Support the VK_KHR_swapchain_mutable_format extension.
This allows clients to create views of a swapchain image with a
different format, just like a regular image created with the
`VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT` set. This extension also supports
the additional features provided by `VK_KHR_maintenance2` and
`VK_KHR_image_format_list` for swapchain images.
We... admittedly don't do much with any of this. There wasn't really
anything in Metal stopping clients from doing this to begin with. This
change does, however, set the `MUTABLE_FORMAT` and `EXTENDED_USAGE`
image bits on any swapchain created with the new
`VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR`.
diff --git a/Docs/MoltenVK_Runtime_UserGuide.md b/Docs/MoltenVK_Runtime_UserGuide.md
index 2c60941..0077861 100644
--- a/Docs/MoltenVK_Runtime_UserGuide.md
+++ b/Docs/MoltenVK_Runtime_UserGuide.md
@@ -239,6 +239,7 @@
- `VK_KHR_storage_buffer_storage_class`
- `VK_KHR_surface`
- `VK_KHR_swapchain`
+- `VK_KHR_swapchain_mutable_format`
- `VK_EXT_shader_viewport_index_layer`
- `VK_EXT_vertex_attribute_divisor`
- `VK_MVK_moltenvk`
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
index d26732e..970e32a 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
@@ -214,7 +214,7 @@
_mtlLayerOrigDrawSize = _mtlLayer.updatedDrawableSizeMVK;
VkExtent2D imgExtent = mvkVkExtent2DFromCGSize(_mtlLayerOrigDrawSize);
- const VkImageCreateInfo imgInfo = {
+ VkImageCreateInfo imgInfo = {
.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
.pNext = VK_NULL_HANDLE,
.imageType = VK_IMAGE_TYPE_2D,
@@ -228,6 +228,10 @@
.flags = 0,
};
+ if (mvkAreFlagsEnabled(pCreateInfo->flags, VK_SWAPCHAIN_CREATE_MUTABLE_FORMAT_BIT_KHR)) {
+ mvkEnableFlag(imgInfo.flags, VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT|VK_IMAGE_CREATE_EXTENDED_USAGE_BIT);
+ }
+
VkSurfaceCapabilitiesKHR srfcProps;
MVKSurface* mvkSrfc = (MVKSurface*)pCreateInfo->surface;
_device->getPhysicalDevice()->getSurfaceCapabilities(mvkSrfc, &srfcProps);
diff --git a/MoltenVK/MoltenVK/Layers/MVKExtensions.def b/MoltenVK/MoltenVK/Layers/MVKExtensions.def
index 0a4fa6a..f2a2c6c 100644
--- a/MoltenVK/MoltenVK/Layers/MVKExtensions.def
+++ b/MoltenVK/MoltenVK/Layers/MVKExtensions.def
@@ -48,6 +48,7 @@
MVK_EXTENSION(KHR_storage_buffer_storage_class, KHR_STORAGE_BUFFER_STORAGE_CLASS)
MVK_EXTENSION(KHR_surface, KHR_SURFACE)
MVK_EXTENSION(KHR_swapchain, KHR_SWAPCHAIN)
+MVK_EXTENSION(KHR_swapchain_mutable_format, KHR_SWAPCHAIN_MUTABLE_FORMAT)
MVK_EXTENSION(EXT_shader_viewport_index_layer, EXT_SHADER_VIEWPORT_INDEX_LAYER)
MVK_EXTENSION(EXT_vertex_attribute_divisor, EXT_VERTEX_ATTRIBUTE_DIVISOR)
MVK_EXTENSION(MVK_ios_surface, MVK_IOS_SURFACE)
