Battle Map

Mix.install([
  {:kino, github: "livebook-dev/kino", override: true},
  {:kino_lab, "~> 0.1.0-dev", github: "jonatanklosko/kino_lab"},
  {:vega_lite, "~> 0.1.4"},
  {:kino_vega_lite, "~> 0.1.1"},
  {:benchee, "~> 0.1"},
  {:ecto, "~> 3.7"},
  {:math, "~> 0.7.0"},
  {:faker, "~> 0.17.0"},
  {:utils, path: "#{__DIR__}/../utils"},
  {:tested_cell, git: "https://github.com/BrooklinJazz/tested_cell"}
])

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Overview

You’re developing a 2D tactical combat game.

Characters in your game fight on a grid of potentially infinite size.

Character Attack

You’re going to create a Character.can_attack?/3 function that expects the following:

1. A struct
2. The player’s coordinate {x, y}
3. An enemy’s coordinate {x, y}

It should then return a boolean.

Wizard

A Wizard can attack in straight or diagonal lines of any length.

We’ve created a Wizard struct below. It does not need to store any information in the struct.

defmodule Wizard do
  defstruct []
end

A Barbarian can attack in 2 square radius.

We’ve created a Barbarian struct below. It does not need to store any information in the struct.

defmodule Barbarian do
  defstruct []
end

You should be able to check if a character can attack a coordinate {x, y} given their starting location in {x, y}.

Character.can_attack?(%Barbarian{}, {4, 4}, {6, 6})
true

Character.can_attack?(%Wizard{}, {4, 4}, {6, 6})
true

Enter your solution between the comments below. You may consider making Character a protocol or a module.

# Enter your solution below
defprotocol Character do
  def can_attack?(character, origin, target)
end

defimpl Character, for: Wizard do
  def can_attack?(_character, {init_x, init_y}, {x, y}) do
    x_diff = init_x - x
    y_diff = init_y - y

    init_x == x || init_y == y || abs(x_diff) == abs(y_diff)
  end
end

defimpl Character, for: Barbarian do
  def can_attack?(_character, {init_x, init_y}, {x, y}) do
    x_diff = init_x - x
    y_diff = init_y - y

    abs(x_diff) <= 2 &amp;&amp; abs(y_diff) <= 2
  end
end

# Enter your solution above
Utils.feedback(:battle_map, [Character, Barbarian, Wizard])

Custom Character (BONUS)

Create your own customer character with an attack pattern than you decide on. It should not match the existing characters.

For example, you might create an Archer who can only attack in a 3 radius square.

Character.can_attack?(%Archer{}, {4, 4}, {7, 7})
true

Modify the existing solution above to add your custom character.

Commit Your Progress

Run the following in your command line from the project folder to track and save your progress in a Git commit.

$ git add .
$ git commit -m "finish battle map exercise"