From a10928dc929718873e6ee0e508bce051a19bd86a Mon Sep 17 00:00:00 2001
From: Théo de la Hogue
Date: Wed, 4 May 2022 16:06:34 +0200
Subject: Adding looked_pixel function and making look_at function based on non
 orthogonal projection.

---
 src/argaze/AreaOfInterest/AOIFeatures.py | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/src/argaze/AreaOfInterest/AOIFeatures.py b/src/argaze/AreaOfInterest/AOIFeatures.py
index dc38eb8..001affa 100644
--- a/src/argaze/AreaOfInterest/AOIFeatures.py
+++ b/src/argaze/AreaOfInterest/AOIFeatures.py
@@ -41,20 +41,39 @@ class AreaOfInterest(numpy.ndarray):
         return mpath.Path(self).contains_points([gaze_position])[0]
 
     def look_at(self, gaze_position):
-        """Get where the area is looked."""
+        """Get where the area is looked using non orthogonal projection."""
 
         if self.dimension() != 2:
             raise RuntimeError(f'Bad area dimension ({self.dimension()})')
 
-        P = numpy.array(gaze_position)
+        clockwise_area = self.clockwise()
+
+        O = clockwise_area[0]                                               # Origin
+        G = numpy.array(gaze_position) - O                                  # Gaze point
+
+        M = numpy.array([clockwise_area[1] - O, clockwise_area[-1] - O])    # Basis projection matrix M = {U | V}
+        Mt = numpy.transpose(M)
+        
+        Gp = numpy.dot(numpy.dot(numpy.linalg.inv(numpy.dot(Mt, M)), Mt), G)# Projected gaze point
+
+        return numpy.around(Gp, 4).tolist()
+
+    def looked_pixel(self, look_at):
+        """Get which pixel is looked."""
+
+        if self.dimension() != 2:
+            raise RuntimeError(f'Bad area dimension ({self.dimension()})')
 
         clockwise_area = self.clockwise()
 
-        O = clockwise_area[0]
-        OX, OY = clockwise_area[1] - O, clockwise_area[-1] - O
-        OP = P - O
+        O = clockwise_area[0]                                               # Origin
+        Gp = numpy.array(look_at)                                           # Projected gaze point
+        M = numpy.array([clockwise_area[1] - O, clockwise_area[-1] - O])    # Basis projection matrix M = {U | V}
+        Mt = numpy.transpose(M)
+
+        Lp = O + numpy.dot(M, Gp)                                           # Projected gaze pixel
 
-        return ( round(numpy.dot(OP, OX) / numpy.dot(OX, OX), 3), round(numpy.dot(OP, OY) / numpy.dot(OY, OY), 3))
+        return numpy.rint(Lp).astype(int).tolist()
 
     def draw(self, frame, color):
 
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