initial commit

3 files changed, 381 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/CMakeLists.txt
diff --git a/dwm_load.c b/dwm_load.c
new file mode 100644
index 0000000..d29fb4a
--- /dev/null
+++ b/dwm_load.c
@@ -0,0 +1,264 @@
+#include "dwm_load.h"
+
+#include <windows.h>
+#include <winbase.h>
+
+#define E_INVALID_FUNCTION HRESULT_FROM_WIN32(ERROR_INVALID_FUNCTION)
+
+static void
+dwmload_getproc(LPCSTR procname, FARPROC *pp)
+{
+	if( *pp )  {
+		return;
+	}
+
+	static HMODULE g_h_dwmapi = NULL;
+	if(!g_h_dwmapi) do {
+		HMODULE h_dwmapi = NULL;
+		if( !GetModuleHandleExA(0, "dwmapi", &h_dwmapi) ) {
+			h_dwmapi = LoadLibraryA("dwmapi");
+		}
+		if( !h_dwmapi ) {
+			break;
+		}
+
+		/* loading the dwmapi module may trigger a rance
+		 * condition if dwmload is used concurrently.
+		 * We catch this here, by performing an atomic
+		 * compare and exchange here.
+		 *
+		 * If the C&E returns a not NULL pointer another
+		 * thread beat the race; the resolve is to release
+		 * the module reference just acquired. */
+		if( InterlockedCompareExchangePointer(
+			(PVOID volatile *)&g_h_dwmapi,
+			(PVOID)h_dwmapi,
+			NULL )
+		) {
+			FreeLibrary(h_dwmapi);
+		}
+	} while(0);
+
+	FARPROC p = NULL;
+	if( g_h_dwmapi ) {
+		p = GetProcAddress(g_h_dwmapi, procname);
+	}
+
+	/* The compiler should optimize this to a single
+	 * unconditional code path. */
+	switch(sizeof(FARPROC)) {
+	/* 8 bit and 16 bit sizes for FARPROC are quite unlikely,
+	 * but we're good and cover these cases as well. */
+	case 1:
+		InterlockedExchange8((char volatile*)pp, (char)p);
+		break;
+	case 2:
+		InterlockedExchange16((SHORT volatile*)pp, (SHORT)p);
+		break;
+	case 4:
+		InterlockedExchange((LONG volatile*)pp, (LONG)p);
+		break;
+	case 8:
+		InterlockedExchange64((LONGLONG volatile*)pp, (LONGLONG)p);
+		break;
+
+	/* practically we should never end up here */
+	default:
+		InterlockedExchangePointer((PVOID volatile *)pp, (PVOID)p);
+		break;
+	}
+}
+
+BOOL dwmload_DefWindowProc(
+    HWND hwnd,
+    UINT msg,
+    WPARAM wParam,
+    LPARAM lParam,
+    LRESULT *plResult
+)
+{
+	static BOOL (*p)(HWND, UINT, WPARAM, LPARAM, LRESULT*) = NULL;
+	dwmload_getproc("DwmDefWindowProc", (FARPROC*)&p);
+	return p ? p(hwnd, msg, wParam, lParam, plResult) : FALSE;
+}
+
+HRESULT dwmload_EnableBlurBehindWindow(
+    HWND hWnd,
+    const DWM_BLURBEHIND *pBlurBehind
+)
+{
+	static HRESULT (*p)(HWND, const DWM_BLURBEHIND*) = NULL;
+	dwmload_getproc("DwmEnableBlurBehindWindow", (FARPROC*)&p);
+	return p ? p(hWnd, pBlurBehind) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_EnableComposition(
+    UINT uCompositionAction
+)
+{
+	static HRESULT (*p)(UINT) = NULL;
+	dwmload_getproc("DwmEnableComposition", (FARPROC*)&p);
+	return p ? p(uCompositionAction) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_EnableMMCSS(
+    BOOL fEnableMMCSS
+)
+{
+	static HRESULT (*p)(BOOL) = NULL;
+	dwmload_getproc("DwmEnableMMCSS", (FARPROC*)&p);
+	return p ? p(fEnableMMCSS) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_ExtendFrameIntoClientArea(
+    HWND hWnd,
+    const MARGINS *pMarInset
+)
+{
+	static HRESULT (*p)(HWND, const MARGINS*) = NULL;
+	dwmload_getproc("DwmExtendFrameIntoClientArea", (FARPROC*)&p);
+	return p ? p(hWnd, pMarInset) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_GetColorizationColor(
+    DWORD *pcrColorization,
+    BOOL *pfOpaqueBlend
+)
+{
+	static HRESULT (*p)(DWORD*, BOOL*) = NULL;
+	dwmload_getproc("DwmGetColorizationColor", (FARPROC*)&p);
+	/* TODO: Implement Fallback that returns GDI system colors */
+	return p ? p(pcrColorization, pfOpaqueBlend) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_GetCompositionTimingInfo(
+    HWND hwnd,
+    DWM_TIMING_INFO *pTimingInfo
+)
+{
+	static HRESULT (*p)(HWND, DWM_TIMING_INFO*) = NULL;
+	dwmload_getproc("DwmGetCompositionTimingInfo", (FARPROC*)&p);
+	return p ? p(hwnd, pTimingInfo) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_GetWindowAttribute(
+    HWND hwnd,
+    DWORD dwAttribute,
+    PVOID pvAttribute,
+    DWORD cbAttribute
+)
+{
+	static HRESULT (*p)(HWND, DWORD, PVOID, DWORD) = NULL;
+	dwmload_getproc("DwmGetWindowAttribute", (FARPROC*)&p);
+	if(!p) {
+		memset(pvAttribute, 0, cbAttribute);
+	}
+	return p ? p(hwnd, dwAttribute, pvAttribute, cbAttribute) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_IsCompositionEnabled(
+    BOOL *pfEnabled
+)
+{
+	static HRESULT (*p)(BOOL*) = NULL;
+	dwmload_getproc("DwmIsCompositionEnabled", (FARPROC*)&p);
+	if(!p) {
+		*pfEnabled = FALSE;
+	}
+	/* Don't return a error if DWM API is not available;
+	 * it makes sense to inform the program, that composition
+	 * is not enabled ony a system that does not support
+	 * composition. */
+	return p ? p(pfEnabled) : S_OK;
+}
+
+HRESULT dwmload_ModifyPreviousDxFrameDuration(
+    HWND hwnd,
+    INT cRefreshes,
+    BOOL fRelative
+)
+{
+	static HRESULT (*p)(HWND, INT, BOOL) = NULL;
+	dwmload_getproc("DwmModifyPreviousDxFrameDuration", (FARPROC*)&p);
+	return p ? p(hwnd, cRefreshes, fRelative) : S_OK;
+}
+
+
+HRESULT dwmload_QueryThumbnailSourceSize(
+    HTHUMBNAIL hThumbnail,
+    PSIZE pSize
+)
+{
+	static HRESULT (*p)(HTHUMBNAIL, PSIZE) = NULL;
+	dwmload_getproc("DwmQueryThumbnailSourceSize", (FARPROC*)&p);
+	if(!p) {
+		memset(pSize, 0, sizeof(*pSize));
+	}
+	return p ? p(hThumbnail, pSize) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_RegisterThumbnail(
+    HWND hwndDestination,
+    HWND *hwndSource,
+    PHTHUMBNAIL phThumbnailId
+)
+{
+	static HRESULT (*p)(HWND, HWND*, PHTHUMBNAIL) = NULL;
+	dwmload_getproc("DwmRegisterThumbnail", (FARPROC*)&p);
+	if(!p) {
+		if( phThumbnailId) *phThumbnailId = NULL;
+	}
+	return p ? p(hwndDestination, hwndSource, phThumbnailId) : E_INVALID_FUNCTION;
+}
+
+HRESULT dwmload_SetDxFrameDuration(
+    HWND hwnd,
+    INT cRefreshes
+)
+{
+	static HRESULT (*p)(HWND, INT) = NULL;
+	dwmload_getproc("DwmSetDxFrameDuration", (FARPROC*)&p);
+	return p ? p(hwnd, cRefreshes) : S_OK;
+}
+
+HRESULT dwmload_SetPresentParameters(
+    HWND hwnd,
+    DWM_PRESENT_PARAMETERS *pPresentParams
+)
+{
+	static HRESULT (*p)(HWND, DWM_PRESENT_PARAMETERS*) = NULL;
+	dwmload_getproc("DwmSetPresentParameters", (FARPROC*)&p);
+	return p ? p(hwnd, pPresentParams) : S_OK;
+}
+
+HRESULT dwmload_SetWindowAttribute(
+    HWND hwnd,
+    DWORD dwAttribute,
+    LPCVOID pvAttribute,
+    DWORD cbAttribute
+)
+{
+	static HRESULT (*p)(HWND, DWORD, LPCVOID, DWORD) = NULL;
+	dwmload_getproc("DwmSetWindowAttribute", (FARPROC*)&p);
+	return p ? p(hwnd, dwAttribute, pvAttribute, cbAttribute) : S_OK;
+}
+
+HRESULT dwmload_UnregisterThumbnail(
+    HTHUMBNAIL hThumbnailId
+)
+{
+	static HRESULT (*p)(HTHUMBNAIL) = NULL;
+	dwmload_getproc("DwmUnregisterThumbnail", (FARPROC*)&p);
+	return p ? p(hThumbnailId) : S_OK;
+}
+
+HRESULT dwmload_UpdateThumbnailProperties(
+    HTHUMBNAIL hThumbnailId,
+    const DWM_THUMBNAIL_PROPERTIES *ptnProperties
+)
+{
+	static HRESULT (*p)(HTHUMBNAIL, const DWM_THUMBNAIL_PROPERTIES*) = NULL;
+	dwmload_getproc("DwmUpdateThumbnailProperties", (FARPROC*)&p);
+	return p ? p(hThumbnailId, ptnProperties) : S_OK;
+}
+
diff --git a/dwm_load.h b/dwm_load.h
new file mode 100644
index 0000000..34ef87b
--- /dev/null
+++ b/dwm_load.h
@@ -0,0 +1,117 @@
+#ifndef DWM_LOAD_H
+#define DWM_LOAD_H
+
+#include <dwmapi.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+BOOL dwmload_DefWindowProc(
+    HWND hwnd,
+    UINT msg,
+    WPARAM wParam,
+    LPARAM lParam,
+    LRESULT *plResult
+);
+#define DwmDefWindowProc dwmload_DefWindowProc
+
+HRESULT dwmload_EnableBlurBehindWindow(
+    HWND hWnd,
+    const DWM_BLURBEHIND *pBlurBehind
+);
+#define DwmEnableBlurBehindWindow dwmload_EnableBlurBehindWindow
+
+HRESULT dwmload_EnableComposition(
+    UINT uCompositionAction
+);
+#define DwmEnableComposition dwmload_EnableComposition
+
+HRESULT dwmload_EnableMMCSS(
+    BOOL fEnableMMCSS
+);
+#define DwmEnableMMCSS dwmload_EnableMMCSS
+
+HRESULT dwmload_ExtendFrameIntoClientArea(
+    HWND hWnd,
+    const MARGINS *pMarInset
+);
+#define DwmExtendFrameIntoClientArea dwmload_ExtendFrameIntoClientArea
+
+HRESULT dwmload_GetColorizationColor(
+    DWORD *pcrColorization,
+    BOOL *pfOpaqueBlend
+);
+#define DwmGetColorizationColor dwmload_GetColorizationColor
+
+HRESULT dwmload_GetCompositionTimingInfo(
+    HWND hwnd,
+    DWM_TIMING_INFO *pTimingInfo
+);
+#define DwmGetCompositionTimingInfo dwmload_GetCompositionTimingInfo
+
+HRESULT dwmload_GetWindowAttribute(
+    HWND hwnd,
+    DWORD dwAttribute,
+    PVOID pvAttribute,
+    DWORD cbAttribute
+);
+#define DwmGetWindowAttribute dwmload_GetWindowAttribute
+
+HRESULT dwmload_IsCompositionEnabled(
+    BOOL *pfEnabled
+);
+#define DwmIsCompositionEnabled dwmload_IsCompositionEnabled
+
+HRESULT dwmload_ModifyPreviousDxFrameDuration(
+    HWND hwnd,
+    INT cRefreshes,
+    BOOL fRelative
+);
+#define DwmModifyPreviousDxFrameDuration dwmload_ModifyPreviousDxFrameDuration
+
+HRESULT dwmload_QueryThumbnailSourceSize(
+    HTHUMBNAIL hThumbnail,
+    PSIZE pSize
+);
+#define DwmQueryThumbnailSourceSize dwmload_QueryThumbnailSourceSize
+
+HRESULT dwmload_RegisterThumbnail(
+    HWND hwndDestination,
+    HWND *hwndSource,
+    PHTHUMBNAIL phThumbnailId
+);
+#define DwmRegisterThumbnail dwmload_RegisterThumbnail
+
+HRESULT dwmload_SetDxFrameDuration(
+    HWND hwnd,
+    INT cRefreshes
+);
+#define DwmSetDxFrameDuration dwmload_SetDxFrameDuration
+
+HRESULT dwmload_SetPresentParameters(
+    HWND hwnd,
+    DWM_PRESENT_PARAMETERS *pPresentParams
+);
+#define DwmSetPresentParameters dwmload_SetPresentParameters
+
+HRESULT dwmload_SetWindowAttribute(
+    HWND hwnd,
+    DWORD dwAttribute,
+    LPCVOID pvAttribute,
+    DWORD cbAttribute
+);
+#define DwmSetWindowAttribute dwmload_SetWindowAttribute
+
+HRESULT dwmload_UnregisterThumbnail(
+    HTHUMBNAIL hThumbnailId
+);
+#define DwmUnregisterThumbnail dwmload_UnregisterThumbnail
+
+HRESULT dwmload_UpdateThumbnailProperties(
+    HTHUMBNAIL hThumbnailId,
+    const DWM_THUMBNAIL_PROPERTIES *ptnProperties
+);
+#define DwmUpdateThumbnailProperties dwmload_UpdateThumbnailProperties
+
+#endif/*DWM_LOAD_H*/