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

   1 --[[
   2
   3 Luci statistics - diagram color helper class
   4 (c) 2008 Freifunk Leipzig / Jo-Philipp Wich <xm@leipzig.freifunk.net>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13
  14 ]]--
  15
  16 module("luci.statistics.rrdtool.colors", package.seeall)
  17
  18 require("luci.util")
  19 require("luci.bits")
  20
  21
  22 Instance = luci.util.class()
  23
  24 function Instance.from_string( self, s )
  25         return {
  26                 luci.bits.Hex2Dec(s:sub(1,2)),
  27                 luci.bits.Hex2Dec(s:sub(3,4)),
  28                 luci.bits.Hex2Dec(s:sub(5,6))
  29         }
  30 end
  31
  32 function Instance.to_string( self, c )
  33         return string.format(
  34                 "%02x%02x%02x",
  35                 math.floor(c[1]),
  36                 math.floor(c[2]),
  37                 math.floor(c[3])
  38         )
  39 end
  40
  41 function Instance.random( self )
  42         local r   = math.random(255)
  43         local g   = math.random(255)
  44         local min = 0
  45         local max = 255
  46
  47         if ( r + g ) < 255 then
  48                 min = 255 - r - g
  49         else
  50                 max = 511 - r - g
  51         end
  52
  53         local b = min + math.floor( math.random() * ( max - min ) )
  54
  55         return { r, g, b }
  56 end
  57
  58 function Instance.faded( self, fg, opts )
  59         opts = opts or {}
  60         opts.background = opts.background or { 255, 255, 255 }
  61         opts.alpha      = opts.alpha      or 0.25
  62
  63         if type(opts.background) == "string" then
  64                 opts.background = _string_to_color(opts.background)
  65         end
  66
  67         local bg = opts.background
  68
  69         return {
  70                 ( opts.alpha * fg[1] ) + ( ( 1.0 - opts.alpha ) * bg[1] ),
  71                 ( opts.alpha * fg[2] ) + ( ( 1.0 - opts.alpha ) * bg[2] ),
  72                 ( opts.alpha * fg[3] ) + ( ( 1.0 - opts.alpha ) * bg[3] )
  73         }
  74 end