# Shader A reference to a function in a Metal shader library, along with its bound uniform argument values. ``` struct Shader ``` ## Overview Shader values can be used as filter effects on views, see the [`colorEffect(_:isEnabled:)`](/documentation/SwiftUI/View/colorEffect(_:isEnabled:)), [`distortionEffect(_:maxSampleOffset:isEnabled:)`](/documentation/SwiftUI/View/distortionEffect(_:maxSampleOffset:isEnabled:)), and [`layerEffect(_:maxSampleOffset:isEnabled:)`](/documentation/SwiftUI/View/layerEffect(_:maxSampleOffset:isEnabled:)) functions. Shaders also conform to the [`ShapeStyle`](/documentation/SwiftUI/ShapeStyle) protocol, letting their MSL shader function provide per-pixel color to fill any shape or text view. For a shader function to act as a fill pattern it must have a function signature matching: ``` [[ stitchable ]] half4 name(float2 position, args...) ``` where `position` is the user-space coordinates of the pixel applied to the shader, and `args...` should be compatible with the uniform arguments bound to `shader`. The function should return the premultiplied color value in the color space of the destination (typically extended sRGB). ## Topics ### Creating a shader [`init(function:arguments:)`](/documentation/SwiftUI/Shader/init(function:arguments:)) Creates a new shader from a function and the uniform argument values to bind to the function. [`Argument`](/documentation/SwiftUI/Shader/Argument) A single uniform argument value to a shader function. ### Getting the shader function [`function`](/documentation/SwiftUI/Shader/function) The shader function called by the shader. [`arguments`](/documentation/SwiftUI/Shader/arguments) The uniform argument values passed to the shader function. ### Configuring the shader [`dithersColor`](/documentation/SwiftUI/Shader/dithersColor) For shader functions that return color values, whether the returned color has dither noise added to it, or is simply rounded to the output bit-depth. For shaders generating smooth gradients, dithering is usually necessary to prevent visible banding in the result. ## Relationships ### Conforms To [`Equatable`](/documentation/Swift/Equatable) [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`ShapeStyle`](/documentation/SwiftUI/ShapeStyle) [`Escapable`](/documentation/Swift/Escapable) [`Copyable`](/documentation/Swift/Copyable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)