Added a hint to disable windows message processing in SDL_PumpEvents()

SDL_SetHint( SDL_HINT_WINDOWS_ENABLE_MESSAGELOOP, "0" );
libsdl-org · Jun 4, 2014 · 3e3b34a · 3e3b34a
1 parent 0d1f0fe
commit 3e3b34a
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Showing 4 changed files with 41 additions and 16 deletions.
diff --git a/include/SDL_hints.h b/include/SDL_hints.h
@@ -196,6 +196,17 @@ extern "C" {
  */
 #define SDL_HINT_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN    "SDL_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN"
 
+/**
+ *  \brief  A variable controlling whether the windows message loop is processed by SDL 
+ *
+ *  This variable can be set to the following values:
+ *    "0"       - The window message loop is not run
+ *    "1"       - The window message loop is processed in SDL_PumpEvents()
+ *
+ *  By default SDL will process the windows message loop
+ */
+#define SDL_HINT_WINDOWS_ENABLE_MESSAGELOOP "SDL_WINDOWS_ENABLE_MESSAGELOOP"
+
 /**
  *  \brief  A variable controlling whether grabbing input grabs the keyboard
  *

diff --git a/src/video/windows/SDL_windowsevents.c b/src/video/windows/SDL_windowsevents.c
@@ -890,14 +890,16 @@ WIN_PumpEvents(_THIS)
     MSG msg;
     DWORD start_ticks = GetTickCount();
 
-    while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
-        /* Always translate the message in case it's a non-SDL window (e.g. with Qt integration) */
-        TranslateMessage(&msg);
-        DispatchMessage(&msg);
-
-        /* Make sure we don't busy loop here forever if there are lots of events coming in */
-        if (SDL_TICKS_PASSED(msg.time, start_ticks)) {
-            break;
+    if (g_WindowsEnableMessageLoop) {
+        while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
+            /* Always translate the message in case it's a non-SDL window (e.g. with Qt integration) */
+            TranslateMessage(&msg);
+            DispatchMessage(&msg);
+
+            /* Make sure we don't busy loop here forever if there are lots of events coming in */
+            if (SDL_TICKS_PASSED(msg.time, start_ticks)) {
+                break;
+            }
         }
     }
 

diff --git a/src/video/windows/SDL_windowsvideo.c b/src/video/windows/SDL_windowsvideo.c
@@ -39,8 +39,18 @@ static int WIN_VideoInit(_THIS);
 static void WIN_VideoQuit(_THIS);
 
 /* Hints */
+SDL_bool g_WindowsEnableMessageLoop = SDL_TRUE;
 SDL_bool g_WindowFrameUsableWhileCursorHidden = SDL_TRUE;
 
+static void UpdateWindowsEnableMessageLoop(void *userdata, const char *name, const char *oldValue, const char *newValue)
+{
+    if (newValue && *newValue == '0') {
+        g_WindowsEnableMessageLoop = SDL_FALSE;
+    } else {
+        g_WindowsEnableMessageLoop = SDL_TRUE;
+    }
+}
+
 static void UpdateWindowFrameUsableWhileCursorHidden(void *userdata, const char *name, const char *oldValue, const char *newValue)
 {
     if (newValue && *newValue == '0') {
@@ -97,9 +107,9 @@ WIN_CreateDevice(int devindex)
 
     data->userDLL = SDL_LoadObject("USER32.DLL");
     if (data->userDLL) {
-        data->CloseTouchInputHandle = (BOOL (WINAPI *)( HTOUCHINPUT )) SDL_LoadFunction(data->userDLL, "CloseTouchInputHandle");
-        data->GetTouchInputInfo = (BOOL (WINAPI *)( HTOUCHINPUT, UINT, PTOUCHINPUT, int )) SDL_LoadFunction(data->userDLL, "GetTouchInputInfo");
-        data->RegisterTouchWindow = (BOOL (WINAPI *)( HWND, ULONG )) SDL_LoadFunction(data->userDLL, "RegisterTouchWindow");
+        data->CloseTouchInputHandle = (BOOL (WINAPI *)(HTOUCHINPUT)) SDL_LoadFunction(data->userDLL, "CloseTouchInputHandle");
+        data->GetTouchInputInfo = (BOOL (WINAPI *)(HTOUCHINPUT, UINT, PTOUCHINPUT, int)) SDL_LoadFunction(data->userDLL, "GetTouchInputInfo");
+        data->RegisterTouchWindow = (BOOL (WINAPI *)(HWND, ULONG)) SDL_LoadFunction(data->userDLL, "RegisterTouchWindow");
     }
 
     /* Set the function pointers */
@@ -178,7 +188,8 @@ WIN_VideoInit(_THIS)
     WIN_InitKeyboard(_this);
     WIN_InitMouse(_this);
 
-    SDL_AddHintCallback( SDL_HINT_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN, UpdateWindowFrameUsableWhileCursorHidden, NULL );
+    SDL_AddHintCallback(SDL_HINT_WINDOWS_ENABLE_MESSAGELOOP, UpdateWindowsEnableMessageLoop, NULL);
+    SDL_AddHintCallback(SDL_HINT_WINDOW_FRAME_USABLE_WHILE_CURSOR_HIDDEN, UpdateWindowFrameUsableWhileCursorHidden, NULL);
 
     return 0;
 }
@@ -196,7 +207,7 @@ WIN_VideoQuit(_THIS)
 #include <d3d9.h>
 
 SDL_bool 
-D3D_LoadDLL( void **pD3DDLL, IDirect3D9 **pDirect3D9Interface )
+D3D_LoadDLL(void **pD3DDLL, IDirect3D9 **pDirect3D9Interface)
 {
     *pD3DDLL = SDL_LoadObject("D3D9.DLL");
     if (*pD3DDLL) {
@@ -239,7 +250,7 @@ D3D_LoadDLL( void **pD3DDLL, IDirect3D9 **pDirect3D9Interface )
 
 
 int
-SDL_Direct3D9GetAdapterIndex( int displayIndex )
+SDL_Direct3D9GetAdapterIndex(int displayIndex)
 {
     void *pD3DDLL;
     IDirect3D9 *pD3D;
@@ -287,7 +298,7 @@ DXGI_LoadDLL(void **pDXGIDLL, IDXGIFactory **pDXGIFactory)
 {
     *pDXGIDLL = SDL_LoadObject("DXGI.DLL");
     if (*pDXGIDLL) {
-        HRESULT (WINAPI *CreateDXGI)( REFIID riid, void **ppFactory );
+        HRESULT (WINAPI *CreateDXGI)(REFIID riid, void **ppFactory);
 
         CreateDXGI =
             (HRESULT (WINAPI *) (REFIID, void**)) SDL_LoadFunction(*pDXGIDLL,
@@ -365,7 +376,7 @@ SDL_DXGIGetOutputInfo(int displayIndex, int *adapterIndex, int *outputIndex)
                     *adapterIndex = nAdapter;
                     *outputIndex = nOutput;
                 }
-                SDL_free( outputName );
+                SDL_free(outputName);
             }
             IDXGIOutput_Release(pDXGIOutput);
             nOutput++;

diff --git a/src/video/windows/SDL_windowsvideo.h b/src/video/windows/SDL_windowsvideo.h
@@ -171,6 +171,7 @@ typedef struct SDL_VideoData
     TSFSink *ime_ippasink;
 } SDL_VideoData;
 
+extern SDL_bool g_WindowsEnableMessageLoop;
 extern SDL_bool g_WindowFrameUsableWhileCursorHidden;
 
 typedef struct IDirect3D9 IDirect3D9;