From f651268309263fa67fa84caf9fb6dbebb5c900d9 Mon Sep 17 00:00:00 2001
From: Sean Hall <r.sean.hall@gmail.com>
Date: Tue, 7 Jul 2020 14:04:39 +1000
Subject: Add DpiuSetProcessDpiAwareness.

---
 src/dutil/dpiutil.cpp   | 78 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/dutil/inc/dpiutil.h | 26 +++++++++++++++++
 2 files changed, 104 insertions(+)

(limited to 'src')

diff --git a/src/dutil/dpiutil.cpp b/src/dutil/dpiutil.cpp
index 02a9580c..4096c8d3 100644
--- a/src/dutil/dpiutil.cpp
+++ b/src/dutil/dpiutil.cpp
@@ -18,6 +18,9 @@
 static PFN_ADJUSTWINDOWRECTEXFORDPI vpfnAdjustWindowRectExForDpi = NULL;
 static PFN_GETDPIFORMONITOR vpfnGetDpiForMonitor = NULL;
 static PFN_GETDPIFORWINDOW vpfnGetDpiForWindow = NULL;
+static PFN_SETPROCESSDPIAWARE vpfnSetProcessDPIAware = NULL;
+static PFN_SETPROCESSDPIAWARENESS vpfnSetProcessDpiAwareness = NULL;
+static PFN_SETPROCESSDPIAWARENESSCONTEXT vpfnSetProcessDpiAwarenessContext = NULL;
 
 static HMODULE vhShcoreDll = NULL;
 static HMODULE vhUser32Dll = NULL;
@@ -32,6 +35,7 @@ DAPI_(void) DpiuInitialize()
     {
         // Ignore failures.
         vpfnGetDpiForMonitor = reinterpret_cast<PFN_GETDPIFORMONITOR>(::GetProcAddress(vhShcoreDll, "GetDpiForMonitor"));
+        vpfnSetProcessDpiAwareness = reinterpret_cast<PFN_SETPROCESSDPIAWARENESS>(::GetProcAddress(vhShcoreDll, "SetProcessDpiAwareness"));
     }
 
     hr = LoadSystemLibrary(L"User32.dll", &vhUser32Dll);
@@ -40,6 +44,8 @@ DAPI_(void) DpiuInitialize()
         // Ignore failures.
         vpfnAdjustWindowRectExForDpi = reinterpret_cast<PFN_ADJUSTWINDOWRECTEXFORDPI>(::GetProcAddress(vhUser32Dll, "AdjustWindowRectExForDpi"));
         vpfnGetDpiForWindow = reinterpret_cast<PFN_GETDPIFORWINDOW>(::GetProcAddress(vhUser32Dll, "GetDpiForWindow"));
+        vpfnSetProcessDPIAware = reinterpret_cast<PFN_SETPROCESSDPIAWARE>(::GetProcAddress(vhUser32Dll, "SetProcessDPIAware"));
+        vpfnSetProcessDpiAwarenessContext = reinterpret_cast<PFN_SETPROCESSDPIAWARENESSCONTEXT>(::GetProcAddress(vhUser32Dll, "SetProcessDpiAwarenessContext"));
     }
 
     vfDpiuInitialized = TRUE;
@@ -194,3 +200,75 @@ DAPI_(int) DpiuScaleValue(
 {
     return ::MulDiv(nDefaultDpiValue, nTargetDpi, USER_DEFAULT_SCREEN_DPI);
 }
+
+DAPI_(HRESULT) DpiuSetProcessDpiAwareness(
+    __in DPIU_AWARENESS supportedAwareness,
+    __in_opt DPIU_AWARENESS* pSelectedAwareness
+    )
+{
+    HRESULT hr = S_OK;
+    DPIU_AWARENESS selectedAwareness = DPIU_AWARENESS_NONE;
+    DPI_AWARENESS_CONTEXT awarenessContext = DPI_AWARENESS_CONTEXT_UNAWARE;
+    PROCESS_DPI_AWARENESS awareness = PROCESS_DPI_UNAWARE;
+
+    if (vpfnSetProcessDpiAwarenessContext)
+    {
+        if (DPIU_AWARENESS_PERMONITORV2 & supportedAwareness)
+        {
+            awarenessContext = DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2;
+            selectedAwareness = DPIU_AWARENESS_PERMONITORV2;
+        }
+        else if (DPIU_AWARENESS_PERMONITOR & supportedAwareness)
+        {
+            awarenessContext = DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE;
+            selectedAwareness = DPIU_AWARENESS_PERMONITOR;
+        }
+        else if (DPIU_AWARENESS_SYSTEM & supportedAwareness)
+        {
+            awarenessContext = DPI_AWARENESS_CONTEXT_SYSTEM_AWARE;
+            selectedAwareness = DPIU_AWARENESS_SYSTEM;
+        }
+        else if (DPIU_AWARENESS_GDISCALED & supportedAwareness)
+        {
+            awarenessContext = DPI_AWARENESS_CONTEXT_UNAWARE_GDISCALED;
+            selectedAwareness = DPIU_AWARENESS_GDISCALED;
+        }
+
+        if (!vpfnSetProcessDpiAwarenessContext(awarenessContext))
+        {
+            DpiuExitOnLastError(hr, "Failed to set process DPI awareness context.");
+        }
+    }
+    else if (vpfnSetProcessDpiAwareness)
+    {
+        if (DPIU_AWARENESS_PERMONITOR & supportedAwareness)
+        {
+            awareness = PROCESS_PER_MONITOR_DPI_AWARE;
+            selectedAwareness = DPIU_AWARENESS_PERMONITOR;
+        }
+        else if (DPIU_AWARENESS_SYSTEM & supportedAwareness)
+        {
+            awareness = PROCESS_SYSTEM_DPI_AWARE;
+            selectedAwareness = DPIU_AWARENESS_SYSTEM;
+        }
+
+        hr = vpfnSetProcessDpiAwareness(awareness);
+        DpiuExitOnFailure(hr, "Failed to set process DPI awareness.");
+    }
+    else if (vpfnSetProcessDPIAware && (DPIU_AWARENESS_SYSTEM & supportedAwareness))
+    {
+        selectedAwareness = DPIU_AWARENESS_SYSTEM;
+        if (!vpfnSetProcessDPIAware())
+        {
+            DpiuExitOnLastError(hr, "Failed to set process DPI aware.");
+        }
+    }
+
+LExit:
+    if (pSelectedAwareness)
+    {
+        *pSelectedAwareness = selectedAwareness;
+    }
+
+    return hr;
+}
diff --git a/src/dutil/inc/dpiutil.h b/src/dutil/inc/dpiutil.h
index 4ea689c5..216d3dc6 100644
--- a/src/dutil/inc/dpiutil.h
+++ b/src/dutil/inc/dpiutil.h
@@ -14,6 +14,15 @@ extern "C" {
 #define USER_DEFAULT_SCREEN_DPI 96
 #endif
 
+typedef enum DPIU_AWARENESS
+{
+    DPIU_AWARENESS_NONE = 0x0,
+    DPIU_AWARENESS_SYSTEM = 0x1,
+    DPIU_AWARENESS_PERMONITOR = 0x2,
+    DPIU_AWARENESS_PERMONITORV2 = 0x4,
+    DPIU_AWARENESS_GDISCALED = 0x8,
+} DPIU_PROCESS_AWARENESS;
+
 typedef struct _DPIU_MONITOR_CONTEXT
 {
     UINT nDpi;
@@ -41,6 +50,13 @@ typedef HRESULT (APIENTRY *PFN_GETDPIFORMONITOR)(
 typedef UINT (APIENTRY *PFN_GETDPIFORWINDOW)(
     __in HWND hwnd
     );
+typedef BOOL (APIENTRY* PFN_SETPROCESSDPIAWARE)();
+typedef HRESULT (APIENTRY* PFN_SETPROCESSDPIAWARENESS)(
+    __in PROCESS_DPI_AWARENESS value
+    );
+typedef BOOL (APIENTRY* PFN_SETPROCESSDPIAWARENESSCONTEXT)(
+    __in DPI_AWARENESS_CONTEXT value
+    );
 
 void DAPI DpiuInitialize();
 void DAPI DpiuUninitialize();
@@ -86,6 +102,16 @@ int DAPI DpiuScaleValue(
     __in UINT nTargetDpi
     );
 
+/********************************************************************
+ DpiuSetProcessDpiAwareness - set the process DPI awareness. The ranking is
+     PERMONITORV2 > PERMONITOR > SYSTEM > GDISCALED > NONE.
+
+*******************************************************************/
+HRESULT DAPI DpiuSetProcessDpiAwareness(
+    __in DPIU_AWARENESS supportedAwareness,
+    __in_opt DPIU_AWARENESS* pSelectedAwareness
+    );
+
 #ifdef __cplusplus
 }
 #endif
-- 
cgit v1.2.3-55-g6feb