1 files changed, 69 insertions, 0 deletions
diff --git a/Examples/lua/funcptr3/example.i b/Examples/lua/funcptr3/example.i
new file mode 100644
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+++ b/Examples/lua/funcptr3/example.i
@@ -0,0 +1,69 @@
+/* File : example.i */
+/*
+This demonstrates how to pass a lua function, into some C code and then call it.
+
+There are two examples, the first is as a parameter, the second as a global variable.
+
+*/
+%module example
+%{
+#include "example.h"
+%}
+/* the extra wrappers for lua functions, see SWIG/Lib/lua/lua_fnptr.i for more details */
+%include "lua_fnptr.i"
+
+/* these are a bunch of C functions which we want to be able to call from lua */
+extern int add(int,int);
+extern int sub(int,int);
+extern int mul(int,int);
+
+/* this function takes a lua function as a parameter and calls it.
+As this is takes a lua fn it needs lua code
+*/
+%inline %{
+	
+int callback(int a, int b, SWIGLUA_FN fn)
+{
+	SWIGLUA_FN_GET(fn);
+	lua_pushnumber(fn.L,a);
+	lua_pushnumber(fn.L,b);
+	lua_call(fn.L,2,1);    /* 2 in, 1 out */
+	return (int)luaL_checknumber(fn.L,-1);
+}	
+%}	
+
+/******************
+Second code uses a stored reference.
+*******************/
+
+%inline %{
+/* note: this is not so good to just have it as a raw ref
+ people could set anything to this
+ a better solution would to be to have a fn which wants a SWIGLUA_FN, then
+ checks the type & converts to a SWIGLUA_REF.
+*/	
+SWIGLUA_REF the_func={0,0};
+	
+void call_the_func(int a)
+{
+	int i;
+	if (the_func.L==0){
+		printf("the_func is zero\n");
+		return;
+	}
+	swiglua_ref_get(&the_func);
+	if (!lua_isfunction(the_func.L,-1))
+	{
+		printf("the_func is not a function\n");
+		return;
+	}
+	lua_pop(the_func.L,1); /* tidy stack */
+	for(i=0;i<a;i++)
+	{
+		swiglua_ref_get(&the_func);
+		lua_pushnumber(the_func.L,i);
+		lua_call(the_func.L,1,0);    /* 1 in, 0 out */
+	}
+}	
+
+%}