|
| 1 | +""" |
| 2 | +Generalized Bresenham's Line Drawing Algorithm |
| 3 | +---------------------------------------------- |
| 4 | +
|
| 5 | +Handles all possible line slopes and directions. |
| 6 | +
|
| 7 | +Reference: |
| 8 | +https://www.geeksforgeeks.org/dsa/bresenhams-line-generation-algorithm/ |
| 9 | +
|
| 10 | +>>> generalized_bresenham_line((0, 0), (5, 3)) |
| 11 | +[(0, 0), (1, 1), (2, 1), (3, 2), (4, 2), (5, 3)] |
| 12 | +>>> generalized_bresenham_line((5, 5), (2, 3)) |
| 13 | +[(5, 5), (4, 4), (3, 4), (2, 3)] |
| 14 | +""" |
| 15 | + |
| 16 | +import matplotlib.pyplot as plt |
| 17 | + |
| 18 | + |
| 19 | +def generalized_bresenham_line( |
| 20 | + p1: tuple[int, int], p2: tuple[int, int] |
| 21 | +) -> list[tuple[int, int]]: |
| 22 | + x1, y1 = p1 |
| 23 | + x2, y2 = p2 |
| 24 | + dx = abs(x2 - x1) |
| 25 | + dy = abs(y2 - y1) |
| 26 | + sx = 1 if x1 < x2 else -1 |
| 27 | + sy = 1 if y1 < y2 else -1 |
| 28 | + err = dx - dy |
| 29 | + |
| 30 | + points = [] |
| 31 | + |
| 32 | + while True: |
| 33 | + points.append((x1, y1)) |
| 34 | + if x1 == x2 and y1 == y2: |
| 35 | + break |
| 36 | + e2 = 2 * err |
| 37 | + if e2 > -dy: |
| 38 | + err -= dy |
| 39 | + x1 += sx |
| 40 | + if e2 < dx: |
| 41 | + err += dx |
| 42 | + y1 += sy |
| 43 | + |
| 44 | + return points |
| 45 | + |
| 46 | + |
| 47 | +if __name__ == "__main__": |
| 48 | + import doctest |
| 49 | + |
| 50 | + doctest.testmod() |
| 51 | + |
| 52 | + x1 = int(input("Enter x1: ")) |
| 53 | + y1 = int(input("Enter y1: ")) |
| 54 | + x2 = int(input("Enter x2: ")) |
| 55 | + y2 = int(input("Enter y2: ")) |
| 56 | + |
| 57 | + points = generalized_bresenham_line((x1, y1), (x2, y2)) |
| 58 | + print("Generated points:", points) |
| 59 | + |
| 60 | + xs, ys = zip(*points) |
| 61 | + plt.plot(xs, ys, marker="o") |
| 62 | + plt.title("Generalized Bresenham's Line Algorithm (All Slopes)") |
| 63 | + plt.grid() |
| 64 | + plt.show() |
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