Swiftshader on macOS

[Richard Wright]

Hello,

I'm having some difficulties using Swiftshader on macOS and I just want to check some of my assumptions. I have it configured so that the loader sees it as one of three available ICD's (the Intel and NVidia hardware being the other ones). When I select the Swiftshader ICD however I cannot get a valid surface. I'm hoping someone here has trod this path before and might have a pointer.

Notes:

1. I'm using the Qt framework, but not using the Qt's built in Vulkan support (doing it myself - and it works fine against the hardware ICD's).

2. I am creating a QWindow for rendering, and have the surface type set to QSurface::MetalSurface (I have also tried QSurface::VulkanSurface). Do I actually need a Metal Surface since this is a software renderer... which leads me to...

3. I'm using  VkMetalSurfaceCreateInfoEXT and vkCreateMetalSurfaceEXT to create the surface. The VkSurfaceCapabilitiesKHR structure comes back blank, but vkGetPhysicalDeviceSurfaceSupportKHR returns VK_SUCCESS. 

Since the ICD can supposedly be used as a drop in replacement, I assumed all the original metal calls were fine, and that Swiftshader was using Metal for perhaps very fast blits. Assumptions get us into trouble do they not?

Am I going about this the right way at all?

Thanks in advance for any tips or pointers,

Richard

[Alexis Hétu]

Hi Richard,

  I don't have a lot of experience using Qt on MacOS, but I'm curious about one thing:

  Creating a surface through vkCreateMetalSurfaceEXT should go through here:

https://cs.opensource.google/swiftshader/SwiftShader/+/master:src/Vulkan/libVulkan.cpp;l=3474

  and vkGetPhysicalDeviceSurfaceSupportKHR does always return VK_SUCCESS, no matter what:

https://cs.opensource.google/swiftshader/SwiftShader/+/master:src/Vulkan/libVulkan.cpp;l=3510

  But using vkGetPhysicalDeviceSurfaceCapabilitiesKHR to query the VkSurfaceCapabilitiesKHR structure should end up here:

https://cs.opensource.google/swiftshader/SwiftShader/+/master:src/WSI/MetalSurface.mm;l=134

  which unconditionally calls SurfaceKHR::getSurfaceCapabilities, which should do something:

https://cs.opensource.google/swiftshader/SwiftShader/+/master:src/WSI/VkSurfaceKHR.cpp;l=114

  So how is it possible for that "VkSurfaceCapabilitiesKHR structure comes back blank"? Can you double check that you're using the right surface when calling vkGetPhysicalDeviceSurfaceCapabilitiesKHR?

--
You received this message because you are subscribed to the Google Groups "swiftshader" group.
To unsubscribe from this group and stop receiving emails from it, send an email to swiftshader...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/swiftshader/CAGaq4HpvEsMF8L91%3D82OENeAZGs4Vs661jJHsVbB2jXVd%2Bj93Q%40mail.gmail.com.