
Create a colored chart to display relative values:

my_chart=fltk:Fl_Chart(x-position,y-position,width,height,label)
my_chart:add(item_number,item_label,color) -- add a value

The visual size of each item will always be relative to the
total number of items and to the dimensions of the chart.
For example, a pie chart will always figure that the degrees
of the arcs of all items will add up to 360. When an item is
added, the scale of all others will decrease.
