/* Removes empty slots between instruments */

address 'OCTAMED_REXX'
max_instr = 63
do scnt = 1 to max_instr
    if IsSlotUsed(scnt) then lastinstr = scnt
end
do scnt = 1 to lastinstr-1
    if (IsSlotUsed(scnt) = 0) then do
        cnt2 = scnt + 1
        swapped = 0
        do until (cnt2 > lastinstr) | (swapped = 1)
            if IsSlotUsed(cnt2) then do
                'in_swapinstruments 'scnt' 'cnt2
                'rn_changeinum 'scnt' 'cnt2' swap affect=1'
                swapped = 1
                if (cnt2 = lastinstr) then do
                    do while (IsSlotUsed(lastinstr) = 0) & (lastinstr > 1)
                        lastinstr = lastinstr - 1
                    end
                end
            end
            cnt2 = cnt2 + 1
        end
    end
end
'in_select ins 1'
exit

IsSlotUsed:
    arg slt
    'in_select ins 'slt
    'in_isslotused var slotused'
    'in_getmidichannel var midich'
    if (slotused > 0) | (midich > 0) then return 1
    return 0