This adds basic support for MoltenVK, a Vulkan implementation on top of
Metal, on macOS 10.11 and later. It looks for MoltenVK in the process
via RTLD_DEFAULT symbol lookup if _GLFW_VULKAN_STATIC is disabled.
glfwCreateWindowSurface now creates and sets a CAMetalLayer for the
window content view, which is required for MoltenVK to function.
You must help CMake find MoltenVK for the Vulkan test to be built.
Fixes#870.
Cleanup of 8bdb105897.
Add build macro to configuration header and documentation. Add
corresponding CMake option. Add change log entry and credit. Add
loader static library to link dependencies and add detection to
FindVulkan.cmake.
Added GLFW_INCLUDE_VULKAN. Added glfwVulkanSupported,
glfwGetRequiredInstanceExtensions, glfwGetInstanceProcAddress,
glfwGetPhysicalDevicePresentationSupport and glfwCreateWindowSurface.
Added port of LunarG SDK tri example.
