Color.lua

---@module 'common.Class'

---Color object class.
---@class Color : Class
---@operator add(Color): Color
---@operator sub(Color): Color
---@operator mul(Color): Color
---@field r number @Red value in RGB color model. (int: 0:255)
---@field g number @Green value in RGB color model. (int: 0:255)
---@field b number @Blue value in RGB color model. (int: 0:255)
---@field src number @Source alpha. (int: 0:255)
---@field dst number @Destination alpha. (int: 0:255)
Color = Class:new('Color')
do
	--;===========================================================
	--; PROPERTIES
	--;===========================================================
	
	Color.r = 255
	Color.g = 255
	Color.b = 255
	Color.src = 255
	Color.dst = 255

	--;===========================================================
	--; CONSTRUCTORS
	--;===========================================================
	
	---Constructor for creating new object instance.
	---@param t table<string, number> @Table storing data for object creation.
	---@return Color @New object instance.
	function Color:new(t)
		t = t or {}

		setmetatable(t, self)

		return t
	end

	--;===========================================================
	--; METHODS
	--;===========================================================
	
	---Add operator overloading. Adds RGB. (color + color)
	---@param colorA Color @First arg.
	---@param colorB Color @Second arg.
	---@return Color @New object instance.
	function Color.__add(colorA, colorB)
		local r = math.max(0, math.min(colorA.r + colorB.r, 255))
		local g = math.max(0, math.min(colorA.g + colorB.g, 255))
		local b = math.max(0, math.min(colorA.b + colorB.b, 255))
		return Color:new({r = r, g = g, b = b, src = colorA.src, dst = colorA.dst})
	end

	---Sub operator overloading. Subtracts RGB. (color - color)
	---@param colorA Color @First arg.
	---@param colorB Color @Second arg.
	---@return Color @New object instance.
	function Color.__sub(colorA, colorB)
		local r = math.max(0, math.min(colorA.r - colorB.r, 255))
		local g = math.max(0, math.min(colorA.g - colorB.g, 255))
		local b = math.max(0, math.min(colorA.b - colorB.b, 255))
		return Color:new({r = r, g = g, b = b, src = colorA.src, dst = colorA.dst})
	end

	---Mul operator overloading. Multiplies RGB. (color * color)
	---@param colorA Color @First arg.
	---@param colorB Color @Second arg.
	---@return Color @New object instance.
	function Color.__mul(colorA, colorB)
		local r = (colorA.r / 255) * (colorB.r / 255) * 255
		local g = (colorA.g / 255) * (colorB.g / 255) * 255
		local b = (colorA.b / 255) * (colorB.b / 255) * 255
		return Color:new({r = r, g = g, b = b, src = colorA.src, dst = colorA.dst})
	end

	---Eq operator overloading. Compares r, g, b, src, and dst (color == color)
	---@param colorA Color @First arg.
	---@param colorB Color @Second arg.
	---@return boolean @True if objects are the same.
	function Color.__eq(colorA, colorB)
		if colorA.r == colorB.r and colorA.g == colorB.g and colorA.b == colorB.b and colorA.src == colorB.src and colorA.dst == colorB.dst then
			return true
		else
			return false
		end
	end

	---Creates a new object instance from *hex* value.
	---@param hex string @Color values as hex string.
	---@return Color @New object instance.
	function Color:fromHex(hex)
		hex = tostring(hex)
		if hex:sub(0, 1) == "#" then hex = hex:sub(2, -1) end
		if hex:sub(0, 2) == "0x" then hex = hex:sub(3, -1) end
		local r = tonumber(hex:sub(1, 2), 16)
		local g = tonumber(hex:sub(3, 4), 16)
		local b = tonumber(hex:sub(5, 6), 16)
		local src = tonumber(hex:sub(7, 8), 16) or 255
		local dst = tonumber(hex:sub(9, 10), 16) or 0
		return Color:new({r = r, g = g, b = b, src = src, dst = dst})
	end

	---Creates string of *Color* converted to hex.
	---@return string @Color values as hex string.
	function Color:toHex()
		local r = string.format("%x", self.r)
		local g = string.format("%x", self.g)
		local b = string.format("%x", self.b)
		local src = string.format("%x", self.src)
		local dst = string.format("%x", self.dst)
		local hex = tostring((r:len() < 2 and "0") .. r .. (g:len() < 2 and "0") .. g .. (b:len() < 2 and "0") .. b .. (src:len() < 2 and "0") .. src .. (dst:len() < 2 and "0") .. dst)
		return hex
	end

	---Returns RGB and alpha values stored in Color object.
	---@return number, number, number, number, number @Red, Green, Blue values in RGB color model, source and destination alpha.
	function Color:unpack()
		return tonumber(self.r) or 255, tonumber(self.g) or 255, tonumber(self.b) or 255, tonumber(self.src) or 255, tonumber(self.dst) or 255
	end
end

return Color