Peek / Poke newbie

H!

I don't understand the peek poke function :S

I have this code:

bnkTest=CreateBank(2) 

PokeShort bnkTest,0,2044
PokeShort bnkTest,1,355

Print PeekShort(bnkTest,0) 
Print PeekShort(bnkTest,1) 

FreeBank bnkTest 
WaitKey

And the result I get is
25596
355

But I want
2044
355

Why is he changing the first number ?

Thanks

A short is two bytes long, so the second PokeShort is overwriting one of the bytes occupied by the first. The offset is always in bytes regardless of whether you're poking a byte, short or long, so you need to multiply your offsets by 1, 2 or 4 bytes to avoid overwriting.

ow now i understand it.

A short(65535) : 0 2 4 etc
A int(2147483647): 0 4 8 etc

Thanks :)

How would I poke something to a bank other than a number, such as a string, type, array, image, ect?

Check your help docs for the following commands: PokeShort, PokeInt, PokeByte, PokeString, and the resulting Peek functions.

As far as images, sounds, etc, most of those are generally described with 'handles', which are essentially just int's.. so you can take it from there :)

For images, you must make your own 'raw' format then. Since you have access to imagebuffers you can copy data between banks and images.. you can't access soundbuffers atm, so that's a nono ..

For those other formats, you have to 'code' native variables yourself..

A string, is ofcourse a number of ascii values .. so, if you want to store the word "Blitzbasic" then you need a bank with the size of 10 .. and each byte holds the ascii value of each of those characters.. Naturally.. you can't store more than those 10 then.. there's no bounds-checking on banks. @ win98se orso this might lead to a serious crash! If you want to store a string in a bank, then you prolly have to make your own String2Bank(bank,s$) function, where the function checks the bounds for you.. (and optionally resizes the bank!)

An array of bytes for example, is just the bank with the banksize being the number of elements..

An array of ints (handles are ints!) is a bank with the banksize being the amount of elements / 4 ..

An array of types .. dunno, I'm not the type-type .. question is why you would want to put a type into a bank anyway ..

If you want to work with banks, you definitly want a monitor: http://www.blitzbasic.co.nz/Community/posts.php?topic=29266

Well, I want to have a list of types stored in a bank. I asked about other things because I want to learn as much about Blitz as I possibly can.

The easiest option for storing types are arrays (for me anyway).

There are many topics related to arrays of types.

And you cannot ever miscalculate the offset when using arrays.

A quick example:

; Create a window of size 800x600
Graphics 800, 600, 0, 2

; Create the type and add fields to it
Type MyType
	Field x%, y%
End Type

; Create an array with the name "MyArray", tell it to hold pointers to the type "MyType"
; (as you would tell an array to hold strings: Dim MyArray$(10)) and give it 11 indexes (0 - 10)
Dim MyArray.MyType(10)

; Now create all type instances and put their pointer into the array
For i = 0 To 10
	MyArray(i) = New MyType
Next

; Put some data into it
For i = 0 To 10
	MyArray(i)\x% = i
	MyArray(i)\y% = i * 2
Next

; Print all data
For i = 0 To 10
	Print i + ": " + MyArray(i)\x% + ", " + MyArray(i)\y%
Next

; Wait for a keypress to close the window
WaitKey()
End