Undo/Redo system, hierarchy for models in scene, uuid for basic_nodes, menu bar 'windows' options

utils/uuid.hpp

@@ -0,0 +1,69 @@
+#pragma once
+#include <array>
+#include <random>
+#include <sstream>
+#include <iomanip>
+#include <string>
+#include <algorithm>
+#include <cstdint>
+
+class UID {
+public:
+    std::array<uint8_t,16> bytes;
+
+
+    static UID random() {
+        static thread_local std::mt19937_64 gen(std::random_device{}());
+        UID u;
+        uint64_t a = gen();
+        uint64_t b = gen();
+        for (int i = 0; i < 8; ++i) u.bytes[i] = uint8_t((a >> (i*8)) & 0xFF);
+        for (int i = 0; i < 8; ++i) u.bytes[8 + i] = uint8_t((b >> (i*8)) & 0xFF);
+
+        u.bytes[6] = (u.bytes[6] & 0x0F) | 0x40;
+        u.bytes[8] = (u.bytes[8] & 0x3F) | 0x80;
+
+        return u;
+    }
+
+    std::string to_string() const {
+        std::ostringstream os;
+        os << std::hex << std::setfill('0');
+        auto put = [&](int i){
+            os << std::setw(2) << static_cast<int>(bytes[i]);
+        };
+        // format 8-4-4-4-12
+        for (int i = 0; i < 4; ++i) put(i);
+        for (int i = 4; i < 6; ++i) put(i);
+        os << '-';
+        for (int i = 6; i < 8; ++i) put(i);
+        os << '-';
+        for (int i = 8; i < 10; ++i) put(i);
+        os << '-';
+        for (int i = 10; i < 12; ++i) put(i);
+        os << '-';
+        for (int i = 12; i < 16; ++i) put(i);
+        return os.str();
+    }
+
+    static UID from_string(const std::string& str) {
+        std::istringstream is(str);
+        is >> std::hex;
+        UID u;
+        for (int i = 0; i < 16; ++i) {
+            int byte;
+            is >> byte;
+            u.bytes[i] = static_cast<uint8_t>(byte);
+            if (is.peek() == '-') is.get();
+        }
+        return u;
+    }
+
+    bool operator==(const UID &other) const noexcept {
+        return bytes == other.bytes;
+    }
+
+    bool operator!=(const UID &other) const noexcept {
+        return !(*this == other);
+    }
+};