Make the previous commit work with mod elements too

For this to work, loading code needed to stop trusting DEFAULT_PT_ identifiers, which it trusted because there have been some identifier changes between vanilla releases. I dug these up and listed them explicitly; they are now taken into account as needed when loading old enough saves.

src/client/GameSave.cpp

@@ -4,6 +4,7 @@
 #include "simulation/Simulation.h"
 #include "simulation/ElementClasses.h"
 #include "common/tpt-compat.h"
+#include "common/Version.h"
 #include "bson/BSON.h"
 #include "graphics/Renderer.h"
 #include "Config.h"
@@ -641,6 +642,25 @@ void GameSave::readOPS(const std::vector<char> &data)
 		}
 	}
 
+	auto paletteRemap = [this, saveVersion = Version(majorVersion, minorVersion)](auto maxVersion, ByteString from, ByteString to) {
+		if (saveVersion <= maxVersion)
+		{
+			auto it = std::find_if(palette.begin(), palette.end(), [&from](auto &item) {
+				return item.first == from;
+			});
+			if (it != palette.end())
+			{
+				it->first = to;
+			}
+		}
+	};
+	paletteRemap(Version(87, 1), "DEFAULT_PT_TUGN", "DEFAULT_PT_TUNG");
+	paletteRemap(Version(90, 1), "DEFAULT_PT_REPL", "DEFAULT_PT_RPEL");
+	paletteRemap(Version(92, 0), "DEFAULT_PT_E180", "DEFAULT_PT_HEAC");
+	paletteRemap(Version(92, 0), "DEFAULT_PT_E181", "DEFAULT_PT_SAWD");
+	paletteRemap(Version(92, 0), "DEFAULT_PT_E182", "DEFAULT_PT_POLO");
+	paletteRemap(Version(93, 3), "DEFAULT_PT_RAYT", "DEFAULT_PT_LDTC");
+
 	//Read wall and fan data
 	if(wallData)
 	{

src/common/Version.h

@@ -0,0 +1,32 @@
+#pragma once
+#include <array>
+#include <algorithm>
+
+template<size_t ComponentCount>
+struct Version
+{
+	std::array<size_t, ComponentCount> components;
+
+	template<class ...Args>
+	constexpr Version(Args ...args) : components{ size_t(args)... }
+	{
+	}
+
+	constexpr bool operator <(const Version &other) const
+	{
+		return std::lexicographical_compare(components.begin(), components.end(), other.components.begin(), other.components.end());
+	}
+
+	constexpr bool operator ==(const Version &other) const
+	{
+		return std::equal(components.begin(), components.end(), other.components.begin(), other.components.end());
+	}
+
+	constexpr bool operator <=(const Version &other) const
+	{
+		return *this < other || *this == other;
+	}
+};
+
+template<class ...Args>
+Version(Args ...args) -> Version<sizeof...(Args)>;

src/simulation/Simulation.cpp

@@ -32,6 +32,10 @@ std::vector<ByteString> Simulation::Load(const GameSave *save, bool includePress
 	}
 	if(save->palette.size())
 	{
+		for(int i = 0; i < PT_NUM; i++)
+		{
+			partMap[i] = 0;
+		}
 		for(auto &pi : save->palette)
 		{
 			if (pi.second > 0 && pi.second < PT_NUM)
@@ -40,19 +44,17 @@ std::vector<ByteString> Simulation::Load(const GameSave *save, bool includePress
 				for (int i = 0; i < PT_NUM; i++)
 				{
 					if (elements[i].Enabled && elements[i].Identifier == pi.first)
+					{
 						myId = i;
+					}
 				}
-				// if this is a custom element, set the ID to the ID we found when comparing identifiers in the palette map
-				// set type to 0 if we couldn't find an element with that identifier present when loading,
-				//  unless this is a default element, in which case keep the current ID, because otherwise when an element is renamed it wouldn't show up anymore in older saves
-				if (myId != 0)
+				if (myId)
 				{
 					partMap[pi.second] = myId;
 				}
-				else if (!pi.first.BeginsWith("DEFAULT_PT_"))
+				else
 				{
 					missingElementTypes.push_back(pi.first);
-					partMap[pi.second] = myId;
 				}
 			}
 		}