[Feat] (iOS): support MobileGL builds and Metal surfaces

CMakeLists.txt

@@ -7,7 +7,9 @@ option(MOBILEGL_BUILD_BENCHMARK   "Build MobileGL benchmarks"
 option(MOBILEGL_FORCE_RELEASE_OPT "Enable Release optimization flags in Debug build" ON )
 option(MOBILEGL_ENABLE_TRACY      "Enable tracy for profiling"                       OFF)
 option(MOBILEGL_BUILD_TRACE_REPLAY "Build desktop apitrace replay runner"            OFF)
+option(MOBILEGL_IOS               "Build MobileGL for iOS instead of macOS when APPLE is set" OFF)
 set(MOBILEGL_LOG_ACTIVE_LEVEL "MOBILEGL_LOG_LEVEL_INFO" CACHE STRING "MobileGL active log level macro")
+set(MOBILEGL_VULKAN_LIBRARY "" CACHE FILEPATH "Vulkan loader/MoltenVK library to link for iOS builds")
 
 if (ANDROID)
     set(MOBILEGL_BUILD_TEST       OFF CACHE BOOL "Build MobileGL tests"      FORCE)
@@ -273,7 +275,7 @@ set(SOURCE_FILES
     MobileGL/MG_State/GLState/RenderbufferState/RenderbufferState.cpp
 )
 
-if (APPLE)
+if (APPLE AND NOT MOBILEGL_IOS)
     list(APPEND SOURCE_FILES
         MobileGL/MG_Impl/CGLImpl/CGLImpl.cpp
         MobileGL/MG_Impl/CGLImpl/Exporting/Definitions.cpp
@@ -393,7 +395,7 @@ if (ANDROID)
     )
 endif()
 
-if (APPLE)
+if (APPLE AND NOT MOBILEGL_IOS)
     target_link_libraries(${CMAKE_PROJECT_NAME} PUBLIC
         "-framework Cocoa"
         "-framework QuartzCore"
@@ -410,7 +412,31 @@ if (APPLE)
     endif()
 endif()
 
-if (NOT ANDROID)
+if (APPLE AND MOBILEGL_IOS)
+    target_compile_definitions(${CMAKE_PROJECT_NAME} PUBLIC MOBILEGL_IOS=1 _LIBCPP_DISABLE_AVAILABILITY)
+    target_link_libraries(${CMAKE_PROJECT_NAME} PUBLIC
+        "-framework CoreGraphics"
+        "-framework Foundation"
+        "-framework QuartzCore"
+        objc)
+    if (MOBILEGL_VULKAN_LIBRARY)
+        target_link_libraries(${CMAKE_PROJECT_NAME} PUBLIC "${MOBILEGL_VULKAN_LIBRARY}")
+    endif()
+
+    if(TARGET ${CMAKE_PROJECT_NAME}_s)
+        target_compile_definitions(${CMAKE_PROJECT_NAME}_s PUBLIC MOBILEGL_IOS=1 _LIBCPP_DISABLE_AVAILABILITY)
+        target_link_libraries(${CMAKE_PROJECT_NAME}_s PUBLIC
+            "-framework CoreGraphics"
+            "-framework Foundation"
+            "-framework QuartzCore"
+            objc)
+        if (MOBILEGL_VULKAN_LIBRARY)
+            target_link_libraries(${CMAKE_PROJECT_NAME}_s PUBLIC "${MOBILEGL_VULKAN_LIBRARY}")
+        endif()
+    endif()
+endif()
+
+if (NOT ANDROID AND NOT MOBILEGL_IOS)
     find_package(Vulkan)
     if (Vulkan_FOUND)
         target_link_libraries(${CMAKE_PROJECT_NAME} PUBLIC Vulkan::Vulkan Vulkan::Headers)
@@ -418,7 +444,9 @@ if (NOT ANDROID)
         target_include_directories(${CMAKE_PROJECT_NAME} PUBLIC ${Vulkan_INCLUDE_DIR})
         target_include_directories(${CMAKE_PROJECT_NAME}_s PUBLIC ${Vulkan_INCLUDE_DIR})
     endif ()
+endif ()
 
+if (NOT ANDROID)
     if (MOBILEGL_BUILD_TEST)
         add_subdirectory(MobileGL/MG_Test)
     endif()

MobileGL/MG_Backend/DirectGLES/BackendObject_DirectGLES.cpp

@@ -666,8 +666,11 @@ namespace MobileGL::MG_Backend::DirectGLES {
             return false;
         }
 
-        if ((handle.Backend != WindowBackend::Android && handle.Backend != WindowBackend::X11) || !handle.Handle) {
+        if ((handle.Backend != WindowBackend::Android &&
-            MGLOG_E("DirectGLES backend only supports Android and X11 native windows");
+             handle.Backend != WindowBackend::X11 &&
+             handle.Backend != WindowBackend::MetalLayer) ||
+            !handle.Handle) {
+            MGLOG_E("DirectGLES backend only supports Android, X11, and CAMetalLayer native windows");
             return false;
         }
 

MobileGL/MG_Backend/DirectVulkan/Renderer/VulkanRenderer.cpp

@@ -5476,15 +5476,28 @@ void main() {
         } // TODO: support more platforms
 
 #if defined(VK_USE_PLATFORM_METAL_EXT)
-        exts.push_back(VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME);
+        if (IsExtensionSupported(m_extensions, VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME)) {
-        instanceInfo.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
+            exts.push_back(VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME);
+            instanceInfo.flags |= VK_INSTANCE_CREATE_ENUMERATE_PORTABILITY_BIT_KHR;
+        } else {
+            MGLOG_I("Optional Vulkan instance extension not supported: %s",
+                    VK_KHR_PORTABILITY_ENUMERATION_EXTENSION_NAME);
+        }
 #endif
 
         if (m_validationLayersEnabled) {
             exts.push_back(VK_EXT_DEBUG_UTILS_EXTENSION_NAME);
         }
 
+        MGLOG_I("Enabling %d Vulkan instance extensions:", exts.size());
         for (const char* ext : exts) {
+            MGLOG_I("    %s", ext);
+        }
+
+        for (const char* ext : exts) {
+            if (!IsExtensionSupported(m_extensions, ext)) {
+                MGLOG_E("Required Vulkan instance extension not found: %s", ext);
+            }
             MOBILEGL_ASSERT(IsExtensionSupported(m_extensions, ext), "Required Vulkan instance extension not found: %s",
                             ext);
         }

MobileGL/MG_Impl/GetProcAddress.cpp

@@ -7,7 +7,7 @@
 // End of Source File Header
 
 #include "GetProcAddress.h"
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(MOBILEGL_IOS)
 #ifndef GL_SILENCE_DEPRECATION
 #define GL_SILENCE_DEPRECATION
 #endif
@@ -67,7 +67,7 @@ namespace MobileGL::MG_Impl {
         GETPROC(eglCreatePlatformPixmapSurface, name);
         GETPROC(eglWaitSync, name);
 
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(MOBILEGL_IOS)
         GETPROC(CGLChoosePixelFormat, name);
         GETPROC(CGLDestroyPixelFormat, name);
         GETPROC(CGLDescribePixelFormat, name);

MobileGL/MG_Impl/Init.cpp

@@ -10,7 +10,7 @@
 
 #include "GLImpl/Texture/ProxyTexture.h"
 #include "GLImpl/Framebuffer/GL_Framebuffer.h"
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(MOBILEGL_IOS)
 #include "NSOpenGLImpl/NSOpenGLImpl.h"
 #endif
 
@@ -48,7 +48,7 @@ namespace MobileGL::MG_Impl {
             MakeUnique<GLImpl::FramebufferImpl::DefaultFramebufferInfo>(fbo0, colorTex, depthTex, stencilTex);
         MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Draw).Bind(fbo0);
         MG_State::pGLContext->GetFramebufferBindingSlot(FramebufferTarget::Read).Bind(fbo0);
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(MOBILEGL_IOS)
         NSOpenGLImpl::InstallHooks();
 #endif
     }

MobileGL/MG_Util/BackendLoaders/OpenGL/Loader.cpp

@@ -8,6 +8,9 @@
 
 #include "Loader.h"
 #include "MG_Util/Types.h"
+#if defined(MOBILEGL_IOS)
+#include <dlfcn.h>
+#endif
 
 namespace MobileGL::MG_Util::BackendLoader {
     static Bool UseRetraceAngle() {
@@ -29,10 +32,14 @@ namespace MobileGL::MG_Util::BackendLoader {
     }
 
     static void* OpenLib(const Vector<String>& names) {
-#if !defined(__WIN32) && !defined(_WIN32) && !defined(__APPLE__)
+#if !defined(__WIN32) && !defined(_WIN32) && (!defined(__APPLE__) || defined(MOBILEGL_IOS))
         static const String LibPathPrefixes[] = {
+#if defined(MOBILEGL_IOS)
+            "@rpath/", "@executable_path/Frameworks/", "@loader_path/Frameworks/",
+#else
             "/opt/vc/lib/", "/usr/local/lib/", "/usr/lib/", "/usr/lib/x86_64-linux-gnu/",
             "/usr/lib64/", "/lib64/",
+#endif
             "" // We should put this to the end of the list to avoid breaking `LD_LIBRARY_PATH` usage
         };
 
@@ -53,7 +60,7 @@ namespace MobileGL::MG_Util::BackendLoader {
     }
 
     inline void* ProcAddress(void* lib, const char* name) {
-#if !defined(__WIN32) && !defined(_WIN32) && !defined(__APPLE__)
+#if !defined(__WIN32) && !defined(_WIN32) && (!defined(__APPLE__) || defined(MOBILEGL_IOS))
         return dlsym(lib, name);
 #else
         return nullptr;
@@ -465,7 +472,11 @@ namespace MobileGL::MG_Util::BackendLoader {
                 return;
             }
         } else {
+#if defined(MOBILEGL_IOS)
+            eglLib = OpenLib({"libtinygl4angle.dylib"});
+#else
             eglLib = OpenLib({"libEGL.so"});
+#endif
         }
 
         if (!eglLib) {