MoltenVK: Add patch to turn on framebuffer fetch in SPIRV-Cross

Externals/MoltenVK/CMakeLists.txt

@@ -8,6 +8,8 @@ ExternalProject_Add(MoltenVK
 
   CONFIGURE_COMMAND ${CMAKE_CURRENT_LIST_DIR}/configure.sh <LOG_DIR> <SOURCE_DIR> ${MOLTENVK_VERSION}
 
+  PATCH_COMMAND ${CMAKE_CURRENT_LIST_DIR}/patch.sh ${CMAKE_SOURCE_DIR}/Externals/MoltenVK/patches/ ${MOLTENVK_VERSION}
+
   BUILD_COMMAND make -C <SOURCE_DIR> macos
   BUILD_IN_SOURCE ON
   BUILD_BYPRODUCTS <SOURCE_DIR>/Package/Release/MoltenVK/dylib/macOS/libMoltenVK.dylib

Externals/MoltenVK/patch.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Applies all patches in the "patches" folder to the cloned MoltenVK git repository.
+#
+# Usage: patch.sh <patches folder> <MoltenVK version>
+#
+
+set -e
+
+# Reset the git repository first to ensure that it's in the base state.
+git reset --hard $2
+
+git apply $1/*.patch

Externals/MoltenVK/patches/0001-SPIRVToMSLConverter-Enable-use_framebuffer_fetch_sub.patch

@@ -0,0 +1,24 @@
+From 4ca33b7a9b149c6fbcc1c88ce08fc49f21294f6d Mon Sep 17 00:00:00 2001
+From: OatmealDome <julian@oatmealdome.me>
+Date: Sat, 31 Jul 2021 19:18:35 -0400
+Subject: [PATCH] SPIRVToMSLConverter: Enable use_framebuffer_fetch_subpasses
+
+---
+ .../MoltenVKShaderConverter/SPIRVToMSLConverter.cpp              | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/MoltenVKShaderConverter/MoltenVKShaderConverter/SPIRVToMSLConverter.cpp b/MoltenVKShaderConverter/MoltenVKShaderConverter/SPIRVToMSLConverter.cpp
+index 17c79394..97e98004 100644
+--- a/MoltenVKShaderConverter/MoltenVKShaderConverter/SPIRVToMSLConverter.cpp
++++ b/MoltenVKShaderConverter/MoltenVKShaderConverter/SPIRVToMSLConverter.cpp
+@@ -92,6 +92,7 @@ MVK_PUBLIC_SYMBOL SPIRVToMSLConversionOptions::SPIRVToMSLConversionOptions() {
+ #endif
+ 
+ 	mslOptions.pad_fragment_output_components = true;
++	mslOptions.use_framebuffer_fetch_subpasses = true;
+ }
+ 
+ MVK_PUBLIC_SYMBOL bool mvk::MSLShaderInput::matches(const mvk::MSLShaderInput& other) const {
+-- 
+2.30.1 (Apple Git-130)
+