defmodule Graditar do
require ColorUtils
require XmlBuilder
alias ColorUtils.{ RGB }
alias Graditar.{ Avatar, Options }
@moduledoc ~S"""
Generate avatars made of an angled gradient
## Examples
Generate a generic svg
iex> Graditar.generate
"\n"
Generate from a string
iex> Graditar.generate("bobthebuilder@canwefix.it")
"\n"
Add options
iex> Graditar.generate("bobthebuilder@canwefix.it", %{ size: 128 })
"\n"
"""
defp gen_hash(string, _opts) do
hashlist = :crypto.hash(:md5, string)
|> :binary.bin_to_list
%Avatar{ hex: hashlist }
end
defp gen_primary_color(%Avatar{ hex: [r, g, b | _] } = avatar, _opts) do
color = %RGB{ red: r, green: g, blue: b }
%Avatar{ avatar | primary_color: color }
end
defp gen_secondary_color(%Avatar{ primary_color: primary_color } = avatar, _opts) do
[_, color] = ColorUtils.get_triad_colors primary_color
%Avatar{ avatar | secondary_color: color }
end
defp gen_angle(%Avatar{ hex: [num | _] } = avatar, _opts) do
# Generate an angle, one of 45, 135, 225, or 315
angle = (round(Float.floor(num / 64)) + 1) * 45 * 2 - 45
%Avatar{ avatar | angle: angle }
end
defp gen_svg(avatar, %{ size: size } = _opts) do
%Avatar{ primary_color: primary_color, secondary_color: secondary_color, angle: angle } = avatar
%RGB{ red: p_r, blue: p_b, green: p_g } = primary_color
%RGB{ red: s_r, blue: s_b, green: s_g } = secondary_color
primary_color_stop = XmlBuilder.element(:stop, %{
offset: "0%",
"stop-color": "rgb(#{p_r}, #{p_g}, #{p_b})",
"stop-opacity": "1",
})
secondary_color_stop = XmlBuilder.element(:stop, %{
offset: "100%",
"stop-color": "rgb(#{s_r}, #{s_g}, #{s_b})",
"stop-opacity": "1",
})
gradient = XmlBuilder.element(:linearGradient, %{
id: "gradient",
gradientUnits: "userSpaceOnUse",
gradientTransform: "rotate(#{angle} .5 .5)",
x1: "0%",
x2: "0%",
y1: "0%",
y2: "100%",
}, [primary_color_stop, secondary_color_stop])
rect = XmlBuilder.element(:rect, %{
x: 0,
y: 0,
width: 1,
height: 1,
fill: "url(#gradient)",
})
svg = XmlBuilder.element(:svg, %{
xmlns: "http://www.w3.org/2000/svg",
width: "#{size}px",
height: "#{size}px",
viewBox: "0 0 1 1",
preserveAspectRatio: "none",
}, [gradient, rect])
XmlBuilder.doc svg
end
def generate(string \\ "", opts \\ %Options{}) do
string
|> gen_hash(opts)
|> gen_primary_color(opts)
|> gen_secondary_color(opts)
|> gen_angle(opts)
|> gen_svg(opts)
end
end