Hi Gerard,

You can take a look at the EyeXMouse Github repository and see if it contains the example code you need to get started.

Hi everyone,
I actually tried translating the C headers to Delphi, but I failed miserably…
Nontheless, it is very well possible to control the EyeX in Delphi by using a facade DLL:

1. Make a copy of the C++ sample project that fits your requirement best. In my case I used MinimalGazeDataStream.
2. Rename the copy of that project to something like “EyexFacade”.
3. Open your EyexFacade project in the coding IDE of your choice (I used Visual Studio Express 2015) and configure the settings:
• Configuration / Output Type = Dynamic Link Library (DLL)
• Call Convention = _cdecl (important! Do NOT use stdcall!)
4. Define the functions you need as dllexport and compile EyexFacade.dll
5. Write your Delphi application and use EyexFacade.dll to control the EyeX

Here’s some sample code to get the gaze coordinates via callback:
========== EyexFacade ==========

typedef void (TX_CALLCONVENTION *EC_OnGazeCallback)(int gazeX, int gazeY); // type definition of the callback function
static EC_OnGazeCallback OnGazeCallback; // global variable pointing to the registered callback

// the Delphi app calls this function to register a callback
__declspec(dllexport) void SetOnGazeCallback(EC_OnGazeCallback callback) 
{
	OnGazeCallback = callback;
}

// this function should already be included in the sample project. 
void OnGazeDataEvent(TX_HANDLE hGazeDataBehavior) 
{
	TX_GAZEPOINTDATAEVENTPARAMS eventParams;
	if (txGetGazePointDataEventParams(hGazeDataBehavior, &eventParams) == TX_RESULT_OK) 
	{
		OnGazeCallback((int)eventParams.X, (int)eventParams.Y); // call Delphi callback
	}
}

========== Delphi application ==========

type
  TEyexOnGazeCallback = procedure(GazeX: Integer; GazeY: Integer); cdecl;
  PEyexOnGazeCallback = ^TEyexOnGazeCallback;
  TEyexSetCallback    = procedure(callback: PEyexOnGazeCallback); cdecl;
implementation

procedure TForm1.FormCreate(Sender: TObject);
var 
  hDLL: THandle;
  hSetCallback: TEyexSetCallback;
begin
  hDLL := LoadLibrary('EyexFacade.dll');
  hSetCallback := GetProcAddress(hDLL, PAnsiChar(AnsiString('SetOnGazeCallback')));
  hSetCallback(@OnGaze);
end;

procedure OnGaze(GazeX: Integer; GazeY: Integer);
begin
  // do something usefull ;)
end;

I’ve written a complete header file for delphi if anyone needs it. It’s only had limited testing but a conversion of the eye tracking C demo works perfectly.

There are a couple of versions; one employs dynamic linking and the other static. The statically linked version is the more up to date and it is also complete in the sense that the comments have been converted to an xml style more friendly to the ‘code insight’ system I use. There are a couple of hard coded paths to the dll files in the eyeX.pas header file that would need to be adjusted or removed by any user.

When converting the functions to a delphi header variables passed as pointers always provide a design choice. One can pass it as a simple parameter with the ‘var’ declaration in delphi which means it is passed a pointer but this is transparent to the user, however, where a null pointer is allowed (as is often the case in the eyeX library) this cannot be done with a var parameter. In that case a pointer must be used instead. I think I’ve made sensible choices in each case but there are a lot of functions and a few may need to be altered. In addition where C structs have been converted to delphi records it is possible there may be errors if the byte alignment differs (easily fixed once identified). I suppose what I’m trying to say is that it is an early version and subject to revision.

I can upload the eye tracking test project as well if you wish. I haven’t written a delphi version of the c++ class yet but it looks trivial to implement.

The eyeX.pas header file is a little over 8500 lines long, and the eye tracking project is several files. Where would you like me to upload them? I could do it as inline code here but it would be a big post…

Files are here.

The header file is called EyeX.pas All the other files are associated with the EyePositionSample project.

I’ve added a port of the activatable buttons sample. The executable should work if there is a copy of the eyeX dll in the folder or on the path (not the case in the first version I posted). I changed it a bit to enable tentative focus events, it seems to work better that way for me.