Table of Contents

Use Graphite with Metal

Graphite Metal is available on macOS, iOS, Mac Catalyst, and tvOS, including Apple Silicon simulators. SKGraphiteContext.IsBackendAvailable(SKGraphiteBackend.Metal) reports whether the Metal factory was compiled into the current native library; it does not validate the selected MTLDevice.

Create the Graphite context

Warning

Before creating the command queue or calling CreateMetal, use the platform binding for supportsFamily: to confirm that the device reports a GPU family accepted by the current Skia build. Current macOS builds check Apple 7 through 9 and Mac 2; iOS-family builds also check Apple 2 through 6. If none of those families is reported, Skia calls SK_ABORT instead of returning null, which terminates the process.

Supply an MTLDevice and MTLCommandQueue. On Apple target frameworks you can assign typed IMTLDevice and IMTLCommandQueue objects; from other targets, assign their native handles:

using var backendContext = new SKGraphiteMtlBackendContext
{
    MtlDevice = mtlDeviceHandle,
    MtlQueue = mtlCommandQueueHandle,
};

using var context = SKGraphiteContext.CreateMetal(backendContext);

Wrap Metal textures

Describe an existing MTLTexture with SKGraphiteBackendTexture.CreateMetal, then use the shared surface-wrapping call:

using var backendTexture = SKGraphiteBackendTexture.CreateMetal(
    width, height, mtlTextureHandle);
using var surface = SKSurface.Create(
    recorder, backendTexture, SKColorType.Rgba8888);

The native MTLTexture remains owned by the code that created it. If you supply a release callback, release the native allocation only after the callback fires.

Simulator caveats

Graphite Metal works on the iOS and tvOS Simulator on Apple Silicon because it uses the host GPU. The simulator's MTLDevice can under-report its family, so detect the Apple Simulator explicitly and allow it as an exception to the family probe. Do not apply that exception to other devices or virtualized Metal environments.

The simulator's Metal shader compiler cannot build some Graphite pipelines, including some gradient shaders. In that case, recorder.Snap() returns null for the frame. The same content renders with Graphite Metal on macOS and physical iOS hardware, and with Ganesh Metal on the simulator. See mono/SkiaSharp#4555, and always check the result of Snap().

Next steps

Continue with the shared Graphite recording, submission, readback, texture, and resource flow.

Edit this page