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Fix Rc comparison logic

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This commit is contained in:
Oliver Jowett 2018-09-17 22:40:48 +01:00
parent cdba7566fd
commit b327848d75
1 changed files with 17 additions and 5 deletions
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22
track.c
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@ -302,6 +302,18 @@ static int speed_check(struct aircraft *a, double lat, double lon, int surface)
return inrange;
}
// return 1 if left_rc is worse (less accurate) than right_rc
static int rcIsWorse(int left_rc, int right_rc)
{
if (left_rc == 0 && right_rc == 0) // both unknown
return 0;
if (left_rc == 0)
return 1; // left unknown < right known
if (right_rc == 0)
return 0; // left known > right unknown
return (left_rc > right_rc);
}
static int doGlobalCPR(struct aircraft *a, struct modesMessage *mm, double *lat, double *lon, unsigned *nic, unsigned *rc)
{
int result;
@ -309,9 +321,9 @@ static int doGlobalCPR(struct aircraft *a, struct modesMessage *mm, double *lat,
int surface = (mm->cpr_type == CPR_SURFACE);
// derive NIC, Rc from the worse of the two position
// smaller NIC is worse; larger Rc is worse
// smaller NIC is worse
*nic = (a->cpr_even_nic < a->cpr_odd_nic ? a->cpr_even_nic : a->cpr_odd_nic);
*rc = (a->cpr_even_rc > a->cpr_odd_rc ? a->cpr_even_rc : a->cpr_odd_rc);
*rc = (rcIsWorse(a->cpr_even_rc, a->cpr_odd_rc) ? a->cpr_even_rc : a->cpr_odd_rc);
if (surface) {
// surface global CPR
@ -372,7 +384,7 @@ static int doGlobalCPR(struct aircraft *a, struct modesMessage *mm, double *lat,
return result;
// check speed limit
if (trackDataValid(&a->position_valid) && a->pos_nic >= *nic && a->pos_rc <= *rc && !speed_check(a, *lat, *lon, surface)) {
if (trackDataValid(&a->position_valid) && a->pos_nic >= *nic && !rcIsWorse(a->pos_rc, *rc) && !speed_check(a, *lat, *lon, surface)) {
Modes.stats_current.cpr_global_speed_checks++;
return -2;
}
@ -404,7 +416,7 @@ static int doLocalCPR(struct aircraft *a, struct modesMessage *mm, double *lat,
if (a->pos_nic < *nic)
*nic = a->pos_nic;
if (a->pos_rc < *rc)
if (rcIsWorse(a->pos_rc, *rc))
*rc = a->pos_rc;
range_limit = 50e3;
@ -454,7 +466,7 @@ static int doLocalCPR(struct aircraft *a, struct modesMessage *mm, double *lat,
}
// check speed limit
if (trackDataValid(&a->position_valid) && a->pos_nic >= *nic && a->pos_rc <= *rc && !speed_check(a, *lat, *lon, surface)) {
if (trackDataValid(&a->position_valid) && a->pos_nic >= *nic && !rcIsWorse(a->pos_rc, *rc) && !speed_check(a, *lat, *lon, surface)) {
#ifdef DEBUG_CPR_CHECKS
fprintf(stderr, "Speed check for %06X with local decoding failed\n", a->addr);
#endif