ASM Community

Well I have been playing around with frames now for about a couple of days and
I thought up an interesting question while I was driving home. Here is a normal
everyday function to move a window to a new position...

MoveWindow:

	; params

	virtual at ebp+8

	.arg1 dd ?

	.arg2 dd ?

	X equ .arg1

	Y equ .arg2

	end virtual

	enter 0, 0



	; main

	invoke SetWindowPos, [mainhwnd], 0, [X], [Y], 0, 0, SWP_NOSIZE



	; end main

	leave

	retn 8

Where mainhwnd is defined globally in the data section. This is being called
(in template.asm) from WindowProc. The way I understand it, X is @ ebp+8,
and Y is at ebp+12. If WindowProc is defined as:

proc WindowProc, hwnd,wmsg,wparam,lparam

then is it possible to point further up using ebp and grab the hwnd thats
already on the stack? Something like this I would assume...

MoveWindow:

	; params

	virtual at ebp+8

	.arg1 dd ?

	.arg2 dd ?

	.padding rb 12

	.prevhwnd dd ?

	X equ .arg1

	Y equ .arg2

	hwnd equ .prevhwnd

	end virtual

	enter 0, 0



	; main

	invoke SetWindowPos, [hwnd], 0, [X], [Y], 0, 0, SWP_NOSIZE



	; end main

	leave

	retn 8

I realise this is perhaps a poor example and little to no gain can be had
in this case, but if this can be done I can see it reducing the amount of
gobals needed as most of them more than likely are already on the stack
somewhere anyways...

Maybe what I am trying to do will cause a stack overflow? Seems I have
heard that term from somewhere...