Question how Petr did that:

[ReneMiner]

It's not TBGL-question but I saw in TBGL-Module a technique where I'm nosy about.
It's about TBGL_EntitySetUserData( SceneID, EntityID, UserData )

In UserData-parameter I just pass the name of the variable of an arbitrary type - the function does the rest...

Now what I want to know:
How does the function know, what data & which size to store - how does it get the information of correct varptr and varsize?
I know how to get correct pointer - but how to get size then?




Uses "console"

Type t_Type
A As Long
B As Byte
C As Double
End Type

Dim foo As t_Type
Long mySize
DWord myPtr

Sub GetInfo(ByRef var As Any, ByRef lSize As Long, ByRef vPtr As DWord)

vPtr = VarPtr var
lSize = SizeOf(var)

End Sub

GetInfo foo, mySize, myPtr

PrintL VarPtr( foo ) + $TAB + myPtr ' should both be equal...
PrintL SizeOf( foo ) + $TAB + mySize ' but size is not...

PrintL Repeat$(50, "-" )
PrintL "key to end" + $CRLF
WaitKey


Got a hint for me?

Edit:
- I think I've found out...

just


Sub GetInfo(ByRef var, ByRef lSize As Long, ByRef vPtr As DWord)

but not working if foo were an array....but no problem here- I intend to pass simple absolute variables only

[Petr Schreiber]

Hi Rene,

the TBGL_EntitySetUserData uses thinBasic_ParseVariableInfo from ThinBASIC module SDK. This allows to retrieve pointer and length of data, so I can perform copy of them to internal TBGL buffers.


Petr