---
title: "init(radialSpace:start:startRadius:end:endRadius:function:extendStart:extendEnd:)"
framework: coregraphics
role: symbol
role_heading: Initializer
path: "coregraphics/cgshading/init(radialspace:start:startradius:end:endradius:function:extendstart:extendend:)"
---

# init(radialSpace:start:startRadius:end:endRadius:function:extendStart:extendEnd:)

Creates a shading object to use for radial shading.

## Declaration

```swift
init?(radialSpace space: CGColorSpace, start: CGPoint, startRadius: CGFloat, end: CGPoint, endRadius: CGFloat, function: CGFunction, extendStart: Bool, extendEnd: Bool)
```

## Parameters

- `space`: The color space in which color values are expressed. Core Graphics retains this object; upon return, you may safely release it.
- `start`: The center of the starting circle, in the shading’s target coordinate space.
- `startRadius`: The radius of the starting circle, in the shading’s target coordinate space.
- `end`: The center of the ending circle, in the shading’s target coordinate space.
- `endRadius`: The radius of the ending circle, in the shading’s target coordinate space.
- `function`: A CGFunction object created by the function doc://com.apple.coregraphics/documentation/CoreGraphics/CGFunction/init(info:domainDimension:domain:rangeDimension:range:callbacks:). This object refers to your function for creating a radial shading. Core Graphics retains this object; upon return, you may safely release it.
- `extendStart`: A Boolean value that specifies whether to extend the shading beyond the starting circle.
- `extendEnd`: A Boolean value that specifies whether to extend the shading beyond the ending circle.

## Return Value

Return Value A new Core Graphics radial shading. In Objective-C, you’re responsible for releasing this object using CGShadingRelease.

## Discussion

Discussion A radial shading is a color blend that varies between two circles. To draw the shading, call the function drawShading(_:).

## See Also

### Creating Shading Objects

- [init(axialSpace:start:end:function:extendStart:extendEnd:)](coregraphics/cgshading/init(axialspace:start:end:function:extendstart:extendend:).md)