1 files changed, 95 insertions, 0 deletions
diff --git a/src/nativewindow/native/win32/WindowsDWM.c b/src/nativewindow/native/win32/WindowsDWM.c
new file mode 100644
index 000000000..cc9ed6d8c
--- /dev/null
+++ b/src/nativewindow/native/win32/WindowsDWM.c
@@ -0,0 +1,95 @@
+
+#include "WindowsDWM.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+
+// #define VERBOSE_ON 1
+
+#ifdef VERBOSE_ON
+    #define DBG_PRINT(args...) fprintf(stderr, args);
+#else
+    #define DBG_PRINT(args...)
+#endif
+
+/* GetProcAddress doesn't exist in A/W variants under desktop Windows */
+#ifndef UNDER_CE
+#define GetProcAddressA GetProcAddress
+#endif
+
+typedef HRESULT (WINAPI *DwmEnableCompositionPROCADDR)(UINT uCompositionAction);
+typedef HRESULT (WINAPI *DwmIsCompositionEnabledPROCADDR)(BOOL * pfEnabled);
+typedef HRESULT (WINAPI *DwmEnableBlurBehindWindowPROCADDR)(HWND hWnd, const DWM_BLURBEHIND* pBlurBehind);  
+typedef HRESULT (WINAPI *DwmExtendFrameIntoClientAreaPROCADDR)(HWND hwnd, const MARGINS *pMarInset);  
+
+static int _init = 0; // 1: init, 2: has DWM extension
+static DwmEnableCompositionPROCADDR _DwmEnableComposition = NULL;
+static DwmIsCompositionEnabledPROCADDR _DwmIsCompositionEnabled = NULL;
+static DwmEnableBlurBehindWindowPROCADDR _DwmEnableBlurBehindWindow = NULL;
+static DwmExtendFrameIntoClientAreaPROCADDR _DwmExtendFrameIntoClientArea = NULL;
+
+static int initWindowsDWM() {
+    if(0 == _init) {
+        _init = 1;
+        HANDLE shell = LoadLibrary(TEXT("dwmapi.dll"));
+        if (shell) {
+            _DwmEnableComposition = (DwmEnableCompositionPROCADDR) GetProcAddressA (shell, "DwmEnableComposition");
+            _DwmIsCompositionEnabled = (DwmIsCompositionEnabledPROCADDR) GetProcAddressA (shell, "DwmIsCompositionEnabled");
+            _DwmEnableBlurBehindWindow = (DwmEnableBlurBehindWindowPROCADDR) GetProcAddressA (shell, "DwmEnableBlurBehindWindow");
+            _DwmExtendFrameIntoClientArea = (DwmExtendFrameIntoClientAreaPROCADDR) GetProcAddressA (shell, "DwmExtendFrameIntoClientArea");
+            if(NULL != _DwmEnableComposition && NULL != _DwmIsCompositionEnabled && 
+               NULL != _DwmEnableBlurBehindWindow && NULL != _DwmExtendFrameIntoClientArea) {
+                _init = 2;
+            }
+        }
+        // FreeLibrary (shell);  
+        DBG_PRINT("DWM - initWindowsDWM: %d - s %p, e %p, c %p\n", _init, shell, _DwmEnableBlurBehindWindow, _DwmExtendFrameIntoClientArea);
+    }
+    return _init;
+}
+
+BOOL DwmIsExtensionAvailable() {
+    return (2 == initWindowsDWM()) ? TRUE : FALSE;
+}
+
+BOOL DwmIsCompositionEnabled( ) {
+    if(2 == initWindowsDWM()) {
+        BOOL fEnabled = FALSE;
+        if( 0 == _DwmIsCompositionEnabled(&fEnabled) ) {
+            DBG_PRINT("DWM - DwmIsCompositionEnabled: %d\n", fEnabled);
+            return fEnabled;
+        }
+    }
+    DBG_PRINT("DWM - DwmIsCompositionEnabled failed\n");
+    return FALSE;
+}
+
+BOOL DwmEnableComposition( UINT uCompositionAction ) {
+    if(2 == initWindowsDWM()) {
+        return 0 == _DwmEnableComposition(uCompositionAction) ? TRUE : FALSE;
+    }
+    return FALSE;
+}
+
+BOOL DwmEnableBlurBehindWindow(HWND hwnd, const DWM_BLURBEHIND* pBlurBehind) {  
+    if(2 == initWindowsDWM()) {
+        _DwmEnableBlurBehindWindow(hwnd, pBlurBehind);
+        DBG_PRINT("DWM - DwmEnableBlurBehindWindow: hwnd %p, f %d, on %d, %p\n", 
+            (void *)hwnd, 
+            (int) pBlurBehind->dwFlags,
+            (int) pBlurBehind->fEnable,
+            (void *)pBlurBehind->hRgnBlur);
+        return TRUE;
+    }
+    DBG_PRINT("DWM - DwmEnableBlurBehindWindow: n/a\n");
+    return FALSE;
+}  
+
+BOOL DwmExtendFrameIntoClientArea(HWND hwnd, const MARGINS *pMarInset) {
+    if(2 == initWindowsDWM()) {
+        _DwmExtendFrameIntoClientArea(hwnd, pMarInset);
+        return TRUE;
+    }
+    return FALSE;
+}  
+