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-rw-r--r--src/lib/util/delegate.cpp62
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diff --git a/src/lib/util/delegate.cpp b/src/lib/util/delegate.cpp
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+// license:BSD-3-Clause
+// copyright-holders:Aaron Giles
+/***************************************************************************
+
+ delegate.c
+
+ Templates and classes to enable delegates for callbacks.
+
+***************************************************************************/
+
+#include <assert.h>
+
+#include "osdcomm.h"
+#include "delegate.h"
+
+
+//**************************************************************************
+// GLOBAL VARIABLES
+//**************************************************************************
+
+#if (USE_DELEGATE_TYPE == DELEGATE_TYPE_COMPATIBLE)
+
+delegate_mfp::raw_mfp_data delegate_mfp::s_null_mfp = { {0 }};
+
+#endif
+
+
+
+//**************************************************************************
+// INTERNAL DELEGATE HELPERS
+//**************************************************************************
+
+#if (USE_DELEGATE_TYPE == DELEGATE_TYPE_INTERNAL)
+
+/**
+ * @fn delegate_generic_function delegate_mfp::convert_to_generic(delegate_generic_class *&object) const
+ *
+ * @brief -------------------------------------------------
+ * delegate_convert_raw - given an object and an raw function, adjust the object base
+ * and return the actual final code pointer
+ * -------------------------------------------------.
+ *
+ * @param [in,out] object [in,out] If non-null, the object.
+ *
+ * @return The given data converted to a generic.
+ */
+
+delegate_generic_function delegate_mfp::convert_to_generic(delegate_generic_class *&object) const
+{
+ // apply the "this" delta to the object first
+ object = reinterpret_cast<delegate_generic_class *>(reinterpret_cast<UINT8 *>(object) + m_this_delta);
+
+ // if the low bit of the vtable index is clear, then it is just a raw function pointer
+ if (!(m_function & 1))
+ return reinterpret_cast<delegate_generic_function>(m_function);
+
+ // otherwise, it is the byte index into the vtable where the actual function lives
+ UINT8 *vtable_base = *reinterpret_cast<UINT8 **>(object);
+ return *reinterpret_cast<delegate_generic_function *>(vtable_base + m_function - 1);
+}
+
+#endif