Win32: Use the proper HInstance value

src/platform/win/gl.rs

@@ -4,7 +4,7 @@ use std::rc::Rc;
 use windows_sys::{
     core::s,
     Win32::{
-        Foundation::{FreeLibrary, HINSTANCE, HMODULE, HWND},
+        Foundation::{FreeLibrary, HMODULE, HWND},
         Graphics::{
             Gdi::{GetDC, ReleaseDC, HDC},
             OpenGL::{
@@ -14,10 +14,7 @@ use windows_sys::{
                 PFD_TYPE_RGBA, PIXELFORMATDESCRIPTOR,
             },
         },
-        System::{
-            LibraryLoader::{GetProcAddress, LoadLibraryA},
-            SystemServices::IMAGE_DOS_HEADER,
-        },
+        System::LibraryLoader::{GetProcAddress, LoadLibraryA},
         UI::WindowsAndMessaging::{
             CreateWindowExW, DefWindowProcW, DestroyWindow, RegisterClassW, UnregisterClassW,
             CS_OWNDC, CW_USEDEFAULT, WNDCLASSW,
@@ -26,6 +23,7 @@ use windows_sys::{
 };
 
 use crate::gl::*;
+use crate::wrappers::win32::h_instance::HInstance;
 use crate::wrappers::win32::uuid::Uuid;
 use crate::wrappers::win32::window::HWnd;
 // See https://www.khronos.org/registry/OpenGL/extensions/ARB/WGL_ARB_create_context.txt
@@ -82,10 +80,6 @@ pub struct GlContextInner {
     gl_library: HMODULE,
 }
 
-extern "C" {
-    static __ImageBase: IMAGE_DOS_HEADER;
-}
-
 impl GlContextInner {
     pub unsafe fn create(window: HWnd, config: GlConfig) -> Result<Self, GlError> {
         // Create temporary window and context to load function pointers
@@ -94,12 +88,12 @@ impl GlContextInner {
         let mut class_name: Vec<u16> = OsStr::new(&class_name_str).encode_wide().collect();
         class_name.push(0);
 
-        let hinstance = &__ImageBase as *const IMAGE_DOS_HEADER as HINSTANCE;
+        let hinstance = HInstance::get_from_dll();
 
         let wnd_class = WNDCLASSW {
             style: CS_OWNDC,
             lpfnWndProc: Some(DefWindowProcW),
-            hInstance: hinstance,
+            hInstance: hinstance.as_raw(),
             lpszClassName: class_name.as_ptr(),
             ..std::mem::zeroed()
         };
@@ -120,7 +114,7 @@ impl GlContextInner {
             CW_USEDEFAULT,
             std::ptr::null_mut(),
             std::ptr::null_mut(),
-            hinstance,
+            hinstance.as_raw(),
             std::ptr::null_mut(),
         );
 
@@ -148,7 +142,7 @@ impl GlContextInner {
         let hglrc_tmp = wglCreateContext(hdc_tmp);
         if hglrc_tmp.is_null() {
             ReleaseDC(hwnd_tmp, hdc_tmp);
-            UnregisterClassW(class as *const _, hinstance);
+            UnregisterClassW(class as *const _, hinstance.as_raw());
             DestroyWindow(hwnd_tmp);
             return Err(GlError::CreationFailed(()));
         }
@@ -173,7 +167,7 @@ impl GlContextInner {
         wglMakeCurrent(hdc_tmp, std::ptr::null_mut());
         wglDeleteContext(hglrc_tmp);
         ReleaseDC(hwnd_tmp, hdc_tmp);
-        UnregisterClassW(class as *const _, hinstance);
+        UnregisterClassW(class as *const _, hinstance.as_raw());
         DestroyWindow(hwnd_tmp);
 
         // Create actual context

src/platform/win/mod.rs

@@ -4,6 +4,7 @@ mod keyboard;
 mod window;
 mod window_state;
 
+use crate::wrappers::win32::h_instance::HInstance;
 use raw_window_handle::{DisplayHandle, Win32WindowHandle};
 use std::fmt::Debug;
 use std::num::NonZeroIsize;
@@ -22,8 +23,9 @@ pub struct PlatformHandle {
 
 impl PlatformHandle {
     pub fn window_handle(&self) -> Option<raw_window_handle::WindowHandle<'_>> {
-        let handle = Win32WindowHandle::new(self.hwnd);
-        // TODO: add HINSTANCE
+        let mut handle = Win32WindowHandle::new(self.hwnd);
+        handle.hinstance = Some(HInstance::get_from_dll().addr());
+
         Some(unsafe { raw_window_handle::WindowHandle::borrow_raw(handle.into()) })
     }
 
@@ -34,6 +36,9 @@ impl PlatformHandle {
 
 impl Debug for PlatformHandle {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("PlatformHandle (Win32)").field("hwnd", &self.hwnd.get()).finish()
+        f.debug_struct("PlatformHandle (Win32)")
+            .field("hwnd", &self.hwnd.get())
+            .field("hinstance", &HInstance::get_from_dll().addr().get())
+            .finish()
     }
 }

src/platform/win/window_state.rs

@@ -1,6 +1,7 @@
 use crate::platform::win::keyboard::KeyboardState;
 use crate::platform::PlatformHandle;
 use crate::wrappers::win32::cursor::SystemCursor;
+use crate::wrappers::win32::h_instance::HInstance;
 use crate::wrappers::win32::window::HWnd;
 use crate::wrappers::win32::{Dpi, ExtendedUser32};
 use crate::{Event, EventStatus, MouseCursor, WindowHandler, WindowScalePolicy, WindowSize};
@@ -132,8 +133,9 @@ impl WindowState {
 
     pub fn window_handle(&self) -> Option<raw_window_handle::WindowHandle<'_>> {
         let Some(hwnd) = NonZeroIsize::new(self.hwnd as _) else { unreachable!() };
-        let handle = Win32WindowHandle::new(hwnd);
-        // TODO: add HINSTANCE
+        let mut handle = Win32WindowHandle::new(hwnd);
+        handle.hinstance = Some(HInstance::get_from_dll().addr());
+
         Some(unsafe { raw_window_handle::WindowHandle::borrow_raw(handle.into()) })
     }
 

src/wrappers/win32/h_instance.rs

@@ -1,8 +1,8 @@
 use std::ffi::c_void;
-use std::ptr::{null_mut, NonNull};
-use windows_core::Error;
+use std::num::NonZeroIsize;
+use std::ptr::NonNull;
 use windows_sys::Win32::Foundation::HINSTANCE;
-use windows_sys::Win32::System::LibraryLoader::GetModuleHandleW;
+use windows_sys::Win32::System::SystemServices::IMAGE_DOS_HEADER;
 
 #[derive(Copy, Clone, PartialEq)]
 pub struct HInstance(NonNull<c_void>);
@@ -16,21 +16,23 @@ unsafe impl Send for HInstance {}
 unsafe impl Sync for HInstance {}
 
 impl HInstance {
-    pub fn get() -> Self {
-        let result = unsafe { GetModuleHandleW(null_mut()) };
+    pub fn get_from_dll() -> Self {
+        extern "C" {
+            static __ImageBase: IMAGE_DOS_HEADER;
+        }
 
-        let Some(result) = NonNull::new(result) else {
-            panic!(
-                "Failed to get HInstance pointer: GetModuleHandleW failed: {}",
-                Error::from_thread()
-            )
-        };
-
-        Self(result)
+        unsafe { Self(NonNull::from(&__ImageBase).cast()) }
     }
 
     #[inline]
     pub fn as_raw(&self) -> HINSTANCE {
         self.0.as_ptr()
     }
+
+    pub fn addr(&self) -> NonZeroIsize {
+        match NonZeroIsize::new(self.0.as_ptr() as isize) {
+            Some(addr) => addr,
+            None => unreachable!(),
+        }
+    }
 }

src/wrappers/win32/window.rs

@@ -54,7 +54,7 @@ pub fn create_window<W: WindowImpl>(
     title: &HSTRING, style: WindowStyle, nc_size: PhysicalSize<u32>, parent: HWND,
     _dpi_ctx: &DpiAwarenessContext, initializer: impl FnOnce(HWnd) -> W + 'static,
 ) -> Result<HWND> {
-    let instance = HInstance::get();
+    let instance = HInstance::get_from_dll();
     let window_class = RegisteredClass::register_new(instance, Some(wnd_proc::<W>))?;
 
     let data = WindowData::new(initializer, window_class.clone());