G2.3: auto-reload instruments from state file after bridge respawn

2026-08-16 07:33:14 +07:00
parent 28441566c2
commit 4faa5a3504
7 changed files with 130 additions and 1 deletions
@@ -587,6 +587,67 @@ std::string Vst3Instrument::serializeState() const {
 #endif
 }

+// G2.3: base64 decode (RFC 4648). Empty / invalid -> false.
+static int b64val(unsigned char c) {
+    if (c >= 'A' && c <= 'Z') return c - 'A';
+    if (c >= 'a' && c <= 'z') return c - 'a' + 26;
+    if (c >= '0' && c <= '9') return c - '0' + 52;
+    if (c == '+') return 62;
+    if (c == '/') return 63;
+    return -1;
+}
+static bool base64Decode(const std::string& in, std::vector<uint8_t>& out) {
+    out.clear();
+    out.reserve((in.size() / 4) * 3);
+    uint32_t acc = 0;
+    int bits = 0;
+    for (unsigned char ch : in) {
+        if (ch == '=' || ch == '\n' || ch == '\r' || ch == ' ') continue;
+        int v = b64val(ch);
+        if (v < 0) return false;
+        acc = (acc << 6) | (uint32_t)v;
+        bits += 6;
+        if (bits >= 8) {
+            bits -= 8;
+            out.push_back((uint8_t)((acc >> bits) & 0xFF));
+        }
+    }
+    return true;
+}
+
+// G2.3: restore a preset previously saved by serializeState() (base64 of
+// [4B BE componentLen][component][4B BE controllerLen][controller]).
+// Decodes into the saved-state buffers and applies them to the live instance.
+void Vst3Instrument::loadSerializedState(const std::string& base64) {
+#ifndef HAVE_VST3SDK
+    (void)base64;
+    return;
+#else
+    std::vector<uint8_t> blob;
+    if (!base64Decode(base64, blob) || blob.size() < 8) {
+        std::cerr << "[Vst3Instrument] loadSerializedState: bad base64 ch=" << channel_ << std::endl;
+        return;
+    }
+    auto read32 = [&blob](size_t off) -> uint32_t {
+        return ((uint32_t)blob[off] << 24) | ((uint32_t)blob[off + 1] << 16) |
+               ((uint32_t)blob[off + 2] << 8) | (uint32_t)blob[off + 3];
+    };
+    size_t off = 0;
+    uint32_t clen = read32(off); off += 4;
+    if (off + clen > blob.size()) { std::cerr << "[Vst3Instrument] loadSerializedState: bad compLen" << std::endl; return; }
+    savedComponentState_.assign(blob.begin() + off, blob.begin() + off + clen);
+    off += clen;
+    if (off + 4 > blob.size()) { std::cerr << "[Vst3Instrument] loadSerializedState: bad ctrlLen" << std::endl; return; }
+    uint32_t klen = read32(off); off += 4;
+    if (off + klen > blob.size()) { std::cerr << "[Vst3Instrument] loadSerializedState: bad ctrlLen" << std::endl; return; }
+    savedControllerState_.assign(blob.begin() + off, blob.begin() + off + klen);
+    std::cout << "[Vst3Instrument] loaded serialized state ch=" << channel_
+              << " component=" << savedComponentState_.size()
+              << " controller=" << savedControllerState_.size() << std::endl;
+    restoreState();
+#endif
+}
+
 // G0.4: restore the captured state onto the freshly loaded instance.
 void Vst3Instrument::restoreState() {
 #ifndef HAVE_VST3SDK