basaran · June 6, 2021 09:35 · Jun 6, 2021 · Jun 6, 2021
diff --git a/lama.lua b/lama.lua
@@ -0,0 +1,117 @@
+-- u/linuxFoolDumDum
+-- https://www.reddit.com/r/awesomewm/comments/nph6ew/i_made_a_module_to_automatically_lightendarken/
+
+local M = {}
+
+-- Rounds to whole number
+local function round(num)
+    return math.floor(num + 0.5)
+end
+-- Rounds to hundredths
+local function roundH(num)
+    return math.floor((num * 100) +0.5) / 100
+end
+
+-- Converts hexadecimal color to HSL
+-- Lightness (L) is changed based on amt
+-- Converts HSL back to hex
+-- amt (0-100) can be negative to darken or positive to lighten
+-- The amt specified is added to the color's existing Lightness
+-- e.g., (#000000, 25) L = 25 but (#404040, 25) L = 50
+
+function M.lighten(hex_color, amt)
+    local r, g, b, a
+    local hex = hex_color:gsub("#", "")
+    if #hex < 6 then
+        local t = {}
+        for i = 1, #hex do
+            local char = hex:sub(i, i)
+            t[i] = char..char
+        end
+        hex = table.concat(t)
+    end
+    r = tonumber(hex:sub(1,2), 16)/255
+    g = tonumber(hex:sub(3,4), 16)/255
+    b = tonumber(hex:sub(5,6), 16)/255
+    if #hex ~= 6 then
+        a = roundH(tonumber(hex:sub(7,8), 16)/255)
+    end
+
+    local max = math.max(r, g, b)
+    local min = math.min(r, g, b)
+    local c = max - min
+    -----------------------------
+    -- Hue
+    local h
+    if c == 0 then
+        h = 0
+    elseif max == r then
+        h = ((g - b) / c)%6
+    elseif max == g then
+        h = ((b - r) / c)+2
+    elseif max == b then
+        h = ((r - g) / c)+4
+    end
+    h = h*60
+    -----------------------------
+    -- Luminance
+    local l = (max + min) * 0.5
+    -----------------------------
+    -- Saturation
+    local s
+    if l <= 0.5 then
+        s = c / (l*2)
+    elseif l > 0.5 then
+        s = c / (2 - (l*2))
+    end
+    -----------------------------
+    local H, S, L, A
+    H = round(h)/360
+    S = round(s*100)/100
+    L = round(l*100)/100
+
+    amt = amt/100
+    if L + amt > 1 then
+        L = 1
+    elseif L + amt < 0 then
+        L = 0
+    else
+        L = L + amt
+    end
+
+    local R, G, B
+    if S == 0 then
+        R, G, B = round(L*255), round(L*255), round(L*255)
+    else
+        local function hue2rgb(p, q, t)
+            if t < 0 then t = t + 1 end
+            if t > 1 then t = t - 1 end
+            if t < 1/6 then
+                return p + (q - p) * (6 * t) end
+            if t < 1/2 then
+                return q end
+            if t < 2/3 then
+                return p + (q - p) * (2/3 - t) * 6 end
+            return p
+        end
+        local q
+        if L < 0.5 then
+            q = L * (1 + S)
+        else
+            q = L + S - (L*S)
+        end
+        local p = 2 * L - q
+        R = round(hue2rgb(p, q, (H + 1/3))*255)
+        G = round(hue2rgb(p, q, H)*255)
+        B = round(hue2rgb(p, q, (H - 1/3))*255)
+    end
+
+    if a ~= nil then
+        A = round(a*255)
+        return string.format("#"..'%.2x%.2x%.2x%.2x', R, G, B, A)
+    else
+        return string.format("#"..'%.2x%.2x%.2x', R, G, B)
+    end
+end
+
+return M