feat(lib): initial release of color library (#118)

Author: A-Lamia

lua/astrotheme/lib/color.lua

@@ -0,0 +1,337 @@
+---AstroTheme Configuration
+---
+---Default configuration of AstroTheme
+---
+---This module can be loaded with `local astrotheme_config = require "astrotheme.lib.color"`
+---
+---copyright 2023 license GNU General Public License v3.0 @class astrocore
+---@class astrotheme.lib.color
+
+---Converts an RGB array or single number to a
+---RGB dictionary.
+---@private
+---@param color Color | table | number
+---@return Color | table
+local function _to_rgb(color)
+  if type(color) == "table" and color["r"] == nil then
+    color.r = color[1]
+    color.g = color[2]
+    color.b = color[3]
+  elseif type(color) == "number" then
+    local num = color
+    color = { r = num, g = num, b = num }
+  end
+  return color
+end
+
+---@class Color
+---@field r number
+---@field g number
+---@field b number
+local Color = {}
+
+Color.__index = Color
+
+Color.__add = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  return setmetatable({
+    r = lhs.r + rhs.r,
+    g = lhs.g + rhs.g,
+    b = lhs.b + rhs.b,
+  }, Color)
+end
+
+Color.__sub = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  return setmetatable({
+    r = lhs.r - rhs.r,
+    g = lhs.g - rhs.g,
+    b = lhs.b - rhs.b,
+  }, Color)
+end
+
+Color.__div = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  return setmetatable({
+    r = lhs.r / rhs.r,
+    g = lhs.g / rhs.g,
+    b = lhs.b / rhs.b,
+  }, Color)
+end
+
+Color.__mul = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  return setmetatable({
+    r = lhs.r * rhs.r,
+    g = lhs.g * rhs.g,
+    b = lhs.b * rhs.b,
+  }, Color)
+end
+
+Color.__eq = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  local bool = false
+  if lhs.r == rhs.r and lhs.g == rhs.g and lhs.b == rhs.b then bool = true end
+  return bool
+end
+
+Color.__lt = function(lhs, rhs)
+  lhs = _to_rgb(lhs)
+  rhs = _to_rgb(rhs)
+  local y1 = 0.2126 * lhs.r + 0.7152 * lhs.g + 0.0722 * lhs.b
+  local y2 = 0.2126 * rhs.r + 0.7152 * rhs.g + 0.0722 * rhs.b
+
+  return y1 < y2
+end
+
+Color.__tostring = function(rgb)
+  -- local text = string.format("{%f, %f, %f}", rgb.r, rgb.g, rgb.b)
+  local text = " " .. rgb:tohex() .. " "
+  local text_color = "0;0;0"
+  if rgb:less(127) then text_color = "255;255;255" end
+  local out = string.format("\27[48;2;%d;%d;%dm\27[38;2;%sm%s\27[0m", rgb.r, rgb.g, rgb.b, text_color, text)
+  return out
+end
+
+--- Creates a new Color object from a RGB table,
+--- a hex value, or neovim raw value.
+---@param color table | string | number
+---@return Color
+Color.new = function(color)
+  if type(color) == "string" then
+    local hex = color:gsub("#", "")
+
+    local r = tonumber("0x" .. hex:sub(1, 2))
+    local g = tonumber("0x" .. hex:sub(3, 4))
+    local b = tonumber("0x" .. hex:sub(5, 6))
+
+    color = { r = r, g = g, b = b }
+  elseif type(color) == "table" then
+    color = { r = color[1], g = color[2], b = color[3] }
+  elseif type(color) == "number" then
+    local raw = string.format("%06x", color)
+    color = {
+      r = tonumber(raw:sub(1, 2), 16),
+      g = tonumber(raw:sub(3, 4), 16),
+      b = tonumber(raw:sub(5, 6), 16),
+    }
+  end
+  return setmetatable(color, Color)
+end
+
+---Clamps RGB values between 0 and 255.
+---@param self Color
+---@return Color
+Color.clamp = function(self)
+  local function clamp(num) return math.max(0, math.min(255, num)) end
+
+  return setmetatable({
+    r = clamp(self.r),
+    g = clamp(self.g),
+    b = clamp(self.b),
+  }, Color)
+end
+
+---Rounds RGB values to the nearest integer.
+---@param self Color
+---@return Color
+Color.round = function(self)
+  return setmetatable({
+    r = math.floor(self.r + 0.5),
+    g = math.floor(self.g + 0.5),
+    b = math.floor(self.b + 0.5),
+  }, Color)
+end
+
+---Converts negative values to positive.
+---@param self Color
+---@return Color
+Color.abs = function(self)
+  return setmetatable({
+    r = math.abs(self.r),
+    g = math.abs(self.g),
+    b = math.abs(self.b),
+  }, Color)
+end
+
+---Evaluates if your base color is a lesser lightness value,
+---then your supplied value.
+---@param self Color
+---@param value number lightness
+---@return boolean
+Color.less = function(self, value)
+  local y1 = 0.2126 * self.r + 0.7152 * self.g + 0.0722 * self.b
+  return y1 < value
+end
+
+---Evaluates if the base color is a higher lightness value,
+---then your supplied value.
+---@param self Color
+---@param value number lightness
+---@return boolean
+Color.more = function(self, value)
+  local y1 = 0.2126 * self.r + 0.7152 * self.g + 0.0722 * self.b
+  return y1 > value
+end
+
+---Sorts color from min to max in a dictionary.
+---@param self Color
+---@return string[]
+Color.sort = function(self)
+  local keys = {}
+  for k, _ in pairs(self) do
+    table.insert(keys, k)
+  end
+
+  table.sort(keys, function(a, b) return self[a] < self[b] end)
+
+  return keys
+end
+
+---Lerps between 2 colors.
+---@param self Color
+---@param color Color | string | number
+---@param amount number
+---@return Color
+Color.blend = function(self, color, amount)
+  self = (self + (color - self) * amount):round():clamp()
+  return self
+end
+
+---Darken color.
+---@param self Color
+---@param amount number
+---@return Color
+Color.darken = function(self, amount)
+  self = (self - amount):clamp()
+  return self
+end
+
+---Lighten color.
+---@param self Color
+---@param amount number
+---@return Color
+Color.lighten = function(self, amount)
+  self = (self + amount):clamp()
+  return self
+end
+
+---Alternate darken mode with a bias none linear and can look better.
+---@param self Color
+---@param amount number
+---@return Color
+Color.darken_2 = function(self, amount)
+  self = (self - { amount * 0.6, amount * 0.8, amount * 0.6 }):clamp()
+  return self
+end
+
+---Alternate lighten mode with a bias none linear and can look better.
+---@param self Color
+---@param amount number
+---@return Color
+Color.lighten_2 = function(self, amount)
+  self = (self + { amount, amount * 0.6, amount * 0.6 }):clamp()
+  return self
+end
+
+---Desaturates color bringing it to it's lightness grey value.
+---@param self Color
+---@param amount number
+---@return Color
+Color.desat = function(self, amount)
+  local y1 = 0.2126 * self.r + 0.7152 * self.g + 0.0722 * self.b
+  self = self:blend(y1, amount)
+  return self
+end
+
+--- TODO: This is a work in progress more artistic way of saturating
+--- this function is not ready and should not be used.
+
+---Do not use this is a WIP algorithm
+-- Color.sat_2 = function(self, amount)
+--   local min, mid, max = unpack(self:sort())
+--   if self[mid] == self[max] then
+--     self[min] = self[min] - amount
+--   elseif self[min] == self[mid] then
+--     self[min] = self[min] - amount
+--     self[mid] = self[mid] - amount
+--   elseif self[min] == self[mid] and self[min] == self[max] then
+--     self[min] = self[min] - amount
+--     self[mid] = self[mid] - amount
+--     self[max] = self[max] - amount
+--   else
+--     local offset = 1 + (self[mid] - self[min]) / 255
+--     local adjust = math.abs(self[min] - amount)
+--     -- self[min] = self[min] - (amount * offset)
+--     self[min] = self[min] - (amount * 2)
+--     if self[min] >= 0 then adjust = 0 end
+--     self[mid] = (self[mid] - amount) + adjust
+--   end
+--   return self:clamp()
+-- end
+
+---Saturates color while trying to preserve hue.
+---@param self Color
+---@param amount number
+---@return Color
+Color.sat = function(self, amount)
+  local min, mid, max = unpack(self:sort())
+  local sat = Color.new { self.r, self.g, self.b }
+
+  if self[mid] == self[max] then
+    sat[min] = sat[min] - sat[min]
+  elseif self[min] == self[mid] then
+    sat[min] = sat[min] - sat[min]
+    sat[mid] = sat[mid] - sat[mid]
+  elseif self[min] == self[mid] and self[min] == self[max] then
+    sat[min] = sat[min] - sat[min]
+    sat[mid] = sat[mid] - sat[mid]
+    sat[max] = sat[max] - sat[max]
+  else
+    local offset = (sat[mid] - sat[min]) / 255
+    sat[min] = sat[min] - sat[min]
+    sat[mid] = sat[mid] - (self[min] * offset)
+  end
+  return self:blend(sat, amount)
+end
+
+---Calculates the difference between 2 colors lightness values.
+---@param self Color
+---@param color Color
+---@return number
+Color.dif = function(self, color)
+  local y1 = 0.2126 * self.r + 0.7152 * self.g + 0.0722 * self.b
+  local y2 = 0.2126 * color.r + 0.7152 * color.g + 0.0722 * color.b
+  return math.abs(math.floor((y1 - y2) + 0.5))
+end
+
+Color.di = function(self, color) return Color.abs(color - self) end
+
+---Converts Color object to a hex string.
+---@param self Color
+---@return string
+Color.tohex = function(self)
+  local r = string.format("%02X", self.r)
+  local g = string.format("%02X", self.g)
+  local b = string.format("%02X", self.b)
+
+  return "#" .. r .. g .. b
+end
+
+---Debug function that prints an int array of RGB value with,
+---terminal color support.
+---@param self Color
+---@return string
+Color.debug = function(self)
+  local text = string.format("{ %.2f, %.2f, %.2f }", self.r, self.g, self.b)
+  local text_color = "0;0;0"
+  if self:less(127) then text_color = "255;255;255" end
+  print(string.format("\27[48;2;%d;%d;%dm\27[38;2;%sm%s\27[0m", self.r, self.g, self.b, text_color, text))
+end
+
+return Color