Load shcore at runtime and fallback if newer DPI funcs are unavailable

Fixes Windows 7 and 8.1 support

Author: CakeLancelot

Makefile

@@ -20,7 +20,7 @@ ffrunner.res: ffrunner.rc
 	$(WINDRES) ffrunner.rc -O coff -o ffrunner.res
 
 ffrunner.exe: ffrunner.res $(SRC) $(HDR)
-	$(CC) -std=c99 -pedantic -mwindows -Wl,--large-address-aware -O0 -g $(SRC) -o ffrunner.exe ffrunner.res -lwindowscodecs -lwininet -ldxgi -lshcore
+	$(CC) -std=c99 -pedantic -mwindows -Wl,--large-address-aware -O0 -g $(SRC) -o ffrunner.exe ffrunner.res -lwindowscodecs -lwininet -ldxgi
 
 gdbs:
 	wine /usr/share/win32/gdbserver.exe localhost:10000 ffrunner.exe

ffrunner.c

@@ -551,6 +551,26 @@ print_args()
     printf("force-opengl: %s\n", args.forceOpenGl ? "true" : "false");
 }
 
+void
+enable_dpi_awareness() {
+    HMODULE shcore = LoadLibraryA("shcore.dll");
+    if (shcore) {
+        SetProcessDpiAwarenessFunc setDpiAwareness =
+            (SetProcessDpiAwarenessFunc)GetProcAddress(shcore, "SetProcessDpiAwareness");
+        if (setDpiAwareness) {
+            if (setDpiAwareness(PROCESS_PER_MONITOR_DPI_AWARE) == S_OK) {
+                logmsg("Set DPI awareness to PROCESS_PER_MONITOR_DPI_AWARE\n");
+            } else {
+                logmsg("Failed to set DPI awareness: %d\n", GetLastError());
+            }
+        }
+        FreeLibrary(shcore);
+    } else {
+        // Fallback for older systems
+        SetProcessDPIAware();
+    }
+}
+
 int
 main(int argc, char **argv)
 {
@@ -565,18 +585,7 @@ main(int argc, char **argv)
     print_args();
     init_logging(args.logPath, args.verboseLogging);
 
-    PROCESS_DPI_AWARENESS dpi;
-    if (GetProcessDpiAwareness(NULL, &dpi) == S_OK) {
-        if (dpi == PROCESS_DPI_UNAWARE) {
-            if (SetProcessDpiAwareness(PROCESS_PER_MONITOR_DPI_AWARE) == S_OK) {
-                logmsg("Set DPI awareness to PROCESS_PER_MONITOR_DPI_AWARE\n");
-            } else {
-                logmsg("Failed to set DPI awareness: %d\n", GetLastError());
-            }
-        }
-    } else {
-        logmsg("Failed to get DPI awareness: %d\n", GetLastError());
-    }
+    enable_dpi_awareness();
 
     if (args.serverAddress == NULL) {
         logmsg("No server address provided.");

ffrunner.h

@@ -35,6 +35,8 @@
 #define ARRLEN(x) (sizeof(x)/sizeof(*x))
 #define MIN(a, b) (a > b ? b : a)
 
+typedef HRESULT (WINAPI *SetProcessDpiAwarenessFunc)(PROCESS_DPI_AWARENESS awareness);
+
 typedef NPError     (OSCALL *NP_GetEntryPointsFuncOS)(NPPluginFuncs*);
 typedef NPError     (OSCALL *NP_InitializeFuncOS)(NPNetscapeFuncs*);
 typedef NPError     (OSCALL *NP_ShutdownFuncOS)(void);