerSpeed(iMaxNumPlayers)
DIM g_PlayerAcceleration(iMaxNumPlayers)
DIM g_PlayerDirection(iMaxNumPlayers)
DIM g_PlayerVehicle(iMaxNumPlayers)
EndFunction

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Lampton Worm

23

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Joined: 4th Sep 2002

Location: United Kingdom

Posted: 13th May 2004 16:30

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No worries. p.s. not sure if its something you've considered already, but you may want to use typed arrays -

e.g.

DIM g_PlayerX(iMaxNumPlayers)
DIM g_PlayerY(iMaxNumPlayers)
DIM g_PlayerSpeed(iMaxNumPlayers)
DIM g_PlayerAcceleration(iMaxNumPlayers)
DIM g_PlayerDirection(iMaxNumPlayers)
DIM g_PlayerVehicle(iMaxNumPlayers)

Could be...

type playertype
x as integer
y as integer
speed# as float
etc.
endtype

dim player(iMaxNumPlayers) as playertype

...then you can refer to the array as - player(1).x, player(1).speed# etc. and it only uses up 1 array, cool.

Just a thought,
Cheers.

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The Boy Chris

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Joined: 13th May 2004

Location: Liverpool - UK

Posted: 13th May 2004 17:09

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That is the absolute best thing I've heard yet

Thanks man! (Off to implement that now heh...)

http://www.bizarrecreations.com

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