projects.mako.cc - selectricity/blob - lib/gruff-0.2.8/lib/gruff/bar_conversion.rb

   1 ##
   2 # Original Author: David Stokar
   3 #
   4 #       This class perfoms the y coordinats conversion for the bar class.
   5 #
   6 #       There are three cases:
   7 #
   8 #   1. Bars all go from zero in positive direction
   9 #               2. Bars all go from zero to negative direction
  10 #               3. Bars either go from zero to positive or from zero to negative
  11 #
  12 class Gruff::BarConversion
  13         attr_writer :mode
  14         attr_writer :zero
  15         attr_writer :graph_top
  16         attr_writer :graph_height
  17         attr_writer :minimum_value
  18         attr_writer :spread
  19
  20         def getLeftYRightYscaled( data_point, result )
  21                 case @mode
  22                 when 1 then # Case one
  23                         # minimum value >= 0 ( only positiv values )
  24       result[0] = @graph_top + @graph_height*(1 - data_point) + 1
  25                 result[1] = @graph_top + @graph_height - 1
  26                 when 2 then  # Case two
  27                         # only negativ values
  28                 result[0] = @graph_top + 1
  29                 result[1] = @graph_top + @graph_height*(1 - data_point) - 1
  30                 when 3 then # Case three
  31                         # positiv and negativ values
  32         val = data_point-@minimum_value/@spread
  33         if ( data_point >= @zero ) then
  34                 result[0] = @graph_top + @graph_height*(1 - (val-@zero)) + 1
  35                 result[1] = @graph_top + @graph_height*(1 - @zero) - 1
  36         else
  37                                 result[0] = @graph_top + @graph_height*(1 - (val-@zero)) + 1
  38                 result[1] = @graph_top + @graph_height*(1 - @zero) - 1
  39         end
  40                 else
  41                         result[0] = 0.0
  42                         result[1] = 0.0
  43                 end
  44         end
  45
  46 end