From c9a9b3c9d0d4fed0b02d9935923bfd7dcbc45d1e Mon Sep 17 00:00:00 2001
From: Mattes D <github@xoft.cz>
Date: Tue, 14 Apr 2020 16:43:21 +0200
Subject: Bindings: Allow coercion between Vector3 subtypes. (#4646)

In manually bound functions, allows one to use any Vector3<T> value, as well as a {x, y, z} table, in Lua as any Vector3<T> parameter.
Has example in Debuggers' /vector command.
Unfortunately doesn't work in auto-bindings.
---
 src/Bindings/LuaState.cpp | 75 ++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 71 insertions(+), 4 deletions(-)

(limited to 'src/Bindings/LuaState.cpp')

diff --git a/src/Bindings/LuaState.cpp b/src/Bindings/LuaState.cpp
index ad1021001..0541af793 100644
--- a/src/Bindings/LuaState.cpp
+++ b/src/Bindings/LuaState.cpp
@@ -1451,6 +1451,57 @@ bool cLuaState::GetStackValue(int a_StackPos, cUUID & a_Value)
 
 
 
+template <typename T>
+bool cLuaState::GetStackValue(int a_StackPos, Vector3<T> & a_ReturnedVal)
+{
+	tolua_Error err;
+	if (lua_isnil(m_LuaState, a_StackPos))
+	{
+		return false;
+	}
+	if (tolua_isusertype(m_LuaState, a_StackPos, "Vector3<double>", 0, &err))
+	{
+		a_ReturnedVal = **(static_cast<const Vector3d **>(lua_touserdata(m_LuaState, a_StackPos)));
+		return true;
+	}
+	if (tolua_isusertype(m_LuaState, a_StackPos, "Vector3<float>", 0, &err))
+	{
+		a_ReturnedVal = **(static_cast<const Vector3f **>(lua_touserdata(m_LuaState, a_StackPos)));
+		return true;
+	}
+	if (tolua_isusertype(m_LuaState, a_StackPos, "Vector3<int>", 0, &err))
+	{
+		a_ReturnedVal = **(static_cast<const Vector3i **>(lua_touserdata(m_LuaState, a_StackPos)));
+		return true;
+	}
+
+	// Bonus: Allow simple tables to work as Vector3:
+	if (lua_istable(m_LuaState, a_StackPos))
+	{
+		lua_rawgeti(m_LuaState, a_StackPos, 1);
+		lua_rawgeti(m_LuaState, a_StackPos, 2);
+		lua_rawgeti(m_LuaState, a_StackPos, 3);
+		T x, y, z;
+		if (!GetStackValues(-3, x, y, z))
+		{
+			return false;
+		}
+		a_ReturnedVal = Vector3<T>(x, y, z);
+		return true;
+	}
+
+	return false;
+}
+
+// Explicitly instantiate the previous function for all Vector3 types:
+template bool cLuaState::GetStackValue(int a_StackPos, Vector3d & a_ReturnedVal);
+template bool cLuaState::GetStackValue(int a_StackPos, Vector3f & a_ReturnedVal);
+template bool cLuaState::GetStackValue(int a_StackPos, Vector3i & a_ReturnedVal);
+
+
+
+
+
 cLuaState::cStackValue cLuaState::WalkToValue(const AString & a_Name)
 {
 	// There needs to be at least one value on the stack:
@@ -1937,24 +1988,40 @@ bool cLuaState::CheckParamStaticSelf(const char * a_SelfClassName)
 
 
 
-bool cLuaState::IsParamUserType(int a_Param, AString a_UserType)
+bool cLuaState::IsParamUserType(int a_ParamIdx, AString a_UserType)
 {
 	ASSERT(IsValid());
 
 	tolua_Error tolua_err;
-	return (tolua_isusertype(m_LuaState, a_Param, a_UserType.c_str(), 0, &tolua_err) == 1);
+	return (tolua_isusertype(m_LuaState, a_ParamIdx, a_UserType.c_str(), 0, &tolua_err) == 1);
 }
 
 
 
 
 
-bool cLuaState::IsParamNumber(int a_Param)
+bool cLuaState::IsParamNumber(int a_ParamIdx)
 {
 	ASSERT(IsValid());
 
 	tolua_Error tolua_err;
-	return (tolua_isnumber(m_LuaState, a_Param, 0, &tolua_err) == 1);
+	return (tolua_isnumber(m_LuaState, a_ParamIdx, 0, &tolua_err) == 1);
+}
+
+
+
+
+
+bool cLuaState::IsParamVector3(int a_ParamIdx)
+{
+	ASSERT(IsValid());
+
+	return (
+		IsParamUserType(a_ParamIdx, "Vector3<double>") ||
+		IsParamUserType(a_ParamIdx, "Vector3<float>") ||
+		IsParamUserType(a_ParamIdx, "Vector3<int>") ||
+		lua_istable(m_LuaState, a_ParamIdx)  // Assume any table is good enough
+	);
 }
 
 
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