Dynamically request all vk functions

src/device_handles.rs

@@ -3,6 +3,10 @@ use vulkan_sys::prelude::*;
 
 static mut DEVICE_FN_HANDLES: Option<VkDeviceHandles> = None;
 
+pub fn is_device_fns_initialized() -> bool {
+    unsafe { DEVICE_FN_HANDLES.is_some() }
+}
+
 pub fn device_fns() -> &'static VkDeviceHandles {
     unsafe { DEVICE_FN_HANDLES.as_ref().unwrap() }
 }

src/instance_handles.rs

@@ -2,6 +2,10 @@ use vulkan_sys::prelude::*;
 
 static mut INSTANCE_FN_HANDLES: Option<VkInstanceHandles> = None;
 
+pub fn is_instance_fns_initialized() -> bool {
+    unsafe { INSTANCE_FN_HANDLES.is_some() }
+}
+
 pub fn instance_fns() -> &'static VkInstanceHandles {
     unsafe { INSTANCE_FN_HANDLES.as_ref().unwrap() }
 }

src/lib.rs

@@ -8,6 +8,7 @@ mod instance_handles;
 mod device_handles;
 
 use std::{
+    ffi::c_void,
     fs::{File, OpenOptions},
     io::Write,
     mem,
@@ -265,11 +266,41 @@ fn get_function(function_name: *const c_char) -> PFN_vkVoidFunction {
         _ => (),
     };
 
+    if let Some(vk_fn) = load_vk_fn(&func_string) {
+        return vk_fn;
+    }
+
     write_log(format!("\trequested fn: {}", s));
     write_log(format!("\t-> not found"));
     Functions::Null.convert()
 }
 
+fn load_vk_fn(name: &VkString) -> Option<PFN_vkVoidFunction> {
+    unsafe {
+        if is_instance_fns_initialized() {
+            let instance_fn = instance_fns()
+                .static_functions
+                .vkGetInstanceProcAddr(instance_fns().instance, name.as_ptr());
+
+            if mem::transmute::<PFN_vkVoidFunction, *const c_void>(instance_fn) != ptr::null() {
+                return Some(instance_fn);
+            }
+        }
+
+        if is_device_fns_initialized() {
+            let device_fn = instance_fns()
+                .instance_functions
+                .vkGetDeviceProcAddr(device_fns().device, name.as_ptr());
+
+            if mem::transmute::<PFN_vkVoidFunction, *const c_void>(device_fn) != ptr::null() {
+                return Some(device_fn);
+            }
+        }
+
+        return None;
+    }
+}
+
 extern "system" fn create_instance(
     create_info: *const VkInstanceCreateInfo,
     allocator: *const VkAllocationCallbacks,