Tag: Controls

Here I’m listing some of the more commonly used Module plug names, the types of data they carry, and their usage along with useful notes.

BLOB: (Binary Large OBject) (Pink plug)

Not used very often in SynthEdit, except in passing large amounts of binary data in or between modules when using or creating samplers, or sample players.
In SynthEdit it has a built in limit of 5Mb.
A “BLOB” is a common acronym for “Binary Large Object”, which means it’s an object holding a large amount of binary data. Some languages has native blob types, but C++ doesn’t. Never the less, creating a blob is simple enough – you just create an array of bytes. In your example, this is done by creating an array of chars. This might be confusing, though, as an array of chars has a special meaning in C++ – it’s also a string.
For more information on BLOBS you really need to read in depth C++/DSP programming tutorials and documentation.

Boolean: (Bools) (Black plug)

A Boolean or Bool is a data type with two possible values:
true or false (0 or 1). It’s named after the English mathematician and logician George Boole, whose algebraic and logical systems are used in all modern digital computers.
In SynthEdit any value above 0 is considered as “True”.

Floating Point values: (Float) (Light blue plug)

A floating point number, is a positive or negative whole number with a decimal point. For example, 5.5, 0.25, and -103.342 are all floating point numbers, while 91, and 0 are not. Floating point numbers get their name from the way the decimal point can “float” to any position necessary within the number.
Note: Floating point math by it’s nature cannot be precise when handling very large numbers so you can’t always trust math modules when they are applied to floating point data.

Integer: (Int) (Orange Plug)

The Integer data type stores whole numbers that range from -2,147,483,647 to 2,147,483,647 for 9 or 10 digits of precision. Note:- The number 2,147,483,648 is a reserved value and cannot be used. The Integer value is stored as a signed binary integer and is typically used to store counts, quantities, and so on.

MIDI Data: (MIDI) (Yellow Plug)

MIDI is an acronym that stands for Musical Instrument Digital Interface. It’s a way to connect devices that make and control sound — such as synthesizers, samplers, and computers — so that they can communicate with each other, using MIDI messages.
These messages are not only the note that is played on a keyboard, it can be a wide range of data related to volume, positions of controls, how hard the key is pressed etc.
SynthEdit takes the MIDI input from your chosen device, and converts it into control signals (voltages) that it’s modules can understand to control those module’s actions.
With the new MIDI2 standard this has become more complex.

Text: (String) (Red Plug)

The Text data type stores any kind of text data including numbers (but these are always treated as text, not values). It can contain both single-byte and multibyte characters that the locale supports. The term simple large object refers to an instance of a Text or Byte data type.

Voltage: (Volts) (Blue Plug)

Used to carry Audio, or Control voltage signals. Voltage is essentially floating point data. It is used to send Audio from one DSP module to another, or to send control voltages from one DSP module to another to control the recipients behaviour. DSP Floating Point and Volts pins will inter-connect, but you really should use a Float to Volts converter. You can then set the rate at which the conversion takes place and ensure that the control operates smoothly, and predictably. Leaving out the Float to Volts module can result in the possibility of the control being somewhat “glitchy” and unpredictable.

Control and Audio voltage plugs.

Voltage (audio):
Audio voltage plugs transmit blocks of samples to be processed at sample rate by other input audio plugs. This means that they are operating at the sample rate set in the preferences.
Voltage (Control):
Plugs used for control signals like Volts (non-audio), float, int, string, bool and BLOB work differently, they are event based meaning that processing of a single value at time happens only when a new value is created, for example a control is moved/operated.
The Audio module code is managed differently: it’s done by using a sub process which processes the sample blocks or by an “event handler” respectively.
Accuracy:
Both kinds of data however are transmitted and processed on a sample rate accurate clock. Nothing technically prevents a module from sending an update to a control plug (e.g. float) 48 000 times a second but that would be very inefficient in terms of CPU because the handler used for the receiving modules will be processed continuously at 48 000 times a second to process occasional single control update values.
Control plugs are not meant to transport audio data:
Jeff programmed a suitable converter module which “down samples” an audio stream to send the sample values to a float pin at a much slower rate of 60Hz or even less. Control pins are only suitable for slowly changing parameters or automations, and must never be used for audio streams.

An Example showing an Audio and control plugs:
The Oscillator:- The Audio Out plug carries a very rapidly changing audio voltage (up to the current audio stream rate), so this would naturally be an Audio voltage.
All of the left hand voltage plugs however are considered as control voltages and are not updated as frequently as the Audio output.
The ADSR2:- All of these plugs, both left and right hand side are considered as Control Voltages, and not updated as frequently. Also even though the Attack/Decay/Release sections may change quite rapidly, even the signal out plug carrying the ADSR envelope voltage is not handled as audio.

Note: Voltage plugs are always DSP Plugs, whereas Float Plugs can be DSP or GUI. You cannot connect GUI plugs to DSP plugs without a suitable converter such as a Patch Memory module.
You should never convert a DSP audio voltage to a GUI signal to process using GUI modules…it will be very inefficient and glitchy! Converting Control signals is fine as long as you use the correct modules for the job.

Patch cables.

These are our links between the plugs on the modules, much like hardware patch leads. The colours of the leads match the types of data they carry. Synthedit will not allow you to connect incompatible data plugs and sockets- you will just get an error message:

Or if you try and connect a DSP plug to a GUI plug even if it’s the same data-type you’ll get this error message:

More about patch cables.
When you click on a cable it’s highlighted in yellow. As you can see below there are also different styles of line; some have nodes added (the white dots) which can be added by clicking on the line once it’s selected. These allow us to “bend” the cables. By right clicking on a selected patch cable we get the menu shown, with the options; Straighten line (remove all bends), Delete Line, Curvey (I know it’s miss spelled-but I’m using the spelling from Synthedit to save confusion), and Straight. Curvey give us a line in the style of the one highlighted, and straight – the one with sharp corners. To move a node just select the cable then click on a node and drag it to the new position.

Spare Plugs.
Where you see a plug like the one below with the title “Spare Output” this is a self replicating plug which means that as soon as you connect it, another appears below it titled “Spare Output“. These plugs when connected take their title from that of the plug they are connected to.

The correct way to convert a GUI Floating Point control value to a DSP Voltage control value.

You should always use a Patch Memory module to convert from GUI to DSP and vice versa. Likewise Floating Point must always be converted to Volts using a Float to Volts module to ensure the controls work smoothly with no data loss.

Some ways in which data plugs are used:

Hint:- (Text) This text displays as a popup yellow tooltip when the mouse hovers over a control on the VST’s panel.
Both of the items below (Menu Item and Choice) form the replacement for the older “Drop Down List” and form a selection menu based on an “Enumerated List“
Menu Items:- (Text) Comma separated text list. Provides a right-click popup context menu for the image. Commonly used for adding a MIDI-Learn menu.
Choice or Menu Selection:- (Integer) Selects items from the list based on their numeric position in the text also Commonly used for adding a MIDI-Learn menu.
(NOTE: An enumerated list starts always at 0, not at 1). This also provides a right-click popup context menu for a control or image. Commonly used for adding a MIDI-Learn menu.

Animation Position: (Floating Point) Returns the position of a knob or slider control. The value of this is (normalized) to between 0 and 1, so for controlling DSP modules needs to be scaled up to the usual 0 to 10 Volts range Patch Memory (Float) modules do this scaling automatically.
This Animation Position data is normally Bi-Directional.

Mouse Down: (Boolean) Sends a “True” value when a control or image receives a left click from a mouse.

Properties.
Some settings or controls may not always be available as Plugs, they may only be available in the Module’s Properties panel:
Writeable:- (Boolean) Makes read-only or writeable.
Greyed:- (Boolean) Displays text in a disabled, grey style.
Background Colour: (Text)
Foreground Colour: (Text)
Ignore Program Change: (Boolean)
Mouse Down:- (Boolean) Provides a Boolean “True” signal whenever the mouse is left clicked on the image.
Read Only:- You can only read data from a module when this is set to True, it will not accept any inputs.
Greyed:-

NOTE: Fixed value modules only have outputs, and their values are set in the properties panel so they cannot be altered in any way from the VST’s control panel, however you can allow the VST plug-in’s user to select from a bank of fixed values via a drop down list, or similar selector.