applications/luci-app-statistics/luasrc/statistics/rrdtool/colors.lua

   1 -- Copyright 2008 Freifunk Leipzig / Jo-Philipp Wich <jow@openwrt.org>
   2 -- Licensed to the public under the Apache License 2.0.
   3
   4 module("luci.statistics.rrdtool.colors", package.seeall)
   5
   6 local util = require("luci.util")
   7
   8
   9 Instance = util.class()
  10
  11 function Instance.from_string( self, s )
  12         return {
  13                 tonumber(s:sub(1,2), 16),
  14                 tonumber(s:sub(3,4), 16),
  15                 tonumber(s:sub(5,6), 16)
  16         }
  17 end
  18
  19 function Instance.to_string( self, c )
  20         return string.format(
  21                 "%02x%02x%02x",
  22                 math.floor(c[1]),
  23                 math.floor(c[2]),
  24                 math.floor(c[3])
  25         )
  26 end
  27
  28 function Instance.random( self )
  29         local r   = math.random(255)
  30         local g   = math.random(255)
  31         local min = 0
  32         local max = 255
  33
  34         if ( r + g ) < 255 then
  35                 min = 255 - r - g
  36         else
  37                 max = 511 - r - g
  38         end
  39
  40         local b = min + math.floor( math.random() * ( max - min ) )
  41
  42         return { r, g, b }
  43 end
  44
  45 function Instance.faded( self, fg, opts )
  46         opts = opts or {}
  47         opts.background = opts.background or { 255, 255, 255 }
  48         opts.alpha      = opts.alpha      or 0.25
  49
  50         if type(opts.background) == "string" then
  51                 opts.background = _string_to_color(opts.background)
  52         end
  53
  54         local bg = opts.background
  55
  56         return {
  57                 ( opts.alpha * fg[1] ) + ( ( 1.0 - opts.alpha ) * bg[1] ),
  58                 ( opts.alpha * fg[2] ) + ( ( 1.0 - opts.alpha ) * bg[2] ),
  59                 ( opts.alpha * fg[3] ) + ( ( 1.0 - opts.alpha ) * bg[3] )
  60         }
  61 end