From 20d9c7181f3c8dfbac92e27b241e06a957ff368b Mon Sep 17 00:00:00 2001
From: stefnotch <brandmairstefan@gmail.com>
Date: Mon, 8 Feb 2021 10:07:38 +0100
Subject: [PATCH] Untested cross platform implementation

---
 Source/Engine/Platform/Android/AndroidWindow.cpp | 4 ++++
 Source/Engine/Platform/Linux/LinuxWindow.cpp     | 4 ++++
 Source/Engine/Platform/UWP/UWPWindow.h           | 1 -
 Source/Engine/Platform/Windows/WindowsWindow.cpp | 2 +-
 4 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/Source/Engine/Platform/Android/AndroidWindow.cpp b/Source/Engine/Platform/Android/AndroidWindow.cpp
index abfee9d13..4d3c4ca67 100644
--- a/Source/Engine/Platform/Android/AndroidWindow.cpp
+++ b/Source/Engine/Platform/Android/AndroidWindow.cpp
@@ -6,10 +6,14 @@
 #include "Engine/Graphics/RenderTask.h"
 #include <Engine/Main/Android/android_native_app_glue.h>
 
+#define DefaultDPI 96
+
 AndroidWindow::AndroidWindow(const CreateWindowSettings& settings)
     : WindowBase(settings)
 {
     _clientSize = settings.Size;
+    _dpi = DefaultDPI;
+    _dpiScale = (float)_dpi / (float)DefaultDPI;
 }
 
 AndroidWindow::~AndroidWindow()
diff --git a/Source/Engine/Platform/Linux/LinuxWindow.cpp b/Source/Engine/Platform/Linux/LinuxWindow.cpp
index 768df66bd..c83298bc8 100644
--- a/Source/Engine/Platform/Linux/LinuxWindow.cpp
+++ b/Source/Engine/Platform/Linux/LinuxWindow.cpp
@@ -31,6 +31,7 @@
 #define _NET_WM_STATE_REMOVE 0L // remove/unset property
 #define _NET_WM_STATE_ADD 1L // add/set property
 #define _NET_WM_STATE_TOGGLE 2L // toggle property
+#define DefaultDPI 96
 
 // Window routines function prolog
 #define LINUX_WINDOW_PROLOG X11::Display* display = (X11::Display*)LinuxPlatform::GetXDisplay(); X11::Window window =  (X11::Window)_window
@@ -138,6 +139,9 @@ LinuxWindow::LinuxWindow(const CreateWindowSettings& settings)
 	if (settings.Parent)
 		X11::XSetTransientForHint(display, window, (X11::Window)((LinuxWindow*)settings.Parent)->GetNativePtr());
 
+    _dpi = Platform::GetDpi();
+    _dpiScale = (float)_dpi / (float)DefaultDPI;
+    
 	// Set mask
 	long eventMask =
 			ExposureMask | FocusChangeMask |
diff --git a/Source/Engine/Platform/UWP/UWPWindow.h b/Source/Engine/Platform/UWP/UWPWindow.h
index e687ba32a..f73a046dc 100644
--- a/Source/Engine/Platform/UWP/UWPWindow.h
+++ b/Source/Engine/Platform/UWP/UWPWindow.h
@@ -100,7 +100,6 @@ private:
 
     UWPWindowImpl* _impl;
 
-    float _dpi, _dpiScale;
     Vector2 _logicalSize;
 
 public:
diff --git a/Source/Engine/Platform/Windows/WindowsWindow.cpp b/Source/Engine/Platform/Windows/WindowsWindow.cpp
index 74d56d4b9..cec9f6cf1 100644
--- a/Source/Engine/Platform/Windows/WindowsWindow.cpp
+++ b/Source/Engine/Platform/Windows/WindowsWindow.cpp
@@ -98,7 +98,7 @@ WindowsWindow::WindowsWindow(const CreateWindowSettings& settings)
         (HINSTANCE)Platform::Instance,
         nullptr);
     
-    _dpi = DefaultDPI;
+    _dpi = Platform::GetDpi();
     
     const HMODULE user32Dll = LoadLibraryW(L"user32.dll");
     if (user32Dll)