opengl3 driver now works on windows including multi window

fixed and simplified gl_manager_windows
swap buffers now called for all windows
fixed missing pixel format setting in additional windows
    this makes them work in OpenGL contexts
changed verbose error printing to write once
    this error message happens very frequently while opengl3 is not finished
removed dead code no longer needed after changes
fixed comments that were misinformation
window messages during window creation now handled
    these were previously discarded
    messages now tunnel the required context
changed failure to create opengl3 window on windows to be more fatal
marked a problem with pen code
conditional compilation of vulkan and opengl3 on windows fixed
windows debug builds now show messages on debug console also
rendering driver selection box now shows only compiled drivers
marked some problematic code
thanks to akien-mga for patiently rewriting my style mistakes

1 files changed, 74 insertions, 14 deletions

diff --git a/platform/windows/display_server_windows.cpp b/platform/windows/display_server_windows.cpp
index b548277f95..7bfe9b64ea 100644
--- a/platform/windows/display_server_windows.cpp
+++ b/platform/windows/display_server_windows.cpp
@@ -607,8 +607,11 @@ void DisplayServerWindows::show_window(WindowID p_id) {
 		_update_window_style(p_id);
 	}
 
-	ShowWindow(wd.hWnd, (wd.no_focus || wd.is_popup) ? SW_SHOWNOACTIVATE : SW_SHOW); // Show the window.
-	if (!wd.no_focus && !wd.is_popup) {
+	if (wd.no_focus || wd.is_popup) {
+		// https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-showwindow
+		ShowWindow(wd.hWnd, SW_SHOWNA);
+	} else {
+		ShowWindow(wd.hWnd, SW_SHOW);
 		SetForegroundWindow(wd.hWnd); // Slightly higher priority.
 		SetFocus(wd.hWnd); // Set keyboard focus.
 	}
@@ -1794,7 +1797,9 @@ void DisplayServerWindows::make_rendering_thread() {
 
 void DisplayServerWindows::swap_buffers() {
 #if defined(GLES3_ENABLED)
-	gl_manager->swap_buffers();
+	if (gl_manager) {
+		gl_manager->swap_buffers();
+	}
 #endif
 }
 
@@ -1946,14 +1951,18 @@ void DisplayServerWindows::set_icon(const Ref<Image> &p_icon) {
 void DisplayServerWindows::window_set_vsync_mode(DisplayServer::VSyncMode p_vsync_mode, WindowID p_window) {
 	_THREAD_SAFE_METHOD_
 #if defined(VULKAN_ENABLED)
-	context_vulkan->set_vsync_mode(p_window, p_vsync_mode);
+	if (context_vulkan) {
+		context_vulkan->set_vsync_mode(p_window, p_vsync_mode);
+	}
 #endif
 }
 
 DisplayServer::VSyncMode DisplayServerWindows::window_get_vsync_mode(WindowID p_window) const {
 	_THREAD_SAFE_METHOD_
 #if defined(VULKAN_ENABLED)
-	return context_vulkan->get_vsync_mode(p_window);
+	if (context_vulkan) {
+		return context_vulkan->get_vsync_mode(p_window);
+	}
 #endif
 	return DisplayServer::VSYNC_ENABLED;
 }
@@ -2187,8 +2196,39 @@ LRESULT DisplayServerWindows::MouseProc(int code, WPARAM wParam, LPARAM lParam)
 	return ::CallNextHookEx(mouse_monitor, code, wParam, lParam);
 }
 
-// Our default window procedure to handle processing of window-related system messages/events.
-// Also known as DefProc or DefWindowProc.
+// Handle a single window message received while CreateWindowEx is still on the stack and our data
+// structures are not fully initialized.
+LRESULT DisplayServerWindows::_handle_early_window_message(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
+	switch (uMsg) {
+		case WM_GETMINMAXINFO: {
+			// We receive this during CreateWindowEx and we haven't initialized the window
+			// struct, so let Windows figure out the maximized size.
+			// Silently forward to user/default.
+		} break;
+		case WM_NCCREATE: {
+			// We tunnel an unowned pointer to our window context (WindowData) through the
+			// first possible message (WM_NCCREATE) to fix up our window context collection.
+			CREATESTRUCTW *pCreate = (CREATESTRUCTW *)lParam;
+			WindowData *pWindowData = reinterpret_cast<WindowData *>(pCreate->lpCreateParams);
+
+			// Fix this up so we can recognize the remaining messages.
+			pWindowData->hWnd = hWnd;
+		} break;
+		default: {
+			// Additional messages during window creation should happen after we fixed
+			// up the data structures on WM_NCCREATE, but this might change in the future,
+			// so report an error here and then we can implement them.
+			ERR_PRINT_ONCE(vformat("Unexpected window message 0x%x received for window we cannot recognize in our collection; sequence error.", uMsg));
+		} break;
+	}
+
+	if (user_proc) {
+		return CallWindowProcW(user_proc, hWnd, uMsg, wParam, lParam);
+	}
+	return DefWindowProcW(hWnd, uMsg, wParam, lParam);
+}
+
+// The window procedure for our window class "Engine", used to handle processing of window-related system messages/events.
 // See: https://docs.microsoft.com/en-us/windows/win32/winmsg/window-procedures
 LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {
 	if (drop_events) {
@@ -2202,7 +2242,9 @@ LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARA
 	WindowID window_id = INVALID_WINDOW_ID;
 	bool window_created = false;
 
-	// Check whether window exists.
+	// Check whether window exists
+	// FIXME this is O(n), where n is the set of currently open windows and subwindows
+	// we should have a secondary map from HWND to WindowID or even WindowData* alias, if we want to eliminate all the map lookups below
 	for (const KeyValue<WindowID, WindowData> &E : windows) {
 		if (E.value.hWnd == hWnd) {
 			window_id = E.key;
@@ -2211,10 +2253,12 @@ LRESULT DisplayServerWindows::WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARA
 		}
 	}
 
-	// Window doesn't exist or creation in progress, don't handle messages yet.
+	// WARNING: we get called with events before the window is registered in our collection
+	// specifically, even the call to CreateWindowEx already calls here while still on the stack,
+	// so there is no way to store the window handle in our collection before we get here
 	if (!window_created) {
-		window_id = window_id_counter;
-		ERR_FAIL_COND_V(!windows.has(window_id), 0);
+		// don't let code below operate on incompletely initialized window objects or missing window_id
+		return _handle_early_window_message(hWnd, uMsg, wParam, lParam);
 	}
 
 	// Process window messages.
@@ -3382,11 +3426,17 @@ DisplayServer::WindowID DisplayServerWindows::_create_window(WindowMode p_mode,
 				WindowRect.top,
 				WindowRect.right - WindowRect.left,
 				WindowRect.bottom - WindowRect.top,
-				nullptr, nullptr, hInstance, nullptr);
+				nullptr,
+				nullptr,
+				hInstance,
+				// tunnel the WindowData we need to handle creation message
+				// lifetime is ensured because we are still on the stack when this is
+				// processed in the window proc
+				reinterpret_cast<void *>(&wd));
 		if (!wd.hWnd) {
 			MessageBoxW(nullptr, L"Window Creation Error.", L"ERROR", MB_OK | MB_ICONEXCLAMATION);
 			windows.erase(id);
-			return INVALID_WINDOW_ID;
+			ERR_FAIL_V_MSG(INVALID_WINDOW_ID, "Failed to create Windows OS window.");
 		}
 		if (p_mode != WINDOW_MODE_FULLSCREEN && p_mode != WINDOW_MODE_EXCLUSIVE_FULLSCREEN) {
 			wd.pre_fs_valid = true;
@@ -3406,7 +3456,14 @@ DisplayServer::WindowID DisplayServerWindows::_create_window(WindowMode p_mode,
 #ifdef GLES3_ENABLED
 		if (gl_manager) {
 			Error err = gl_manager->window_create(id, wd.hWnd, hInstance, WindowRect.right - WindowRect.left, WindowRect.bottom - WindowRect.top);
-			ERR_FAIL_COND_V_MSG(err != OK, INVALID_WINDOW_ID, "Failed to create an OpenGL window.");
+
+			// shut down OpenGL, to mirror behavior of Vulkan code
+			if (err != OK) {
+				memdelete(gl_manager);
+				gl_manager = nullptr;
+				windows.erase(id);
+				ERR_FAIL_V_MSG(INVALID_WINDOW_ID, "Failed to create an OpenGL window.");
+			}
 		}
 #endif
 
@@ -3451,6 +3508,8 @@ DisplayServer::WindowID DisplayServerWindows::_create_window(WindowMode p_mode,
 		ImmReleaseContext(wd.hWnd, wd.im_himc);
 
 		wd.im_position = Vector2();
+
+		// FIXME this is wrong in cases where the window coordinates were changed due to full screen mode; use WindowRect
 		wd.last_pos = p_rect.position;
 		wd.width = p_rect.size.width;
 		wd.height = p_rect.size.height;
@@ -3741,6 +3800,7 @@ DisplayServerWindows::~DisplayServerWindows() {
 
 #ifdef GLES3_ENABLED
 	// destroy windows .. NYI?
+	// FIXME wglDeleteContext is never called
 #endif
 
 	if (windows.has(MAIN_WINDOW_ID)) {