#!/usr/bin/env python
# coding: utf-8

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from simpleimage import SimpleImage


# As a reminder, here are the image functions we learned about in class.
# 
# ```
# # Create image:
# image = SimpleImage.blank(400, 200)   # create new image of size 400, 200
# 
# # Access size:
# w = image.width
# h = image.height
# 
# # Get pixel at x,y (0,0 is the top left corner):
# pix = image.get_rgb(x, y)
# # pix is an RGB list like [100, 200, 0], where the color components of the
# # pixel are Red = 100, Green = 200, and Blue = 0.
# 
# # Set pixel at x,y:
# image.set_rgb(x, y, r, g, b)
# 
# # Show image on screen:
# image.show()
# 
# # Show a small image zoomed-in (larger) so it's easier to see the pixels:
# image.show(resize_width=200)
# ```
# 

# ### Question 1
# 
# Let's create a blank image with a white background, that is an 11 by 11 square.

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size = 11


# ### Question 2
# Now, let's set the middle pixel to a black dot by using the `set_rgb()` function.

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# ### Question 3
# 
# After painting the center pixel of the picture black, let us paint the four corners black.
# 
# It should look something like this. 
# 
# ![](four_dots_and_middle_dot.png)

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# ### Question 4
# 
# Define a function called `draw_horizontal(img, x, y,length)` that will draw a horizontal line given an image, starting pixel, ending pixel and its length.

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image = SimpleImage.blank(size, size)
def draw_horizontal(img,x,y,length): 
    # YOUR CODE GOES HERE
    pass


# ### Question 5
# Define a function called `draw_vertical(img, x, y,length)` that draws a vertical line given an image, starting pixel, ending pixel and its length.

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# ### Question 6
# 
# Define a function called `draw_line(img,x,y,length,vertical)` that draws a vertical line if the argument vertical is true and horizontal line if false. Use the functions you create in **Question 4** and **Question 5**.

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image = SimpleImage.blank(size, size)
def draw_line(img,x,y,length,vertical):
    # YOUR CODE GOES HERE
    pass


# ### Question 7
# 
# Define a function called `draw_diagonal(img)` that draws a diagonal line from the `pixel(0,0)` to `(size-1,size-1)`. It should look something like this: 
# 
# ![](diagonal.png)

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# ###  Question 8
# 
# Define a function that draws a triangle. The triangle could be a right angle triangle, an equilateral one as well. 

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# ###  Question 9
# 
# Define a function that draws a checker board pattern. `Pixel(0,0)` should be white, `Pixel(0,1)` should black be and so on. It should look something like this: 
# 
# ![](checkers.png)

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# ###  Question 10
# 
# 
# Write a function that inverts the color of each square in the board above. i.e `Pixel(0,0)` should now be black, `Pixel(0,1)` white and so on. The function should only take the image as an argument and invert the color of each cell in the given image. It should look like this: 
# 
# ![](checkers2.png)

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# DON'T USE 'image = SimpleImage.blank(size, size)' TO REMOVE THE PREVIOUSLY DRAWN IMAGE.


# ###  Question 11
# 
# Now that you have inverted the colors of the board, let's create a function that changes the black tiles to red tiles. It should look something like this: 
# ![](red_checkers.png)

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# DON'T USE 'image = SimpleImage.blank(size, size)' TO REMOVE THE PREVIOUSLY DRAWN IMAGE.


# ## Gradients

# ### Question 12
# 
# Make a horizontal gradient from black to white.
# 
# Note:
# - The RGB values for black are `[0, 0, 0]`
# - The RGB values for white are `[255, 255, 255]`
# - The RGB values for grey are `[k, k, k]` for some `k`. Larger `k` is lighter grey, smaller `k` is darker grey.
# - as `x` goes from 0 to `size`, `k` should go from 0 to `255`. So compute `k = x*255//size`
# 
# ![](grayscale-horizontal.png)

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# ### Question 13 

# Change your code so that the gradient goes from black to red.
# 
# Note:
# - red is [255, 0, 0]
# 
# ![](red-horizontal.png)

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE


# Change your code so that the gradient is vertical.
# 
# Hint: before, the value `k` depended on `x`. What should it depend on now?
# 
# ![](red-vertical.png)

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image = SimpleImage.blank(size, size)
# YOUR CODE GOES HERE