Generate and Save the Identicon image

Author: venriq

identicon.iml

@@ -36,5 +36,6 @@
     <orderEntry type="library" name="benchee" level="project" />
     <orderEntry type="library" name="benchee_markdown" level="project" />
     <orderEntry type="library" name="stream_data" level="project" />
+    <orderEntry type="library" name="vix" level="project" />
   </component>
 </module>

lib/identicon.ex

@@ -11,6 +11,10 @@ defmodule Identicon do
     |> hash_input()
     |> pick_color()
     |> build_grid()
+    |> filter_odd_squares()
+    |> build_pixel_map()
+    |> draw_image()
+    |> save_image("images/#{input}.png")
   end
 
   @doc """
@@ -58,4 +62,77 @@ defmodule Identicon do
     [first, second | _rest] = row
     row ++ [second, first]
   end
+
+  @doc """
+  Filters out the grid cells with odd codes, keeping only those with even codes.
+
+  ## Examples
+
+      iex> image = %Identicon.Image{grid: [{0, 0}, {1, 1}, {2, 2}, {3, 3}]}
+      iex> Identicon.filter_odd_squares(image)
+      %Identicon.Image{grid: [{0, 0}, {2, 2}]}
+  """
+  def filter_odd_squares(%Identicon.Image{grid: grid} = image) do
+    even_cells_grid =
+      Enum.filter(grid, fn {code, _index} ->
+        rem(code, 2) == 0
+      end)
+
+    %Identicon.Image{image | grid: even_cells_grid}
+  end
+
+  @doc """
+  Builds the pixel map for the identicon by calculating the top-left and bottom-right
+  coordinates for each cell in the grid.
+
+  ## Examples
+
+      iex> image = %Identicon.Image{grid: [{0, 0}, {1, 1}, {2, 2}]}
+      iex> Identicon.build_pixel_map(image)
+      %Identicon.Image{grid: [{0, 0}, {1, 1}, {2, 2}], pixel_map: [{{0, 0}, {60, 60}}, {{60, 60}, {120, 120}}, {{120, 120}, {180, 180}}]}
+  """
+  def build_pixel_map(%Identicon.Image{grid: grid} = image) do
+    pixel_map =
+      Enum.map(grid, fn {_code, index} ->
+        x = rem(index, 5) * 60
+        y = div(index, 5) * 60
+
+        top_left = {x, y}
+        bottom_right = {x + 60, y + 60}
+
+        {top_left, bottom_right}
+      end)
+
+    %Identicon.Image{image | pixel_map: pixel_map}
+  end
+
+  @doc """
+  Draws the identicon image and saves it to the specified filename.
+  Uses the Vix library to create and manipulate the image.
+  """
+  def draw_image(%Identicon.Image{color: color, pixel_map: pixel_map}) do
+    {r, g, b} = color
+
+    # Create a black image 
+    {:ok, img} = Vix.Vips.Operation.black(300, 300, bands: 3)
+    # Make it white
+    {:ok, img} = Vix.Vips.Operation.linear(img, [1, 1, 1], [255, 255, 255])
+
+    # Draw each colored rectangle
+    Enum.reduce(pixel_map, img, fn {{x1, y1}, {x2, y2}}, acc_img ->
+      width = x2 - x1
+      height = y2 - y1
+      {:ok, rect} = Vix.Vips.Operation.black(width, height, bands: 3)
+      {:ok, rect} = Vix.Vips.Operation.linear(rect, [1, 1, 1], [r, g, b])
+      {:ok, result} = Vix.Vips.Operation.insert(acc_img, rect, x1, y1)
+      result
+    end)
+  end
+
+  @doc """
+    Saves the image to the specified filename.
+  """
+  def save_image(img, filename) do
+    Vix.Vips.Image.write_to_file(img, filename)
+  end
 end

lib/image.ex

@@ -5,5 +5,6 @@ defmodule Identicon.Image do
 
   defstruct hex: nil,
             color: nil,
-            grid: nil
+            grid: nil,
+            pixel_map: nil
 end

mix.exs

@@ -23,7 +23,8 @@ defmodule Identicon.MixProject do
     [
       # {:dep_from_hexpm, "~> 0.3.0"},
       # {:dep_from_git, git: "https://github.com/elixir-lang/my_dep.git", tag: "0.1.0"}
-      {:ex_doc, "~> 0.40.0"}
+      {:ex_doc, "~> 0.40.0"},
+      {:vix, "~> 0.35.0"}
     ]
   end
 end

mix.lock

@@ -1,8 +1,11 @@
 %{
+  "cc_precompiler": {:hex, :cc_precompiler, "0.1.11", "8c844d0b9fb98a3edea067f94f616b3f6b29b959b6b3bf25fee94ffe34364768", [:mix], [{:elixir_make, "~> 0.7", [hex: :elixir_make, repo: "hexpm", optional: false]}], "hexpm", "3427232caf0835f94680e5bcf082408a70b48ad68a5f5c0b02a3bea9f3a075b9"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.44", "f20830dd6b5c77afe2b063777ddbbff09f9759396500cdbe7523efd58d7a339c", [:mix], [], "hexpm", "4778ac752b4701a5599215f7030989c989ffdc4f6df457c5f36938cc2d2a2750"},
+  "elixir_make": {:hex, :elixir_make, "0.9.0", "6484b3cd8c0cee58f09f05ecaf1a140a8c97670671a6a0e7ab4dc326c3109726", [:mix], [], "hexpm", "db23d4fd8b757462ad02f8aa73431a426fe6671c80b200d9710caf3d1dd0ffdb"},
   "ex_doc": {:hex, :ex_doc, "0.40.0", "2635974389b80fd3ca61b0f993d459dad05b4a8f9b069dcfbbc5f6a8a6aef60e", [:mix], [{:earmark_parser, "~> 1.4.44", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_c, ">= 0.1.0", [hex: :makeup_c, repo: "hexpm", optional: true]}, {:makeup_elixir, "~> 0.14 or ~> 1.0", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1 or ~> 1.0", [hex: :makeup_erlang, repo: "hexpm", optional: false]}, {:makeup_html, ">= 0.1.0", [hex: :makeup_html, repo: "hexpm", optional: true]}], "hexpm", "c040735250e2752b6e1102eeb4aa3f1dca74c316db873ae09f955d42136e7e5b"},
   "makeup": {:hex, :makeup, "1.2.1", "e90ac1c65589ef354378def3ba19d401e739ee7ee06fb47f94c687016e3713d1", [:mix], [{:nimble_parsec, "~> 1.4", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "d36484867b0bae0fea568d10131197a4c2e47056a6fbe84922bf6ba71c8d17ce"},
   "makeup_elixir": {:hex, :makeup_elixir, "1.0.1", "e928a4f984e795e41e3abd27bfc09f51db16ab8ba1aebdba2b3a575437efafc2", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}, {:nimble_parsec, "~> 1.2.3 or ~> 1.3", [hex: :nimble_parsec, repo: "hexpm", optional: false]}], "hexpm", "7284900d412a3e5cfd97fdaed4f5ed389b8f2b4cb49efc0eb3bd10e2febf9507"},
   "makeup_erlang": {:hex, :makeup_erlang, "1.0.3", "4252d5d4098da7415c390e847c814bad3764c94a814a0b4245176215615e1035", [:mix], [{:makeup, "~> 1.0", [hex: :makeup, repo: "hexpm", optional: false]}], "hexpm", "953297c02582a33411ac6208f2c6e55f0e870df7f80da724ed613f10e6706afd"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.4.2", "8efba0122db06df95bfaa78f791344a89352ba04baedd3849593bfce4d0dc1c6", [:mix], [], "hexpm", "4b21398942dda052b403bbe1da991ccd03a053668d147d53fb8c4e0efe09c973"},
+  "vix": {:hex, :vix, "0.35.0", "f6319b715e3b072e53eba456a21af5f2ff010a7a7b19b884600ea98a0609b18c", [:make, :mix], [{:cc_precompiler, "~> 0.1.4 or ~> 0.2", [hex: :cc_precompiler, repo: "hexpm", optional: false]}, {:elixir_make, "~> 0.7.3 or ~> 0.8", [hex: :elixir_make, repo: "hexpm", optional: false]}, {:kino, "~> 0.7", [hex: :kino, repo: "hexpm", optional: true]}], "hexpm", "a3e80067a89d0631b6cf2b93594e03c1b303a2c7cddbbdd28040750d521984e5"},
 }