reingineer compat layer

not totally sure whether that's actually better

9 files changed, 256 insertions, 158 deletions

diff --git a/alf/alf.cpp b/alf/alf.cpp
index 40b4156..64b4cc4 100644
--- a/alf/alf.cpp
+++ b/alf/alf.cpp
@@ -55,7 +55,7 @@ ALF_ApplyFontsPriv(HWND win, ALFWindowPriv *priv)
 void
 ALF_UpdateFontsPriv(HWND win, ALFWindowPriv *priv)
 {
-    priv->fonts.dpi = priv->app->compatFn->GetDpiForWindow(win);
+    priv->fonts.dpi = ALF_Compat_GetDpiForWindow(win);
 
     if (LOBYTE(LOWORD(GetVersion())) < 4) {
         // NT 3.x uses System font for everything, we copy that
@@ -68,7 +68,7 @@ ALF_UpdateFontsPriv(HWND win, ALFWindowPriv *priv)
         ZeroMemory(&ncm, sizeof(ncm));
         ncm.cbSize = ALF_SizeOf_NONCLIENTMETRICS();
 
-        if (priv->app->compatFn->SystemParametersInfoForDpi(SPI_GETNONCLIENTMETRICS, ncm.cbSize, &ncm, 0, priv->fonts.dpi)) {
+        if (ALF_Compat_SystemParametersInfoForDpi(SPI_GETNONCLIENTMETRICS, ncm.cbSize, &ncm, 0, priv->fonts.dpi)) {
             priv->fonts.lfMessageFont = ncm.lfMessageFont;
         } else {
             // FIXME! fallback to default font, 8pt MS Shell Dlg
@@ -202,7 +202,7 @@ ALF_DefWindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
         tmp.right = priv->layout.totalMinWidth;
         tmp.bottom = priv->layout.totalMinHeight;
 
-        if (priv->app->compatFn->AdjustWindowRectExForDpi(
+        if (ALF_Compat_AdjustWindowRectExForDpi(
                                &tmp,
                                GetWindowLong(hwnd, GWL_STYLE),
                                GetMenu(hwnd) != NULL,
@@ -341,7 +341,6 @@ ALF_CreateApplication(HINSTANCE hInstance)
 
     InitCommonControls();
 
-    app->compatFn = ALF_CreateCompatFuncTable();
     ALF_RegisterComboClass(app);
     ALF_RegisterPanelClass(app);
 
@@ -353,43 +352,20 @@ ALF_TeardownApplication(ALFAPP app)
 {
     UnregisterClass(app->comboClass, app->hInstance);
     UnregisterClass(app->panelClass, app->hInstance);
-    HeapFree(GetProcessHeap(), 0, app->compatFn);
     HeapFree(GetProcessHeap(), 0, app);
 }
 
-static void
-ALF_IntToHex(TCHAR *buf, unsigned long num, int chars)
-{
-    char letters[] = { '0', '1', '2', '3', '4', '5', '6', '7',
-                       '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
-    for (int i = 0; i < chars; ++i) {
-        buf[chars-i-1] = letters[(num >> (i*4)) & 0xf];
-    }
-}
-
-static void
-ALF_UuidToString(const GUID *guid, TCHAR *buf)
-{
-    ALF_IntToHex(buf, guid->Data1, 8);
-    buf[8] = '-';
-    ALF_IntToHex(buf + 9, guid->Data2, 4);
-    buf[13] = '-';
-    ALF_IntToHex(buf + 14, guid->Data3, 4);
-    buf[18] = '-';
-    for (int i = 0; i < 8; ++i) {
-        ALF_IntToHex(buf + 19 + 2*i, guid->Data4[i], 2);
-    }
-    buf[35] = 0;
-}
-
 void
-ALF_BuildRandomClassName(ALFAPP app, const TCHAR* prefix, TCHAR* buf)
+ALF_BuildRandomClassName(const TCHAR* prefix, TCHAR* buf, DWORD cchBuf)
 {
-    UUID uuid;
-    app->compatFn->UuidCreate(&uuid);
+    LONG_PTR c1, c2;
+    ALF_UniqueCounterValue(&c1, &c2);
+
+    DWORD_PTR params[] = { (DWORD_PTR)prefix, (DWORD_PTR)c1, (DWORD_PTR)c2 };
 
-    lstrcpy(buf, prefix);
-    ALF_UuidToString(&uuid, &buf[lstrlen(buf)]);
+    FormatMessage(FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_FROM_STRING,
+                  TEXT("%1.%2!d!.%3!d!"), 0, 0,
+                  buf, cchBuf, (va_list*)params);
 }
 
 LPTSTR
@@ -404,7 +380,7 @@ ALF_RegisterWindowClass(ALFAPP app, const ALFWindowClassParams *params)
         ZeroMemory(classNameBuf, sizeof(classNameBuf));
         classNamePtr = classNameBuf;
 
-        ALF_BuildRandomClassName(app, TEXT("ALFWindow."), classNameBuf);
+        ALF_BuildRandomClassName(TEXT("ALFWindow"), classNameBuf, 256);
     }
 
     cls.style = params->classStyle;
@@ -419,7 +395,7 @@ ALF_RegisterWindowClass(ALFAPP app, const ALFWindowClassParams *params)
     cls.lpszClassName = classNamePtr;
     cls.cbWndExtra = sizeof(void*);
     cls.cbClsExtra = sizeof(void*)*2;
-    cls.lpfnWndProc = DefWindowProc;
+    cls.lpfnWndProc = ALF_WindowProc;
 
     ATOM classatom = RegisterClass(&cls);
     if (!classatom)
@@ -432,7 +408,6 @@ ALF_RegisterWindowClass(ALFAPP app, const ALFWindowClassParams *params)
     HWND tmp = CreateWindowEx(0, MAKEINTATOM(classatom), TEXT("dummy"), 0, 0, 0, 0, 0, NULL, 0, app->hInstance, 0);
     SetClassLongPtr(tmp, 0, (LONG_PTR)pvtbl);
     SetClassLongPtr(tmp, sizeof(void*), (LONG_PTR)app);
-    SetClassLongPtr(tmp, GCLP_WNDPROC, (LONG_PTR)ALF_WindowProc);
     DestroyWindow(tmp);
 
     return MAKEINTATOM(classatom);
diff --git a/alf/alfbutton.cpp b/alf/alfbutton.cpp
index 95e8e8d..b0458b2 100644
--- a/alf/alfbutton.cpp
+++ b/alf/alfbutton.cpp
@@ -7,8 +7,6 @@ ALF__ButtonSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT
     (void)uIdSubclass;
     (void)dwRefData;
 
-    ALFAPP app = (ALFAPP)dwRefData;
-
     if (uMsg == ALF_WM_QUERYSIZE) {
         HDC hdc = GetDC(hwnd);
         HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
@@ -32,9 +30,9 @@ ALF__ButtonSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT
 
         HeapFree(GetProcessHeap(), 0, textbuf);
 
-        int xpadding = app->compatFn->GetSystemMetricsForDpi(SM_CXEDGE,
+        int xpadding = ALF_Compat_GetSystemMetricsForDpi(SM_CXEDGE,
             ALF_CentipointsToPixels(GetParent(hwnd), 7200)) * 2 + 6;
-        int ypadding = app->compatFn->GetSystemMetricsForDpi(SM_CYEDGE,
+        int ypadding = ALF_Compat_GetSystemMetricsForDpi(SM_CYEDGE,
             ALF_CentipointsToPixels(GetParent(hwnd), 7200)) * 2 + 6;
 
         SIZE *pSize = (SIZE*)(void*)lParam;
@@ -58,7 +56,7 @@ ALF__ButtonSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT
 
         RECT *p = (RECT *)lParam;
 
-        int padding = app->compatFn->IsAppThemed() ? 0 : 1;
+        int padding = ALF_Compat_IsAppThemed() ? 0 : 1;
 
         return (LRESULT)DeferWindowPos((HDWP)wParam,
                                        hwnd, NULL,
@@ -66,10 +64,10 @@ ALF__ButtonSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT
                                        p->right - p->left, p->bottom - p->top - 2*padding,
                                        SWP_NOZORDER|SWP_NOACTIVATE);
     } else if (uMsg == WM_DESTROY) {
-        app->compatFn->RemoveWindowSubclass(hwnd, ALF__ButtonSubclassProc, 0);
+        ALF_Compat_RemoveWindowSubclass(hwnd, ALF__ButtonSubclassProc, 0);
     }
 
-    return app->compatFn->DefSubclassProc(hwnd, uMsg, wParam, lParam);
+    return ALF_Compat_DefSubclassProc(hwnd, uMsg, wParam, lParam);
 }
 
 HWND
@@ -85,9 +83,7 @@ ALF_AddButton(HWND win, WORD id, UINT x, UINT y, const TCHAR *text)
                                       (HINSTANCE)GetWindowLongPtr(win, GWLP_HINSTANCE),
                                       NULL);
 
-    ALFAPP app = ALF_ApplicationFromWindow(win);
-
-    app->compatFn->SetWindowSubclass(hwndButton, ALF__ButtonSubclassProc, 0, (DWORD_PTR)app);
+    ALF_Compat_SetWindowSubclass(hwndButton, ALF__ButtonSubclassProc, 0, 0);
     SetWindowPos(hwndButton, NULL, 0, 0, 0, 0, SWP_NOMOVE|SWP_NOSIZE|SWP_NOZORDER|SWP_FRAMECHANGED);
 
     ALFWidgetLayoutParams p;
diff --git a/alf/alfcombobox.cpp b/alf/alfcombobox.cpp
index a6e846f..409d64f 100644
--- a/alf/alfcombobox.cpp
+++ b/alf/alfcombobox.cpp
@@ -44,8 +44,7 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
         SetWindowLongPtr(hwnd, 0, (LONG_PTR)params->app);
     }
 
-    ALFAPP app = (ALFAPP)GetWindowLongPtr(hwnd, 0);
-    HWND   hwndChild = (HWND)GetWindowLongPtr(hwnd, sizeof(void*));
+    HWND   hwndChild = (HWND)GetWindowLongPtr(hwnd, 0);
 
     if (uMsg == WM_CREATE) {
         ALFComboCreateParams *params = (ALFComboCreateParams*)((CREATESTRUCT*)lParam)->lpCreateParams;
@@ -61,7 +60,7 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
                                         ((CREATESTRUCT*)lParam)->hInstance,
                                         NULL);
 
-        SetWindowLongPtr(hwnd, sizeof(void*), (LONG_PTR)hwndCombo);
+        SetWindowLongPtr(hwnd, 0, (LONG_PTR)hwndCombo);
     }
     if (uMsg == WM_ENABLE && hwndChild) {
         EnableWindow(hwndChild, (BOOL)wParam);
@@ -152,7 +151,7 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
                 }
 
                 if (!ps->cy) {
-                    ps->cy = tm.tmHeight + 2*app->compatFn->GetSystemMetricsForDpi(
+                    ps->cy = tm.tmHeight + 2*ALF_Compat_GetSystemMetricsForDpi(
                             SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
                         + 4 /* padding internal to the edit control */
                         + 2 /* external padding to line up with themed button */;
@@ -247,7 +246,7 @@ ALF__ComboWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 
             DWORD heightOffset = 0;
             if (LOBYTE(LOWORD(GetVersion())) >= 4) {
-                heightOffset = - 2*app->compatFn->GetSystemMetricsForDpi(
+                heightOffset = - 2*ALF_Compat_GetSystemMetricsForDpi(
                             SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
                             - 4;
             } else {
@@ -274,7 +273,7 @@ ALF_RegisterComboClass(ALFAPP app)
     ZeroMemory(&cls, sizeof(cls));
 
     TCHAR  classNameBuf[256];
-    ALF_BuildRandomClassName(app, TEXT("ALFComboBox."), classNameBuf);
+    ALF_BuildRandomClassName(TEXT("ALFComboBox"), classNameBuf, 256);
 
     cls.hInstance = app->hInstance;
     cls.hCursor = LoadCursor(NULL, (LPTSTR)IDC_ARROW);
@@ -285,7 +284,7 @@ ALF_RegisterComboClass(ALFAPP app)
         cls.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
     }
     cls.lpszClassName = classNameBuf;
-    cls.cbWndExtra = sizeof(void*)*2;
+    cls.cbWndExtra = sizeof(void*);
     cls.lpfnWndProc = ALF__ComboWindowProc;
 
     ATOM classatom = RegisterClass(&cls);
diff --git a/alf/alfcompat.cpp b/alf/alfcompat.cpp
index 9a36d4d..aee27fb 100644
--- a/alf/alfcompat.cpp
+++ b/alf/alfcompat.cpp
@@ -2,6 +2,58 @@
 
 #include <shlwapi.h>
 
+#if defined(_MSC_VER) && defined(_M_IX86)
+
+#   pragma warning(push)
+#   pragma warning(disable:4035)
+
+    // HACK: inline assembly for MSVC 6
+    // TODO: add version detection to use intrinsic on newer MSVC versions
+
+    static inline LONG
+    ALF_Compat_InterlockedIncrement(LONG volatile *addend)
+    {
+        __asm {
+            mov         eax,1
+            mov         edx,addend
+            lock xadd   [edx],eax
+        }
+    }
+#   ifdef InterlockedIncrement
+#       undef InterlockedIncrement
+#   endif
+#   define InterlockedIncrement(d) ALF_Compat_InterlockedIncrement(d)
+
+    static inline LONG
+    ALF_Compat_InterlockedCompareExchange(volatile LONG *destination, LONG exchange, LONG comparand)
+    {
+        __asm {
+            mov             eax,comparand
+            mov             ecx,exchange
+            mov             edx,destination
+            lock cmpxchg    [edx],ecx
+        }
+    }
+
+#   ifdef InterlockedCompareExchange
+#       undef InterlockedCompareExchange
+#   endif
+#   define InterlockedCompareExchange(d,e,c) ALF_Compat_InterlockedCompareExchange(d,e,c)
+
+    static inline PVOID
+    ALF_Compat_InterlockedCompareExchangePointer(PVOID volatile *destination, PVOID exchange, PVOID comparand)
+    {
+        return (void*)InterlockedCompareExchange((LONG volatile *)destination, (LONG)exchange, (LONG)comparand);
+    }
+
+#   ifdef InterlockedCompareExchangePointer
+#       undef InterlockedCompareExchangePointer
+#   endif
+#   define InterlockedCompareExchangePointer(d,e,c) ALF_Compat_InterlockedCompareExchangePointer(d,e,c)
+
+#   pragma warning(pop)
+#endif
+
 static
 DWORD ALF_DllGetVersion(const char *dll)
 {
@@ -29,7 +81,7 @@ DWORD ALF_DllGetVersion(const char *dll)
 }
 
 static int WINAPI
-fallbackGetSystemMetricsForDpi(int nIndex, UINT dpi)
+ALF_Compat_fallbackGetSystemMetricsForDpi(int nIndex, UINT dpi)
 {
     (void)dpi;
     if (LOBYTE(LOWORD(GetVersion())) < 4) {
@@ -44,13 +96,13 @@ fallbackGetSystemMetricsForDpi(int nIndex, UINT dpi)
 }
 
 static BOOL WINAPI
-fallbackIsAppThemed(void)
+ALF_Compat_fallbackIsAppThemed(void)
 {
     return FALSE;
 }
 
 static UINT WINAPI
-fallbackGetDpiForWindow(HWND win)
+ALF_Compat_fallbackGetDpiForWindow(HWND win)
 {
     (void)win;
 
@@ -70,7 +122,7 @@ fallbackGetDpiForWindow(HWND win)
 }
 
 static BOOL WINAPI
-fallbackSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni, UINT dpi)
+ALF_Compat_fallbackSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni, UINT dpi)
 {
     (void)dpi;
 
@@ -78,7 +130,7 @@ fallbackSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, U
 }
 
 static BOOL WINAPI
-fallbackAdjustWindowRectExForDpi(LPRECT lpRect, DWORD dwStyle, BOOL bMenu, DWORD dwExStyle, UINT dpi)
+ALF_Compat_fallbackAdjustWindowRectExForDpi(LPRECT lpRect, DWORD dwStyle, BOOL bMenu, DWORD dwExStyle, UINT dpi)
 {
     (void)dpi;
 
@@ -97,7 +149,7 @@ typedef struct {
 } ALFWindowSubclassData;
 
 static LRESULT CALLBACK
-fallbackSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+ALF_Compat_fallbackSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
     ALFWindowSubclassData *data = (ALFWindowSubclassData *)GetWindowLongPtr(hwnd, GWLP_USERDATA);
 
@@ -121,7 +173,7 @@ fallbackSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 }
 
 static BOOL WINAPI
-fallbackSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
+ALF_Compat_fallbackSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
 {
     ALFWindowSubclassData *data = (ALFWindowSubclassData *)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, sizeof(ALFWindowSubclassData));
 
@@ -131,13 +183,13 @@ fallbackSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_P
     data->orig = (WNDPROC)GetWindowLongPtr(hwnd, GWLP_WNDPROC);
 
     SetWindowLongPtr(hwnd, GWLP_USERDATA, (LONG_PTR)data);
-    SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)fallbackSubclassProc);
+    SetWindowLongPtr(hwnd, GWLP_WNDPROC, (LONG_PTR)ALF_Compat_fallbackSubclassProc);
 
     return TRUE;
 }
 
 static LRESULT WINAPI
-fallbackDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+ALF_Compat_fallbackDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
     ALFWindowSubclassData *data = (ALFWindowSubclassData *)GetWindowLongPtr(hwnd, GWLP_USERDATA);
 
@@ -145,7 +197,7 @@ fallbackDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 }
 
 static BOOL WINAPI
-fallbackRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass)
+ALF_Compat_fallbackRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass)
 {
     (void)pfnSubclass;
     (void)uIdSubclass;
@@ -166,72 +218,158 @@ fallbackRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UIN
     return TRUE;
 }
 
-ALFCompatFunctions *
-ALF_CreateCompatFuncTable(void)
-{
-    ALFCompatFunctions *compatfn = (ALFCompatFunctions*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY|HEAP_GENERATE_EXCEPTIONS, sizeof(ALFCompatFunctions));
-
-#define COMPAT(dll, entrypoint, ordinal, fallback) \
-    do { \
-        FARPROC p = GetProcAddress(GetModuleHandleA(#dll), #entrypoint); \
-        if (!p && ordinal) \
-            p = GetProcAddress(GetModuleHandleA(#dll), (char*)ordinal); \
-        CopyMemory(&compatfn->entrypoint, &p, sizeof(void*)); \
-        \
-        if (!compatfn->entrypoint) \
-            compatfn->entrypoint = fallback; \
-    } while (0)
-
-    COMPAT(comctl32.dll, SetWindowSubclass, 410, fallbackSetWindowSubclass);
-    COMPAT(comctl32.dll, DefSubclassProc, 413, fallbackDefSubclassProc);
-    COMPAT(comctl32.dll, RemoveWindowSubclass, 412, fallbackRemoveWindowSubclass);
-    COMPAT(user32.dll, GetSystemMetricsForDpi, 0, fallbackGetSystemMetricsForDpi);
-    COMPAT(user32.dll, GetDpiForWindow, 0, fallbackGetDpiForWindow);
-
-    // FIXME: SystemParametersInfoForDpi is Unicode-Only.
-    // Writing a wrapper function would have been The Right Way, but such a function
-    // is yet to be written. So the current practical recommendation is to make
-    // ANSI builds System DPI aware only.
-#ifdef UNICODE
-    COMPAT(user32.dll, SystemParametersInfoForDpi, 0, fallbackSystemParametersInfoForDpi);
-#else
-    compatfn->SystemParametersInfoForDpi = fallbackSystemParametersInfoForDpi;
-#endif
+long
+ALF_GetAveCharWidth(HDC hdc)
+{
+    // see: HOWTO: Calculate Dialog Units When Not Using the System Font
+
+    SIZE s;
+    GetTextExtentPoint32A(hdc, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 52, &s);
+
+    return (s.cx / 26 + 1) / 2;
+}
+
+void
+ALF_UniqueCounterValue(LONG_PTR *pCounterId, LONG_PTR *pCounterValue)
+{
+    static LONG counter = 0;
+
+    LONG r = InterlockedIncrement(&counter);
+    *pCounterId    = (LONG_PTR)&counter;
+    *pCounterValue = r;
+}
+
+static BOOL WINAPI
+ALF_Compat_loadIsAppThemed(void)
+{
+    HMODULE hUxTheme = GetModuleHandleA("uxtheme.dll");
+    FARPROC p = GetProcAddress(hUxTheme, "IsAppThemed");
+
+    if (!p || ALF_DllGetVersion("comctl32.dll") < 0x60000)
+        p = (FARPROC)ALF_Compat_fallbackIsAppThemed;
+
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_IsAppThemed, (void*)p, (void*)ALF_Compat_loadIsAppThemed);
+
+    return ALF_Compat_IsAppThemed();
+}
+
+static UINT WINAPI
+ALF_Compat_loadGetDpiForWindow(HWND window)
+{
+    FARPROC p = GetProcAddress(GetModuleHandleA("user32.dll"), "GetDpiForWindow");
+
+    if (!p)
+        p = (FARPROC)(void*)ALF_Compat_fallbackGetDpiForWindow;
+
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_GetDpiForWindow, (void*)p, (void*)ALF_Compat_loadGetDpiForWindow);
+
+    return ALF_Compat_GetDpiForWindow(window);
+}
+
+static BOOL WINAPI
+ALF_Compat_loadAdjustWindowRectExForDpi(LPRECT lpRect, DWORD dwStyle, BOOL bMenu, DWORD dwExStyle, UINT dpi)
+{
+    FARPROC p = GetProcAddress(GetModuleHandleA("user32.dll"), "AdjustWindowRectExForDpi");
+
+    if (!p)
+        p = (FARPROC)(void*)ALF_Compat_fallbackAdjustWindowRectExForDpi;
+
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_AdjustWindowRectExForDpi, (void*)p, (void*)ALF_Compat_loadAdjustWindowRectExForDpi);
+
+    return ALF_Compat_AdjustWindowRectExForDpi(lpRect, dwStyle, bMenu, dwExStyle, dpi);
+}
 
-    COMPAT(user32.dll, AdjustWindowRectExForDpi, 0, fallbackAdjustWindowRectExForDpi);
+static int WINAPI
+ALF_Compat_loadGetSystemMetricsForDpi(int nIndex, UINT dpi)
+{
+    void *p = (void*)GetProcAddress(GetModuleHandleA("user32.dll"), "GetSystemMetricsForDpi");
+
+    if (!p)
+        p = (void*)ALF_Compat_fallbackGetSystemMetricsForDpi;
+
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_GetSystemMetricsForDpi, p, (void*)ALF_Compat_loadGetSystemMetricsForDpi);
+
+    return ALF_Compat_GetSystemMetricsForDpi(nIndex, dpi);
+}
+
+static BOOL WINAPI
+ALF_Compat_loadSetWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
+{
+    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");
+
+    void *p = (void*)GetProcAddress(comctl32, "SetWindowSubclass");
+    if (!p) {
+        p = (void*)GetProcAddress(comctl32, (char*)410);
+        if (!p) {
+            p = (void*)ALF_Compat_fallbackSetWindowSubclass;
+        }
+    }
+
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_SetWindowSubclass, p, (void*)ALF_Compat_loadSetWindowSubclass);
+
+    return ALF_Compat_SetWindowSubclass(hwnd, pfnSubclass, uIdSubclass, dwRefData);
+}
+
+static BOOL WINAPI
+ALF_Compat_loadRemoveWindowSubclass(HWND hwnd, ALF_COMPAT_SUBCLASSPROC pfnSubclass, UINT_PTR uIdSubclass)
+{
+    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");
 
-    // IsAppThemed would return TRUE even when we're linked against comctl32 v5
-    if (ALF_DllGetVersion("comctl32.dll") >= 0x60000) {
-        LoadLibraryA("uxtheme.dll");
-        COMPAT(uxtheme.dll, IsAppThemed, 0, fallbackIsAppThemed);
-    } else {
-        compatfn->IsAppThemed = fallbackIsAppThemed;
+    void *p = (void*)GetProcAddress(comctl32, "RemoveWindowSubclass");
+    if (!p) {
+        p = (void*)GetProcAddress(comctl32, (char*)412);
+        if (!p) {
+            p = (void*)ALF_Compat_fallbackRemoveWindowSubclass;
+        }
     }
 
-#undef COMPAT
-
-    UINT oldErrorMode = SetErrorMode(SEM_NOOPENFILEERRORBOX); // stop win32s from barking about rpcrt4
-    HMODULE rpc = LoadLibraryA("rpcrt4.dll");
-    if (rpc) {
-        // NT always has rpcrt4.dll
-        compatfn->UuidCreate = (ULONG(WINAPI*)(UUID*))(void*)GetProcAddress(rpc, "UuidCreate");
-    } else {
-        // Win32s always has OLE32
-        HMODULE ole32 = LoadLibraryA("ole32.dll");
-        compatfn->UuidCreate = (ULONG(WINAPI*)(UUID*))(void*)GetProcAddress(ole32, "CoCreateGuid");
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_RemoveWindowSubclass, p, (void*)ALF_Compat_loadRemoveWindowSubclass);
+
+    return ALF_Compat_RemoveWindowSubclass(hwnd, pfnSubclass, uIdSubclass);
+}
+
+static LRESULT WINAPI
+ALF_Compat_loadDefSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+{
+    HMODULE comctl32 = GetModuleHandleA("comctl32.dll");
+
+    void *p = (void*)GetProcAddress(comctl32, "DefSubclassProc");
+    if (!p) {
+        p = (void*)GetProcAddress(comctl32, (char*)413);
+        if (!p) {
+            p = (void*)ALF_Compat_fallbackDefSubclassProc;
+        }
     }
-    SetErrorMode(oldErrorMode);
 
-    return compatfn;
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_DefSubclassProc, p, (void*)ALF_Compat_loadDefSubclassProc);
+
+    return ALF_Compat_DefSubclassProc(hwnd, uMsg, wParam, lParam);
 }
 
-long
-ALF_GetAveCharWidth(HDC hdc)
+static BOOL WINAPI
+ALF_Compat_loadSystemParametersInfoForDpi(UINT uiAction, UINT uiParam, PVOID pvParam, UINT fWinIni, UINT dpi)
 {
-    // see: HOWTO: Calculate Dialog Units When Not Using the System Font
+    void *p = (void*)GetProcAddress(GetModuleHandleA("user32.dll"), "SystemParametersInfoForDpi");
+    if (!p)
+        p = (void*)ALF_Compat_fallbackSystemParametersInfoForDpi;
 
-    SIZE s;
-    GetTextExtentPoint32A(hdc, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 52, &s);
+    InterlockedCompareExchangePointer((void**)&ALF_Compat_SystemParametersInfoForDpi, p, (void*)ALF_Compat_loadSystemParametersInfoForDpi);
 
-    return (s.cx / 26 + 1) / 2;
+    return ALF_Compat_SystemParametersInfoForDpi(uiAction, uiParam, pvParam, fWinIni, dpi);
 }
+
+
+BOOL (WINAPI *ALF_Compat_IsAppThemed)(void) = ALF_Compat_loadIsAppThemed;
+UINT (WINAPI *ALF_Compat_GetDpiForWindow)(HWND /*window*/) = ALF_Compat_loadGetDpiForWindow;
+BOOL (WINAPI *ALF_Compat_AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT) = ALF_Compat_loadAdjustWindowRectExForDpi;
+int (WINAPI *ALF_Compat_GetSystemMetricsForDpi)(int,  UINT) = ALF_Compat_loadGetSystemMetricsForDpi;
+BOOL (WINAPI *ALF_Compat_SetWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR, DWORD_PTR) = ALF_Compat_loadSetWindowSubclass;
+LRESULT (WINAPI *ALF_Compat_DefSubclassProc)(HWND, UINT, WPARAM, LPARAM) = ALF_Compat_loadDefSubclassProc;
+BOOL (WINAPI *ALF_Compat_RemoveWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR) = ALF_Compat_loadRemoveWindowSubclass;
+
+// FIXME! do Unicode properly for SystemParametersInfoForDpi
+#ifdef UNICODE
+BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT) = ALF_Compat_loadSystemParametersInfoForDpi;
+#else
+BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT) = ALF_Compat_fallbackSystemParametersInfoForDpi;
+#endif
diff --git a/alf/alfcompat.h b/alf/alfcompat.h
index 98a2abc..b0a43ec 100644
--- a/alf/alfcompat.h
+++ b/alf/alfcompat.h
@@ -8,18 +8,6 @@
 #endif
 
 typedef LRESULT (CALLBACK *ALF_COMPAT_SUBCLASSPROC)(HWND,UINT,WPARAM,LPARAM,UINT_PTR,DWORD_PTR);
-typedef struct {
-    BOOL (WINAPI *SetWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR, DWORD_PTR);
-    LRESULT (WINAPI *DefSubclassProc)(HWND, UINT, WPARAM, LPARAM);
-    BOOL (WINAPI *RemoveWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR);
-    int (WINAPI *GetSystemMetricsForDpi)(int,  UINT);
-    BOOL (WINAPI *IsAppThemed)(void);
-    UINT (WINAPI *GetDpiForWindow)(HWND);
-    BOOL (WINAPI *SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT);
-    BOOL (WINAPI *AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT);
-    ULONG (WINAPI *UuidCreate)(UUID *);
-} ALFCompatFunctions;
-
 
 typedef struct {
     UINT    cbSize;
@@ -50,8 +38,18 @@ ALF_SizeOf_NONCLIENTMETRICS(void)
     }
 }
 
-ALFCompatFunctions *
-ALF_CreateCompatFuncTable(void);
-
 long
 ALF_GetAveCharWidth(HDC hdc);
+
+void
+ALF_UniqueCounterValue(LONG_PTR *pCounterId, LONG_PTR *pCounterValue);
+
+
+extern BOOL (WINAPI *ALF_Compat_IsAppThemed)(void);
+extern UINT (WINAPI *ALF_Compat_GetDpiForWindow)(HWND);
+extern BOOL (WINAPI *ALF_Compat_AdjustWindowRectExForDpi)(LPRECT,DWORD,BOOL,DWORD,UINT);
+extern int (WINAPI *ALF_Compat_GetSystemMetricsForDpi)(int,  UINT);
+extern BOOL (WINAPI *ALF_Compat_SetWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR, DWORD_PTR);
+extern LRESULT (WINAPI *ALF_Compat_DefSubclassProc)(HWND, UINT, WPARAM, LPARAM);
+extern BOOL (WINAPI *ALF_Compat_RemoveWindowSubclass)(HWND, ALF_COMPAT_SUBCLASSPROC, UINT_PTR);
+extern BOOL (WINAPI *ALF_Compat_SystemParametersInfoForDpi)(UINT,UINT,PVOID,UINT,UINT);
diff --git a/alf/alfedit.cpp b/alf/alfedit.cpp
index bbe36b8..1fde70d 100644
--- a/alf/alfedit.cpp
+++ b/alf/alfedit.cpp
@@ -7,8 +7,6 @@ ALF__EditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_P
     (void)uIdSubclass;
     (void)dwRefData;
 
-    ALFAPP app = (ALFAPP)dwRefData;
-
     if (uMsg == ALF_WM_QUERYSIZE) {
         HDC hDc = GetDC(hwnd);
         HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
@@ -26,7 +24,7 @@ ALF__EditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_P
                 }
 
                 if (!ps->cy) {
-                    ps->cy = tm.tmHeight + 2*app->compatFn->GetSystemMetricsForDpi(
+                    ps->cy = tm.tmHeight + 2*ALF_Compat_GetSystemMetricsForDpi(
                             SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
                         + 4 /* padding internal to the edit control */
                         + 2 /* external padding to line up with themed button */;
@@ -48,10 +46,10 @@ ALF__EditSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_P
                                        p->right - p->left, p->bottom - p->top - 2,
                                        SWP_NOZORDER|SWP_NOACTIVATE|SWP_NOCOPYBITS);
     } else if (uMsg == WM_DESTROY) {
-        app->compatFn->RemoveWindowSubclass(hwnd, ALF__EditSubclassProc, 0);
+        ALF_Compat_RemoveWindowSubclass(hwnd, ALF__EditSubclassProc, 0);
     }
 
-    return app->compatFn->DefSubclassProc(hwnd, uMsg, wParam, lParam);
+    return ALF_Compat_DefSubclassProc(hwnd, uMsg, wParam, lParam);
 }
 
 HWND
@@ -78,9 +76,7 @@ ALF_AddEdit(HWND win, WORD id, UINT x, UINT y, const TCHAR *text)
                                     (HINSTANCE)GetWindowLongPtr(win, GWLP_HINSTANCE),
                                     NULL);
 
-    ALFAPP app = ALF_ApplicationFromWindow(win);
-
-    app->compatFn->SetWindowSubclass(hwndEdit, ALF__EditSubclassProc, 0, (DWORD_PTR)app);
+    ALF_Compat_SetWindowSubclass(hwndEdit, ALF__EditSubclassProc, 0, 0);
     SetWindowPos(hwndEdit, NULL, 0, 0, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOMOVE | SWP_NOACTIVATE | SWP_FRAMECHANGED);
 
     ALFWidgetLayoutParams p;
diff --git a/alf/alflabel.cpp b/alf/alflabel.cpp
index 108c8d5..eb27fb1 100644
--- a/alf/alflabel.cpp
+++ b/alf/alflabel.cpp
@@ -3,11 +3,11 @@
 /* LABEL */
 
 static
-int ALF__LabelTopPadding(HWND hwnd, ALFAPP app)
+int ALF__LabelTopPadding(HWND hwnd)
 {
     // some pixels on top to align with the edit control
     // see also: alfedit.cpp
-    return app->compatFn->GetSystemMetricsForDpi(
+    return ALF_Compat_GetSystemMetricsForDpi(
                 SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
             + ((LOBYTE(LOWORD(GetVersion())) < 4) ? 2 : 1) /* internal padding in edit control */
             + 1 /* external padding around edit control */;
@@ -19,8 +19,6 @@ ALF__LabelSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_
     (void)uIdSubclass;
     (void)dwRefData;
 
-    ALFAPP app = (ALFAPP)dwRefData;
-
     if (uMsg == ALF_WM_QUERYSIZE) {
         HDC hdcLabel = GetDC(hwnd);
         HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
@@ -52,7 +50,7 @@ ALF__LabelSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_
         if (pSize->cx == 0)
             pSize->cx = r.right - r.left;
         if (pSize->cy == 0)
-            pSize->cy = r.bottom - r.top + ALF__LabelTopPadding(hwnd, app);
+            pSize->cy = r.bottom - r.top + ALF__LabelTopPadding(hwnd);
 
         if (font)
             SelectFont(hdcLabel, oldFont);
@@ -61,7 +59,7 @@ ALF__LabelSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_
     } else if (uMsg == ALF_WM_APPLYSIZE) {
         RECT *p = (RECT *)lParam;
 
-        int topPadding = ALF__LabelTopPadding(hwnd, app);
+        int topPadding = ALF__LabelTopPadding(hwnd);
 
         return (LRESULT)DeferWindowPos((HDWP)wParam,
                                        hwnd, NULL,
@@ -69,10 +67,10 @@ ALF__LabelSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_
                                        p->right - p->left, p->bottom - p->top - topPadding,
                                        SWP_NOZORDER|SWP_NOACTIVATE);
     } else if (uMsg == WM_DESTROY) {
-        app->compatFn->RemoveWindowSubclass(hwnd, ALF__LabelSubclassProc, 0);
+        ALF_Compat_RemoveWindowSubclass(hwnd, ALF__LabelSubclassProc, 0);
     }
 
-    return app->compatFn->DefSubclassProc(hwnd, uMsg, wParam, lParam);
+    return ALF_Compat_DefSubclassProc(hwnd, uMsg, wParam, lParam);
 }
 
 HWND
@@ -87,8 +85,7 @@ ALF_AddLabel(HWND win, WORD id, UINT x, UINT y, const TCHAR *text)
                                   (HINSTANCE)GetWindowLongPtr(win, GWLP_HINSTANCE),
                                   NULL);
 
-    ALFAPP app = ALF_ApplicationFromWindow(win);
-    app->compatFn->SetWindowSubclass(hwndLabel, ALF__LabelSubclassProc, 0, (DWORD_PTR)app);
+    ALF_Compat_SetWindowSubclass(hwndLabel, ALF__LabelSubclassProc, 0, 0);
 
     ALFWidgetLayoutParams p;
     ZeroMemory(&p, sizeof(p));
diff --git a/alf/alfpanel.cpp b/alf/alfpanel.cpp
index 74db788..070c286 100644
--- a/alf/alfpanel.cpp
+++ b/alf/alfpanel.cpp
@@ -59,7 +59,7 @@ ALF_RegisterPanelClass(ALFAPP app)
     ZeroMemory(&cls, sizeof(cls));
 
     TCHAR  classNameBuf[256];
-    ALF_BuildRandomClassName(app, TEXT("ALFPanel."), classNameBuf);
+    ALF_BuildRandomClassName(TEXT("ALFPanel"), classNameBuf, 256);
 
     cls.hInstance = app->hInstance;
     cls.hCursor = LoadCursor(NULL, (LPTSTR)IDC_ARROW);
diff --git a/alf/alfpriv.h b/alf/alfpriv.h
index 8f28b59..ec7a447 100644
--- a/alf/alfpriv.h
+++ b/alf/alfpriv.h
@@ -30,7 +30,6 @@ typedef struct {
 
 struct ALFAppPriv {
     HINSTANCE           hInstance;
-    ALFCompatFunctions *compatFn;
     TCHAR              *comboClass;
     TCHAR              *panelClass;
 };
@@ -51,7 +50,7 @@ void
 ALF_RegisterPanelClass(ALFAPP app);
 
 void
-ALF_BuildRandomClassName(ALFAPP app, const TCHAR *prefix, TCHAR *buf);
+ALF_BuildRandomClassName(const TCHAR *prefix, TCHAR *buf, DWORD cchBuf);
 
 BOOL
 ALF_ShouldMessageBubble(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam);