# ‹curve›

One curve header is used to define each curve.
The values for various points along the curve can then be set, from `v000`

to `v127`

.
The default is `v000=0`

and `v127=1`

. Any points along the curve not defined explicitly
will be interpolated linearly between points which are defined.

There are default built-in curves in ARIA. If no curve is specified for a modulation, curve 0 is used. The built-in ARIA curves are:

Default curve (number 0). linear, from 0 to 1 1. bipolar, from -1 to 1 (useful for things such as tuning and panning, used by CC10 panning by default) 2. linear inverted, from 1 to 0 3. bipolar inverted, from 1 to -1 4. concave (used for CC7 volume tracking and amp_veltrack) 5. Xfin power curve 6. Xfout power curve

These can be overwritten, but as they are used by the engine for their normal
functions, it's safer to use `curve_index`

numbers of 7 and above for custom curves.
Curve_index in ARIA can be any integer from 0 to 255.

## Examples

```
<curve>curve_index=17
v000=0
v095=1
v127=1
<curve>curve_index=18
v000=0
v095=0.5
v127=1
```

Here's a scenario using one MIDI CC to control the amplitude of two samples along two different curves.

```
<region>
amplitude_oncc110=100
amplitude_curvecc110=9
sample=bigger.wav
<region>
amplitude_oncc110=100
amplitude_curvecc110=10
sample=smaller.wav
//The curves for the room ambiences - bigger room first
<curve>curve_index=9
v000=0
v063=0
v127=1
<curve>curve_index=10
v000=0
v063=1
v127=0.1
```

And how to use the default curve 1 to create a tuning control which goes down and up, with the pitch unmodulated when the control is in the middle.

```
pitch_oncc27=100
pitch_curvecc27=1
```