From 5e1a73a28c07ba8c9c80b27abdacdc6da5f080bd Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sun, 1 Dec 2019 21:32:10 +0100
Subject: [PATCH] Add Lua typecast from C++ vector to C-Array

This is useful for MIDI bytes amongst other things
---
 libs/ardour/luabindings.cc             | 19 +++++++------------
 libs/lua/LuaBridge/detail/CFunctions.h | 11 +++++++++++
 libs/lua/LuaBridge/detail/Namespace.h  |  4 ++--
 3 files changed, 20 insertions(+), 14 deletions(-)

diff --git a/libs/ardour/luabindings.cc b/libs/ardour/luabindings.cc
index b05a625396..6deb7accf4 100644
--- a/libs/ardour/luabindings.cc
+++ b/libs/ardour/luabindings.cc
@@ -352,32 +352,27 @@ LuaBindings::stddef (lua_State* L)
 		.beginStdList <std::string> ("StringList")
 		.endClass ()
 
-	// std::vector<std::string>
 		.beginStdVector <std::string> ("StringVector")
 		.endClass ()
 
-	// std::vector<float>
 		.beginStdVector <float> ("FloatVector")
 		.endClass ()
 
-	// register float array (uint8_t*)
-		.registerArray <uint8_t> ("ByteArray")
+		.beginStdVector <uint8_t> ("ByteVector")
+		.endClass ()
 
-	// register float array (float*)
-		.registerArray <float> ("FloatArray")
-
-	// register float array (int32_t*)
-		.registerArray <int32_t> ("IntArray")
-
-	// std::vector<float*>
 		.beginStdVector <float*> ("FloatArrayVector")
 		.endClass ()
 
+		.registerArray <uint8_t> ("ByteArray")
+		.registerArray <float> ("FloatArray")
+		.registerArray <int32_t> ("IntArray")
+
 		// samplepos_t, sampleoffset_t lists e.g. AnalysisFeatureList
 		.beginStdList <int64_t> ("Int64List")
 		.endClass ()
 
-	// TODO std::set
+		// TODO std::set
 		.endNamespace ();
 }
 
diff --git a/libs/lua/LuaBridge/detail/CFunctions.h b/libs/lua/LuaBridge/detail/CFunctions.h
index 22dc115a6a..88c30fc4ad 100644
--- a/libs/lua/LuaBridge/detail/CFunctions.h
+++ b/libs/lua/LuaBridge/detail/CFunctions.h
@@ -1148,6 +1148,17 @@ struct CFunc
     if (!t) { return luaL_error (L, "cannot derefencee shared_ptr"); }
     return tableToListHelper<T, C> (L, t->get());
   }
+  //--------------------------------------------------------------------------
+
+
+  template <class T, class C>
+  static int vectorToArray (lua_State *L)
+  {
+    C * const t = Userdata::get<C> (L, 1, false);
+    T * a = &((*t)[0]);
+    Stack <T*>::push (L, a);
+    return 1;
+  }
 
   //--------------------------------------------------------------------------
   template <class T, class C>
diff --git a/libs/lua/LuaBridge/detail/Namespace.h b/libs/lua/LuaBridge/detail/Namespace.h
index 0ea453e932..46fdaa5252 100644
--- a/libs/lua/LuaBridge/detail/Namespace.h
+++ b/libs/lua/LuaBridge/detail/Namespace.h
@@ -1938,11 +1938,11 @@ public:
     return beginConstStdVector<T> (name)
       .addVoidConstructor ()
       .addFunction ("push_back", (void (LT::*)(const T&))&LT::push_back)
+      .addFunction ("clear", (void (LT::*)())&LT::clear)
+      .addExtCFunction ("to_array", &CFunc::vectorToArray<T, LT>)
       .addExtCFunction ("add", &CFunc::tableToList<T, LT>);
   }
 
-
-
   //----------------------------------------------------------------------------
 
   template <class T>