import math

# The list called red is a list of varying strengths of red (all values
# need to be between 0 and 1. Similarly for green and blue.
red = []
green = []
blue = []

# Stroke size is the width of the stroke, set when calling set_parameters()
stroke_size = 0.1

# These are the x,y coordinates of the start and end of the brush stroke.
start_x = 2
start_y = 3
end_x = 5
end_y = 3

# Each stroke is implemented by drawing circles.
num_circles = 0

def set_parameters(x1, y1, x2, y2, size):
    global start_x, start_y, end_x, end_y, stroke_size
    start_x = x1
    start_y = y1
    end_x = x2
    end_y = y2
    stroke_size = size

def compute_num_circles():
    # Note: we need to state our intent to modify a global:
    global num_circles
    # Write your code here to compute the number of circles needed
    # Compute the distance between start point and end point. Then
    # divide by the stroke size. The minimum is one circle.

def get_num_circles():
    return num_circles

def make_red_stroke_colors(start_r, end_r, g, b):
    # Look through and understand how we're computing all
    # the intermediate red values between start_r and end_r.
    # And how the lists for red, green, blue are being built.
    global red, green, blue
    d = (end_r - start_r) / num_circles
    red = []
    green = []
    blue = []
    for i in range(num_circles):
        red.append(start_r + i*d)
        green.append(g)
        blue.append(b)

def make_green_stroke_colors(r, start_g, end_g, b):
    # Write your code here

def make_blue_stroke_colors(r, g, start_b, end_b):
    # Write your code here