From 37df9cb7d764891f29b433e80a0d5663fee1a94f Mon Sep 17 00:00:00 2001
From: red-001 <red-001@outlook.ie>
Date: Mon, 30 Jan 2017 19:10:37 +0000
Subject: [PATCH] [CSM] Add `get_node` and `get_node_or_nil`

---
 clientmods/preview/init.lua     | 10 ++++++++-
 doc/client_lua_api.txt          |  8 ++++++-
 src/client.cpp                  |  5 +++++
 src/client.h                    |  1 +
 src/script/lua_api/l_client.cpp | 37 +++++++++++++++++++++++++++++++++
 src/script/lua_api/l_client.h   |  8 +++++++
 6 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/clientmods/preview/init.lua b/clientmods/preview/init.lua
index 3085eda24..91b12d810 100644
--- a/clientmods/preview/init.lua
+++ b/clientmods/preview/init.lua
@@ -39,6 +39,14 @@ core.register_chatcommand("dump", {
 	end,
 })
 
+core.register_chatcommand("test_node", {
+	func = function(param)
+		core.display_chat_message(dump(core.get_node({x=0, y=0, z=0})))
+		core.display_chat_message(dump(core.get_node_or_nil({x=0, y=0, z=0})))
+	end,
+})
+
+
 core.after(2, function()
 	print("[PREVIEW] loaded " .. modname .. " mod")
 end)
@@ -47,4 +55,4 @@ core.register_on_dignode(function(pos, node)
 	print("pos:" .. dump(pos))
 	print("node:" .. dump(node))
 	return false
-end)
\ No newline at end of file
+end)
diff --git a/doc/client_lua_api.txt b/doc/client_lua_api.txt
index 886dbc6e1..7b24452e8 100644
--- a/doc/client_lua_api.txt
+++ b/doc/client_lua_api.txt
@@ -717,7 +717,13 @@ Call these functions only at load time!
 * `minetest.after(time, func, ...)`
     * Call the function `func` after `time` seconds, may be fractional
     * Optional: Variable number of arguments that are passed to `func`
-
+### Map
+* `minetest.get_node(pos)`
+    * Returns the node at the given position as table in the format
+      `{name="node_name", param1=0, param2=0}`, returns `{name="ignore", param1=0, param2=0}`
+      for unloaded areas.
+* `minetest.get_node_or_nil(pos)`
+    * Same as `get_node` but returns `nil` for unloaded areas.
 ### Misc.
 * `minetest.parse_json(string[, nullvalue])`: returns something
     * Convert a string containing JSON data into the Lua equivalent
diff --git a/src/client.cpp b/src/client.cpp
index 4bb63fef1..049616c63 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -1447,6 +1447,11 @@ void Client::removeNode(v3s16 p)
 	}
 }
 
+MapNode Client::getNode(v3s16 p, bool *is_valid_position)
+{
+	return m_env.getMap().getNodeNoEx(p, is_valid_position);
+}
+
 void Client::addNode(v3s16 p, MapNode n, bool remove_metadata)
 {
 	//TimeTaker timer1("Client::addNode()");
diff --git a/src/client.h b/src/client.h
index 9b7130268..dc4469350 100644
--- a/src/client.h
+++ b/src/client.h
@@ -441,6 +441,7 @@ public:
 
 	// Causes urgent mesh updates (unlike Map::add/removeNodeWithEvent)
 	void removeNode(v3s16 p);
+	MapNode getNode(v3s16 p, bool *is_valid_position);
 	void addNode(v3s16 p, MapNode n, bool remove_metadata = true);
 
 	void setPlayerControl(PlayerControl &control);
diff --git a/src/script/lua_api/l_client.cpp b/src/script/lua_api/l_client.cpp
index 9a04bd02f..41e33889c 100644
--- a/src/script/lua_api/l_client.cpp
+++ b/src/script/lua_api/l_client.cpp
@@ -23,6 +23,8 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/string.h"
 #include "cpp_api/s_base.h"
 #include "gettext.h"
+#include "common/c_converter.h"
+#include "common/c_content.h"
 
 int ModApiClient::l_get_current_modname(lua_State *L)
 {
@@ -97,6 +99,39 @@ int ModApiClient::l_gettext(lua_State *L)
 	return 1;
 }
 
+// get_node(pos)
+// pos = {x=num, y=num, z=num}
+int ModApiClient::l_get_node(lua_State *L)
+{
+	// pos
+	v3s16 pos = read_v3s16(L, 1);
+	// Do it
+	bool pos_ok;
+	MapNode n = getClient(L)->getNode(pos, &pos_ok);
+	// Return node
+	pushnode(L, n, getClient(L)->ndef());
+	return 1;
+}
+
+// get_node_or_nil(pos)
+// pos = {x=num, y=num, z=num}
+int ModApiClient::l_get_node_or_nil(lua_State *L)
+{
+	// pos
+	v3s16 pos = read_v3s16(L, 1);
+	// Do it
+	bool pos_ok;
+	MapNode n = getClient(L)->getNode(pos, &pos_ok);
+	if (pos_ok) {
+		// Return node
+		pushnode(L, n, getClient(L)->ndef());
+	}
+	else {
+		lua_pushnil(L);
+	}
+	return 1;
+}
+
 void ModApiClient::Initialize(lua_State *L, int top)
 {
 	API_FCT(get_current_modname);
@@ -106,4 +141,6 @@ void ModApiClient::Initialize(lua_State *L, int top)
 	API_FCT(show_formspec);
 	API_FCT(send_respawn);
 	API_FCT(gettext);
+	API_FCT(get_node);
+	API_FCT(get_node_or_nil);
 }
diff --git a/src/script/lua_api/l_client.h b/src/script/lua_api/l_client.h
index d0e230630..207a5bca0 100644
--- a/src/script/lua_api/l_client.h
+++ b/src/script/lua_api/l_client.h
@@ -47,6 +47,14 @@ private:
 	// set_last_run_mod(modname)
 	static int l_set_last_run_mod(lua_State *L);
 
+	// get_node(pos)
+	static int l_get_node(lua_State *L);
+
+	// get_node_or_nil(pos)
+	static int l_get_node_or_nil(lua_State *L);
+
+
+
 public:
 	static void Initialize(lua_State *L, int top);
 };
-- 
2.25.1