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Location Lib. Potential fix for bad angle and distance calcs. 

last_lat changed to int32_t since it can be negative.
This commit is contained in:
Jason Short 2012-08-15 21:36:55 -07:00
parent 93c644fd0f
commit 555e26d5fa
1 changed files with 13 additions and 12 deletions
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25
libraries/AP_Math/location.cpp
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@ -29,15 +29,16 @@
static float longitude_scale(const struct Location *loc)
{
static uint32_t last_lat;
static int32_t last_lat;
static float scale = 1.0;
if (abs(last_lat - loc->lat) < 100000) {
// we are within 0.01 degrees (about 1km) of the
// we are within 0.01 degrees (about 1km) of the
// same latitude. We can avoid the cos() and return
// the same scale factor.
// the same scale factor.
return scale;
}
scale = cos((fabs((float)loc->lat)/1.0e7) * 0.0174532925);
last_lat = loc->lat;
return scale;
}
@ -73,13 +74,13 @@ int32_t get_bearing_cd(const struct Location *loc1, const struct Location *loc2)
return bearing;
}
// see if location is past a line perpendicular to
// the line between point1 and point2. If point1 is
// see if location is past a line perpendicular to
// the line between point1 and point2. If point1 is
// our previous waypoint and point2 is our target waypoint
// then this function returns true if we have flown past
// the target waypoint
bool location_passed_point(struct Location &location,
struct Location &point1,
bool location_passed_point(struct Location &location,
struct Location &point1,
struct Location &point2)
{
// the 3 points form a triangle. If the angle between lines
@ -90,7 +91,7 @@ bool location_passed_point(struct Location &location,
Vector2f pt2(point2.lat, point2.lng);
float angle = (loc1 - pt2).angle(pt1 - pt2);
if (isinf(angle)) {
// two of the points are co-located.
// two of the points are co-located.
// If location is equal to point2 then say we have passed the
// waypoint, otherwise say we haven't
if (get_distance(&location, &point2) == 0) {
@ -102,14 +103,14 @@ bool location_passed_point(struct Location &location,
// point2 then we are past the waypoint if the
// distance from location to point1 is greater then
// the distance from point2 to point1
return get_distance(&location, &point1) >
return get_distance(&location, &point1) >
get_distance(&point2, &point1);
}
if (degrees(angle) > 90) {
return true;
}
return false;
return false;
}
/*
@ -127,7 +128,7 @@ void location_update(struct Location *loc, float bearing, float distance)
float lat2 = asin(sin(lat1)*cos(dr) +
cos(lat1)*sin(dr)*cos(brng));
float lon2 = lon1 + atan2(sin(brng)*sin(dr)*cos(lat1),
float lon2 = lon1 + atan2(sin(brng)*sin(dr)*cos(lat1),
cos(dr)-sin(lat1)*sin(lat2));
loc->lat = degrees(lat2)*1.0e7;
loc->lng = degrees(lon2)*1.0e7;