From 27b0e9c40fb3f4bca6a829d16a51170173725456 Mon Sep 17 00:00:00 2001
From: Oliver Jowett <oliver@mutability.co.uk>
Date: Thu, 15 Jun 2017 18:23:28 +0100
Subject: [PATCH] Rename TARGET_* -> INTENT_ALT_* Rearrange the intent tracking
 a bit.

---
 comm_b.c   | 12 ++++++------
 dump1090.h |  2 +-
 mode_s.c   |  8 ++++----
 track.c    | 24 ++++++++++++------------
 4 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/comm_b.c b/comm_b.c
index b03ea43..085454b 100644
--- a/comm_b.c
+++ b/comm_b.c
@@ -391,23 +391,23 @@ static int decodeBDS40(struct modesMessage *mm, bool store)
         if (source_valid) {
             switch (source_raw) {
             case 0:
-                mm->intent.altitude_source = TARGET_UNKNOWN;
+                mm->intent.altitude_source = INTENT_ALT_UNKNOWN;
                 break;
             case 1:
-                mm->intent.altitude_source = TARGET_AIRCRAFT;
+                mm->intent.altitude_source = INTENT_ALT_AIRCRAFT;
                 break;
             case 2:
-                mm->intent.altitude_source = TARGET_MCP;
+                mm->intent.altitude_source = INTENT_ALT_MCP;
                 break;
             case 3:
-                mm->intent.altitude_source = TARGET_FMS;
+                mm->intent.altitude_source = INTENT_ALT_FMS;
                 break;
             default:
-                mm->intent.altitude_source = TARGET_INVALID;
+                mm->intent.altitude_source = INTENT_ALT_INVALID;
                 break;
             }
         } else {
-            mm->intent.altitude_source = TARGET_INVALID;
+            mm->intent.altitude_source = INTENT_ALT_INVALID;
         }
     }
 
diff --git a/dump1090.h b/dump1090.h
index ffc6c27..2e4408b 100644
--- a/dump1090.h
+++ b/dump1090.h
@@ -529,7 +529,7 @@ struct modesMessage {
         unsigned mcp_altitude;  // MCP/FCU selected altitude
         float    alt_setting;   // altimeter setting (QFE or QNH/QNE), millibars
 
-        enum { TARGET_INVALID, TARGET_UNKNOWN, TARGET_AIRCRAFT, TARGET_MCP, TARGET_FMS } altitude_source;
+        enum { INTENT_ALT_INVALID, INTENT_ALT_UNKNOWN, INTENT_ALT_AIRCRAFT, INTENT_ALT_MCP, INTENT_ALT_FMS } altitude_source;
 
         unsigned mode_autopilot : 1;    // Autopilot engaged
         unsigned mode_vnav : 1;         // Vertical Navigation Mode active
diff --git a/mode_s.c b/mode_s.c
index 16aec58..7f087ce 100644
--- a/mode_s.c
+++ b/mode_s.c
@@ -1716,16 +1716,16 @@ void displayModesMessage(struct modesMessage *mm) {
         if (mm->intent.alt_setting_valid)
             printf("    Altimeter setting:       %.1f millibars\n", mm->intent.alt_setting);
 
-        if (mm->intent.altitude_source != TARGET_INVALID) {
+        if (mm->intent.altitude_source != INTENT_ALT_INVALID) {
             printf("    Target altitude source:  ");
             switch (mm->intent.altitude_source) {
-            case TARGET_AIRCRAFT:
+            case INTENT_ALT_AIRCRAFT:
                 printf("aircraft altitude\n");
                 break;
-            case TARGET_MCP:
+            case INTENT_ALT_MCP:
                 printf("MCP selected altitude\n");
                 break;
-            case TARGET_FMS:
+            case INTENT_ALT_FMS:
                 printf("FMS selected altitude\n");
                 break;
             default:
diff --git a/track.c b/track.c
index 8fb3f24..b2ae5dd 100644
--- a/track.c
+++ b/track.c
@@ -622,20 +622,20 @@ struct aircraft *trackUpdateFromMessage(struct modesMessage *mm)
         memcpy(a->callsign, mm->callsign, sizeof(a->callsign));
     }
 
-    if (mm->intent.valid) {
-        if (mm->intent.mcp_altitude_valid && accept_data(&a->intent_altitude_valid, mm->source, now)) {
-            a->intent_altitude = mm->intent.mcp_altitude;
-        } else if (mm->intent.fms_altitude_valid && accept_data(&a->intent_altitude_valid, mm->source, now)) {
-            a->intent_altitude = mm->intent.fms_altitude;
-        }
+    // prefer MCP over FMS
+    // unless the source says otherwise
+    if (mm->intent.mcp_altitude_valid && mm->intent.altitude_source != INTENT_ALT_FMS && accept_data(&a->intent_altitude_valid, mm->source, now)) {
+        a->intent_altitude = mm->intent.mcp_altitude;
+    } else if (mm->intent.fms_altitude_valid && accept_data(&a->intent_altitude_valid, mm->source, now)) {
+        a->intent_altitude = mm->intent.fms_altitude;
+    }
 
-        if (mm->intent.heading_valid && accept_data(&a->intent_heading_valid, mm->source, now)) {
-            a->intent_heading = mm->intent.heading;
-        }
+    if (mm->intent.heading_valid && accept_data(&a->intent_heading_valid, mm->source, now)) {
+        a->intent_heading = mm->intent.heading;
+    }
 
-        if (mm->intent.alt_setting_valid && accept_data(&a->alt_setting_valid, mm->source, now)) {
-            a->alt_setting = mm->intent.alt_setting;
-        }
+    if (mm->intent.alt_setting_valid && accept_data(&a->alt_setting_valid, mm->source, now)) {
+        a->alt_setting = mm->intent.alt_setting;
     }
 
     // CPR, even