Search area dimensions (#71)

* FOV for vertical frustum

* Variable frustum

* Fixed trig errors

* Parameter for degrees or radians

* Fixed factor bug; decimal default values

modules/search-dimensions/search_area_dimensions.py

@@ -0,0 +1,60 @@
+"""
+Converts field of view to display dimensions in metres.
+"""
+
+from math import tan, pi
+
+
+# Measurements from https://uwarg-docs.atlassian.net/wiki/spaces/CV/pages/2236613655/200+CV+Camera
+FIELD_OF_VISION_X = 0.64889
+FIELD_OF_VISION_Y = 0.41438
+
+
+def search_area_dimensions(
+    height: int,
+    frustum_angle_x: float,
+    frustum_angle_y: float,
+    frustum_radians: bool = True,
+    field_of_vision_x: float = FIELD_OF_VISION_X,
+    field_of_vision_y: float = FIELD_OF_VISION_Y,
+    field_of_vision_radians: bool = True,
+) -> "tuple[float, float]":
+    """
+    Parameters:
+        - height: height of the drone, in metres
+        - frustum_angle_x: the left-right camera direction angle w/ respect to vertical
+        - frustum_angle_y: the up-down camera direction angle w/ respect to vertical
+        - frustum_radians: Boolean for whether frustum input is in radians or not
+        - field_of_vision_x: the horizontal field of vision of the camera, in radians (default to measured constant)
+        - field_of_vision_y: the vertical field of vision of the camera, in radians (default to measured constant)
+        - field_of_vision_radians: Boolean for whether field of vision input is in radians or not
+
+    Return:
+        - tuple containing the rectangular dimensions of the field of view of the camera, in metres
+    """
+    frustum_factor = 1
+    if not frustum_radians:
+        frustum_factor = pi / 180
+    field_of_vision_factor = 1
+    if not field_of_vision_radians:
+        field_of_vision_factor = pi / 180
+
+    left_distance = (
+        tan((field_of_vision_x * field_of_vision_factor) / 2 - frustum_angle_x * frustum_factor)
+        * height
+    )
+    right_distance = (
+        tan((field_of_vision_x * field_of_vision_factor) / 2 + frustum_angle_x * frustum_factor)
+        * height
+    )
+    horizontal_distance = left_distance + right_distance
+    up_distance = (
+        tan((field_of_vision_y * field_of_vision_factor) / 2 - frustum_angle_y * frustum_factor)
+        * height
+    )
+    down_distance = (
+        tan((field_of_vision_y * field_of_vision_factor) / 2 + frustum_angle_y * frustum_factor)
+        * height
+    )
+    vertical_distance = up_distance + down_distance
+    return horizontal_distance, vertical_distance