Merge pull request #371 from cdavis5e/swapchain-mutable-format

Support the VK_KHR_swapchain_mutable_format extension.

Author: billhollings

Docs/MoltenVK_Runtime_UserGuide.md

@@ -239,6 +239,7 @@ In addition to the core *Vulkan* API, **MoltenVK**  also supports the following
 - `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`

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);

MoltenVK/MoltenVK/Layers/MVKExtensions.def

@@ -48,6 +48,7 @@ MVK_EXTENSION(KHR_shader_float16_int8, KHR_SHADER_FLOAT16_INT8)
 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)