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
  20
  21 Instance = luci.util.class()
  22
  23 function Instance.from_string( self, s )
  24         return {
  25                 tonumber(s:sub(1,2), 16),
  26                 tonumber(s:sub(3,4), 16),
  27                 tonumber(s:sub(5,6), 16)
  28         }
  29 end
  30
  31 function Instance.to_string( self, c )
  32         return string.format(
  33                 "%02x%02x%02x",
  34                 math.floor(c[1]),
  35                 math.floor(c[2]),
  36                 math.floor(c[3])
  37         )
  38 end
  39
  40 function Instance.random( self )
  41         local r   = math.random(255)
  42         local g   = math.random(255)
  43         local min = 0
  44         local max = 255
  45
  46         if ( r + g ) < 255 then
  47                 min = 255 - r - g
  48         else
  49                 max = 511 - r - g
  50         end
  51
  52         local b = min + math.floor( math.random() * ( max - min ) )
  53
  54         return { r, g, b }
  55 end
  56
  57 function Instance.faded( self, fg, opts )
  58         opts = opts or {}
  59         opts.background = opts.background or { 255, 255, 255 }
  60         opts.alpha      = opts.alpha      or 0.25
  61
  62         if type(opts.background) == "string" then
  63                 opts.background = _string_to_color(opts.background)
  64         end
  65
  66         local bg = opts.background
  67
  68         return {
  69                 ( opts.alpha * fg[1] ) + ( ( 1.0 - opts.alpha ) * bg[1] ),
  70                 ( opts.alpha * fg[2] ) + ( ( 1.0 - opts.alpha ) * bg[2] ),
  71                 ( opts.alpha * fg[3] ) + ( ( 1.0 - opts.alpha ) * bg[3] )
  72         }
  73 end