Tracking Formulas
I’ve long been a fan of Renoise for the amount of control you have over every aspect of your sound. The meta devices are a key tool to utilize that control. Using these you can create, mix and route control signals within your effects chain. In many respects they are analogous to control voltage signals within a modular synth. Today while looking through the meta devices I started to experiment with one I had overlooked.
The formula device allows you to enter code in order to create control signals. When you first load the device you will see three sliders labeled A, B and C. These are the input parameters to your formula and can be used for any purpose you require. Each will output a decimal value between 0.00 and 1.00. I have relabeled the parameters as Amount, Speed and Offset for this example.
Next you will want to look at the textbox labeled “Y=“. This is where you will calculate what the output value of this device will be. In the example above I have entered “A * SteppedLFO(B) + C”. A and C are simply used to scale and offset the output of my SteppedLFO function.
The box above this is where you will enter any functions to be called from your formula. This is where I entered the definition of my SteppedLFO function that we called previously.
function SteppedLFO(s) local steps = ceil(s * 32) local stepSize = (1 / (steps - 1)) return stepSize * (LINES % steps) end
The function takes one input parameter (”s” in this example). In order to turn this value into a number between 0 and 32 I multiply then round this value. This is stored as the number of steps within the LFO. Next I figure out the value to increment the output on each step. Finally, I return the step size multiplied by the step we are on. I used the predefined variable LINES to figure out the current line within the pattern. To find out other predefined variables hit the Help button on the device GUI.
The final portion of the device is the destination box. This allows you to pick a channel, a device and a parameter to receive your formula output.
Don’t forget to save your formula into the user library so you can reuse it. The example above is very basic but look through some of the factory provided patches to get an idea of the full power of the device.