MetalViewUI

MetalView is a SwiftUI view wrapper over a MTKView. This package allows users to draw in a MTKView natively in SwiftUI, by exposing the two callbacks of MTKViewDelegate. Both callbacks are optional and a default render is provided to display the clearColor.

The MetalView exposes the following view modifiers that are directly mapped to the MTKView properties:

• colorPixelFormat
• framebufferOnly
• drawableSize
• autoResizeDrawable
• clearColor
• preferredFramesPerSecond
• isPaused
• enableSetNeedsDisplay
• presentWithTransaction

All these properties uses the same default values as defined in the MTKView.

Drawing Modes

The MetalView supports two drawing modes:

• Time updates: the MTKView content is redrawn based on the internal timer, driven by preferredFramesPerSecond property.
• Draw notifications: the MTKView content is refreshed upon calling setNeedsDisplay like a traditional UIView.

The drawing mode can be configured by calling the drawingMode view modifiers.

The time updates mode requires to specify the preferredFramesPerSecond, whereas the draw notifications mode requires a publisher to trigger the redraw of the MTKView from the external.

Installation

This package supports both Cocoapods and Swift Package Manager.

Cocoapods

To import this package in a Podfile add the following line:

pod 'MetalViewUI', :git => 'https://github.com/AlessandroToschi/MetalViewUI.git'

Swift Package Manager

Xcode --> File --> Add packages... and paste the following link: https://github.com/AlessandroToschi/MetalViewUI

or add the following line to Project.swift:

.Package(url: "https://github.com/AlessandroToschi/MetalViewUI", branch: "main")

Demo

The Demo folder contains two pratical examples on how to use the MetalView:

• Background color: change the clearColor of the MTKView using the default ColorPicker and updates the content whenever a new color has been selected. The drawing mode is draw notification because the view needs to be redrawn only when the color change, and so an external trigger is used.

• Random color: change the clearColor of the MTKView according to a user configurable delay in seconds. The drawing mode is time updates since we need to change the color as time passes.