fix(dda): fix docstring #enhancement 13905

graphics/digital_differential_analyzer_line.py

@@ -1,52 +1,53 @@
-import matplotlib.pyplot as plt
-
-
 def digital_differential_analyzer_line(
     p1: tuple[int, int], p2: tuple[int, int]
 ) -> list[tuple[int, int]]:
     """
-    Draws a line between two points using the DDA algorithm.
+    Draw a line between two points using the Digital Differential Analyzer (DDA)
+    algorithm.
+
+    The DDA algorithm increments the dominant axis in unit steps and updates the
+    other axis proportionally. After each step coordinates are rounded to the
+    nearest integer to obtain pixel coordinates.
 
     Args:
-    - p1: Coordinates of the starting point.
-    - p2: Coordinates of the ending point.
+        p1: Starting coordinate (x1, y1).
+        p2: Ending coordinate (x2, y2).
+
     Returns:
-    - List of coordinate points that form the line.
+        A list of integer coordinate tuples representing the rasterized line.
+        The list includes the end point and excludes the start point.
 
+    Examples:
     >>> digital_differential_analyzer_line((1, 1), (4, 4))
     [(2, 2), (3, 3), (4, 4)]
+
+    >>> digital_differential_analyzer_line((0, 0), (0, 5))
+    [(0, 1), (0, 2), (0, 3), (0, 4), (0, 5)]
+
+    >>> digital_differential_analyzer_line((5, 5), (2, 5))
+    [(4, 5), (3, 5), (2, 5)]
+
+    >>> digital_differential_analyzer_line((3, 3), (3, 3))
+    [(3, 3)]
     """
     x1, y1 = p1
     x2, y2 = p2
     dx = x2 - x1
     dy = y2 - y1
+
     steps = max(abs(dx), abs(dy))
-    x_increment = dx / float(steps)
-    y_increment = dy / float(steps)
-    coordinates = []
-    x: float = x1
-    y: float = y1
+    if steps == 0:
+        return [p1]
+
+    x_inc = dx / float(steps)
+    y_inc = dy / float(steps)
+
+    x, y = float(x1), float(y1)
+    points: list[tuple[int, int]] = []
+
     for _ in range(steps):
-        x += x_increment
-        y += y_increment
-        coordinates.append((round(x), round(y)))
-    return coordinates
-
-
-if __name__ == "__main__":
-    import doctest
-
-    doctest.testmod()
-
-    x1 = int(input("Enter the x-coordinate of the starting point: "))
-    y1 = int(input("Enter the y-coordinate of the starting point: "))
-    x2 = int(input("Enter the x-coordinate of the ending point: "))
-    y2 = int(input("Enter the y-coordinate of the ending point: "))
-    coordinates = digital_differential_analyzer_line((x1, y1), (x2, y2))
-    x_points, y_points = zip(*coordinates)
-    plt.plot(x_points, y_points, marker="o")
-    plt.title("Digital Differential Analyzer Line Drawing Algorithm")
-    plt.xlabel("X-axis")
-    plt.ylabel("Y-axis")
-    plt.grid()
-    plt.show()
+        x += x_inc
+        y += y_inc
+        points.append((round(x), round(y)))
+
+    return points