# tile_grid.py
# ------------
# By MWC Contributors
#
# Implements `draw_tile_grid`, which draws a grid of tiles. 

from turtle import *
from tile import fly

def draw_tile_grid(width, height, tile_size, tile_function):
    """Draws a (width x height) grid, with tile_function drawn on each tile.

    The code is making it go so many spaces that you put for the with-y 
    and then it runs the code making it once then jumps to the next 
    spot and does it again. Then runs the height and then the width again 
    until its done.
    """
    for y in range(height):
        for x in range(width):
            tile_function(tile_size)
            fly(tile_size)
        return_to_x_origin(tile_size, width)
        move_up_one_row(tile_size)
    return_to_y_origin(tile_size, height)

def return_to_x_origin(tile_size, width):
    "After drawing a row of tiles, returns the turtle to the starting x position"
    fly(-1 * tile_size * width)

def return_to_y_origin(tile_size, height):
    "After drawing all rows of tiles, returns the turtle to the starting y position"
    right(90)
    fly(tile_size * height)
    left(90)

def move_up_one_row(tile_size):
    "Moves the turtle up one row"
    left(90)
    fly(tile_size)
    right(90)