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+Gaze position
+=============
+
+[GazeFeatures](/argaze/#argaze.GazeFeatures) defines a [GazePosition](/argaze/#argaze.GazeFeatures.GazePosition) class to handle point coordinates with a precision value.
+
+``` python
+from argaze import GazeFeatures
+
+# Define a basic gaze position
+gaze_position = GazeFeatures.GazePosition((123, 456))
+
+# Define a gaze position with a precision value
+gaze_position = GazeFeatures.GazePosition((789, 765), precision=10)
+
+# Access to gaze position value and precision
+print(f'position: {gaze_position.value}')
+print(f'precision: {gaze_position.precision}')
+
+```
+
+## Validity
+
+[GazeFeatures](/argaze/#argaze.GazeFeatures) defines also a [UnvalidGazePosition](/argaze/#argaze.GazeFeatures.UnvalidGazePosition) class that inherits from [GazePosition](/argaze/#argaze.GazeFeatures.GazePosition) to handle case where no gaze position exists because of any specific device reason.
+
+``` python
+from argaze import GazeFeatures
+
+# Define a basic unvalid gaze position
+gaze_position = GazeFeatures.UnvalidGazePosition()
+
+# Define a basic unvalid gaze position with a message value
+gaze_position = GazeFeatures.UnvalidGazePosition("Something bad happened")
+
+# Access to gaze position validity
+print(f'validity: {gaze_position.valid}')
+
+```
+
+## Distance
+
+[GazePosition](/argaze/#argaze.GazeFeatures.GazePosition) class provides a **distance** method to calculate the distance to another gaze position instance.
+
+![Distance](../../img/distance.png)
+
+``` python
+# Distance between A and B positions
+d = gaze_position_A.distance(gaze_position_B)
+``` 
+
+## Overlapping
+
+[GazePosition](/argaze/#argaze.GazeFeatures.GazePosition) class provides an **overlap** method to test if a gaze position overlaps another one considering their precisions.
+
+![Gaze overlapping](../../img/overlapping.png)
+
+``` python
+# Check that A overlaps B
+if gaze_position_A.overlap(gaze_position_B): 
+
+        # Do something if A overlaps B
+        ...
+
+# Check that A overlaps B and B overlaps A
+if gaze_position_A.overlap(gaze_position_B, both=True): 
+
+        # Do something if A overlaps B AND B overlaps A
+        ...
+```