how to make an explosion animation

[Descolado]

In this code bellow (file ST3.BAS posted in other topic) the explosion uses WAIT to keep the animation in screen, but it "freeze" the screen and all mobs some seconds. How I create an animation explosion WITHOUT use "WAIT" (with no freeze the other mobs in screen).

 

REM Explosion

Boom:
resetsprite(2)
resetsprite(1)
For t = 1 to 16
WAIT
SPRITE 3, EX + VISIBLE + ZOOMX2, EY + ZOOMY4, SPR03 + SPR_RED
MODE 0,T,0,0,0
Next t

resetsprite(3)
#Score=#Score+50
PRINT AT 227 COLOR CS_WHITE, <6>#Score
goto Start

[Kiwi]

You can try,

 

if T<>0 then

 

SPRITE 3, EX + VISIBLE + ZOOMX2, EY + ZOOMY4, SPR03 + SPR_RED
MODE 0,T,0,0,0

T=T+1

if T=16 then T=0

 

end if

 

Basically, when T is not 0 then then it'll do what in the if/end if bracket. One thing I don't know if MODE 0,T,0,0,0 will execute or be que'd until WAIT function is reached in the game loop.

 

Whenever event requires explosion, just do T=1. Then the routine above will run along the game without freezing.

[Descolado]

You can try,

 

if T<>0 then

 

SPRITE 3, EX + VISIBLE + ZOOMX2, EY + ZOOMY4, SPR03 + SPR_RED

MODE 0,T,0,0,0

T=T+1

if T=16 then T=0

 

end if

 

Basically, when T is not 0 then then it'll do what in the if/end if bracket. One thing I don't know if MODE 0,T,0,0,0 will execute or be que'd until WAIT function is reached in the game loop.

 

Whenever event requires explosion, just do T=1. Then the routine above will run along the game without freezing.

 

Humm... Yes, it was how I imagined. You need set "flags" to control automatic movement and explosion sprites in Intybasic, because you need put your code in "loop". Is hard create PROCEDURES to move or explode sprites because you must use "global variables" and it is difficult to manage.

Ok, thanks, let me continue my game!

[+DZ-Jay]

 

Humm... Yes, it was how I imagined. You need set "flags" to control automatic movement and explosion sprites in Intybasic, because you need put your code in "loop". Is hard create PROCEDURES to move or explode sprites because you must use "global variables" and it is difficult to manage.

Ok, thanks, let me continue my game!

 

Well, the language doesn't support the automatic handling of sprite animations or movement. That means that you will have to do it from your code and manage those resources yourself, and a common way to do this is using a state machine.

 

Moreover, being a procedural language and not an object-oriented one, there is no natural way to encapsulate the data structures for such machines, so you must use global variables.

 

What I advocate is for people to think of their core game logic not as a sequential set of routines, but as a "cyclical engine" where conditions are tested, events are triggered, and the system (i.e., the logical game world) is updated. Each cycle may or may not correspond to an actual frame, though it is easier to consider when it does.

 

If you think about it that way, then those "global variables" are not so much stray and scattered data in the global space, but the actual state of your game engine.

 

dZ.

[+Tarzilla]

As DZJay says, think about things in terms of a master game loop.

 

Set up a bunch of frame counters and state variables

Use On Gosub to drastically reduce the If/Then cycles penalty

PlayerAnimationCounter=0
ExplosionFrame=0
ExplosionFrameDelay=0
ExplosionActive=0
Playerx=100
Playery=30

GameLoop:
    Gosub CheckController
    Gosub MovePlayer
    Gosub MoveEnemies
   Gosub CheckCollisions
   Gosub UpdateAnimations
   Wait
Goto GameLoop

In the UpdateAnimations procedure, check if an explosion is active (set in CheckCollisions,) update ExplosionFrameDelay, update ExplosionFrame when the delay hits a certain value, reset the delay etc.

A variable like ExplosionFrameDelay lets you easily change how long the the explosion lingers, ExplosionFrame lets you have cycle thru as many frames as you want.

UpdateAnimations:Procedure
If ExplosionActive=1 then
    ExplosionFrameDelay=ExplosionFrameDelay+1:If ExplosionFrameDelay>4 then ExplosionFrameDelay=0:ExplosionFrame=ExplosionFrame+1
   On ExplosionFrame gosub ExplodeFrame0,ExplodeFrame1,ExplodeFrame2
End If
End

ExplodeFrame0:Procedure
Define 60,1,ExplodeBitmap0
End

ExplodeFrame1:Procedure
Define 60,1,ExplodeBitmap1
End

Oh, and don't use 1 or 2 character Variable names like Ex and Ey. IntyBASIC doesn't care, but you will when you code gets bigger

 

IntyBASIC likes PlayerExplosionX/PlayerExplosionY just as much as Ex/Ey

 

Even better, if you have to track several explosions, use arrays that correspond to enemy slots

Lets say you have 4 possible enemies that can be shot

Dim EnemyExplosionX(4)

Dim EnemyExplosionY(4)

Dim EnemyExplosionFrame(4)

Dim EnemyExplosionFrameDelay(4)

Dim EnemyExplosionActive(4)

 

Now you can deal with all 4 in one loop, remembering that arrays start at 0

 

ExplodeFrame0:Procedure

Define 60,1,ExplodeBitmap0

End