# Shader.Argument A single uniform argument value to a shader function. ``` struct Argument ``` ## Topics ### Creating argument values [`boundingRect`](/documentation/SwiftUI/Shader/Argument/boundingRect) Returns an argument value representing the bounding rect of the shape or view that the shader is attached to, as `float4(x, y, width, height)`. This value is undefined for shaders that do not have a natural bounding rect (e.g. filter effects drawn into `GraphicsContext`). [`color(_:)`](/documentation/SwiftUI/Shader/Argument/color(_:)) Returns an argument value representing `color`. When passed to a MSL function it will convert to a `half4` value, as a premultiplied color in the target color space. [`colorArray(_:)`](/documentation/SwiftUI/Shader/Argument/colorArray(_:)) Returns an argument value defined by the provided array of color values. When passed to an MSL function it will convert to a `device const half4 *ptr, int count` pair of parameters. [`data(_:)`](/documentation/SwiftUI/Shader/Argument/data(_:)) Returns an argument value defined by the provided data value. When passed to an MSL function it will convert to a `device const void *ptr, int size_in_bytes` pair of parameters. [`float(_:)`](/documentation/SwiftUI/Shader/Argument/float(_:)) Returns an argument value representing the MSL value `float(x)`. [`float2(_:)`](/documentation/SwiftUI/Shader/Argument/float2(_:)) Returns an argument value representing the MSL value `float2(point.x, point.y)`. [`float2(_:_:)`](/documentation/SwiftUI/Shader/Argument/float2(_:_:)) Returns an argument value representing the MSL value `float2(x, y)`. [`float3(_:_:_:)`](/documentation/SwiftUI/Shader/Argument/float3(_:_:_:)) Returns an argument value representing the MSL value `float3(x, y, z)`. [`float4(_:_:_:_:)`](/documentation/SwiftUI/Shader/Argument/float4(_:_:_:_:)) Returns an argument value representing the MSL value `float4(x, y, z, w)`. [`floatArray(_:)`](/documentation/SwiftUI/Shader/Argument/floatArray(_:)) Returns an argument value defined by the provided array of floating point numbers. When passed to an MSL function it will convert to a `device const float *ptr, int count` pair of parameters. [`image(_:)`](/documentation/SwiftUI/Shader/Argument/image(_:)) Returns an argument value defined by the provided image. When passed to an MSL function it will convert to a `texture2d` value. Currently only one image parameter is supported per `Shader` instance. --- 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)