feat(udpscope): per-element timestamp reconstruction from UDPS frames

Implements FrameDecoder with five timing rules that mirror UDPSourceSession.cpp: FullArray (per-element time signal), FirstSample and LastSample (rate-spread from anchor), accumulated scalar with declared rate (forward-chain anchoring, immune to arrival jitter), and PACKET burst (backward-span from previous arrival). 9 new tests, 38 pass total. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-08-27 20:01:30 +02:00
parent c89decef8e
commit 5a8479cda9
5 changed files with 583 additions and 0 deletions
@@ -35,4 +35,69 @@ struct Rect {
    }
 };

+/* Protocol constants, spelled out rather than included, so the framework-free
+ * modules stay independent of udps_client.h. They mirror Common/UDP/UDPSProtocol.h. */
+constexpr uint8_t  kTimePacket      = 0;
+constexpr uint8_t  kTimeFullArray   = 1;
+constexpr uint8_t  kTimeFirstSample = 2;
+constexpr uint8_t  kTimeLastSample  = 3;
+constexpr uint32_t kNoTimeSignal    = 0xFFFFFFFFu;
+
+/** Framework-free mirror of udps_signal_t, plus UI state. */
+struct SignalMeta {
+    std::string name;
+    uint8_t     typeCode      = 255;
+    uint8_t     quantType     = 0;
+    uint32_t    numRows       = 1;
+    uint32_t    numCols       = 1;
+    double      rangeMin      = 0.0;
+    double      rangeMax      = 0.0;
+    uint8_t     timeMode      = kTimePacket;
+    double      samplingRate  = 0.0;
+    uint32_t    timeSignalIdx = kNoTimeSignal;
+    std::string unit;
+
+    /** User override: treat an ambiguous PACKET array as a profile, not a burst. */
+    bool profileOverride = false;
+
+    uint32_t numElements() const {
+        const uint64_t n = static_cast<uint64_t>(numRows ? numRows : 1u) *
+                           static_cast<uint64_t>(numCols ? numCols : 1u);
+        return n == 0u ? 1u : static_cast<uint32_t>(n);
+    }
+
+    bool hasTimeSignal(uint32_t numSignals) const {
+        return timeSignalIdx != kNoTimeSignal && timeSignalIdx < numSignals;
+    }
+
+    /**
+     * @brief True when this array should be plotted against element index
+     *        rather than unrolled onto the time axis.
+     *
+     * Only PACKET arrays are ambiguous: the producer stamped the whole datagram
+     * with one time, which is what a genuine vector looks like and also what a
+     * burst carrying no time metadata looks like. Default is burst, matching
+     * UDPSourceSession, with this flag as the user's override.
+     */
+    bool isVectorProfile() const {
+        return profileOverride && numElements() > 1u && timeMode == kTimePacket;
+    }
+};
+
+/**
+ * @brief Non-owning mirror of udps_frame_t.
+ *
+ * Kept separate from the C struct so FrameDecoder can be tested with plain
+ * arrays and no socket. Points at memory owned by the caller.
+ */
+struct FrameView {
+    uint32_t             counter    = 0;
+    uint64_t             hrt        = 0;
+    double               recvTime   = 0.0;
+    uint32_t             numSamples = 1;
+    uint32_t             numSignals = 0;
+    const double* const* values     = nullptr;  /**< values[i][0..counts[i]) */
+    const uint32_t*      counts     = nullptr;
+};
+
 } /* namespace udpscope */