Flames tutorial

[Matrefeytontias]

That's surely a great tutorial, but I haven't really understood how to burn only one sprite, in a big screen with several others

[Xeda112358]

That is tough and it depends... Pretty much, as builder said, the basics are this:
-you shift the pixels up one
-you give it a chance to disappear (For example, 1/8 chance)

Depending on the sprite situation, you will probably have to use 2 For( loops to check each pixel of the sprite as well as giving it an upper limit (like the flames can only go as high as another 8 pixels)

[Matrefeytontias]

Right now, I have a sprite moved by the player, and an inanimated block which I want him to burn. How must I do it ?

[Xeda112358]

okay, I am not sure if this will work as I am not much of an Axe coder, but maybe try this?

Code: Select All | Copy To Clipboard

1 2 3 4 5 6 7 8 9 10

For(B,X,X+7 For(C,Y+1,Y+15 pxl-Test(C,B→A pxl-Off(C-1,B If rand^8 pxl-On(C-1,B End End

[Matrefeytontias]

pxl-Test returns 0 if the pixel tested is off or 1 if it's on o_O what do you do with this command ?

[Xeda112358]

Oops, let me modify that :

Code: Select All | Copy To Clipboard

1 2 3 4 5 6 7 8 9

For(B,X,X+7 For(C,Y+1,Y+15 pxl-Off(C-1,B If rand^8*pxl-Test(C,B pxl-On(C-1,B End End

[Matrefeytontias]

It doesn't work

Here it is the full code I use :

Code: Select All | Copy To Clipboard

1 2 3 4 5 6 7 8 9 10 11 12 13 14

44->X-16->Y Repeat getkey(15)  Pt-On(X,Y,[FFFFFFFFFFFFFFFF  For(B,X,X+7)   For(C,Y+1,Y+15)    Pxl-Off(C-1,B    If rand^8*pxl-Test(C,B)     Pxl-On(C-1,B    End   End  End  DispGraph End

[MGOS]

It burns the pixels below the block. You'd have to do this:

Code: Select All | Copy To Clipboard

1 2 3 4 5 6 7 8 9 10 11 12 13 14

44->X-16->Y Repeat getkey(15)  Pt-On(X,Y,[FFFFFFFFFFFFFFFF  For(B,X,X+7)   For(C,Y-7,Y+7)  //I changed this line    Pxl-Off(C-1,B    If rand^8*pxl-Test(C,B)     Pxl-On(C-1,B    End   End  End  DispGraph End

No guarantee, but I hope it works.

[Matrefeytontias]

it doesn't work anymore >_< but I don't know why, it seems that it would be ok o_O

EDIT : I just found what's wrong :

Code: Select All | Copy To Clipboard

1 2 3 4 5 6 7 8 9 10 11 12 13 14

44->X-16->Y Repeat getkey(15)  Pt-On(X,Y,[FFFFFFFFFFFFFFFF  For(B,X,X+7)   For(C,Y-7,Y+7)  //I changed this line    Pxl-Off(B,C-1     <----------------------- Here    If rand^8*pxl-Test(B,C) <---------------- Here     Pxl-On(B,C-1    <------------------------ and Here    End   End  End  DispGraph End

That's why instead of Grammer, the Axe commands Pxl-xxx give the X as first argument and Y as second xD

[MGOS]

Yeah, ninja'd again.

[Matrefeytontias]

But, I've had the time to put a +1 at your message

[Xeda112358]

So did my code work, otherwise?

[Matrefeytontias]

Yes, that's a great code, thanks and you can make the flame longer by changing the second For loop (and I found that rand^6 is better than rand^8)

[MGOS]

Yes, that's a great code, thanks and you can make the flame longer by changing the second For loop (and I found that rand^6 is better than rand^8)

The number you subtract in the for loop is the height of the flames -1.
This would make the flames 16 pixels high

Code: Select All | Copy To Clipboard

1	For(C,Y-15,Y+7)

Changing the modulus at the rand will change the density of the flames. A high number like 8 or 10 will let the flames have more particles than having a small number like 4 or 6.

Code: Select All | Copy To Clipboard

1 2 3 4

If rand^10*pxl-Test(B,C)  //High density = more particles ... If rand^4*pxl-Test(B,C)  //Low density = less particles

[Matrefeytontias]

Yeah, that's it