[BASIC] how to use type? - GameCreators Forum

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basicFanatic

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Posted: 22nd Jun 2017 10:04

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Hi! I'm unsure how to check if one of my ball types has left the screen area. Do I have to loop through all my ball types, or is there a more clever way?

type BallType
	sprId as integer //Sprite ID
endtype

balls as BallType[255]

for createBall = 1 to 20
	balls[createBall].sprID = CreateSprite(ballImg)	// Create the ball
	SetSpriteActive(balls[createBall].sprID, 1)
	SetSpriteVisible(balls[createBall].sprID, 1)		// Set ball visible
	SetSpriteSize(balls[createBall].sprID, 128.0, -1 )
	SetSpritePositionByOffset (balls[createBall].sprID, random(GetScreenBoundsLeft()+100, GetScreenBoundsRight()-100), random(GetScreenBoundsTop()+100, GetScreenBoundsBottom()-100))
	SetSpriteShapeCircle( balls[createBall].sprID, 0 ,0,64.0)
	SetSpritePhysicsOn( balls[createBall].sprID, 2)
	SetSpritePhysicsCanRotate( balls[createBall].sprID, 0 )
	SetSpritePhysicsDamping( balls[createBall].sprID, 0.0)
	SetSpritePhysicsRestitution( balls[createBall].sprID, 1.0 )
	SetSpritePhysicsFriction( balls[createBall].sprID, 0.0 ) 
	SetSpritePhysicsMass( balls[createBall].sprID, 1.0 )
	SetSpritePhysicsIsBullet( balls[createBall].sprID, 1 )
	SetSpritePhysicsImpulse(balls[createBall].sprID,GetSpriteXByOffset(balls[createBall].sprID),GetSpriteYByOffset(balls[createBall].sprID),random (500, 2500),random (500, 2500))
next

+ Code Snippet

type BallType
	sprId as integer //Sprite ID
endtype

balls as BallType[255]

for createBall = 1 to 20
	balls[createBall].sprID = CreateSprite(ballImg)	// Create the ball
	SetSpriteActive(balls[createBall].sprID, 1)
	SetSpriteVisible(balls[createBall].sprID, 1)		// Set ball visible
	SetSpriteSize(balls[createBall].sprID, 128.0, -1 )
	SetSpritePositionByOffset (balls[createBall].sprID, random(GetScreenBoundsLeft()+100, GetScreenBoundsRight()-100), random(GetScreenBoundsTop()+100, GetScreenBoundsBottom()-100))
	SetSpriteShapeCircle( balls[createBall].sprID, 0 ,0,64.0)
	SetSpritePhysicsOn( balls[createBall].sprID, 2)
	SetSpritePhysicsCanRotate( balls[createBall].sprID, 0 )
	SetSpritePhysicsDamping( balls[createBall].sprID, 0.0)
	SetSpritePhysicsRestitution( balls[createBall].sprID, 1.0 )
	SetSpritePhysicsFriction( balls[createBall].sprID, 0.0 ) 
	SetSpritePhysicsMass( balls[createBall].sprID, 1.0 )
	SetSpritePhysicsIsBullet( balls[createBall].sprID, 1 )
	SetSpritePhysicsImpulse(balls[createBall].sprID,GetSpriteXByOffset(balls[createBall].sprID),GetSpriteYByOffset(balls[createBall].sprID),random (500, 2500),random (500, 2500))
next

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hendron

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Posted: 22nd Jun 2017 20:54 Edited at: 22nd Jun 2017 21:47

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I believe you'd need to loop through them. If you're just wanting to check until you've found any single ball that has left the screen, you could write a function that returns the index using exitfunction when the first out-of-screen ball is found, or -1 for none found.

pseudo code:

+ Code Snippet

function OutOfScreen()
  for index = 0 to BallCount
    if balls[index] is out of screen
      exitfunction index
    endif
  next index
endfunction -1

edit: D'oh, just realized this is probably a poor idea since you'd likely end up looping needlessly through your ball list twice. Ideally you'd have a function/routine that updates your ball list and sets a flag if one of them has gone out of the screen.

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PartTimeCoder

AGK Tool Maker

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Location: London UK

Posted: 23rd Jun 2017 00:06

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Quote: "Ideally you'd have a function/routine that updates your ball list and sets a flag if one of them has gone out of the screen."

Yes this way you can reuse your bullets, there is an example of this method in the examples "Games\SpaceShooter"

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basicFanatic

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Posted: 23rd Jun 2017 17:15 Edited at: 23rd Jun 2017 17:31

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Thanks for the help! I just tried this:
If the balls leave on the right or left of the screen, their horizontal velocity is reversed.
If the balls leave on the top or bottom of the screen, their vertical velocity is reversed.
Seem to work ... !

for xBall = 1 to balls.length
	if getSpriteY (balls[xBall].sprID) < GetScreenBoundsTop ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID), GetSpritePhysicsVelocityY(balls[xBall].sprID)*-1) // reverse the vertical direction
	endif	
	if getSpriteY (balls[xBall].sprID) + GetSpriteHeight(balls[xBall].sprID) > GetScreenBoundsBottom ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID), GetSpritePhysicsVelocityY(balls[xBall].sprID)*-1) // reverse the vertical direction
	endif
	if getSpriteX (balls[xBall].sprID) < GetScreenBoundsLeft ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID)*-1, GetSpritePhysicsVelocityY(balls[xBall].sprID)) // reverse the horizontal direction
	endif
	if getSpriteX (balls[xBall].sprID) + GetSpriteWidth(balls[xBall].sprID) > GetScreenBoundsRight ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID)*-1, GetSpritePhysicsVelocityY(balls[xBall].sprID)) // reverse the horizontal direction
	endif
next

+ Code Snippet

for xBall = 1 to balls.length
	if getSpriteY (balls[xBall].sprID) < GetScreenBoundsTop ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID), GetSpritePhysicsVelocityY(balls[xBall].sprID)*-1) // reverse the vertical direction
	endif	
	if getSpriteY (balls[xBall].sprID) + GetSpriteHeight(balls[xBall].sprID) > GetScreenBoundsBottom ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID), GetSpritePhysicsVelocityY(balls[xBall].sprID)*-1) // reverse the vertical direction
	endif
	if getSpriteX (balls[xBall].sprID) < GetScreenBoundsLeft ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID)*-1, GetSpritePhysicsVelocityY(balls[xBall].sprID)) // reverse the horizontal direction
	endif
	if getSpriteX (balls[xBall].sprID) + GetSpriteWidth(balls[xBall].sprID) > GetScreenBoundsRight ()
		SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID)*-1, GetSpritePhysicsVelocityY(balls[xBall].sprID)) // reverse the horizontal direction
	endif
next

Or even more compressed:

+ Code Snippet

	for xBall = 1 to balls.length
		if getSpriteY (balls[xBall].sprID) < GetScreenBoundsTop () or getSpriteY (balls[xBall].sprID) + GetSpriteHeight(balls[xBall].sprID) > GetScreenBoundsBottom ()
			SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID), GetSpritePhysicsVelocityY(balls[xBall].sprID)*-1) // reverse the vertical direction
		endif	
		if getSpriteX (balls[xBall].sprID) < GetScreenBoundsLeft () or getSpriteX (balls[xBall].sprID) + GetSpriteWidth(balls[xBall].sprID) > GetScreenBoundsRight ()
			SetSpritePhysicsVelocity(balls[xBall].sprID, GetSpritePhysicsVelocityX(balls[xBall].sprID)*-1, GetSpritePhysicsVelocityY(balls[xBall].sprID)) // reverse the horizontal direction
		endif
	next

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blink0k

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Posted: 24th Jun 2017 00:55 Edited at: 24th Jun 2017 00:56

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You could use the SetPhysicsWallLeft/Right/Top/Bottom() as well

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basicFanatic

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Posted: 24th Jun 2017 13:04

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Thanks! But actually, I had to disable SetPhysicsWallSomething(). The reason: I use SetScissor(0,0,0,0), and SetPhysicsWallSomething() are using the old, non-scissorized values.

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janbo

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Location: Germany

Posted: 24th Jun 2017 14:28 Edited at: 24th Jun 2017 14:33

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Pseudocode:

+ Code Snippet

ScreenWidth#=GetScreenBoundsRight ()-GetScreenBoundsLeft ()
ScreenHeight#=GetScreenBoundsBottom ()-GetScreenBoundsTop ()

LeftSpriteID=CreateDummySprite()
SetSpriteSize(LeftSpriteID,10,ScreenHeight#)
SetSpritePosition(LeftSpriteID,GetScreenBoundsLeft ()-10,0)
SetSpriteShapeBox(LeftSpriteID)
SetSpritePhysicsOn(LeftSpriteID,1)

RightSpriteID=CreateDummySprite()
SetSpriteSize(RightSpriteID,10,ScreenHeight#)
SetSpritePosition(RightSpriteID,GetScreenBoundsRight (),0)
SetSpriteShapeBox(RightSpriteID)
SetSpritePhysicsOn(RightSpriteID,1)

TopSpriteID=CreateDummySprite()
SetSpriteSize(TopSpriteID,ScreenWidth#,10)
SetSpritePosition(TopSpriteID,0,GetScreenBoundsTop ()-10)
SetSpriteShapeBox(TopSpriteID)
SetSpritePhysicsOn(TopSpriteID,1)

BottomSpriteID=CreateDummySprite()
SetSpriteSize(BottomSpriteID,ScreenWidth#,10)
SetSpritePosition(BottomSpriteID(),0,GetScreenBoundsBottom ())
SetSpriteShapeBox(BottomSpriteID)
SetSpritePhysicsOn(BottomSpriteID,1)

You can add friction and restitution so it acts like you want

Using AGKv2 Tier1

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