fpc-opengaze Copyright (C) 2024 Carlos Rafael Fernandes Picanço.

The present file is distributed under the terms of the GNU General Public License (GPL v3.0).

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

fpc-opengaze is a Free Pascal client for OpenGaze API v2.0 (by Gazepoint), which is as an open-source alternative to proprietary vendor formats for communicating with eye-tracking devices.

Development enviroment

Lazarus 3.99 (rev main_3_99-1082-g0bd3e44eb4) FPC 3.3.1 x86_64-win64-win32/win64

Dependencies

1. Synaser package;
2. LCL package;
3. TApplication queues
4. BGRABitmap

Start up instructions

1. Install Lazarus and FPC (I recommend fpcupdeluxe)
2. Open Lazarus and create a new Project/Application
3. Add the Synaser package using the Project Inpector and Online Package Manager
4. Make sure all units are visible in your project's settings path

Main features

• custom calibration for setups with a remote server
• blocking and non-blocking alternatives for sending messages
• event based approach for receiving messages
• multi-thread (safe)

Examples

See examples/client/ for a working compilable example.

Code snippets

// main imports
uses opengaze, opengaze.types, opengaze.constants;

// connect to the server and wait for messages
OpenGazeControl.Connect;

// disconnect from the server
OpenGazeControl.Disconnect;

// start calibration
OpenGazeControl.Calibration.Show;
OpenGazeControl.Calibration.Start;

// start recording, send blocking message
OpenGazeControl.Recording.Start;

// start recording, send non-blocking message
OpenGazeControl.Recording.Start(False);

// events setup
procedure TForm1.FormCreate(Sender: TObject);
begin
  OpenGazeControl.Events.OnCalibrationResult := @StartRecording;
end;

// event implementation
procedure TForm1.StartRecording(Sender: TObject; Event: TPairsDictionary);
var
  AverageError : string;
begin
  AverageError := OpenGazeControl.Calibration.ResultSummary;
  ShowMessage(String.Join(#32, [AverageError, Event[ID], Event[STATE]]));
end;

Structure of source units in src/ and utils/

A base class for clients
/src/opengaze.client.pas

A class for Control clients
/src/opengaze.control.pas

A class for Analysis clients (not working yet)
/src/opengaze.analysis.pas

A wrapper for control and analysis instances
/src/opengaze.pas

A base class for Open Gaze commands
/src/opengaze.base.pas

A class to encapsulate Open Gaze API recording commands
/src/opengaze.recording.pas

A class to encapsulate Open Gaze API calibration commands
/src/opengaze.calibration.pas

A class to encapsulate fpc-opengaze events
/src/opengaze.events.pas

A class to encapsulate the incoming thread logic
/src/opengaze.incoming.pas

Convenience functions for parsing Open Gaze API commands.
/src/opengaze.commands.pas

Convenience constants for Open Gaze API tags, ids, parameters, ...
/src/opengaze.constants.pas

Convenience type convertion helpers
/src/opengaze.helpers.pas

A procedural logger
/src/opengaze.logger.pas

A procedural parser
/src/opengaze.parser.pas

A wrapper around Synaser TCP/IP block socket:
/src/opengaze.socket.pas

fpc-opengaze types
/src/opengaze.types.pas

BGRA easing animations used during calibration
/utils/animation.pas
/utils/easings.pas

A wrapper around screen segmentation functions for calibration
/utils/choreographies.pas
/utils/screen.grids.pas
/utils/screen.helpers.pas
/utils/screen.lines.pas
/utils/windows.methods.pas

A default calibration background/window
/utils/forms.background.pas

A debug logger
/utils/windows.debugger.pas

Monotonic timing
/utils/windows.timestamps.pas