From 7caa46e443eb4bb5510288a59bd23b083c79eb6b Mon Sep 17 00:00:00 2001
From: Max Risuhin <risuhin.max@gmail.com>
Date: Mon, 11 Feb 2019 22:27:42 +0200
Subject: [PATCH] Recalculate monitor based DPI scale if Window moved; Set DPI
 awareness of UI on Windows. (#206)

---
 gui/gui.go          | 11 +++++++++++
 platform/winproc.go | 25 +++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/gui/gui.go b/gui/gui.go
index 1b48ded..71a1df6 100644
--- a/gui/gui.go
+++ b/gui/gui.go
@@ -340,6 +340,8 @@ func (gui *GUI) Render() error {
 			gui.terminal.SetDirty()
 		}
 	})
+	gui.window.SetPosCallback(gui.windowPosChangeCallback)
+	glfw.SetMonitorCallback(gui.monitorChangeCallback)
 
 	gui.generateDefaultCell(false)
 
@@ -735,3 +737,12 @@ func (gui *GUI) Screenshot(path string) {
 	defer file.Close()
 	png.Encode(file, img)
 }
+
+func (gui *GUI) windowPosChangeCallback(w *glfw.Window, xpos int, ypos int) {
+	gui.SetDPIScale()
+}
+
+func (gui *GUI) monitorChangeCallback(monitor *glfw.Monitor, event glfw.MonitorEvent) {
+	gui.SetDPIScale()
+}
+
diff --git a/platform/winproc.go b/platform/winproc.go
index 188d183..d816c41 100644
--- a/platform/winproc.go
+++ b/platform/winproc.go
@@ -19,9 +19,11 @@ package platform
 //            PVOID                        lpPreviousValue,
 //            PSIZE_T                      lpReturnSize
 //      );
+//  typedef BOOL (* SetProcessDpiAwarenessContextType)(handle_t);
 //
 //  InitializeProcThreadAttributeListProcType pfnInitializeProcThreadAttributeList = NULL;
 //  UpdateProcThreadAttributeProcType pfnUpdateProcThreadAttribute = NULL;
+//  SetProcessDpiAwarenessContextType pfnSetProcessDpiAwarenessContext = NULL;
 //
 //  #define ProcThreadAttributePseudoConsole 22
 //
@@ -43,6 +45,10 @@ package platform
 //      LPPROC_THREAD_ATTRIBUTE_LIST lpAttributeList;
 //  } STARTUPINFOEXW, *LPSTARTUPINFOEXW;
 //
+//   #ifndef DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2
+//   #define DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 ((handle_t)-4)
+//   #endif
+//
 //  HMODULE hLibKernel32_Proc = NULL;
 //
 //  DWORD initProcKernFuncs()
@@ -68,6 +74,22 @@ package platform
 //      return 0;
 //  }
 //
+//  DWORD enableHiDpiSupport() {
+//      HMODULE hLibUser32_Proc = LoadLibrary( "User32.dll" );
+//      if( hLibUser32_Proc == NULL )
+//      {
+//          return -1;
+//      }
+//
+//      pfnSetProcessDpiAwarenessContext = (SetProcessDpiAwarenessContextType) GetProcAddress(hLibUser32_Proc, "SetProcessDpiAwarenessContext" );
+//      if( pfnInitializeProcThreadAttributeList == NULL )
+//      {
+//          return -1;
+//      }
+//      (*pfnSetProcessDpiAwarenessContext)( DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2 );
+//      return 0;
+//  }
+//
 //  DWORD createGuestProcHelper( uintptr_t hpc, LPCWSTR imagePath, uintptr_t * hProcess, DWORD * dwProcessID )
 //  {
 //      STARTUPINFOEXW si;
@@ -152,6 +174,9 @@ var procsInitSucceeded = false
 
 func init() {
 	ret := int(C.initProcKernFuncs())
+	if ret == 0 {
+		ret = int(C.enableHiDpiSupport())
+	}
 	procsInitSucceeded = (ret == 0)
 }