d3d10core: Use unsafe_impl_from_ID3D10InputLayout for an app provided iface.

dlls/d3d10core/d3d10core_private.h

@@ -164,6 +164,7 @@ struct d3d10_input_layout
 HRESULT d3d10_input_layout_init(struct d3d10_input_layout *layout, struct d3d10_device *device,
         const D3D10_INPUT_ELEMENT_DESC *element_descs, UINT element_count,
         const void *shader_byte_code, SIZE_T shader_byte_code_length) DECLSPEC_HIDDEN;
+struct d3d10_input_layout *unsafe_impl_from_ID3D10InputLayout(ID3D10InputLayout *iface) DECLSPEC_HIDDEN;
 
 /* ID3D10VertexShader */
 struct d3d10_vertex_shader

dlls/d3d10core/device.c

@@ -192,11 +192,12 @@ static void STDMETHODCALLTYPE d3d10_device_IASetInputLayout(ID3D10Device *iface,
         ID3D10InputLayout *input_layout)
 {
     struct d3d10_device *This = impl_from_ID3D10Device(iface);
+    struct d3d10_input_layout *layout = unsafe_impl_from_ID3D10InputLayout(input_layout);
 
     TRACE("iface %p, input_layout %p\n", iface, input_layout);
 
     wined3d_device_set_vertex_declaration(This->wined3d_device,
-            input_layout ? ((struct d3d10_input_layout *)input_layout)->wined3d_decl : NULL);
+            layout ? layout->wined3d_decl : NULL);
 }
 
 static void STDMETHODCALLTYPE d3d10_device_IASetVertexBuffers(ID3D10Device *iface, UINT start_slot,

dlls/d3d10core/inputlayout.c

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "wine/port.h"
+#include <assert.h>
 
 #include "d3d10core_private.h"
 
@@ -100,6 +101,11 @@ static HRESULT d3d10_input_layout_to_wined3d_declaration(const D3D10_INPUT_ELEME
     return S_OK;
 }
 
+static inline struct d3d10_input_layout *impl_from_ID3D10InputLayout(ID3D10InputLayout *iface)
+{
+    return CONTAINING_RECORD(iface, struct d3d10_input_layout, vtbl);
+}
+
 /* IUnknown methods */
 
 static HRESULT STDMETHODCALLTYPE d3d10_input_layout_QueryInterface(ID3D10InputLayout *iface,
@@ -238,3 +244,12 @@ HRESULT d3d10_input_layout_init(struct d3d10_input_layout *layout, struct d3d10_
 
     return S_OK;
 }
+
+struct d3d10_input_layout *unsafe_impl_from_ID3D10InputLayout(ID3D10InputLayout *iface)
+{
+    if (!iface)
+        return NULL;
+    assert(iface->lpVtbl == &d3d10_input_layout_vtbl);
+
+    return impl_from_ID3D10InputLayout(iface);
+}