---
title: CGGammaValue
framework: coregraphics
role: symbol
role_heading: Type Alias
path: coregraphics/cggammavalue
---

# CGGammaValue

A value used to map a color generated in software to a color supported by the display hardware.

## Declaration

```swift
typealias CGGammaValue = Float
```

## Discussion

Discussion In macOS, the Display panel in System Preferences is used to set the default gamma for a display. Quartz also allows an application to provide its own custom gamma information, using functions such as CGSetDisplayTransferByTable(_:_:_:_:_:) and CGSetDisplayTransferByFormula(_:_:_:_:_:_:_:_:_:_:). These functions take CGGammaValue arguments that specify: A set of gamma table entries ranging from 0 to 1 The positive real coefficients in a gamma equation

## See Also

### Data Types

- [CGButtonCount](coregraphics/cgbuttoncount.md)
- [CGCharCode](coregraphics/cgcharcode.md)
- [CGDirectDisplayID](coregraphics/cgdirectdisplayid.md)
- [CGDisplayBlendFraction](coregraphics/cgdisplayblendfraction.md)
- [CGDisplayConfigRef](coregraphics/cgdisplayconfigref.md)
- [CGDisplayCount](coregraphics/cgdisplaycount.md)
- [CGDisplayErr](coregraphics/cgdisplayerr.md)
- [CGDisplayFadeInterval](coregraphics/cgdisplayfadeinterval.md)
- [CGDisplayFadeReservationToken](coregraphics/cgdisplayfadereservationtoken.md)
- [CGDisplayMode](coregraphics/cgdisplaymode.md)
- [CGDisplayReconfigurationCallBack](coregraphics/cgdisplayreconfigurationcallback.md)
- [CGDisplayReservationInterval](coregraphics/cgdisplayreservationinterval.md)
- [CGDisplayStream](coregraphics/cgdisplaystream.md)
- [CGDisplayStreamFrameAvailableHandler](coregraphics/cgdisplaystreamframeavailablehandler.md)
- [CGDisplayStreamUpdate](coregraphics/cgdisplaystreamupdate.md)