Table of Contents

Use Graphite with Vulkan

Graphite Vulkan is available on Linux, Android, and Windows. Apple builds use Metal, not Vulkan. SKGraphiteContext.IsBackendAvailable(SKGraphiteBackend.Vulkan) reports whether the Vulkan factory was compiled into the current native library.

Create the Graphite context

Fill SKGraphiteVkBackendContext with the Vulkan objects owned by your host:

using var backendContext = new SKGraphiteVkBackendContext
{
    VkInstance = instanceHandle,
    VkPhysicalDevice = physicalDeviceHandle,
    VkDevice = deviceHandle,
    VkQueue = graphicsQueueHandle,
    GraphicsQueueIndex = graphicsFamilyIndex,
    MaxApiVersion = apiVersion,
    GetProcedureAddress = (name, instance, device) =>
        System.IntPtr.Zero, // TODO: Forward to vkGetInstanceProcAddr or vkGetDeviceProcAddr.
};

using var context = SKGraphiteContext.CreateVulkan(backendContext);

Replace the zero-returning placeholder with your vkGetInstanceProcAddr and vkGetDeviceProcAddr integration.

There is no typed Graphite-specific Vulkan adapter. With Silk.NET, pass each object's .Handle value:

using Silk.NET.Vulkan;

using var backendContext = new SKGraphiteVkBackendContext
{
    VkInstance = instance.Handle,
    VkPhysicalDevice = physicalDevice.Handle,
    VkDevice = device.Handle,
    VkQueue = graphicsQueue.Handle,
    GraphicsQueueIndex = graphicsFamily,
    MaxApiVersion = apiVersion,
    GetProcedureAddress = getProc,
};

using var context = SKGraphiteContext.CreateVulkan(backendContext);

Use Silk.NET or raw libvulkan P/Invoke for new code. The legacy SharpVk binding is unmaintained.

Wrap and release Vulkan images

Use SKGraphiteBackendTexture.CreateVulkan to describe an existing VkImage. A Vulkan image wrapped as a renderable surface must include both VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT (0x10) and VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT (0x80). Without them, SKSurface.Create returns null.

A typical renderable mask is TRANSFER_SRC | TRANSFER_DST | SAMPLED | COLOR_ATTACHMENT | INPUT_ATTACHMENT (0x97). An image used only for sampling needs SAMPLED, not INPUT_ATTACHMENT.

When Skia is done with a wrapped texture, the parameterless SKGraphiteReleaseDelegate fires after the wrapper is disposed and pending GPU work has drained. Disposing the wrapper alone does not mean the allocation is safe to delete.

Release a wrapped texture

Starting with an initialized Vulkan backendContext, this successful-path sequence allocates a backend texture through the recorder, wraps it, submits work, waits for the release callback, and deletes the allocation while the recorder is still alive:

const int width = 256;
const int height = 256;

using var context = SKGraphiteContext.CreateVulkan(backendContext);
using var recorder = context.CreateRecorder();

var vkInfo = new SKGraphiteVkTextureInfo
{
    Format = 37,           // VK_FORMAT_R8G8B8A8_UNORM
    ImageTiling = 0,       // VK_IMAGE_TILING_OPTIMAL
    SampleCount = 1,
    AspectMask = 1,        // VK_IMAGE_ASPECT_COLOR_BIT
    SharingMode = 0,       // VK_SHARING_MODE_EXCLUSIVE
    ImageUsageFlags = 0x1 | 0x2 | 0x4 | 0x10 | 0x80, // = 0x97
};
using var textureInfo = SKGraphiteTextureInfo.CreateVulkan(vkInfo);
using var backendTexture = recorder.CreateBackendTexture(width, height, textureInfo);

var released = false;
using (var surface = SKSurface.Create(
    recorder, backendTexture, SKColorType.Rgba8888,
    colorSpace: null, props: null,
    releaseProc: () => released = true))
{
    surface.Canvas.Clear(SKColors.Red);
    using var recording = recorder.Snap();
    context.InsertRecording(recording);
    context.Submit(new SKGraphiteSubmitInfo { Sync = true });
}

context.Submit(new SKGraphiteSubmitInfo { Sync = true });
while (!released)
    context.CheckAsyncWorkCompletion();

context.FreeGpuResources();
recorder.DeleteBackendTexture(backendTexture);

The sample assumes wrapping and submission succeed so the release ordering is easy to see. Production code should bound the callback wait. If insertion or submission fails, do not delete an allocation while Skia might still reference it; tear down and recreate the owning Graphite context and native Vulkan device instead.

For a VkImage allocated by your own Vulkan code, construct the wrapper with SKGraphiteBackendTexture.CreateVulkan and release the native image through Vulkan after the callback. SKImage.FromTexture uses the same callback timing.

Next steps

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

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