CODE:

/*"MouseLock" adapted from Torque3D sourcex86 & x64 compatible AutoHotkey_L scriptAutoHotkey_L => http://l.autohotkey.net/Save as "MouseLock.ahk" & drop onto exe.*/Gui,1:-AlwaysOnTop +Caption +OwnDialogs +Resize Gui,1:+LastFoundGlobal Gui1:=WinExist()Gui,1:Margin,0,0Global Gui1_Edit1_hWndGui,1:Add,Edit,R35 W240 HwndGui1_Edit1_hWnd VGui1_Edit1Gui,1:Show,W640 H480OnMessage(0x0200,"WM_MOUSEMOVE")return~Esc::ExitAppGuiClose:GuiEscape:ExitAppWM_MOUSEMOVE(wParam,lParam){; AutoHotkey drops messages without this line.; Unfortunately it makes other messages dodgy.; Actually, it'll deteriorate after some time.Critical,-1Edit:=""VarSetCapacity(POINT,8)NumPut(cursorX:=lParam&0xFFFF,POINT,0,"Int")NumPut(cursorY:=lParam>>16,POINT,4,"Int"); subsequent coordinates unaffected by sibling windowsDllCall("SetCapture","UPtr",Gui1,"UPtr")VarSetCapacity(RECT,16)DllCall("GetClientRect","UPtr",Gui1,"UPtr",&RECT,"Int")DllCall("ClientToScreen","UPtr",Gui1,"UPtr",&RECT,"Int")DllCall("ClientToScreen","UPtr",Gui1,"UPtr",&RECT+8,"Int")RECT_left:=NumGet(RECT,0,"Int"),RECT_top:=NumGet(RECT,4,"Int")RECT_right:=NumGet(RECT,8,"Int"),RECT_bottom:=NumGet(RECT,12,"Int")DllCall("ClipCursor","UPtr",&RECT,"Int");// Convert the incoming client pos into a screen pos, so we can;// accurately convert to relative coordinates.DllCall("ClientToScreen","UPtr",Gui1,"UPtr",&POINT,"Int")mouseX:=NumGet(POINT,0,"Int"),mouseY:=NumGet(POINT,4,"Int");// Hide the cursor before it's moved;DllCall("ShowCursor","Int",FALSE,"Int");// Recenter the mouse if necessary (don't flood the message pump)centerX:=(RECT_right+RECT_left)//2,centerY:=(RECT_bottom+RECT_top)//2if(mouseX!=centerX||mouseY!=centerY){DllCall("SetLastError","UInt",0)BOOL:=DllCall("SetCursorPos","Int",centerX,"Int",centerY,"Int")Edit.="SetCursorPos() returned " BOOL "`r`n" "GetLastError() returned " A_LastError "`r`n" """" FormatMessage(A_LastError) """" "`r`n"};// Now we can calculate the position relative to the center we set.deltaX:=mouseX-centerXdeltaY:=mouseY-centerY;do_something_useful_with(deltaX,deltaY)Text=mouseX=%mouseX% mouseY=%mouseY%`r`ncenterX=%centerX% centerY=%centerY%`r`ndeltaX=%deltaX% deltaY=%deltaY%Edit.=Text "`r`n`r`n"if(deltaX||deltaY){PrependEdit(Edit)}ToolTip,%Text%return 0}PrependEdit(ByRef Text){DllCall("SendMessage","UPtr",Gui1_Edit1_hWnd,"UInt",0x00B1,"UPtr",0,"Ptr",0,"Ptr") ; EM_SETSELDllCall("SendMessage","UPtr",Gui1_Edit1_hWnd,"UInt",0x00C2,"UPtr",FALSE,"Ptr",&Text,"Ptr") ; EM_REPLACESEL}FormatMessage(dwMessageId){static BufferVarSetCapacity(Buffer,nSize:=3000)DllCall("FormatMessage","UInt",0x00001000,"UPtr",0,"UInt",dwMessageId,"UInt",0,"Str",Buffer,"UInt",nSize//2,"UPtr",0)return RegExReplace(Buffer,"(.*)[`r`n]*$","$1")}