d3dx8: Implement ID3DXMatrixStack_LoadMatrix.

dlls/d3dx8/math.c

@@ -674,8 +674,13 @@ static HRESULT WINAPI ID3DXMatrixStackImpl_LoadIdentity(ID3DXMatrixStack *iface)
 static HRESULT WINAPI ID3DXMatrixStackImpl_LoadMatrix(ID3DXMatrixStack *iface, CONST D3DXMATRIX *pm)
 {
     ID3DXMatrixStackImpl *This = (ID3DXMatrixStackImpl *)iface;
-    FIXME("(%p) : stub\n",This);
-    return E_NOTIMPL;
+
+    TRACE("iface %p\n", iface);
+
+    if (!pm) return D3DERR_INVALIDCALL;
+    This->stack[This->current] = *pm;
+
+    return D3D_OK;
 }
 
 static HRESULT WINAPI ID3DXMatrixStackImpl_MultMatrix(ID3DXMatrixStack *iface, CONST D3DXMATRIX *pm)