Enable the Vulkan backend when building Dawn with
the Chromium build system for Fuchsia. To make this
work properly the following is required:
- Modify VulkanInfo.cpp and BackendVk.cpp to correctly probe
the Fuchsia swapchain layer and its layer extension, as well
as enabling them when creating a new VkInstance.
- Modify VulkanFunctions.cpp to load the Fuchsia swapchain
related extension for this platform only.
- Provide a small mock GLFW library for Fuchsia under
src/utils/Glfw3Fuchsia.cpp, since the upstream project
does not support this platform at all. Its purpose is
only to allow the creation of the right VulkanBinding
instance, which depends on the creation of a display
surface for latter swapchain creation.
- Add //third_party/fuchsia-sdk:vulkan_base and
//third_party/fuchsia-sdk:vulkan_validation as
data_deps of the libdawn_native_sources target in
order to ensure that the Fuchsia package created by
the build system will include the correct Vulkan
libraries (loader and validation layers).
This builds correctly, and both dawn_unittests and
dawn_end2end_tests will run on a real Fuchsia device
or inside the Fuchsia emulator, using either GPU
virtualization or a software-based renderer.
Note: dawn_unittests will also run inside QEMU, but
not dawn_end2end_tests, since the latter requires
proper GPU emulation which is not available in this
environment.
NOTE: All end2end tests pass using a device with
an "Intel HD Graphics 615 (Kaby Lake GT2)"
adapter. However:
- For some reason, a single test takes up
to 129 seconds to pass
(BufferSetSubDataTests.ManySetSubData/Vulkan).
- The test process crashes inside VkDestroyInstance(),
apparently inside the Fuchsia-specific imagepipe
layer (which implements swapchain support).
This is likely a bug in the layer itself, and
not Dawn.
Also, may end2end tests will crash when run inside
the Fuchsia emulator (which uses GPU virtualization
to talk to the host GPU). The crashes happen inside
libvulkan-goldfish.so, the emulator-specific Vulkan
ICD on this sytem. Not a Dawn bug either.
Bug=dawn:221
Change-Id: Id3598b673e8c6393f24db728b8da49fdde3cac76
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/8963
Commit-Queue: David Turner <digit@google.com>
Reviewed-by: Austin Eng <enga@chromium.org>
David 'Digit' Turner