Initialise MemoryBlock

[dnaldoog]

Here is a method added to the class MemoryBlock() for initialising a MemoryBlock (usually with zeroes).
The overloaded JUCE function m=MemoryBlock(20) is not implemented or bound to lua (at least in version 5.3.201), so normally one would write something like m=MemoryBlock("00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00") which is a bit cumbersome or use createFromTable

local t={}
for i=1,20 do
t[i]=0
end
m:createFromTable(t)

but this following way is maybe a bit more convenient;

Edit: 03/15/2023

Updated code to support newer versions of Ctrlr.

    function MemoryBlock:initialise(size) -- initialise a Memory Block with data if necessary
        --[[ 
    Versions 5.3.* do not support initialisation of MemoryBlock() with JUCE constructor:
    MemoryBlock (const size_t initialSize, bool initialiseToZero=false)
	This function just offers compatibility between 5.3* and later versions
	    ]]
        local major, minor = utils.getVersionMajor(), utils.getVersionMinor()
        major = tonumber(major)
        minor = tonumber(minor)
        if major > 4 and minor > 3 then
            local tmp = MemoryBlock(size, true) -- use luabind JUCE constructor
            self:loadFromHexString(tmp:toHexString(1))
        else
            local t = {}
            for i = 1, size do
                t[i] = 0
            end
            if self:getSize() > 0 then
                self:removeSection(0, self:getSize())
            end
            self:createFromTable(t)
        end -- looking for 5.3.201/5.3.198
    end

[dobo365]

Great explanation John!
Yes indeed, I also figured out long time ago that the initialization of a MemoryBlock based on size was not implemented in 5.3.201.

What I'm doing is thus similar to your approach...

• in a Tables_Init method called at panel load, I pre-define some tables that I create the MB from
• in other methods, if necessary, I use the append() function to extend my initial MB

Code 1
mbWave128 = MemoryBlock () mbWave128:createFromTable({ -- 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00})

Code 2
mbTemp = MemoryBlock() for i=1,64 do mbTemp:append(mbWave128) end

Sorry... line returns seems lost...

[dnaldoog]

Thanks Goodweather,

Yes your way works perfectly.

With this code, to me what is convenient is that the method initialize extends the MemoryBlock() class. Kind of makes it more readable when coming back to it in 6 months' time etc! 😃

Incidentally, you can create line returns using the html tags <pre> … </pre>

[spiffo-smith]

dnaldoog, that post was extremely timely, thank you ever so much for that!

I had a MemoryBlock that was normally initialised from a MidiMessage but I needed to initialise it 'on Panel Load' but after lots of reference to the JUCE libraries and trying just about every combination I could think of I just couldn't get anything to work!

Your post has cleared all that up and now everything's working great :-)

[dnaldoog]

Great to hear Spiffo!

I was hoping it might be useful for someone!