# 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.

    (creates a tile and then moves to the starting point of the next tile 
    untill there are no more tiles in width and then repates for as many 
    times as heights exist)
    """
    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)