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# FFCUSTOMFORCE

Contains type-specific information for the CUSTOMFORCE effect.

```
struct FFCUSTOMFORCE
```

## Overview

A pointer to a single FFCUSTOMFORCE structure for an effect is passed in the **lpvTypeSpecificParams** member of the FFEFFECT structure.

The structure describes a custom or user-defined force.

## Topics

### Initializers

[`init()`](/documentation/ForceFeedback/FFCUSTOMFORCE/init())

[`init(cChannels:dwSamplePeriod:cSamples:rglForceData:)`](/documentation/ForceFeedback/FFCUSTOMFORCE/init(cChannels:dwSamplePeriod:cSamples:rglForceData:))

### Instance Properties

[`cChannels`](/documentation/ForceFeedback/FFCUSTOMFORCE/cChannels)

Number of channels (axes) affected by this force.

[`cSamples`](/documentation/ForceFeedback/FFCUSTOMFORCE/cSamples)

Total number of samples in the **rglForceData**. It must be an integral multiple of the **cChannels**.

[`dwSamplePeriod`](/documentation/ForceFeedback/FFCUSTOMFORCE/dwSamplePeriod)

Sample period, in microseconds.

[`rglForceData`](/documentation/ForceFeedback/FFCUSTOMFORCE/rglForceData)

Pointer to an array of force values representing the custom force. If multiple channels are provided, the values are interleaved. For example, if **cChannels** is 3, the first element of the array belongs to the first channel, the second to the second, and the third to the third.

## Relationships

### Conforms To

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

---

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