From daff54fe1c8f0bc0b64bf5f18f7ec23c269fc680 Mon Sep 17 00:00:00 2001
From: Marcus Minhorst <marcus.minhorst@gmail.com>
Date: Mon, 11 Aug 2025 12:34:42 -0400
Subject: [PATCH] Added alt+enter fullscreen keybind

---
 src/common/engine/d_event.cpp             | 25 ++++++++++++++++++-----
 src/common/platform/posix/sdl/i_input.cpp |  4 ++++
 src/common/platform/win32/i_input.cpp     |  5 -----
 src/common/platform/win32/i_keyboard.cpp  |  4 +++-
 4 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/src/common/engine/d_event.cpp b/src/common/engine/d_event.cpp
index ce11d3b1e..3aa2d3f8f 100644
--- a/src/common/engine/d_event.cpp
+++ b/src/common/engine/d_event.cpp
@@ -34,15 +34,19 @@
 */ 
 
 #include "c_bind.h"
-#include "d_eventbase.h"
 #include "c_console.h"
+#include "c_cvars.h"
+#include "d_eventbase.h"
 #include "d_gui.h"
-#include "menu.h"
-#include "utf8.h"
-#include "m_joy.h"
-#include "vm.h"
 #include "gamestate.h"
 #include "i_interface.h"
+#include "keydef.h"
+#include "m_joy.h"
+#include "menu.h"
+#include "utf8.h"
+#include "vm.h"
+
+extern bool ToggleFullscreen;
 
 int eventhead;
 int eventtail;
@@ -73,6 +77,7 @@ void D_ProcessEvents (void)
 	while (eventtail != eventhead)
 	{
 		event_t *ev = &events[eventtail];
+
 		eventtail = (eventtail + 1) & (MAXEVENTS - 1);
 
 		if (ev->type == EV_KeyUp && keywasdown[ev->data1])
@@ -86,6 +91,16 @@ void D_ProcessEvents (void)
 		if (ev->type == EV_DeviceChange)
 			UpdateJoystickMenu(I_UpdateDeviceList());
 
+#if defined(__linux__) || defined(_WIN32)
+		// I cannot test on macos, so it is disabled for now
+		if ((ev->type == EV_KeyDown && ev->data1 == KEY_ENTER && (ev->data3 & GKM_ALT))
+		|| (ev->type == EV_GUI_Event && ev->subtype == EV_GUI_KeyDown && ev->data1 == GK_RETURN && (ev->data3 & GKM_ALT)))
+		{
+			ToggleFullscreen = !ToggleFullscreen;
+			continue;
+		}
+#endif
+
 		// allow the game to intercept Escape before dispatching it.
 		if (ev->type != EV_KeyDown || ev->data1 != KEY_ESCAPE || !sysCallbacks.WantEscape || !sysCallbacks.WantEscape())
 		{
diff --git a/src/common/platform/posix/sdl/i_input.cpp b/src/common/platform/posix/sdl/i_input.cpp
index da7ac59c2..ef1c11e9d 100644
--- a/src/common/platform/posix/sdl/i_input.cpp
+++ b/src/common/platform/posix/sdl/i_input.cpp
@@ -449,6 +449,10 @@ void MessagePump (const SDL_Event &sev)
 				{
 					event.data2 = sev.key.keysym.sym;
 				}
+				SDL_Keymod kmod = SDL_GetModState();
+				event.data3 = ((kmod & KMOD_SHIFT) ? GKM_SHIFT : 0) |
+					((kmod & KMOD_CTRL) ? GKM_CTRL : 0) |
+					((kmod & KMOD_ALT) ? GKM_ALT : 0);
 				D_PostEvent (&event);
 			}
 		}
diff --git a/src/common/platform/win32/i_input.cpp b/src/common/platform/win32/i_input.cpp
index 121d06c2d..2a4ea0ddd 100644
--- a/src/common/platform/win32/i_input.cpp
+++ b/src/common/platform/win32/i_input.cpp
@@ -441,11 +441,6 @@ LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
 		break;
 
 	case WM_SYSKEYDOWN:
-		// Pressing Alt+Enter can toggle between fullscreen and windowed.
-		if (wParam == VK_RETURN && k_allowfullscreentoggle && !(lParam & 0x40000000))
-		{
-			ToggleFullscreen = !ToggleFullscreen;
-		}
 		// Pressing Alt+F4 quits the program.
 		if (wParam == VK_F4 && !(lParam & 0x40000000))
 		{
diff --git a/src/common/platform/win32/i_keyboard.cpp b/src/common/platform/win32/i_keyboard.cpp
index 33cf6da5b..4e0a9d451 100644
--- a/src/common/platform/win32/i_keyboard.cpp
+++ b/src/common/platform/win32/i_keyboard.cpp
@@ -277,7 +277,9 @@ void FKeyboard::PostKeyEvent(int key, INTBOOL down, bool foreground)
 	ev.data1 = key;
 	ev.data2 = Convert[key];
 	ev.data3 = 0;
-	if (CheckKey(DIK_LSHIFT) || CheckKey(DIK_RSHIFT)) ev.data3 |= 1;
+	if (CheckKey(DIK_LSHIFT)   || CheckKey(DIK_RSHIFT))   ev.data3 |= GKM_SHIFT;
+	if (CheckKey(DIK_LCONTROL) || CheckKey(DIK_RCONTROL)) ev.data3 |= GKM_CTRL;
+	if (CheckKey(DIK_LALT)     || CheckKey(DIK_RALT))     ev.data3 |= GKM_ALT;
 	D_PostEvent(&ev);
 }