More general vulkan loading

CMakeLists.txt

@@ -43,6 +43,8 @@ option(LOVR_BUILD_SHARED "Build a shared library (takes precedence over LOVR_BUI
 option(LOVR_BUILD_BUNDLE "On macOS, build a .app bundle instead of a raw program" OFF)
 option(LOVR_BUILD_WITH_SYMBOLS "Build with C function symbols exposed" OFF)
 
+option(LOVR_LINK_VULKAN "Links vulkan with lovr bypassing the libvulkan search" OFF)
+
 # Setup
 if(EMSCRIPTEN)
   string(CONCAT EMSCRIPTEN_LINKER_FLAGS
@@ -205,6 +207,10 @@ endif()
 # Vulkan
 if(LOVR_USE_VULKAN)
   list(APPEND LOVR_INCLUDES deps/vulkan-headers/include)
+
+  if(LOVR_LINK_VULKAN)
+    find_package(Vulkan REQUIRED)
+  endif()
 endif()
 
 # OpenXR
@@ -350,6 +356,10 @@ target_link_libraries(lovr
   ${EMSCRIPTEN_LINKER_FLAGS}
 )
 
+if(LOVR_USE_VULKAN AND LOVR_LINK_VULKAN)
+  target_link_libraries(lovr PRIVATE Vulkan::Vulkan)
+endif()
+
 if(LOVR_SANITIZE)
   set(LOVR_SANITIZE_FLAGS "-fsanitize=address,undefined" "-O1" "-fno-omit-frame-pointer")
   target_compile_options(lovr PRIVATE ${LOVR_SANITIZE_FLAGS})

src/core/gpu_vk.c

@@ -1,6 +1,7 @@
 #include "gpu.h"
 #include <string.h>
 #include <threads.h>
+#include <stdlib.h>
 #include <stdatomic.h>
 
 #ifdef _WIN32
@@ -2524,16 +2525,31 @@ bool gpu_init(gpu_config* config) {
   state.library = LoadLibraryA("vulkan-1.dll");
   ASSERT(state.library, "Failed to load vulkan library") goto fail;
   vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) GetProcAddress(state.library, "vkGetInstanceProcAddr");
-#elif __APPLE__
-  state.library = dlopen("libvulkan.1.dylib", RTLD_NOW | RTLD_LOCAL);
+#else
+  // Checking if vulkan was linked in (`-DLOVR_LINK_VULKAN` or `LD_PRELOAD`)
+  state.library = NULL;
+  void *selflib = dlopen(NULL, RTLD_NOW);
+  if (dlsym(selflib, "vkGetInstanceProcAddr"))
+    state.library = selflib;
+  else
+    dlclose(selflib);
+
+#ifdef __APPLE__
+  if (!state.library) state.library = dlopen("libvulkan.1.dylib", RTLD_NOW | RTLD_LOCAL);
+  if (!state.library) state.library = dlopen("libvulkan.dylib", RTLD_NOW | RTLD_LOCAL);
   if (!state.library) state.library = dlopen("libMoltenVK.dylib", RTLD_NOW | RTLD_LOCAL);
+  if (!state.library) state.library = dlopen("vulkan.framework/vulkan", RTLD_NOW | RTLD_LOCAL);
+  if (!state.library) state.library = dlopen("MoltenVK.framework/MoltenVK", RTLD_NOW | RTLD_LOCAL);
+  if (!state.library && getenv("DYLD_FALLBACK_LIBRARY_PATH") == NULL)
+    state.library = dlopen("/usr/local/lib/libvulkan.dylib", RTLD_NOW | RTLD_LOCAL);
   ASSERT(state.library, "Failed to load vulkan library") goto fail;
   vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) dlsym(state.library, "vkGetInstanceProcAddr");
 #else
-  state.library = dlopen("libvulkan.so.1", RTLD_NOW | RTLD_LOCAL);
+  if (!state.library) state.library = dlopen("libvulkan.so.1", RTLD_NOW | RTLD_LOCAL);
   if (!state.library) state.library = dlopen("libvulkan.so", RTLD_NOW | RTLD_LOCAL);
   ASSERT(state.library, "Failed to load vulkan library") goto fail;
   vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr) dlsym(state.library, "vkGetInstanceProcAddr");
+#endif
 #endif
   GPU_FOREACH_ANONYMOUS(GPU_LOAD_ANONYMOUS);