Map Editor feature by valentinoConti · Pull Request #526 · sven-n/MuMain

valentinoConti · 2026-07-13T06:31:11Z

Summary

This PR adds a huge "Map Editor" with multiple features:

Adds a zoom-in / zoom-out feature for the Mu Editor build UI.
Adds a map textures editor
Adds a map objects editor
Adds a map height editor
Adds a map attributes editor
Adds a minimap generator (or most precisely, a top view camera positioning that lets you see ALL the map at once as some kind of god-mode, with tools to help you add/edit the minimap for a map)

All of those can be seen working in this video attached in the Discord channel: https://discord.com/channels/669595902750490698/1297814156275093566/1527317348489363628

Checklist

I have read and followed docs/CODING_RULES.md.
I have built the project locally (see docs/build/README.md).
Changes are focused on one concern
The diff is as small as it reasonably can be. <-- not sure it's possible in this case hehe.

gemini-code-assist · 2026-07-13T06:32:40Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a powerful in-game Map Editor, enabling developers to modify terrain textures, height, walkability attributes, and world objects directly within the client. It includes a minimap generator and comprehensive save functionality to ensure changes are persisted to the game's data files, significantly streamlining the map development workflow.

Highlights

Map Editor UI: Introduced a comprehensive in-game Map Editor with dedicated tabs for managing terrain textures, objects, height, and walkability attributes.
UI Scaling: Added global UI scaling functionality to the editor interface, allowing for better accessibility and visibility.
Minimap Generation: Implemented a top-down camera mode that allows for full-map rendering to capture high-quality minimap screenshots.
Persistence and Encryption: Added robust save logic for terrain mapping, attributes, and objects, including necessary encryption to match the game's native file formats.

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Code Review

This pull request introduces an in-game Map Editor (MuEditor) for editing terrain textures, height, walkability attributes, and world objects, along with support for capturing minimap screenshots. The review feedback identifies several critical issues, including potential out-of-bounds array access in MapObjectImport.cpp (due to using NumMeshs instead of NumTextures and indexing with MAX_MODELS), undefined behavior when casting un-clamped alpha values in MapEditorSave.cpp, and multiple instances of unsafe wide-string formatting (%ls) with snprintf and ImGui::SetTooltip that could lead to rendering issues or crashes.

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gemini-code-assist · 2026-07-13T06:36:29Z

+
+    CopyIfPresent(srcDir + bmdFile, dstDir + ObjectBmdStem(slot) + L".bmd", /*overwrite*/ true);
+
+    for (int k = 0; k < Models[slot].NumMeshs; ++k)


The loop iterates up to NumMeshs but accesses Models[slot].Textures[k]. In the MU client, the number of textures loaded for a model is stored in NumTextures, not NumMeshs. If NumMeshs is greater than NumTextures (or greater than the size of the Textures array), this will cause out-of-bounds array access or memory corruption.

Suggested change

for (int k = 0; k < Models[slot].NumMeshs; ++k)

for (int k = 0; k < Models[slot].NumTextures; ++k)

gemini-code-assist · 2026-07-13T06:36:29Z

+    for (int i = 0; i < CELLS; ++i)
+        plain[p++] = static_cast<BYTE>(TerrainMappingAlpha[i] * 255.f);


If TerrainMappingAlpha[i] is outside the range [0.0f, 1.0f] (or is NaN), multiplying by 255.f and casting to BYTE results in undefined behavior in C++. It is safer to clamp the value to [0.0f, 1.0f] before scaling and casting.

Suggested change

for (int i = 0; i < CELLS; ++i)

plain[p++] = static_cast<BYTE>(TerrainMappingAlpha[i] * 255.f);

for (int i = 0; i < CELLS; ++i)

{

float alpha = TerrainMappingAlpha[i];

plain[p++] = alpha < 0.0f ? 0 : (alpha > 1.0f ? 255 : static_cast<BYTE>(alpha * 255.f));

}

gemini-code-assist · 2026-07-13T06:36:30Z

+    // Models[] is over-allocated past MAX_MODELS, so this index is always valid
+    // memory and sits outside the world-object range (0..159), so it never shows
+    // up as a placeable model on the current map.
+    const int scratch = MAX_MODELS;


The code uses MAX_MODELS as an index into the Models array (Models[scratch]). If Models is declared as BMD Models[MAX_MODELS], then Models[MAX_MODELS] is out of bounds (valid indices are 0 to MAX_MODELS - 1). Relying on over-allocation of a global array is highly unsafe and can lead to memory corruption or crashes if the array size is strictly enforced or changed. Consider using a dedicated slot or ensuring MAX_MODELS is increased in the global definition.

gemini-code-assist · 2026-07-13T06:36:30Z

+            for (const auto& m : m_models)
+                if (m.type == m_selectedModelType)
+                {
+                    snprintf(selName, sizeof(selName), "%d: %ls", m.type, m.file.c_str());


Using %ls with snprintf to format wide strings (std::wstring) into narrow UTF-8 strings is unsafe and incorrect. ImGui expects UTF-8 narrow strings, but %ls in snprintf converts to the local ANSI code page, which will cause rendering issues (mojibake) for non-ASCII characters. Additionally, %ls behavior in narrow vsnprintf is platform-dependent and can fail or truncate. Use StringUtils::WideToNarrow to convert the wide string to a UTF-8 std::string and format it using %s.

Suggested change

snprintf(selName, sizeof(selName), "%d: %ls", m.type, m.file.c_str());

snprintf(selName, sizeof(selName), "%d: %s", m.type, StringUtils::WideToNarrow(m.file).c_str());

gemini-code-assist · 2026-07-13T06:36:30Z

+                if (selected)
+                    ImGui::PopStyleColor();
+                if (ImGui::IsItemHovered())
+                    ImGui::SetTooltip("%d: %ls", m.type, m.file.c_str());


Using %ls with ImGui::SetTooltip to format wide strings (std::wstring) into narrow UTF-8 strings is unsafe and incorrect. ImGui expects UTF-8 narrow strings, but %ls in snprintf converts to the local ANSI code page, which will cause rendering issues (mojibake) for non-ASCII characters. Additionally, %ls behavior in narrow vsnprintf is platform-dependent and can fail or truncate. Use StringUtils::WideToNarrow to convert the wide string to a UTF-8 std::string and format it using %s.

Suggested change

ImGui::SetTooltip("%d: %ls", m.type, m.file.c_str());

ImGui::SetTooltip("%d: %s", m.type, StringUtils::WideToNarrow(m.file).c_str());

gemini-code-assist · 2026-07-13T06:36:30Z

+            char buf[128];
+            snprintf(buf, sizeof(buf), "Wrote %ls (next to Main.exe) - run it on the DB, then restart the server.",


Using %ls with snprintf to format wide strings (std::wstring) into narrow UTF-8 strings is unsafe and incorrect. ImGui expects UTF-8 narrow strings, but %ls in snprintf converts to the local ANSI code page, which will cause rendering issues (mojibake) for non-ASCII characters. Additionally, %ls behavior in narrow vsnprintf is platform-dependent and can fail or truncate. Use StringUtils::WideToNarrow to convert the wide string to a UTF-8 std::string and format it using %s.

snprintf(buf, sizeof(buf), "Wrote %s (next to Main.exe) - run it on the DB, then restart the server.", StringUtils::WideToNarrow(path).c_str());

gemini-code-assist · 2026-07-13T06:36:30Z

+    }
+
+    char msg[192];
+    snprintf(msg, sizeof(msg), "[MapEditor] Also saved a copy next to Main.exe: %ls", dst.wstring().c_str());


Using %ls with snprintf to format wide strings (std::wstring) into narrow UTF-8 strings is unsafe and incorrect. ImGui expects UTF-8 narrow strings, but %ls in snprintf converts to the local ANSI code page, which will cause rendering issues (mojibake) for non-ASCII characters. Additionally, %ls behavior in narrow vsnprintf is platform-dependent and can fail or truncate. Use StringUtils::WideToNarrow to convert the wide string to a UTF-8 std::string and format it using %s.

Suggested change

snprintf(msg, sizeof(msg), "[MapEditor] Also saved a copy next to Main.exe: %ls", dst.wstring().c_str());

snprintf(msg, sizeof(msg), "[MapEditor] Also saved a copy next to Main.exe: %s", StringUtils::WideToNarrow(dst.wstring()).c_str());

valentinoConti added 3 commits July 13, 2026 02:58

Map Editor for MuEditor

38a69a5

Map Editor MVP finished

97bd339

no unnecesary file

ba39790

gemini-code-assist Bot reviewed Jul 13, 2026

View reviewed changes

MapEditor attributes and minimap ready

8be2737

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Map Editor feature#526

Map Editor feature#526
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valentinoConti commented Jul 13, 2026 •

edited

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		CopyIfPresent(srcDir + bmdFile, dstDir + ObjectBmdStem(slot) + L".bmd", /overwrite/ true);

		for (int k = 0; k < Models[slot].NumMeshs; ++k)

	for (int k = 0; k < Models[slot].NumMeshs; ++k)
	for (int k = 0; k < Models[slot].NumTextures; ++k)

		for (int i = 0; i < CELLS; ++i)
		plain[p++] = static_cast<BYTE>(TerrainMappingAlpha[i] * 255.f);

	snprintf(selName, sizeof(selName), "%d: %ls", m.type, m.file.c_str());
	snprintf(selName, sizeof(selName), "%d: %s", m.type, StringUtils::WideToNarrow(m.file).c_str());

	ImGui::SetTooltip("%d: %ls", m.type, m.file.c_str());
	ImGui::SetTooltip("%d: %s", m.type, StringUtils::WideToNarrow(m.file).c_str());

		char buf[128];
		snprintf(buf, sizeof(buf), "Wrote %ls (next to Main.exe) - run it on the DB, then restart the server.",

	snprintf(msg, sizeof(msg), "[MapEditor] Also saved a copy next to Main.exe: %ls", dst.wstring().c_str());
	snprintf(msg, sizeof(msg), "[MapEditor] Also saved a copy next to Main.exe: %s", StringUtils::WideToNarrow(dst.wstring()).c_str());

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valentinoConti commented Jul 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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valentinoConti commented Jul 13, 2026 •

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