Why am I getting an invalid memory access here?

[Mistrel]

Am I missing something here? I get an invalid memory access on "EndProcedure". I'm using PB 4.30.

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OpenWindow(0,0,0,320,240,"")

Procedure PointInClientRect(hWnd, x, y)
	Pt.POINT\x=100
	Pt.POINT\y=100
	ScreenToClient_(WindowID(0),@Pt.POINT)
	GetClientRect_(WindowID(0),@Rc.RECT)
	Lib=OpenLibrary(#PB_Any,"User32.dll")
	Ptr=GetFunction(Lib,"PtInRect")
	CloseLibrary(Lib)
	If Ptr
		CallFunctionFast(Ptr,@Rc,@Pt)
	EndIf
EndProcedure

PointInClientRect(WindowID(0),100,100)

[Mistrel]

I think I found the problem. I need to pass a quad or two longs instead of an address:

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Procedure PointInClientRect(hWnd, x, y)
	Pt.POINT\x=100
	Pt.POINT\y=100
	ScreenToClient_(WindowID(0),@Pt.POINT)
	GetClientRect_(WindowID(0),@Rc.RECT)
	Lib=OpenLibrary(#PB_Any,"User32.dll")
	Ptr=GetFunction(Lib,"PtInRect")
	CloseLibrary(Lib)
	If Ptr
		CallFunctionFast(Ptr,@Rc,PeekL(@Pt),PeekL(@Pt+SizeOf(LONG)))
	EndIf
EndProcedure

[freak]

The second parameter to PtInRect is a POINT structure itself, not just a pointer to it. So the stack gets messed up.
You can solve this by passing the x/y as separate parameters to get the same stack layout as the POINT structure would have on the stack.

btw, this will not work on PB x64. For it to work there you have to put the whole POINT structure into a quad and pass that as a single parameter. It will work on both x86 and x64 if you use the quad way and a prototype instead of CallFunctionFast() (it does not support quads)

[edit] so close!

[Mistrel]

But it should still work in x64 with CallFunctionFast if I push the x and y variables as longs, correct?

[srod]

Use :

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PtInRect_(rc,pt\y<<32+pt\x)

Works with PB x86 and x64.

Why are you loading the function from the dll?

[Mistrel]

Why are you loading the function from the dll?

http://www.purebasic.fr/english/viewtopic.php?t=35790

[srod]

Ahhhh; fair enough! As Freak says though, using a prototype would allow you to pass the entire point structure as a quad ala pt\y<<32+pt\x etc.

[Mistrel]

I still love CallFunctionFast for quick one-line calls.

[ABBKlaus]

Why are you loading the function from the dll?

http://www.purebasic.fr/english/viewtopic.php?t=35790

I wonder why you never responded to that thread
Isn´t it fixed ?

[Mistrel]

It might be. I needed an immediate solution so I just called the dll directly.

[wilbert]

Have you considered creating your own point in structure procedure ?
It's something that should be easy to create.