From eb2fa727a7c634109e6d7c27f1d71892f562869e Mon Sep 17 00:00:00 2001
From: Jonathan Bennett <jbennett@incomsystems.biz>
Date: Thu, 22 Feb 2024 12:32:01 -0600
Subject: [PATCH] Adds support for position_precision

---
 src/mesh/Channels.cpp          |  1 +
 src/modules/PositionModule.cpp | 23 +++++++++++------------
 src/modules/PositionModule.h   |  1 +
 3 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/mesh/Channels.cpp b/src/mesh/Channels.cpp
index 80bcc10c6e..fe1041d3de 100644
--- a/src/mesh/Channels.cpp
+++ b/src/mesh/Channels.cpp
@@ -87,6 +87,7 @@ void Channels::initDefaultChannel(ChannelIndex chIndex)
     channelSettings.psk.bytes[0] = defaultpskIndex;
     channelSettings.psk.size = 1;
     strncpy(channelSettings.name, "", sizeof(channelSettings.name));
+    channelSettings.module_settings.position_precision = 32; // default to sending location on the primary channel
 
     ch.has_settings = true;
     ch.role = meshtastic_Channel_Role_PRIMARY;
diff --git a/src/modules/PositionModule.cpp b/src/modules/PositionModule.cpp
index 32c5a0c411..7ef539b1eb 100644
--- a/src/modules/PositionModule.cpp
+++ b/src/modules/PositionModule.cpp
@@ -23,6 +23,7 @@ PositionModule::PositionModule()
     : ProtobufModule("position", meshtastic_PortNum_POSITION_APP, &meshtastic_Position_msg),
       concurrency::OSThread("PositionModule")
 {
+    precision = 0;        // safe starting value
     isPromiscuous = true; // We always want to update our nodedb, even if we are sniffing on others
     if (config.device.role != meshtastic_Config_DeviceConfig_Role_TRACKER &&
         config.device.role != meshtastic_Config_DeviceConfig_Role_TAK_TRACKER)
@@ -83,20 +84,13 @@ bool PositionModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, mes
 
     nodeDB.updatePosition(getFrom(&mp), p);
 
-    // Only respond to location requests on the channel where we broadcast location.
-    if (channels.getByIndex(mp.channel).role == meshtastic_Channel_Role_PRIMARY) {
-        ignoreRequest = false;
-    } else {
-        ignoreRequest = true;
-    }
-
     return false; // Let others look at this message also if they want
 }
 
 meshtastic_MeshPacket *PositionModule::allocReply()
 {
-    if (ignoreRequest) {
-        ignoreRequest = false; // Reset for next request
+    if (precision == 0) {
+        LOG_DEBUG("Skipping location send because precision is set to 0!\n");
         return nullptr;
     }
 
@@ -116,8 +110,10 @@ meshtastic_MeshPacket *PositionModule::allocReply()
     localPosition.seq_number++;
 
     // lat/lon are unconditionally included - IF AVAILABLE!
-    p.latitude_i = localPosition.latitude_i;
-    p.longitude_i = localPosition.longitude_i;
+    LOG_DEBUG("Sending location with precision %i\n", precision);
+    p.latitude_i = localPosition.latitude_i & (INT32_MAX << (32 - precision));
+    p.longitude_i = localPosition.longitude_i & (INT32_MAX << (32 - precision));
+    p.precision_bits = precision;
     p.time = localPosition.time;
 
     if (pos_flags & meshtastic_Config_PositionConfig_PositionFlags_ALTITUDE) {
@@ -213,9 +209,12 @@ void PositionModule::sendOurPosition(NodeNum dest, bool wantReplies, uint8_t cha
     if (prevPacketId) // if we wrap around to zero, we'll simply fail to cancel in that rare case (no big deal)
         service.cancelSending(prevPacketId);
 
+    // Set's the class precision value for this particular packet
+    precision = channels.getByIndex(channel).settings.module_settings.position_precision;
+
     meshtastic_MeshPacket *p = allocReply();
     if (p == nullptr) {
-        LOG_WARN("allocReply returned a nullptr\n");
+        LOG_DEBUG("allocReply returned a nullptr\n");
         return;
     }
 
diff --git a/src/modules/PositionModule.h b/src/modules/PositionModule.h
index bd7a9def4f..fddafef6f7 100644
--- a/src/modules/PositionModule.h
+++ b/src/modules/PositionModule.h
@@ -50,6 +50,7 @@ class PositionModule : public ProtobufModule<meshtastic_Position>, private concu
   private:
     struct SmartPosition getDistanceTraveledSinceLastSend(meshtastic_PositionLite currentPosition);
     meshtastic_MeshPacket *allocAtakPli();
+    uint32_t precision;
 
     /** Only used in power saving trackers for now */
     void clearPosition();