Sweep-Line_gif2

from manim import *

config.frame_width = config.frame_height = 8
config.pixel_width = config.pixel_height

length = 5
unit = 10
def get_numberplane(x, gapx, y, gapy):
    return NumberPlane(
        x_range = (0.0, x, gapx),
        y_range = (0.0, y, gapy),
        x_length = length,
        y_length = length,
        background_line_style = {
            "stroke_color": GRAY,
            "stroke_opacity": 0.3
        },
        axis_config = {
            "include_ticks": True,
            "include_numbers": True,
            "font_size" : 18
        }
    )

def get_rectangle(plane, a, b, c, d, col):
    a = plane.c2p(a[0], a[1], a[2])
    b = plane.c2p(b[0], b[1], b[2])
    c = plane.c2p(c[0], c[1], c[2])
    d = plane.c2p(d[0], d[1], d[2])
    return Polygon(*[a, b, c, d], color = col)

def create_line(start, end, color, plane):
    line = Line(
        start = plane.c2p(start[0], start[1], 0.0),
        end = plane.c2p(end[0], end[1], 0.0),
        color = color
    )
    return line

class SweepLine(Scene):
    def construct(self):
        plane = get_numberplane(unit, 1, unit, 1)
        self.play(Create(plane))

        rectangles = [get_rectangle(plane, (1, 1, 0), (1, 3, 0), (8, 3, 0), (8, 1, 0), BLUE),
                      get_rectangle(plane, (3, 2, 0), (3, 5, 0), (6, 5, 0), (6, 2, 0), RED),
                      get_rectangle(plane, (2, 4, 0), (2, 7, 0), (5, 7, 0), (5, 4, 0), YELLOW),
                      get_rectangle(plane, (3, 6, 0), (3, 8, 0), (4, 8, 0), (4, 6, 0), PURPLE),
                      get_rectangle(plane, (8, 8, 0), (8, 9, 0), (9, 9, 0), (9, 8, 0), "#6f42f5")]
        self.play(*[Create(rect) for rect in rectangles])

        lines = [[] for i in range(10)]
        cnt = [0 for i in range(10)]
        lines[1].append((1, 3, 1))
        lines[2].append((4, 7, 1))
        lines[3].append((2, 5, 1))
        lines[3].append((6, 8, 1))
        lines[4].append((6, 8, -1))
        lines[5].append((4, 7, -1))
        lines[6].append((2, 5, -1))
        lines[8].append((1, 3, -1))
        lines[8].append((8, 9, 1))
        lines[9].append((8, 9, -1))

        sweep_line = create_line((0, -1), (0, 11), GREEN, plane)
        self.play(Create(sweep_line))

        for i in range(0, 10):
            self.play(sweep_line.animate(run_time = 1).move_to(plane.c2p(i + 0.5, 5, 0)))

            for p in lines[i]:
                for j in range(p[0], p[1]):
                    cnt[j] = cnt[j] + p[2]

            sub = []
            for j in range(10):
                if (cnt[j] > 0):
                    tmp = get_rectangle(plane, (i, j, 0), (i, j + 1, 0), (i + 1, j + 1, 0), (i + 1, j, 0), "#ffb3b3")
                    tmp.set_fill("#ffb3b3", 0.5)
                    sub.append(tmp)
            if (len(sub) != 0):
                self.play(*[Create(x) for x in sub], run_time = 1)

        self.remove(*sweep_line)
        self.wait(2)