From f7e0465dc3ea001f4ae37185fd0ea8479449079f Mon Sep 17 00:00:00 2001
From: Zero <128979226+lux-zero-161@users.noreply.github.com>
Date: Sat, 20 Jun 2026 15:57:06 +0200
Subject: [PATCH] RmlUi: DPI scaling now uses the window size instead of the
 desktop resolution and is updated when the window is resized.

---
 Minecraft.Client/RmlManager.cpp     | 27 ++++++++++++++-------------
 Minecraft.Client/RmlManager.h       |  5 ++++-
 Minecraft.Server/RmlManagerStub.cpp |  2 +-
 3 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/Minecraft.Client/RmlManager.cpp b/Minecraft.Client/RmlManager.cpp
index 38c223df..d0386b6e 100644
--- a/Minecraft.Client/RmlManager.cpp
+++ b/Minecraft.Client/RmlManager.cpp
@@ -26,6 +26,8 @@ RmlManager& RmlManager::Get()
 RmlManager::RmlManager()
 	: m_initialised(false)
 	, m_context(nullptr)
+	, m_viewport_width(0)
+	, m_viewport_height(0)
 {
 }
 
@@ -88,12 +90,15 @@ bool RmlManager::Init(int viewport_width, int viewport_height)
 
 	app.DebugPrintf("[RmlManager] Context created (%dx%d)\n", viewport_width, viewport_height);
 
+	m_viewport_width = viewport_width;
+	m_viewport_height = viewport_height;
+
 	m_renderer->SetViewport(viewport_width, viewport_height);
 	m_initialised = true;
 
 	app.DebugPrintf("[RmlManager] Initialised (%dx%d)\n", viewport_width, viewport_height);
 
-	UpdateDpRatio();
+	UpdateDpRatio(m_viewport_width, m_viewport_height);
 
 	return true;
 }
@@ -170,28 +175,24 @@ void RmlManager::OnResize(int width, int height)
 {
 	if (!m_initialised || !m_context)
 		return;
+	m_viewport_width = width;
+	m_viewport_height = height;
 	m_context->SetDimensions(Rml::Vector2i(width, height));
 	m_renderer->SetViewport(width, height);
+	UpdateDpRatio(width, height);
 }
 
-// GabsPuN: Taken from the Quake port as something temporary
-void RmlManager::UpdateDpRatio()
+void RmlManager::UpdateDpRatio(int viewport_width, int viewport_height)
 {
 	if (!m_context)
 		return;
 
-	int width = GetSystemMetrics(SM_CXSCREEN);
-	int height = GetSystemMetrics(SM_CYSCREEN);
-
-	float scale_x = static_cast<float>(width) / 1920;
-	float scale_y = static_cast<float>(height) / 1080;
+	float scale_x = static_cast<float>(viewport_width) / 1920;
+	float scale_y = static_cast<float>(viewport_height) / 1080;
 	float base_ratio = (scale_x < scale_y) ? scale_x : scale_y;
 
-	float blend = (base_ratio > 1.0f) ? std::min(base_ratio - 1.0f, 1.0f) : 0.0f;
-	float effective_dpi = (1.0f - blend) + blend;
-
-	float auto_dp = base_ratio * effective_dpi;
-	float viewport_cap = 0.88f * static_cast<float>(height) / 850.0f;
+	float auto_dp = base_ratio;
+	float viewport_cap = 0.88f * static_cast<float>(viewport_height) / 850.0f;
 	if (auto_dp > viewport_cap)
 		auto_dp = viewport_cap;
 
diff --git a/Minecraft.Client/RmlManager.h b/Minecraft.Client/RmlManager.h
index 80e30ea0..15f590ab 100644
--- a/Minecraft.Client/RmlManager.h
+++ b/Minecraft.Client/RmlManager.h
@@ -31,7 +31,7 @@ public:
 	RenderInterface_D3D11* GetRenderInterface() const { return m_renderer.get(); }
 
 	void OnResize(int width, int height);
-	void UpdateDpRatio();
+	void UpdateDpRatio(int viewport_width, int viewport_height);
 
 	void OnLanguageChanged();
 
@@ -48,6 +48,9 @@ private:
 	std::unique_ptr<FileInterface_Game> m_file_interface;
 
 	Rml::Context* m_context;
+
+	int m_viewport_width;
+	int m_viewport_height;
 };
 
 #pragma pop_macro("GetFirstChild")
diff --git a/Minecraft.Server/RmlManagerStub.cpp b/Minecraft.Server/RmlManagerStub.cpp
index 0f39b6cc..ce057d64 100644
--- a/Minecraft.Server/RmlManagerStub.cpp
+++ b/Minecraft.Server/RmlManagerStub.cpp
@@ -18,5 +18,5 @@ void RmlManager::Shutdown() {}
 void RmlManager::Update() {}
 void RmlManager::Render() {}
 void RmlManager::OnResize(int width, int height) {}
-void RmlManager::UpdateDpRatio() {}
+void RmlManager::UpdateDpRatio(int, int) {}
 void RmlManager::OnLanguageChanged() {}
\ No newline at end of file