2D Space Flight Program - GameCreators Forum

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Zen Master

16

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Joined: 6th Mar 2008

Location:

Posted: 25th Nov 2008 20:08

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Ok i've spent a lot of time pondering this one until i posted took me forever to get the bullet to fire and go to the top of the screen i just need help to allow the loop below to run at the same time as the main loop.

+ Code Snippet

Repeat
            Dec Spry2,1
            Sprite 2,Sprx2,Spry2,2
         Until Spry2 < 5

If you do just wish to tell me the code is written in a poor way or anything like that please dont post, just looking for help on this problem. Thanks for your time guys!

+ Code Snippet

Rem Project: 2dshooter
Rem Created: 25/11/2008 16:35:14

Rem ***** Main Source File *****

GoSub Setup
GoSub Player

Spry = Sprite Y(1)
Sprx = Sprite X(1)
Bulletfired = 0

Do
   If Upkey() = 1 Then Dec Spry,2
   If Downkey() = 1 Then Inc Spry,2
   If Rightkey() = 1 Then Inc Sprx,2
   If Leftkey() = 1 Then Dec Sprx,2
   Sprite 1,Sprx,Spry,1
   Gosub Bullet
Loop

Bullet:
   If Spacekey() = 1
         Spry2 = Spry
         Sprx2 = Sprx + 35
         Show Sprite 2
         Sprite 2,Sprx2,Spry2,2
         Repeat
            Dec Spry2,1
            Sprite 2,Sprx2,Spry2,2
         Until Spry2 < 5
         Hide Sprite 2
   EndIf
   Return

Player:
   Load Image "sprites/Plyr1.bmp",1
   Sprite 1,450,600,1
   Size Sprite 1,90,138
   Set Sprite Priority 1,2
   Load Image "sprites/Bullet.bmp",2
   Sprite 2,100,100,2
   Set Sprite Priority 2,1
   Hide Sprite 2
Return

Setup:
  Set Display Mode 1024,768,16
  Set Image Colorkey 255,0,255
Return

"Face it, if crime didnt pay there would be very few criminals."
Laughton Lewis Burdock

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IanM

Retired Moderator

22

Years of Service

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Joined: 11th Sep 2002

Location: In my moon base

Posted: 25th Nov 2008 21:30

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You're very close already.

What I'd do is separate out the firing of the bullet and the moving of the bullet into two subroutines.

The firing part would only be called if your BulletFired variable was set to zero, and if the spacekey is pressed - it would initialise the bullet, and set the BulletFired variable to 1.

The moving part would be called if the BulletFired variable was set to non-zero - it would move the bullet one step only, and if the bullet reaches the top of the screen, would hide the bullet and set the BulletFired variable back to zero.

Here's what I mean:

GoSub Setup
GoSub Player

Spry = Sprite Y(1)
Sprx = Sprite X(1)
Bulletfired = 0

Do
   If Upkey() = 1 Then Dec Spry,2
   If Downkey() = 1 Then Inc Spry,2
   If Rightkey() = 1 Then Inc Sprx,2
   If Leftkey() = 1 Then Dec Sprx,2
   Sprite 1,Sprx,Spry,1

if BulletFired = 0
      if spacekey() = 1 then gosub StartBullet
   else
      gosub MoveBullet
   endif

sync
Loop

StartBullet:
   Spry2 = Spry
   Sprx2 = Sprx + 35
   Show Sprite 2
   Sprite 2,Sprx2,Spry2,2
   BulletFired = 1
return

MoveBullet:
   Dec Spry2,1
   Sprite 2,Sprx2,Spry2,2
   if Spry2 < 5
      Hide sprite 2
      BulletFired = 0
   endif
Return

Player:
`   Load Image "sprites/Plyr1.bmp",1
   dot 0, 0
   get image 1, 0, 0, 1, 1
   Sprite 1,450,600,1
   Size Sprite 1,90,138
   Set Sprite Priority 1,2
`   Load Image "sprites/Bullet.bmp",2
   get image 2, 0, 0, 1, 1
   Sprite 2,100,100,2
   Set Sprite Priority 2,1
   Hide Sprite 2
Return

Setup:
  sync on
  sync rate 60
  Set Display Mode 1024,768,16
  Set Image Colorkey 255,0,255
Return

+ Code Snippet

GoSub Setup
GoSub Player

Spry = Sprite Y(1)
Sprx = Sprite X(1)
Bulletfired = 0

Do
   If Upkey() = 1 Then Dec Spry,2
   If Downkey() = 1 Then Inc Spry,2
   If Rightkey() = 1 Then Inc Sprx,2
   If Leftkey() = 1 Then Dec Sprx,2
   Sprite 1,Sprx,Spry,1

   if BulletFired = 0
      if spacekey() = 1 then gosub StartBullet
   else
      gosub MoveBullet
   endif

   sync
Loop

StartBullet:
   Spry2 = Spry
   Sprx2 = Sprx + 35
   Show Sprite 2
   Sprite 2,Sprx2,Spry2,2
   BulletFired = 1
return

MoveBullet:
   Dec Spry2,1
   Sprite 2,Sprx2,Spry2,2
   if Spry2 < 5
      Hide sprite 2
      BulletFired = 0
   endif
Return

Player:
`   Load Image "sprites/Plyr1.bmp",1
   dot 0, 0
   get image 1, 0, 0, 1, 1
   Sprite 1,450,600,1
   Size Sprite 1,90,138
   Set Sprite Priority 1,2
`   Load Image "sprites/Bullet.bmp",2
   get image 2, 0, 0, 1, 1
   Sprite 2,100,100,2
   Set Sprite Priority 2,1
   Hide Sprite 2
Return

Setup:
  sync on
  sync rate 60
  Set Display Mode 1024,768,16
  Set Image Colorkey 255,0,255
Return

I used DOT and GET IMAGE because I haven't got your sprites and didn't want to find any - basically, I was lazy

I've also added SYNC ON/SYNC RATE/SYNC commands in the relevant places - this allows the game to run at a fixed rate. There are other alternatives, but you'd be better sticking to this right now.

Utility plug-ins collection (updated 27/09/08) and
http://www.matrix1.demon.co.uk

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Zen Master

16

Years of Service

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Joined: 6th Mar 2008

Location:

Posted: 25th Nov 2008 21:55

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Ah! IanM your a champion thank you very much! Had a lot of trouble with this one

The sync rate, is that to stabalize the movement of the sprites?

"Face it, if crime didnt pay there would be very few criminals."
Laughton Lewis Burdock

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IanM

Retired Moderator

22

Years of Service

User Offline

Joined: 11th Sep 2002

Location: In my moon base

Posted: 25th Nov 2008 22:06

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Yes, it does that, plus it also controls when the drawing of the display takes place. Without it, the drawing will happen whenever DBPro chooses to draw. With it, it will only draw when you call SYNC.

For example, if you had 2 sprites that needed to move together (ship + powerup maybe), and the syncing was controlled by DBPro, you could move one sprite, then DBPro could draw, then you move the next - they'll be out of step, sometimes fairly obviously.

Utility plug-ins collection (updated 27/09/08) and
http://www.matrix1.demon.co.uk

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Zen Master

16

Years of Service

User Offline

Joined: 6th Mar 2008

Location:

Posted: 26th Nov 2008 14:07 Edited at: 26th Nov 2008 14:11

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Hehe spent a lot of time on this one but having a lot of trouble scoured the forums for hours and tried many a thing, The attached sprite is 2 by 4 grid of 32 x 32 pixels, shouldnt this make the Sprite run from frame 1 to 8 when the enemy is shot?

Rem Project: 2dshooter
Rem Created: 25/11/2008 16:35:14

Rem ***** Main Source File *****

GoSub Setup
GoSub Player

Spry = Sprite Y(1)
Sprx = Sprite X(1)
Bulletfired = 0
Enemyx = Sprite X(3)
Enemyy = Sprite Y(3)

Do
   If Upkey() = 1 Then Dec Spry,4
   If Downkey() = 1 Then Inc Spry,4
   If Rightkey() = 1 Then Inc Sprx,4
   If Leftkey() = 1 Then Dec Sprx,4
   Sprite 1,Sprx,Spry,1
   If BulletFired = 0
      If Spacekey() = 1 Then GoSub StartBullet
   Else
      GoSub MoveBullet
   EndIf
   If Sprite Collision (2,3)
      Hide Sprite 2
      Hide Sprite 3
      Play Sprite 4,1,8,3
   EndIf
   Sync
Loop

StartBullet:
   If Spacekey() = 1
         Spry2 = Spry
         Sprx2 = Sprx + 35
         Show Sprite 2
         Sprite 2,Sprx2,Spry2,2
         BulletFired = 1
   EndIf
   Return

MoveBullet:
   Dec Spry2,6
   Sprite 2,Sprx2,Spry2,2
   If Spry2 < 5
      Hide Sprite 2
      BulletFired = 0
   EndIf
Return

Player:
   Load Image "sprites/Plyr1.bmp",1
   Sprite 1,450,600,1
   Size Sprite 1,90,138
   Set Sprite Priority 1,3
   Load Image "sprites/Bullet.bmp",2
   Sprite 2,100,100,2
   Set Sprite Priority 2,1
   Hide Sprite 2
   Load Image "sprites/Enemy.bmp",3
   Sprite 3,600,300,3
   Set Sprite Priority 3,2
   Create Animated Sprite 4,"sprites/explosion.bmp",2,4,4
   Set Sprite Priority 4,4
Return

Setup:
  Sync on
  Sync rate 60
  Set Display Mode 1024,768,16
  Set Image Colorkey 255,0,255
Return

+ Code Snippet

Rem Project: 2dshooter
Rem Created: 25/11/2008 16:35:14

Rem ***** Main Source File *****

GoSub Setup
GoSub Player

Spry = Sprite Y(1)
Sprx = Sprite X(1)
Bulletfired = 0
Enemyx = Sprite X(3)
Enemyy = Sprite Y(3)

Do
   If Upkey() = 1 Then Dec Spry,4
   If Downkey() = 1 Then Inc Spry,4
   If Rightkey() = 1 Then Inc Sprx,4
   If Leftkey() = 1 Then Dec Sprx,4
   Sprite 1,Sprx,Spry,1
   If BulletFired = 0
      If Spacekey() = 1 Then GoSub StartBullet
   Else
      GoSub MoveBullet
   EndIf
   If Sprite Collision (2,3)
      Hide Sprite 2
      Hide Sprite 3
      Play Sprite 4,1,8,3
   EndIf
   Sync
Loop

StartBullet:
   If Spacekey() = 1
         Spry2 = Spry
         Sprx2 = Sprx + 35
         Show Sprite 2
         Sprite 2,Sprx2,Spry2,2
         BulletFired = 1
   EndIf
   Return

MoveBullet:
   Dec Spry2,6
   Sprite 2,Sprx2,Spry2,2
   If Spry2 < 5
      Hide Sprite 2
      BulletFired = 0
   EndIf
Return


Player:
   Load Image "sprites/Plyr1.bmp",1
   Sprite 1,450,600,1
   Size Sprite 1,90,138
   Set Sprite Priority 1,3
   Load Image "sprites/Bullet.bmp",2
   Sprite 2,100,100,2
   Set Sprite Priority 2,1
   Hide Sprite 2
   Load Image "sprites/Enemy.bmp",3
   Sprite 3,600,300,3
   Set Sprite Priority 3,2
   Create Animated Sprite 4,"sprites/explosion.bmp",2,4,4
   Set Sprite Priority 4,4
Return

Setup:
  Sync on
  Sync rate 60
  Set Display Mode 1024,768,16
  Set Image Colorkey 255,0,255
Return

Appreciate any help this ones been tickling my brain since last night now lol!

Solved this now thanks forgot the Sprite 4,Enemyx,Enemyy,4 command

!

"Face it, if crime didnt pay there would be very few criminals."
Laughton Lewis Burdock

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