From 4aef5c1dd475f8ce2a4f64f1310bd2265beb3136 Mon Sep 17 00:00:00 2001
From: Daniel Gibson <metalcaedes@gmail.com>
Date: Tue, 18 Feb 2025 06:18:43 +0100
Subject: [PATCH] Fix mousecursor handling for menus using "scaleto43 0"

especially useful when using cstAnchor

also providing an easy generic way to figure out if the window of an
idUserInterface is scaled to 4:3 aspect ratio or not, depending on
r_scaleMenusTo43 and the WIN_SCALETO43/WIN_NO_SCALETO43 window flags,
that come from "scaleto43 1" (or 0) set in the GUIs Desktop windowDef
---
 neo/sys/sys_imgui.cpp    |  3 ++-
 neo/ui/UserInterface.cpp | 27 ++++++++++++++++++++++++++-
 neo/ui/UserInterface.h   |  4 ++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/neo/sys/sys_imgui.cpp b/neo/sys/sys_imgui.cpp
index 353b380e..0a23ff1e 100644
--- a/neo/sys/sys_imgui.cpp
+++ b/neo/sys/sys_imgui.cpp
@@ -39,6 +39,7 @@
 #include "renderer/qgl.h"
 #include "renderer/tr_local.h" // glconfig
 #include "ui/DeviceContext.h"
+#include "ui/UserInterface.h"
 
 extern void Com_DrawDhewm3SettingsMenu(); // in framework/dhewm3SettingsMenu.cpp
 extern void Com_OpenCloseDhewm3SettingsMenu( bool open ); // ditto
@@ -487,7 +488,7 @@ bool ShouldShowCursor()
 		}
 		// if scaling Doom3 menus to 4:3 is enabled and the cursor is currently
 		// in a black bar (Doom3 cursor is not drawn there), show the ImGui cursor
-		if ( r_scaleMenusTo43.GetBool() ) {
+		if ( idUserInterface::IsUserInterfaceScaledTo43( sessLocal.GetActiveMenu() ) ) {
 			ImVec2 mousePos = ImGui::GetMousePos();
 			float w = glConfig.winWidth;
 			float h = glConfig.winHeight;
diff --git a/neo/ui/UserInterface.cpp b/neo/ui/UserInterface.cpp
index 01208acd..beda9a29 100644
--- a/neo/ui/UserInterface.cpp
+++ b/neo/ui/UserInterface.cpp
@@ -339,6 +339,31 @@ bool idUserInterfaceLocal::InitFromFile( const char *qpath, bool rebuild, bool c
 	return true;
 }
 
+// static
+bool idUserInterface::IsUserInterfaceScaledTo43( const idUserInterface* ui_ )
+{
+	const idUserInterfaceLocal* ui = (const idUserInterfaceLocal*)ui_;
+	if ( ui == NULL ) {
+		assert( 0 && "why do you call this without a ui?!" );
+		return false;
+	}
+	idWindow* win = ui->GetDesktop();
+	if ( win == NULL ) {
+		return false;
+	}
+	int winFlags = win->GetFlags();
+	if ( (winFlags & WIN_MENUGUI) == 0 || !r_scaleMenusTo43.GetBool() ) {
+		// if the window is no fullscreen menu (but an ingame menu or noninteractive like the HUD)
+		// or scaling menus to 4:3 by default (r_scaleMenusTo43) is disabled,
+		// they only get scaled if they explicitly requested it with "scaleto43 1"
+		return (winFlags & WIN_SCALETO43) != 0;
+	} else {
+		// if it's a fullscreen menu and r_scaleMenusTo43 is enabled,
+		// they get scaled to 4:3 unless they explicitly disable it with "scaleto43 0"
+		return (winFlags & WIN_NO_SCALETO43) == 0;
+	}
+}
+
 const char *idUserInterfaceLocal::HandleEvent( const sysEvent_t *event, int _time, bool *updateVisuals ) {
 
 	time = _time;
@@ -366,7 +391,7 @@ const char *idUserInterfaceLocal::HandleEvent( const sysEvent_t *event, int _tim
 			const float realW = w;
 			const float realH = h;
 
-			if(r_scaleMenusTo43.GetBool()) {
+			if ( IsUserInterfaceScaledTo43(this) ) {
 				// in case we're scaling menus to 4:3, we need to take that into account
 				// when scaling the mouse events.
 				// no, we can't just call uiManagerLocal.dc.GetFixScaleForMenu() or sth like that,
diff --git a/neo/ui/UserInterface.h b/neo/ui/UserInterface.h
index 2b5eb0a1..539b1cae 100644
--- a/neo/ui/UserInterface.h
+++ b/neo/ui/UserInterface.h
@@ -114,6 +114,10 @@ public:
 	virtual void				SetCursor( float x, float y ) = 0;
 	virtual float				CursorX() = 0;
 	virtual float				CursorY() = 0;
+
+	// DG: making this static so it doesn't change the vtable (and thus ABI)
+	// returns true if the ui's window is *not* being scaled to 4:3
+	static bool					IsUserInterfaceScaledTo43( const idUserInterface* ui );
 };