_dashes.py

"""
Rohan Shah
Helper function to essay_writer.py
"""

import numpy
import math
import pygame

def draw_dashed_line(surf, color, start_pos, end_pos, width=1, dash_length=10):
    x1, y1 = start_pos
    x2, y2 = end_pos
    dl = dash_length

    if (x1 == x2):
        ycoords = [y for y in range(y1, y2, dl if y1 < y2 else -dl)]
        xcoords = [x1] * len(ycoords)
    elif (y1 == y2):
        xcoords = [x for x in range(x1, x2, dl if x1 < x2 else -dl)]
        ycoords = [y1] * len(xcoords)
    else:
        a = abs(x2 - x1)
        b = abs(y2 - y1)
        c = round(math.sqrt(a**2 + b**2))
        dx = dl * a / c
        dy = dl * b / c

        xcoords = [x for x in numpy.arange(x1, x2, dx if x1 < x2 else -dx)]
        ycoords = [y for y in numpy.arange(y1, y2, dy if y1 < y2 else -dy)]

    next_coords = list(zip(xcoords[1::2], ycoords[1::2]))
    last_coords = list(zip(xcoords[0::2], ycoords[0::2]))
    for (x1, y1), (x2, y2) in zip(next_coords, last_coords):
        start = (round(x1), round(y1))
        end = (round(x2), round(y2))
        pygame.draw.line(surf, color, start, end, width)