Rockbox

from r27846


New skin tag: %if(<tag>, <operator>, <operand> [,option count]) which lets you do very simple logical comparissons on other tags.
<tag> is the tag to check against
<operator> is the comparisson to do, any one of... =, !=, >, >=, <, <= (when comparring against a string tag like %ia only = and != work, and it is done NOT case sensitive)
<operand> is either another tag, a number, or text.
[option count] is an optinal number to use for the few tags which scale to the amount of options when used as a conditional (i.e %?pv<a|b|c|d> would have 4 options)

example: %?if(%pv, >=, 0)<Warning.. volume clipping|coool...>
That says "If the value from %pv (volume) is greater than or equal to 0 then display the warning line, otherwise the cool line."
%?if(%ia, =, %Ia)<same artist> <= this artist and next artist are the same.

some tags might need a touch of tweaking to work better with this. experiment and have fun