Merge remote-tracking branch 'origin/codex/trend-display-scale' into HEAD

c/set-protocol/src/set_plot.c

@@ -11,10 +11,10 @@ static int finite_values(const double *v, size_t n) {
 uint32_t set_plot_abi_version(void) { return 1U; }
 
 size_t set_plot_eval(uint32_t op, const double *v, size_t n, double *out, size_t cap) {
-    static const size_t sizes[] = {10, 3, 4, 4, 6, 2, 3, 2};
+    static const size_t sizes[] = {10, 3, 4, 4, 6, 2, 3, 2, 4};
     double span, fraction;
-    if (op > SET_PLOT_DB_DELTA || !v || !out || n != sizes[op] ||
-        cap < (op == SET_PLOT_TRANSFORM ? 4U : 1U)) return 0;
+    if (op > SET_PLOT_LIMITS || !v || !out || n != sizes[op] ||
+        cap < (op == SET_PLOT_TRANSFORM || op == SET_PLOT_LIMITS ? 4U : 1U)) return 0;
     if (op == SET_PLOT_TRANSFORM) {
         double w, h, fx, fy;
         if (!finite_values(v, 4) || v[2] < 1.0/128 || v[2] > 1 ||
@@ -69,6 +69,10 @@ size_t set_plot_eval(uint32_t op, const double *v, size_t n, double *out, size_t
         if (v[0] == 0 || v[1] == 0) return 0;
         out[0] = 20 * log10(fabs(v[1] / v[0]));
         break;
+    case SET_PLOT_LIMITS:
+        if (v[0] >= v[1] || v[2] >= v[3]) return 0;
+        out[0] = v[0]; out[1] = v[1]; out[2] = v[2]; out[3] = v[3];
+        return 4;
     default: return 0;
     }
     return isfinite(out[0]) ? 1 : 0;

c/set-protocol/src/set_spectrum.c

@@ -4,6 +4,13 @@
 
 #define PI 3.14159265358979323846
 
+static int compare_double(const void *left, const void *right)
+{
+    const double a = *(const double *)left;
+    const double b = *(const double *)right;
+    return (a > b) - (a < b);
+}
+
 static double window_value(int window, size_t index, size_t n)
 {
     double phase = 2.0 * PI * (double)index / (double)n;
@@ -124,3 +131,35 @@ int set_spectrum_analyze(const double *times, const double *values, size_t count
     free(scratch);
     return result;
 }
+
+int set_spectrum_dominant_peak(const double *amplitudes, size_t count,
+    double bin_hz, double relative_threshold, double absolute_floor,
+    double *scratch, size_t scratch_capacity, double *peak, size_t peak_capacity)
+{
+    size_t i, usable = 0U, peak_bin = 0U;
+    double peak_amplitude = -1.0, median, threshold;
+    if (amplitudes == NULL || scratch == NULL || peak == NULL || count < 3U ||
+        scratch_capacity < count - 1U || peak_capacity < 2U || !isfinite(bin_hz) ||
+        bin_hz <= 0.0 || !isfinite(relative_threshold) || relative_threshold <= 0.0 ||
+        !isfinite(absolute_floor) || absolute_floor < 0.0) return -1;
+    for (i = 1U; i < count; ++i) {
+        if (isfinite(amplitudes[i]) && amplitudes[i] >= 0.0)
+            scratch[usable++] = amplitudes[i];
+    }
+    if (usable < 2U) return 0;
+    qsort(scratch, usable, sizeof(double), compare_double);
+    median = scratch[usable / 2U];
+    for (i = 1U; i + 1U < count; ++i) {
+        const double value = amplitudes[i];
+        if (isfinite(value) && isfinite(amplitudes[i - 1U]) && isfinite(amplitudes[i + 1U]) &&
+            value >= amplitudes[i - 1U] && value > amplitudes[i + 1U] && value > peak_amplitude) {
+            peak_bin = i;
+            peak_amplitude = value;
+        }
+    }
+    threshold = fmax(absolute_floor, median * relative_threshold);
+    if (peak_bin == 0U || peak_amplitude < threshold) return 0;
+    peak[0] = (double)peak_bin * bin_hz;
+    peak[1] = peak_amplitude;
+    return 1;
+}

c/set-protocol/src/set_trends.c

@@ -6,6 +6,12 @@ static uint16_t get16(const uint8_t *p)
     return (uint16_t)((uint16_t)p[0] | ((uint16_t)p[1] << 8));
 }
 
+static uint32_t get32(const uint8_t *p)
+{
+    return (uint32_t)p[0] | ((uint32_t)p[1] << 8) |
+        ((uint32_t)p[2] << 16) | ((uint32_t)p[3] << 24);
+}
+
 static void put16(uint8_t *p, uint16_t value)
 {
     p[0] = (uint8_t)value;
@@ -63,6 +69,12 @@ int set_trend_watch_ack(const uint8_t *payload, size_t size, uint16_t period_ms,
 }
 
 int set_trend_watch_values(const uint8_t *payload, size_t size, uint16_t *words, size_t capacity)
+{
+    return set_trend_watch_decode(payload, size, NULL, words, capacity);
+}
+
+int set_trend_watch_decode(const uint8_t *payload, size_t size, uint32_t *timestamp_ms,
+    uint16_t *words, size_t capacity)
 {
     size_t i, count;
     if (payload == NULL || size < 6U) return -1;
@@ -70,5 +82,6 @@ int set_trend_watch_values(const uint8_t *payload, size_t size, uint16_t *words,
     if (count > SET_TREND_WATCH_MAX || size != 6U + count * 2U || count > capacity ||
         (count > 0U && words == NULL)) return -1;
     for (i = 0U; i < count; ++i) words[i] = get16(payload + 6U + i * 2U);
+    if (timestamp_ms != NULL) *timestamp_ms = get32(payload);
     return (int)count;
 }