GeoPos: pan continuously across 0° lat/lon (#3317) (#3323)

* GeoPos: pan continuously across 0 deg lat/lon (#3317)

The DMS coordinate fields store an unsigned magnitude with the sign in a
separate hemisphere field (#3283). That made (-1, 0) representable but
left interactive panning unable to cross 0: at magnitude zero the minute/
degree carry clamps instead of flipping the hemisphere, so a 1-degree band
along the equator and the Greenwich meridian is skipped by the wheel.

Route each DMS field's encoder through a signed arcsecond model: a turn
moves the coordinate along the number line, and the hemisphere flip plus
magnitude reflection fall out of one set of fields being rewritten. E.g.
0 deg 0' 42" E minus one minute now gives 0 deg 0' 18" W as expected.

The old per-field on_wrap carry handlers are removed; the fields no longer
apply the turn locally.

* Correct latitude adjustment reporting logic

Fix adjustment logic to only report position if latitude changes.

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

* GeoPos: apply the clamp-report guard to longitude too

The latitude fix (Copilot review) left adjust_lon() reporting a pan even
when set_lon_arcseconds() clamped at +-180 deg and changed nothing. Guard
it the same way: report only when the signed arcseconds actually changed.

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

firmware/application/ui/ui_geomap.cpp

@@ -64,19 +64,11 @@ GeoPos::GeoPos(
     set_lon(0);
 
     const auto changed_fn = [this](int32_t) {
-        // Convert degrees/minutes/seconds fields to decimal (floating point) lat/lon degree
+        report_position();
-        float lat_value = lat();
-        float lon_value = lon();
-
-        text_lat_decimal.set(to_string_decimal(lat_value, 5));
-        text_lon_decimal.set(to_string_decimal(lon_value, 5));
-
-        if (on_change && report_change)
-            on_change(altitude(), lat_value, lon_value, speed());
     };
 
-    const auto changed_hemisphere_fn = [changed_fn](size_t, OptionsField::value_t) {
+    const auto changed_hemisphere_fn = [this](size_t, OptionsField::value_t) {
-        changed_fn(0);
+        report_position();
     };
 
     field_altitude.on_change = changed_fn;
@@ -90,44 +82,15 @@ GeoPos::GeoPos(
     field_lon_minutes.on_change = changed_fn;
     field_lon_seconds.on_change = changed_fn;
 
-    const auto wrapped_lat_seconds = [this](int32_t v) {
+    // Route each DMS field's encoder through the signed arcsecond model so a turn moves
-        const auto old_minutes = field_lat_minutes.value();
+    // the coordinate along the number line and crosses 0 correctly (issue #3317). One
-        field_lat_minutes.on_encoder(v);
+    // second is the base unit; minutes and degrees step by 60 and 3600 of it.
-        if (field_lat_minutes.value() == old_minutes) {
+    field_lat_degrees.on_delta = [this](int32_t d) { adjust_lat(d * 3600); };
-            field_lat_seconds.set_value((v > 0) ? 59 : 0);
+    field_lat_minutes.on_delta = [this](int32_t d) { adjust_lat(d * 60); };
-        }
+    field_lat_seconds.on_delta = [this](int32_t d) { adjust_lat(d); };
-    };
+    field_lon_degrees.on_delta = [this](int32_t d) { adjust_lon(d * 3600); };
-
+    field_lon_minutes.on_delta = [this](int32_t d) { adjust_lon(d * 60); };
-    // Degrees now holds a magnitude, so a minutes wrap always carries in the
+    field_lon_seconds.on_delta = [this](int32_t d) { adjust_lon(d); };
-    // same direction regardless of hemisphere.
-    const auto wrapped_lat_minutes = [this](int32_t v) {
-        const auto old_degrees = field_lat_degrees.value();
-        field_lat_degrees.on_encoder(v);
-        if (field_lat_degrees.value() == old_degrees) {
-            field_lat_minutes.set_value((v > 0) ? 59 : 0);
-        }
-    };
-
-    const auto wrapped_lon_seconds = [this](int32_t v) {
-        const auto old_minutes = field_lon_minutes.value();
-        field_lon_minutes.on_encoder(v);
-        if (field_lon_minutes.value() == old_minutes) {
-            field_lon_seconds.set_value((v > 0) ? 59 : 0);
-        }
-    };
-
-    const auto wrapped_lon_minutes = [this](int32_t v) {
-        const auto old_degrees = field_lon_degrees.value();
-        field_lon_degrees.on_encoder(v);
-        if (field_lon_degrees.value() == old_degrees) {
-            field_lon_minutes.set_value((v > 0) ? 59 : 0);
-        }
-    };
-
-    field_lat_seconds.on_wrap = wrapped_lat_seconds;
-    field_lat_minutes.on_wrap = wrapped_lat_minutes;
-    field_lon_seconds.on_wrap = wrapped_lon_seconds;
-    field_lon_minutes.on_wrap = wrapped_lon_minutes;
 
     text_alt_unit.set(altitude_unit_ ? "m" : "ft");
     if (speed_unit_ == KMPH) text_speed_unit.set("kmph");
@@ -199,6 +162,73 @@ float GeoPos::lon() {
     return (field_lon_hemisphere.selected_index_value() != 0) ? -magnitude : magnitude;
 };
 
+int32_t GeoPos::lat_arcseconds() {
+    int32_t magnitude = field_lat_degrees.value() * 3600 + field_lat_minutes.value() * 60 + field_lat_seconds.value();
+    return (field_lat_hemisphere.selected_index_value() != 0) ? -magnitude : magnitude;
+}
+
+int32_t GeoPos::lon_arcseconds() {
+    int32_t magnitude = field_lon_degrees.value() * 3600 + field_lon_minutes.value() * 60 + field_lon_seconds.value();
+    return (field_lon_hemisphere.selected_index_value() != 0) ? -magnitude : magnitude;
+}
+
+void GeoPos::set_lat_arcseconds(int32_t arcseconds) {
+    if (arcseconds > lat_arcsecond_limit) arcseconds = lat_arcsecond_limit;
+    if (arcseconds < -lat_arcsecond_limit) arcseconds = -lat_arcsecond_limit;
+    bool south = arcseconds < 0;
+    int32_t magnitude = south ? -arcseconds : arcseconds;
+    field_lat_hemisphere.set_by_value(south ? 1 : 0);
+    field_lat_degrees.set_value(magnitude / 3600);
+    field_lat_minutes.set_value((magnitude / 60) % 60);
+    field_lat_seconds.set_value(magnitude % 60);
+}
+
+void GeoPos::set_lon_arcseconds(int32_t arcseconds) {
+    if (arcseconds > lon_arcsecond_limit) arcseconds = lon_arcsecond_limit;
+    if (arcseconds < -lon_arcsecond_limit) arcseconds = -lon_arcsecond_limit;
+    bool west = arcseconds < 0;
+    int32_t magnitude = west ? -arcseconds : arcseconds;
+    field_lon_hemisphere.set_by_value(west ? 1 : 0);
+    field_lon_degrees.set_value(magnitude / 3600);
+    field_lon_minutes.set_value((magnitude / 60) % 60);
+    field_lon_seconds.set_value(magnitude % 60);
+}
+
+// Rewrite the fields from a single signed value so a hemisphere flip and the magnitude
+// reflection happen together. report_change is held off while the four fields settle,
+// then the final position is reported once.
+void GeoPos::adjust_lat(int32_t arcsecond_delta) {
+    const int32_t old_arcseconds = lat_arcseconds();
+    bool previous = report_change;
+    report_change = false;
+    set_lat_arcseconds(old_arcseconds + arcsecond_delta);
+    report_change = previous;
+    if (lat_arcseconds() != old_arcseconds)
+        report_position();
+}
+
+void GeoPos::adjust_lon(int32_t arcsecond_delta) {
+    const int32_t old_arcseconds = lon_arcseconds();
+    bool previous = report_change;
+    report_change = false;
+    set_lon_arcseconds(old_arcseconds + arcsecond_delta);
+    report_change = previous;
+    if (lon_arcseconds() != old_arcseconds)
+        report_position();
+}
+
+void GeoPos::report_position() {
+    // Convert degrees/minutes/seconds fields to decimal (floating point) lat/lon degree
+    float lat_value = lat();
+    float lon_value = lon();
+
+    text_lat_decimal.set(to_string_decimal(lat_value, 5));
+    text_lon_decimal.set(to_string_decimal(lon_value, 5));
+
+    if (on_change && report_change)
+        on_change(altitude(), lat_value, lon_value, speed());
+}
+
 int32_t GeoPos::altitude() {
     return field_altitude.value();
 };

firmware/application/ui/ui_geomap.hpp

@@ -172,6 +172,27 @@ class BMPFileCache {
     uint16_t stamp_{0};
 };
 
+// A degrees/minutes/seconds sub-field whose encoder turns are handed to the owning
+// GeoPos instead of being applied locally. GeoPos keeps the coordinate as a signed
+// arcsecond value, so panning stays continuous across 0 - including the (-1, 0) band
+// along the equator and the Greenwich meridian that a magnitude field cannot cross on
+// its own (see issue #3317). The field still displays an unsigned magnitude; the sign
+// lives in the hemisphere field next to it.
+class GeoPosField : public NumberField {
+   public:
+    using NumberField::NumberField;
+
+    std::function<void(int32_t)> on_delta{};
+
+    bool on_encoder(const EncoderEvent delta) override {
+        if (on_delta) {
+            on_delta(delta);
+            return true;
+        }
+        return NumberField::on_encoder(delta);
+    }
+};
+
 class GeoPos : public View {
    public:
     enum alt_unit {
@@ -206,6 +227,19 @@ class GeoPos : public View {
     void set_report_change(bool v);
 
    private:
+    // Signed arcsecond view of the DMS fields. The encoder handlers work on these so a
+    // turn moves the coordinate along the number line, flipping the hemisphere and
+    // reflecting the magnitude when it crosses 0 (issue #3317).
+    static constexpr int32_t lat_arcsecond_limit = 90 * 3600;
+    static constexpr int32_t lon_arcsecond_limit = 180 * 3600;
+    int32_t lat_arcseconds();
+    int32_t lon_arcseconds();
+    void set_lat_arcseconds(int32_t arcseconds);
+    void set_lon_arcseconds(int32_t arcseconds);
+    void adjust_lat(int32_t arcsecond_delta);
+    void adjust_lon(int32_t arcsecond_delta);
+    void report_position();
+
     bool read_only{false};
     bool report_change{true};
     alt_unit altitude_unit_{};
@@ -247,21 +281,21 @@ class GeoPos : public View {
         1,
         {{"N", 0},
          {"S", 1}}};
-    NumberField field_lat_degrees{
+    GeoPosField field_lat_degrees{
         {6 * 8, 1 * 16},
         3,
         {0, 90},
         1,
         ' ',
         false};
-    NumberField field_lat_minutes{
+    GeoPosField field_lat_minutes{
         {10 * 8, 1 * 16},
         2,
         {0, 59},
         1,
         ' ',
         true};
-    NumberField field_lat_seconds{
+    GeoPosField field_lat_seconds{
         {13 * 8, 1 * 16},
         2,
         {0, 59},
@@ -277,21 +311,21 @@ class GeoPos : public View {
         1,
         {{"E", 0},
          {"W", 1}}};
-    NumberField field_lon_degrees{
+    GeoPosField field_lon_degrees{
         {6 * 8, 2 * 16},
         3,
         {0, 180},
         1,
         ' ',
         false};
-    NumberField field_lon_minutes{
+    GeoPosField field_lon_minutes{
         {10 * 8, 2 * 16},
         2,
         {0, 59},
         1,
         ' ',
         true};
-    NumberField field_lon_seconds{
+    GeoPosField field_lon_seconds{
         {13 * 8, 2 * 16},
         2,
         {0, 59},