fix: Better BoundingRectangle.angle and BoundingRectangle.angle_360 computation (#237)

* fix: fix `BoundingRectanble.angle` and `BoundingRectanble.angle_360` computation

Signed-off-by: Clément Doumouro <[email protected]>

* fix: compute page bounding rectangle angle between (0-2pi) / (0-360)

Signed-off-by: Clément Doumouro <[email protected]>

---------

Signed-off-by: Clément Doumouro <[email protected]>
Co-authored-by: Christoph Auer <[email protected]>

Author: ClemDoum

docling_core/types/doc/page.py

@@ -116,33 +116,28 @@ def height(self) -> float:
 
     @property
     def angle(self) -> float:
-        """Calculate the angle of the rectangle in radians."""
+        """Calculate the angle of the rectangle in radians (0-2pi range)."""
         p_0 = ((self.r_x0 + self.r_x3) / 2.0, (self.r_y0 + self.r_y3) / 2.0)
         p_1 = ((self.r_x1 + self.r_x2) / 2.0, (self.r_y1 + self.r_y2) / 2.0)
 
         delta_x, delta_y = p_1[0] - p_0[0], p_1[1] - p_0[1]
 
-        if abs(delta_x) > 1.0e-3:
-            return math.atan(delta_y / delta_x)
-        elif delta_y > 0:
-            return 3.142592 / 2.0
+        if abs(delta_y) < 1.0e-3:
+            angle = 0.0
+        elif abs(delta_x) < 1.0e-3:
+            angle = np.pi / 2.0 if delta_y > 0 else -np.pi / 2.0
         else:
-            return -3.142592 / 2.0
+            angle = math.atan(delta_y / delta_x)
+        if delta_x < 0:
+            angle += np.pi
+        if angle < 0:
+            angle += 2 * np.pi
+        return angle
 
     @property
     def angle_360(self) -> int:
         """Calculate the angle of the rectangle in degrees (0-360 range)."""
-        p_0 = ((self.r_x0 + self.r_x3) / 2.0, (self.r_y0 + self.r_y3) / 2.0)
-        p_1 = ((self.r_x1 + self.r_x2) / 2.0, (self.r_y1 + self.r_y2) / 2.0)
-
-        delta_x, delta_y = p_1[0] - p_0[0], p_1[1] - p_0[1]
-
-        if abs(delta_y) < 1.0e-2:
-            return 0
-        elif abs(delta_x) < 1.0e-2:
-            return 90
-        else:
-            return round(-math.atan(delta_y / delta_x) / np.pi * 180)
+        return round(self.angle / np.pi * 180)
 
     @property
     def centre(self):

test/test_page.py

@@ -0,0 +1,79 @@
+import math
+
+import numpy as np
+import pytest
+
+from docling_core.types.doc.page import BoundingRectangle
+
+SQRT_2 = math.sqrt(2)
+
+R_0 = BoundingRectangle(r_x0=0, r_y0=0, r_x1=1, r_y1=0, r_x2=1, r_y2=1, r_x3=0, r_y3=1)
+R_45 = BoundingRectangle(
+    r_x0=0,
+    r_y0=0,
+    r_x1=SQRT_2 / 2,
+    r_y1=SQRT_2 / 2,
+    r_x2=0,
+    r_y2=SQRT_2,
+    r_x3=-SQRT_2 / 2,
+    r_y3=SQRT_2 / 2,
+)
+R_90 = BoundingRectangle(
+    r_x0=0, r_y0=0, r_x1=0, r_y1=1, r_x2=-1, r_y2=1, r_x3=-1, r_y3=0
+)
+R_135 = BoundingRectangle(
+    r_x0=0,
+    r_y0=0,
+    r_x1=-SQRT_2 / 2,
+    r_y1=SQRT_2 / 2,
+    r_x2=-SQRT_2,
+    r_y2=0,
+    r_x3=-SQRT_2 / 2,
+    r_y3=-SQRT_2 / 2,
+)
+R_180 = BoundingRectangle(
+    r_x0=0, r_y0=0, r_x1=-0, r_y1=0, r_x2=-1, r_y2=-1, r_x3=0, r_y3=-1
+)
+R_MINUS_135 = BoundingRectangle(
+    r_x0=0,
+    r_y0=0,
+    r_x1=-SQRT_2 / 2,
+    r_y1=-SQRT_2 / 2,
+    r_x2=0,
+    r_y2=-SQRT_2,
+    r_x3=SQRT_2 / 2,
+    r_y3=-SQRT_2 / 2,
+)
+R_MINUS_90 = BoundingRectangle(
+    r_x0=0, r_y0=0, r_x1=0, r_y1=-1, r_x2=1, r_y2=-1, r_x3=1, r_y3=0
+)
+R_MINUS_45 = BoundingRectangle(
+    r_x0=0,
+    r_y0=0,
+    r_x1=SQRT_2 / 2,
+    r_y1=-SQRT_2 / 2,
+    r_x2=SQRT_2,
+    r_y2=0,
+    r_x3=SQRT_2 / 2,
+    r_y3=SQRT_2 / 2,
+)
+
+
+@pytest.mark.parametrize(
+    ("rectangle", "expected_angle", "expected_angle_360"),
+    [
+        (R_0, 0, 0.0),
+        (R_45, np.pi / 4, 45),
+        (R_90, np.pi / 2, 90),
+        (R_135, 3 * np.pi / 4, 135),
+        (R_180, np.pi, 180),
+        (R_MINUS_135, 5 * np.pi / 4, 225),
+        (R_MINUS_90, 3 * np.pi / 2, 270),
+        (R_MINUS_45, 7 * np.pi / 4, 315),
+    ],
+)
+def test_bounding_rectangle_angle(
+    rectangle: BoundingRectangle, expected_angle: float, expected_angle_360: int
+):
+    assert pytest.approx(rectangle.angle, abs=1e-6) == expected_angle
+    assert pytest.approx(rectangle.angle_360, abs=1e-6) == expected_angle_360