300 lines
7.2 KiB
Lua
300 lines
7.2 KiB
Lua
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--[[
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* Converts an HSL color value to RGB. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
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* Assumes h, s, and l are contained in the set [0, 1] and
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* returns r, g, and b in the set [0, 1].
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]]
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local function hslToRgb(h, s, l)
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local r, g, b
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if s == 0 then
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r, g, b = l, l, l -- achromatic
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else
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function hue2rgb(p, q, t)
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if t < 0 then t = t + 1 end
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if t > 1 then t = t - 1 end
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if t < 1/6 then return p + (q - p) * 6 * t end
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if t < 1/2 then return q end
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if t < 2/3 then return p + (q - p) * (2/3 - t) * 6 end
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return p
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end
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local q
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if l < 0.5 then q = l * (1 + s) else q = l + s - l * s end
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local p = 2 * l - q
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r = hue2rgb(p, q, h + 1/3)
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g = hue2rgb(p, q, h)
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b = hue2rgb(p, q, h - 1/3)
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end
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return r, g, b
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end
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--[[
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* Converts an HSL color value to RGB. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
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* Assumes h, s, and l are contained in the set [0, 1] and
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* returns r, g, and b in the set [0, 1].
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]]
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local function rgbToHsl(r, g, b)
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local max, min = math.max(r, g, b), math.min(r, g, b)
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local h, s, l
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l = (max + min) / 2
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if max == 0 then s = 0 else s = (max - min) / max end
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if max == min then
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h, s = 0, 0 -- achromatic
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else
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local d = max - min
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local s
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if l > 0.5 then s = d / (2 - max - min) else s = d / (max + min) end
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if max == r then
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h = (g - b) / d
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if g < b then h = h + 6 end
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elseif max == g then h = (b - r) / d + 2
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elseif max == b then h = (r - g) / d + 4
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end
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h = h / 6
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end
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return h, s, l
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end
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--[[
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* Converts an RGB color value to HSV. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
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* Assumes r, g, and b are contained in the set [0, 1] and
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* returns h, s, and v in the set [0, 1].
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]]
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local function rgbToHsv(r, g, b)
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local max, min = math.max(r, g, b), math.min(r, g, b)
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local h, s, v
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v = max
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local d = max - min
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if max == 0 then s = 0 else s = d / max end
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if max == min then
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h = 0 -- achromatic
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else
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if max == r then
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h = (g - b) / d
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if g < b then h = h + 6 end
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elseif max == g then h = (b - r) / d + 2
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elseif max == b then h = (r - g) / d + 4
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end
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h = h / 6
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end
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return h, s, v
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end
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--[[
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* Converts an HSV color value to RGB. Conversion formula
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* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
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* Assumes h, s, and v are contained in the set [0, 1] and
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* returns r, g, and b in the set [0, 1].
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]]
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local function hsvToRgb(h, s, v)
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local r, g, b
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local i = math.floor(h * 6);
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local f = h * 6 - i;
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local p = v * (1 - s);
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local q = v * (1 - f * s);
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local t = v * (1 - (1 - f) * s);
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i = i % 6
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if i == 0 then r, g, b = v, t, p
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elseif i == 1 then r, g, b = q, v, p
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elseif i == 2 then r, g, b = p, v, t
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elseif i == 3 then r, g, b = p, q, v
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elseif i == 4 then r, g, b = t, p, v
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elseif i == 5 then r, g, b = v, p, q
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end
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return r, g, b
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end
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---@class color
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---@field r number @red, 0.0 - 1.0
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---@field g number @green, 0.0 - 1.0
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---@field b number @blue, 0.0 - 1.0
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---@field a number @alpha, 0.0 - 1.0
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---@operator add(color): color
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---@operator add(number): color
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---@operator sub(color): color
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---@operator sub(number): color
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---@operator mul(color): color
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---@operator mul(number): color
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---@operator div(color): color
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---@operator div(number): color
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local col = {}
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--- for use in actor:diffuse(col:unpack())
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---@return number, number, number, number
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function col:unpack()
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return self.r, self.g, self.b, self.a
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end
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-- conversions
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---@return number, number, number
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function col:rgb()
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return self.r, self.g, self.b
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end
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---@return number, number, number
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function col:hsl()
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return rgbToHsl(self.r, self.g, self.b)
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end
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---@return number, number, number
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function col:hsv()
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return rgbToHsv(self.r, self.g, self.b)
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end
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---@return string
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function col:hex()
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return string.format('%02x%02x%02x',
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math.floor(self.r * 255),
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math.floor(self.g * 255),
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math.floor(self.b * 255))
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end
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-- setters
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---@return color
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function col:hue(h)
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local _, s, v = self:hsv()
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return hsv(h % 1, s, v, self.a)
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end
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---@return color
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function col:huesmooth(h)
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local _, s, v = self:hsv()
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return shsv(h % 1, s, v, self.a)
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end
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---@return color
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function col:alpha(a)
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return rgb(self.r, self.g, self.b, a)
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end
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--- multiplies current alpha by provided value
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---@return color
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function col:malpha(a)
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return rgb(self.r, self.g, self.b, self.a * a)
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end
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-- effects
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---@return color
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function col:invert()
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return rgb(1 - self.r, 1 - self.g, 1 - self.b, self.a)
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end
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---@return color
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function col:grayscale()
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return rgb(self.r * 0.299 + self.g * 0.587 + self.b * 0.114, self.a)
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end
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---@return color
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function col:hueshift(a)
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local h, s, v = self:hsv()
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return hsv((h + a) % 1, s, v, self.a)
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end
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local colmeta = {}
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function colmeta:__index(i)
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if i == 1 then return self.r end
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if i == 2 then return self.g end
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if i == 3 then return self.b end
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if i == 4 then return self.a end
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return col[i]
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end
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local function typ(a)
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return (type(a) == 'table' and a.r and a.g and a.b and a.a) and 'color' or type(a)
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end
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local function genericop(a, b, f, name)
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local typea = typ(a)
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local typeb = typ(b)
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if typea == 'number' then
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return rgb(f(b.r, a), f(b.g, a), f(b.b, a), b.a)
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elseif typeb == 'number' then
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return rgb(f(a.r, b), f(a.g, b), f(a.b, b), a.a)
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elseif typea == 'color' and typeb == 'color' then
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return rgb(f(a.r, b.r), f(a.g, b.g), f(a.b, b.b), f(a.a, b.a))
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end
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error('cant apply ' .. name .. ' to ' .. typea .. ' and ' .. typeb, 3)
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end
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function colmeta.__add(a, b)
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return genericop(a, b, function(a, b) return a + b end, 'add')
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end
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function colmeta.__sub(a, b)
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return genericop(a, b, function(a, b) return a - b end, 'sub')
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end
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function colmeta.__mul(a, b)
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return genericop(a, b, function(a, b) return a * b end, 'mul')
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end
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function colmeta.__div(a, b)
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return genericop(a, b, function(a, b) return a / b end, 'div')
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end
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function colmeta.__eq(a, b)
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return (typ(a) == 'color' and typ(b) == 'color') and (a.r == b.r and a.g == b.g and a.b == b.b and a.a == b.a)
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end
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function colmeta:__tostring()
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return '#' .. self:hex()
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end
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colmeta.__name = 'color'
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-- constructors
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---@return color
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function rgb(r, g, b, a)
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a = a or 1
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return setmetatable({r = r, g = g, b = b, a = a or 1}, colmeta)
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end
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---@return color
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function hsl(h, s, l, a)
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a = a or 1
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local r, g, b = hslToRgb(h % 1, s, l)
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return setmetatable({r = r, g = g, b = b, a = a or 1}, colmeta)
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end
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---@return color
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function hsv(h, s, v, a)
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a = a or 1
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local r, g, b = hsvToRgb(h % 1, s, v)
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return setmetatable({r = r, g = g, b = b, a = a or 1}, colmeta)
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end
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--- smoother hsv. not correct but looks nicer
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---@return color
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function shsv(h, s, v, a)
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h = h % 1
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return hsv(h * h * (3 - 2 * h), s, v, a)
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end
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---@param hex string
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---@return color
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function hex(hex)
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hex = string.gsub(hex, '#', '')
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if string.len(hex) == 3 then
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return rgb((tonumber('0x' .. string.sub(hex, 1, 1)) * 17) / 255, (tonumber('0x' .. string.sub(hex, 2, 2)) * 17) / 255, (tonumber('0x' .. string.sub(hex, 3, 3)) * 17) / 255)
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else
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return rgb(tonumber('0x' .. string.sub(hex, 1, 2)) / 255, tonumber('0x' .. string.sub(hex, 3, 4)) / 255, tonumber('0x' .. string.sub(hex, 5, 6)) / 255)
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end
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end |