Merge pull request #708 from billhollings/master

Add support for VkEvent.
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm b/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
index 6966d73..d3d66a8 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
@@ -457,8 +457,8 @@
 	pSurfaceCapabilities->supportedTransforms = (VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR);
 	pSurfaceCapabilities->currentTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
     pSurfaceCapabilities->supportedCompositeAlpha = (VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR |
-                                                     VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR |
-                                                     VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR);
+                                                     VK_COMPOSITE_ALPHA_POST_MULTIPLIED_BIT_KHR |
+                                                     VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR);
 	pSurfaceCapabilities->supportedUsageFlags = (VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT |
                                                  VK_IMAGE_USAGE_STORAGE_BIT |
                                                  VK_IMAGE_USAGE_TRANSFER_SRC_BIT |
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
index ac3eabc..cae47c8 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKSwapchain.mm
@@ -226,6 +226,9 @@
 																			   VK_IMAGE_USAGE_TRANSFER_DST_BIT |
 																			   VK_IMAGE_USAGE_SAMPLED_BIT |
 																			   VK_IMAGE_USAGE_STORAGE_BIT));
+	if (pCreateInfo->compositeAlpha != VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR) {
+		_mtlLayer.opaque = pCreateInfo->compositeAlpha == VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
+	}
 #if MVK_MACOS
 	switch (pCreateInfo->imageColorSpace) {
 		case VK_COLOR_SPACE_SRGB_NONLINEAR_KHR: