Cocoa: Add support for MoltenVK dynamic library

Tested with MoltenVK 0.18.0.

Related to #870.

CMake/modules/FindVulkan.cmake

@@ -28,12 +28,12 @@ if (WIN32)
             "$ENV{VK_SDK_PATH}/Bin32")
     endif()
 elseif (APPLE)
+    set(CMAKE_FIND_FRAMEWORK NEVER)
     find_library(VULKAN_LIBRARY MoltenVK)
-    if (VULKAN_LIBRARY)
-        set(VULKAN_STATIC_LIBRARY ${VULKAN_LIBRARY})
-        find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
-            "${VULKAN_LIBRARY}/Headers")
-    endif()
+    set(CMAKE_FIND_FRAMEWORK ONLY)
+    find_library(VULKAN_STATIC_LIBRARY MoltenVK)
+    find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
+        "${VULKAN_LIBRARY}/Headers")
 else()
     find_path(VULKAN_INCLUDE_DIR NAMES vulkan/vulkan.h HINTS
         "$ENV{VULKAN_SDK}/include")

README.md

@@ -108,8 +108,9 @@ located in the `deps/` directory.
  - [Vulkan headers](https://www.khronos.org/registry/vulkan/) for Vulkan tests
 
 The Vulkan example additionally requires the Vulkan SDK to be installed, or it
-will not be included in the build.  On macOS you need to set the path to the
-MoltenVK SDK manually as it has no standard location.
+will not be included in the build.  On macOS you need to
+[provide the path](@ref vulkan_loader) to the MoltenVK SDK manually as it has no
+standard installation location.
 
 The documentation is generated with [Doxygen](http://doxygen.org/).  If CMake
 does not find Doxygen, the documentation will not be generated when you build.

docs/vulkan.dox

@@ -20,6 +20,11 @@ The GLFW library does not need the Vulkan SDK to enable support for Vulkan.
 However, any Vulkan-specific test and example programs are built only if the
 CMake files find a Vulkan SDK.
 
+@macos Because MoltenVK is typically not installed system-wide, you will need to
+point CMake to it using the `CMAKE_FRAMEWORK_PATH` variable when configuring the
+GLFW source tree.  Set this variable to the `MoltenVK/macOS` subdirectory of the
+SDK, either on the command-line or in the CMake GUI.
+
 For details on a specific function in this category, see the @ref vulkan.  There
 are also guides for the other areas of the GLFW API.
 
@@ -34,19 +39,18 @@ are also guides for the other areas of the GLFW API.
 
 By default, GLFW will look for the Vulkan loader on demand at runtime via its
 standard name (`vulkan-1.dll` on Windows, `libvulkan.so.1` on Linux and other
-Unix-like systems).  This means that GLFW does not need to be linked against the
-loader.  However, it also means that if you are using the static library form of
-the Vulkan loader GLFW will either fail to find it or (worse) use the wrong one.
+Unix-like systems and `libMoltenVK.dylib` on macOS).  This means that GLFW does
+not need to be linked against the loader.  However, it also means that if you
+are using the static library form of the Vulkan loader GLFW will either fail to
+find it or (worse) use the wrong one.
 
 The @ref GLFW_VULKAN_STATIC CMake option makes GLFW link directly against the
-static form.  Not linking against the Vulkan loader will then be a compile-time
-error.
+static library form.  Not linking against the Vulkan loader will then be
+a compile-time error.
 
-@macos MoltenVK only provides the static library form of the Vulkan loader, but
-GLFW is able to find it without @ref GLFW_VULKAN_STATIC as long as it is linked
-into any of the binaries already loaded into the process.  As it is a static
-library, you must also link against its dependencies: the `Cocoa`, `Metal` and
-`QuartzCore` frameworks and the `libc++` library.
+@macos When using the static library form of MoltenVK (i.e. `MetalVK.framework`
+and not `libMoltenVK.dylib`) you must also link against its dependencies: the
+`Cocoa`, `Metal` and `QuartzCore` system frameworks and the `libc++` library.
 
 
 @section vulkan_include Including the Vulkan and GLFW header files

include/GLFW/glfw3.h

@@ -211,13 +211,7 @@ extern "C" {
 #endif /* OpenGL and OpenGL ES headers */
 
 #if defined(GLFW_INCLUDE_VULKAN)
-
- #if defined(__APPLE__)
-  #include <MoltenVK/vulkan/vulkan.h>
- #else
   #include <vulkan/vulkan.h>
- #endif
-
 #endif /* Vulkan header */
 
 #if defined(GLFW_DLL) && defined(_GLFW_BUILD_DLL)

src/vulkan.c

@@ -52,8 +52,7 @@ GLFWbool _glfwInitVulkan(int mode)
 #if defined(_GLFW_WIN32)
     _glfw.vk.handle = _glfw_dlopen("vulkan-1.dll");
 #elif defined(_GLFW_COCOA)
-    // NULL maps to RTLD_DEFAULT, which searches all loaded binaries
-    _glfw.vk.handle = _glfw_dlopen(NULL);
+    _glfw.vk.handle = _glfw_dlopen("libMoltenVK.dylib");
 #else
     _glfw.vk.handle = _glfw_dlopen("libvulkan.so.1");
 #endif
@@ -69,16 +68,8 @@ GLFWbool _glfwInitVulkan(int mode)
         _glfw_dlsym(_glfw.vk.handle, "vkGetInstanceProcAddr");
     if (!_glfw.vk.GetInstanceProcAddr)
     {
-#if defined(_GLFW_COCOA)
-        if (mode == _GLFW_REQUIRE_LOADER)
-        {
-            _glfwInputError(GLFW_API_UNAVAILABLE,
-                            "Vulkan: vkGetInstanceProcAddr not found in process");
-        }
-#else
         _glfwInputError(GLFW_API_UNAVAILABLE,
                         "Vulkan: Loader does not export vkGetInstanceProcAddr");
-#endif
 
         _glfwTerminateVulkan();
         return GLFW_FALSE;

tests/CMakeLists.txt

@@ -53,8 +53,10 @@ set(CONSOLE_BINARIES clipboard events msaa glfwinfo iconify monitors reopen
 if (VULKAN_FOUND)
     add_executable(vulkan WIN32 vulkan.c ${ICON})
     target_include_directories(vulkan PRIVATE "${VULKAN_INCLUDE_DIR}")
-    if (NOT GLFW_VULKAN_STATIC)
-        target_link_libraries(vulkan "${VULKAN_LIBRARY}" ${GLFW_VULKAN_DEPS})
+    if (GLFW_VULKAN_STATIC)
+        target_link_libraries(vulkan "${VULKAN_STATIC_LIBRARY}" ${GLFW_VULKAN_DEPS})
+    else()
+        target_link_libraries(vulkan "${VULKAN_LIBRARY}")
     endif()
     list(APPEND WINDOWS_BINARIES vulkan)
 endif()