dev: added colors util

lua/catppuccino/utils/colors.lua

@@ -0,0 +1,30 @@
+local M = {}
+
+local function color_is_bright(r, g, b)
+    -- Counting the perceptive luminance - human eye favors green color
+    local luminance = (0.299 * r + 0.587 * g + 0.114 * b) / 255
+    if luminance > 0.5 then
+        return true -- Bright colors, black font
+    else
+        return false -- Dark colors, white font
+    end
+end
+
+function M.hex2rgb(hex)
+    return tonumber("0x"..hex:sub(1,2)), tonumber("0x"..hex:sub(3,4)), tonumber("0x"..hex:sub(5,6))
+end
+
+function M.assert_brightness(color)
+    local hex = color:gsub("#", "")
+    local r = M.hex2rgb(string.sub(hex, 1, 2))
+    local g = M.hex2rgb(string.sub(hex, 3, 4))
+    local b = M.hex2rgb(string.sub(hex, 5, 6))
+
+    if (color_is_bright(tonumber(r), tonumber(g), tonumber(b)) == true) then
+		return true -- bright
+    end
+
+	return false -- dull
+end
+
+return M