AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
0c1c2b39dd
skia2/site/user/special/vulkan.md
Brian Salomon f43d0001e4 Revert "Revert "Revert "Revert "Remove GrBackendRenderTargetDesc in favor of GrBackendRenderTarget."""" 
This reverts commit 6df4d6be0d.

Reason for revert: Google3 fix landed

Original change's description:
> Revert "Revert "Revert "Remove GrBackendRenderTargetDesc in favor of GrBackendRenderTarget."""
> 
> This reverts commit 71554bc256.
> 
> Reason for revert: Google3
> 
> Original change's description:
> > Revert "Revert "Remove GrBackendRenderTargetDesc in favor of GrBackendRenderTarget.""
> > 
> > This reverts commit 807371c15b.
> > 
> > Docs-Preview: https://skia.org/?cl=40260
> > Change-Id: I28e0434c455155ff39a5aaa4141abdf442474e87
> > Reviewed-on: https://skia-review.googlesource.com/40260
> > Reviewed-by: Greg Daniel <egdaniel@google.com>
> > Commit-Queue: Brian Salomon <bsalomon@google.com>
> 
> TBR=egdaniel@google.com,bsalomon@google.com
> 
> Change-Id: Ifdfa896a70db69935473276d12dce54de5c6b6f7
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Reviewed-on: https://skia-review.googlesource.com/41500
> Reviewed-by: Brian Salomon <bsalomon@google.com>
> Commit-Queue: Brian Salomon <bsalomon@google.com>

TBR=egdaniel@google.com,bsalomon@google.com

Change-Id: I827419bb19972c3644929a8c984bb9534baab0ba
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/41700
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
2017-08-31 20:04:12 +00:00

2.6 KiB
Raw Blame History

Vulkan

Skia has a Vulkan implementation of its GPU backend. The Vulkan backend can be built alongside the OpenGL backend. The client can select between the OpenGL and Vulkan implementation at runtime. The Vulkan backend has reached feature parity with the OpenGL backend. At this time we find that many Vulkan drivers have bugs that Skia triggers for which we have no workaround. We are reporting bugs to vendors as we find them.

Windows and Linux

To build the Vulkan backend, set skia_vulkan_sdk to the path to your Vulkan SDK in args.gn. This defaults to the environment variable VULKAN_SDK.

Android

The Vulkan backend can run on any device with Vulkan drivers, including all Android N+ devices. To build the Vulkan backend, set ndk_api = 24 in args.gn to target Android N.

Using the Vulkan Backend

To create a GrContext that is backed by Vulkan the client creates a Vulkan device and queue, initializes a GrVkBackendContext to describe the context, and then calls GrContext::MakeVulkan:

sk_sp<GrVkBackendContext> vkContext = new GrVkBackendContext;
vkBackendContext.fInstance = vkInstance;
vkBackendContext.fPhysicalDevice = vkPhysDevice;
...
vkBackendContext.fInterface.reset(GrVkCreateInterface(instance, vkPhysDevice, extensionFlags);
...

sk_sp<GrContext> context = GrContext::MakeVulkan(vkBackendContext);

When using the Vulkan backend, GrVkImageInfo is used to construct GrBackendTexture and GrBackendRenderTarget objects that in turn are used to create SkSurface and SkImage objects that refer to VkImages created by the Skia client.

The GrBackendObject returned by SkImage::getTextureHandle(), SkSurface::getTextureHandle(), and SkSurface::getRenderTargetHandle() should be interpreted as a GrVkImageInfo*. This allows a client to get the backing VkImage of a SkImage or SkSurface.

GrVkImageInfo specifies a VkImage and associated state (tiling, layout, format, etc). After getting a GrVkImageInfo* via getTextureHandle() or getRenderTargetHandle(), the client should check the fImageLayout field to know what layout Skia left the VkImage in before using the VkImage. If the client changes the layout of the VkImage, GrVkImageInfo::updateImageLayout(VkImageLayout layout) should be called before resuming Skia rendering.

The client is responsible for any synchronization or barriers needed before Skia performs I/O on a VkImage imported into Skia via GrVkImageInfo. Skia will assume it can start issuing commands referencing the VkImage without the need for additional synchronization.