ddraw: Use unsafe_impl_from_IDirect3DLight() for application provided ifaces.

dlls/ddraw/ddraw_private.h

@@ -408,6 +408,7 @@ struct IDirect3DLightImpl
 void light_activate(IDirect3DLightImpl *light) DECLSPEC_HIDDEN;
 void light_deactivate(IDirect3DLightImpl *light) DECLSPEC_HIDDEN;
 void d3d_light_init(IDirect3DLightImpl *light, IDirectDrawImpl *ddraw) DECLSPEC_HIDDEN;
+IDirect3DLightImpl *unsafe_impl_from_IDirect3DLight(IDirect3DLight *iface) DECLSPEC_HIDDEN;
 
 /******************************************************************************
  * IDirect3DMaterial implementation structure - Wraps to D3D7

dlls/ddraw/light.c

@@ -281,3 +281,12 @@ void d3d_light_init(IDirect3DLightImpl *light, IDirectDrawImpl *ddraw)
     light->ref = 1;
     light->ddraw = ddraw;
 }
+
+IDirect3DLightImpl *unsafe_impl_from_IDirect3DLight(IDirect3DLight *iface)
+{
+    if (!iface)
+        return NULL;
+    assert(iface->lpVtbl == &d3d_light_vtbl);
+
+    return impl_from_IDirect3DLight(iface);
+}

dlls/ddraw/viewport.c

@@ -715,12 +715,11 @@ static HRESULT WINAPI IDirect3DViewportImpl_Clear(IDirect3DViewport3 *iface,
  *  DDERR_INVALIDPARAMS if there are 8 lights or more
  *
  *****************************************************************************/
-static HRESULT WINAPI
-IDirect3DViewportImpl_AddLight(IDirect3DViewport3 *iface,
+static HRESULT WINAPI IDirect3DViewportImpl_AddLight(IDirect3DViewport3 *iface,
         IDirect3DLight *lpDirect3DLight)
 {
     IDirect3DViewportImpl *This = (IDirect3DViewportImpl *)iface;
-    IDirect3DLightImpl *lpDirect3DLightImpl = (IDirect3DLightImpl *)lpDirect3DLight;
+    IDirect3DLightImpl *lpDirect3DLightImpl = unsafe_impl_from_IDirect3DLight(lpDirect3DLight);
     DWORD i = 0;
     DWORD map = This->map_lights;
 
@@ -771,12 +770,11 @@ IDirect3DViewportImpl_AddLight(IDirect3DViewport3 *iface,
  *  DDERR_INVALIDPARAMS if the light wasn't found
  *
  *****************************************************************************/
-static HRESULT WINAPI
-IDirect3DViewportImpl_DeleteLight(IDirect3DViewport3 *iface,
+static HRESULT WINAPI IDirect3DViewportImpl_DeleteLight(IDirect3DViewport3 *iface,
         IDirect3DLight *lpDirect3DLight)
 {
     IDirect3DViewportImpl *This = (IDirect3DViewportImpl *)iface;
-    IDirect3DLightImpl *l = (IDirect3DLightImpl *)lpDirect3DLight;
+    IDirect3DLightImpl *l = unsafe_impl_from_IDirect3DLight(lpDirect3DLight);
 
     TRACE("iface %p, light %p.\n", iface, lpDirect3DLight);
 
@@ -814,14 +812,11 @@ IDirect3DViewportImpl_DeleteLight(IDirect3DViewport3 *iface,
  *  D3D_OK, because it's a stub
  *
  *****************************************************************************/
-static HRESULT WINAPI
-IDirect3DViewportImpl_NextLight(IDirect3DViewport3 *iface,
-                                IDirect3DLight *lpDirect3DLight,
-                                IDirect3DLight **lplpDirect3DLight,
-                                DWORD dwFlags)
+static HRESULT WINAPI IDirect3DViewportImpl_NextLight(IDirect3DViewport3 *iface,
+        IDirect3DLight *lpDirect3DLight, IDirect3DLight **lplpDirect3DLight, DWORD dwFlags)
 {
     IDirect3DViewportImpl *This = (IDirect3DViewportImpl *)iface;
-    IDirect3DLightImpl *l = (IDirect3DLightImpl *)lpDirect3DLight;
+    IDirect3DLightImpl *l = unsafe_impl_from_IDirect3DLight(lpDirect3DLight);
     struct list *entry;
     HRESULT hr;