Fry3DX 0.4: an easy 3D modeller

Shapes with live settings, shape editing, knife and hole tools, drawing
shapes onto other objects, combining objects (add / subtract / overlap),
copies, thickness, painting with stickers and layers, a Layout tab, a
Print tab with checks, packed .fry files with autosave, export to GLB,
glTF, FBX, OBJ, 3MF, STL and PLY, folders in Layers, its own crash
screen, and a website for GitHub Pages in docs/.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NMSrd5oe1GpUD7E6d825KP

engine/fs/vfs.h

@@ -0,0 +1,52 @@
+#pragma once
+// Virtual filesystem: everything the game loads goes through here. Directories
+// and YMP packs are mounted in order; a file in a later mount overrides the
+// same path in earlier ones (like Source's search paths), which is how patches
+// and mods replace content without touching the base game.
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace keel::fs {
+
+bool mountDir(const std::string& dir);
+bool mountPack(const std::string& file);
+// Mounts dir/*.ymp (in name order: pak0, pak1, ...) and then dir itself, so
+// loose files beat packed ones during development.
+bool mountGameDir(const std::string& dir);
+// Mods: each folder or .ymp in `modsDir` named in `which` ("all" or "a,b,c"),
+// mounted after the game so they override it.
+void mountMods(const std::string& modsDir, const std::string& which);
+// Takes the mods down again (the engine and game stay), e.g. before mounting a new selection.
+void unmountMods();
+void unmountAll();
+
+// A mod in the mods folder: a folder or a .ymp, described by an optional mod.txt inside it:
+//     title "Low gravity"
+//     author "Someone"
+//     version "1.0"
+//     description "Moon gravity and higher jumps."
+struct ModInfo {
+    std::string name;    // folder / pack name: what fs_mods lists
+    std::string path;
+    bool pack = false;
+    std::string title, author, version, description;
+    size_t files = 0;
+    bool replacesAssets = false; // has textures or models (already-loaded ones need a restart)
+};
+std::vector<ModInfo> listMods(const std::string& modsDir);
+// Whether `name` is on in an fs_mods value ("all" or "a,b,c").
+bool modEnabled(const std::string& which, const std::string& name);
+
+std::optional<std::vector<uint8_t>> read(std::string_view path);
+std::optional<std::string> readText(std::string_view path);
+bool exists(std::string_view path);
+// When the file `path` resolves to was last written (loose files only: a pack's never changes
+// under a running game); for hot reload.
+std::optional<int64_t> mtime(std::string_view path);
+// Files under `dir` (recursive) ending in `ext`, across all mounts, no duplicates.
+std::vector<std::string> list(std::string_view dir, std::string_view ext = {});
+
+} // namespace keel::fs