#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <initguid.h>

#include "interfaces.h"

volatile DWORD g_TlsSlot;

LONG __stdcall CallBack(IUnknown *pObj) {
	HRESULT hr;

	_Form *pForm;
	float fWidth, fHeight;

	if (FAILED(hr = pObj->lpVtbl->QueryInterface(pObj, &IID__Form, (void**)&pForm))) {
		return E_UNEXPECTED;
	}

	// Check if already initialized
	if (!TlsGetValue(g_TlsSlot)) {
		TlsSetValue(g_TlsSlot, (LPVOID)1);
		srand(time(NULL));
	}

	if (SUCCEEDED(hr = pForm->lpVtbl->get_ScaleWidth(pForm, &fWidth)) &&
		SUCCEEDED(hr = pForm->lpVtbl->get_ScaleHeight(pForm, &fHeight))) {
		hr = pForm->lpVtbl->Circle(pForm, 0, rand() % (int)fWidth, rand() % (int)fHeight, rand() % 500, 0, 0, 0, 0);
	}

	pForm->lpVtbl->Release(pForm);

	return hr;

}

int main(int argc, char **argv) {
	HINSTANCE hLib = LoadLibrary("CallbackThread.dll");
	DWORD g_TlsSlot = TlsAlloc();

	VOID (__stdcall *SetCallback)(LONG (__stdcall *)(IUnknown *)) = 
		(VOID (__stdcall *)(LONG (__stdcall *)(IUnknown *)))GetProcAddress(hLib, "SetCallback");

	if (!SetCallback)
		return 1;

	SetCallback(CallBack);

	printf("press a button to exit\r\n");
	getchar();

	FreeLibrary(hLib);
	TlsFree(g_TlsSlot);

	return 0;

}

IncludeFile "interfaces.pbi"

Prototype.l CallbackProto(pObj.IUnknown)
Prototype.l SetCallback(CallbackProto_)

Procedure Callback(pObj.IUnknown)
  pFrm._Form
  fWidth.f
  fHeight.f
  
  If pObj\QueryInterface(?IID__Form, @pFrm) = #S_OK

    If pFrm\get_ScaleWidth(@fWidth.f) = #S_OK And pFrm\get_ScaleHeight(@fHeight.f) = #S_OK
      pFrm\Circle(0, Mod(Random(100000), fWidth), Mod(Random(100000), fWidth), Mod(Random(100000), 500), 0, 0, 0, 0)
    EndIf
    
    pFrm\Release()
    
  EndIf
  
EndProcedure

; Load dll
If OpenLibrary(0, "CallbackThread.dll")
  
  ; Get proc address
  SetCallback.SetCallback = GetFunction(0, "SetCallback")

  If SetCallback
    
    ; Call exported function
    SetCallback(@Callback())

  EndIf
  
  OpenConsole()
  PrintN("Press enter to close program")
  Input()
  
EndIf