"""
This code is supported by the website: https://www.guanjihuan.com
The newest version of this code is on the web page: https://www.guanjihuan.com/archives/10909
"""

import numpy as np
import copy
import matplotlib.pyplot as plt
from math import *

def main():
    x_array = np.arange(-20, 20.1)
    y_array = np.arange(-20, 20.1)
    coordinates = []
    for x in x_array:
        for y in y_array:
            coordinates.append([0+x*3, 0+y*np.sqrt(3)])
            coordinates.append([1+x*3, 0+y*np.sqrt(3)])
            coordinates.append([-1/2+x*3, np.sqrt(3)/2+y*np.sqrt(3)])
            coordinates.append([-3/2+x*3, np.sqrt(3)/2+y*np.sqrt(3)])
    x_range1 = max(np.array(coordinates)[:, 0])-min(np.array(coordinates)[:, 0])
    y_range1 = max(np.array(coordinates)[:, 1])-min(np.array(coordinates)[:, 1])
    
    theta = -1.1/180*pi
    rotation_matrix = np.zeros((2, 2))
    rotation_matrix[0, 0] = np.cos(theta)
    rotation_matrix[1, 1] = np.cos(theta)
    rotation_matrix[0, 1] = -np.sin(theta)
    rotation_matrix[1, 0] = np.sin(theta)
    coordinates2 = copy.deepcopy(coordinates)
    for i in range(len(coordinates)):
        coordinates2[i] = np.dot(rotation_matrix, coordinates[i])
    x_range2 = max(np.array(coordinates2)[:, 0])-min(np.array(coordinates2)[:, 0])
    y_range2 = max(np.array(coordinates2)[:, 1])-min(np.array(coordinates2)[:, 1])

    x_range = max([x_range1, x_range2])
    y_range = max([y_range1, y_range2])
    fig, ax = plt.subplots(figsize=(9*x_range/y_range,9))
    plt.subplots_adjust(left=0.05, bottom=0.05, right=0.95, top=0.95)
    plt.axis('off')
    plot_dots_1(ax, coordinates)
    plot_dots_2(ax, coordinates2)
    plot_dots_0(ax, [[0, 0]])
    plt.savefig('twist_graphene.eps') 
    plt.show()


def plot_dots_0(ax, coordinates):
    for i in range(len(coordinates)):
        ax.plot(coordinates[i][0], coordinates[i][1], 'ko', markersize=0.5)


def plot_dots_1(ax, coordinates):
    for i1 in range(len(coordinates)):
        for i2 in range(len(coordinates)):
            if np.sqrt((coordinates[i1][0] - coordinates[i2][0])**2+(coordinates[i1][1] - coordinates[i2][1])**2) < 1.1:
                ax.plot([coordinates[i1][0], coordinates[i2][0]], [coordinates[i1][1], coordinates[i2][1]], '-k', linewidth=0.2)
    for i in range(len(coordinates)):
        ax.plot(coordinates[i][0], coordinates[i][1], 'ro', markersize=0.5)
    

def plot_dots_2(ax, coordinates):
    for i1 in range(len(coordinates)):
        for i2 in range(len(coordinates)):
            if np.sqrt((coordinates[i1][0] - coordinates[i2][0])**2+(coordinates[i1][1] - coordinates[i2][1])**2) < 1.1:
                ax.plot([coordinates[i1][0], coordinates[i2][0]], [coordinates[i1][1], coordinates[i2][1]], '--k', linewidth=0.2)
    for i in range(len(coordinates)):
        ax.plot(coordinates[i][0], coordinates[i][1], 'bo', markersize=0.5)    


if __name__ == '__main__':
    main()