Sutherland Hodgman Algorithm

sutherland-hodgman.py

import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as patches


class Segment:
    def __init__(self, p, q):
        self.p = p
        self.q = q


def show_polygon(ax, vertices, **kwargs):
    verts = vertices + [(0, 0)]
    codes = [Path.MOVETO] + [Path.LINETO] * (len(vertices) - 1) + [Path.CLOSEPOLY]
    path = Path(verts, codes)
    patch = patches.PathPatch(path, **kwargs)
    ax.add_patch(patch)


if __name__ == '__main__':
    subject_polygon = [
        (15.6, 284.38716), 
        (50.6, 389.3872), 
        (70.6, 389.3872), 
        (80.6, 354.3872), 
        (90.6, 389.3872), 
        (110.6, 389.3872), 
        (145.6, 284.38716), 
        (125.6, 284.38716), 
        (100.6, 369.3872), 
        (90.6, 334.38716), 
        (70.6, 334.38716), 
        (60.6, 369.3872), 
        (35.6, 284.38716), 
        (15.6, 284.38716)
    ]
    clip_polygon = [
        (10.6, 334.38716),
        (30.6, 294.38716),
        (85.6, 279.38716),
        (155.6, 334.38716),
        (75.6, 389.3872),
        (10.6, 334.38716)
    ]
    fig = plt.figure()
    ax = fig.add_subplot(111)
    show_polygon(ax, subject_polygon, facecolor='#c8c8c8', edgecolor='#000000')
    show_polygon(ax, clip_polygon, facecolor='#ff000020', edgecolor='#ff0000')
    ax.axis('equal')
    ax.set_xlim(5, 160)
    ax.set_ylim(260, 400)
    plt.show()