Navigation GPS

[alexfish]

openseamap charts

if want png download the mbtiles format and then convert as Posted

my link = en can change lang at site HERE

look for downloads

another link HERE
BR
Alex

[alexfish]

Some Useful Functions

DEF FN DEG2RAD(deg) =  (deg * M_PI / 180.0)
DEF FN RAD2DEG(rad) = (rad / M_PI * 180.0)

' ===================================
FUNCTION LONDEG2LONMIN ( float lon) TYPE STRING
' ===================================

LOCAL lonmin[20] TYPE static char
LOCAL degrees TYPE int
LOCAL minutes TYPE float

degrees = (abs( (lon>0) ? floor(lon) : ceil(lon) ))
minutes = ((fabs(lon) - (float)degrees) * 60)

sprintf (lonmin,"%d°%.3f' %s",degrees,minutes,(lon>0) ? "E" : "W")

RETURN  lonmin

END FUNCTION

' =================================
FUNCTION LATDEG2LATMIN (float lat) TYPE STRING
' =================================

LOCAL  latmin[20] TYPE static char
LOCAL degrees TYPE int
LOCAL minutes TYPE float

degrees = (abs( (lat>0) ? floor(lat) : ceil(lat) ))
minutes = ((fabs(lat) - (float)degrees) * 60)

sprintf (latmin,"%d°%.3f' %s", degrees,minutes,(lat>0) ? "N" : "S")

RETURN  latmin

END FUNCTION

' =================================
FUNCTION LATDEG2LATSEC(float lat)  TYPE STRING
' =================================

LOCAL latsec[20] TYPE static char
LOCAL degrees, full_minutes TYPE int
LOCAL minutes, seconds TYPE float

degrees = abs( (lat>0) ? floor(lat) : ceil(lat) )
minutes = (fabs(lat) - (float)degrees) * 60
full_minutes = floor(minutes)
seconds = (minutes - (float)full_minutes) * 60

sprintf( latsec,"%d°%d'%.2f\" %s", degrees,full_minutes,seconds,(lat>0) ? "N" : "S")

RETURN latsec

END FUNCTION

' ==================================
FUNCTION LONDEG2LONSEC ( float lon) TYPE STRING
' ==================================

LOCAL lonmin[20] TYPE static char
LOCAL degrees, full_minutes TYPE int
LOCAL minutes, seconds TYPE float

degrees = (abs( (lon>0) ? floor(lon) : ceil(lon) ))
minutes = ((fabs(lon) - (float)degrees) * 60)
full_minutes = (floor(minutes))
seconds = ((minutes - (float)full_minutes) * 60)

sprintf(lonmin,"%d°%d'%.2f\" %s",degrees,full_minutes,seconds,(lon>0) ? "E" : "W")

RETURN lonmin

END FUNCTION

' =========================================================
FUNCTION GET_DISTANCE (double lat1, double lon1, double lat2, double lon2) TYPE float
' =========================================================

LOCAL distance = 0 TYPE float
LOCAL tmp TYPE double

tmp = sin(DEG2RAD(lat1)) * sin(DEG2RAD(lat2)) + cos(DEG2RAD(lat1)) * cos(DEG2RAD(lat2)) * cos(DEG2RAD(lon2) - DEG2RAD(lon1))

distance = 6371.0 * acos(tmp)

RETURN distance

END FUNCTION

' ========================================================
FUNCTION GET_BEARING(double lat1, double lon1, double lat2, double lon2) TYPE float
' ========================================================
LOCAL bearing, tmp  TYPE double

tmp = atan2(sin(DEG2RAD(lon2)-DEG2RAD(lon1)) * cos(DEG2RAD(lat2)), \
   cos(DEG2RAD(lat1)) * sin(DEG2RAD(lat2)) - \
   sin(DEG2RAD(lat1)) * cos(DEG2RAD(lat2)) * cos(DEG2RAD(lon2)-DEG2RAD(lon1)) )

bearing = ((tmp < 0) ? tmp + M_PI*2 : tmp)

RETURN  RAD2DEG(bearing)

END FUNCTION
BR
Alex

[vovchik]

Dear Alex,

Thanks for that collection of useful fucntions. They will come in handy...

With kind regards,
vovchik

[alexfish]

Mar 12, 2021 11:23:45 GMT 1 vovchik said:

Dear Alex,

Thanks for that collection of useful fucntions. They will come in handy...

With kind regards,
vovchik

Hi Vovchik

Most Welcome,

as a side note, these function from Known Sources & are implemented in the likes of foxtrot gps
& libosm

where I did get stuck at the time was the Bacon PRINT TO

so, possible someone can try to Baconise ,

I say that since looking at initial render formats =

Libx11 + cairo, here do not need GTK + easy to free the bits

GTK2 using cairo, this we know should work with all distro's ,esp looks like we have a problem with X11 Mint

Peter's WebKit ToolKit , can comment on that one since previous Pi version's gtk bits were problematic
at first stages named as Experimental

so as said busy getting the bits done in that department

Posting a link for

github.com/nzjrs/osm-gps-map

may also find interesting , look at example , yet like most gtk pretty much a locked in affair

BR
Alex

[rikky]

Unfortunately bumped into a major problem elsewhere (but related) that needs my attention.
Just wanted to mention OpenLayers

[alexfish]

Not for me 'J'

This is BaCon = 'C'

. in previous post I touched on Peter's Webkit ToolKit and in a another Post Peter's WebServer.

Joe has a thread going, possible best suited for The 'J' word , there is also a Special forum for such.

BR
Alex

[rikky]

commandline utility that downloads OpenStreet en OpenSea png's, converts them to one svg and stashes them in $HOME/TILES/etc/etc

If no position is given, the location of your ip is used.

If no zoom is given all 20 zoom svg's are created.

This way you can use your app offline

next step is have a boat or car or bike icon on your position 

Attachments:

POS2TILE.bac (6.18 KB)

[rikky]

Latitude is the angle between the equatorial plane and the line extending from the center of the Earth to a certain point on its surface. It references the north-south position on the Earth. It's represented by circles of latitude, or parallels - the lines that go around the globe. The central line of latitude is called the Equator. It has a latitude of 0 degrees. The maximum value of latitude is 90 degrees - found at the poles.

Longitude, on the other hand, refers to a east-west position on the Earth. Lines of longitude, or meridians connect the North and the South Pole. They extend to the east and west of the Prime Meridian, reaching up to 180 degrees. All meridians have the same length - 12,429.9 miles (20,003.93 km).

Latitude = horizontal = φ (phi)
Longitude = vertical = λ (lambda)
First comes the latitude, then the longitude. (I ALWAYS make this mistake)

there are three formats (at least)
DD       decimal degrees - °
DMS    degrees - °, minutes - ', seconds - "
DDM    degrees (°), decimal minutes (')

For latitude, northern directions may be indicated by the letter N or a positive number, and southern directions can be marked with either the letter S or a negative value.

For longitude, you can use the letter E or a positive number for the eastern direction, and the western direction can be indicated by the letter W, or a negative number.

So mistakes are common.
I personally haven't got a clue what to use

My AIS gives output in DDM
SignalK converts them to DD
OpenSeamap shows them in DMS

THE international standard is WGS84 , according to the internet. 
At least it is the standard of the U.S. Department of Offense 
No wonder they always lose.

So the best is probably what3words

[alexfish]

Hi Rik

Just finished testing Previous Post , Looking Good

Need to read and Digest ais bits, There are converters about + will look through what I have here

Just Noted Will the above Functions not be suitable
These
LONDEG2LONMIN
LATDEG2LATMIN
LATDEG2LATSEC
LONDEG2LONSEC

put the decimals values in,it should works

BR
Alex

[alexfish]

OPTION PARSE FALSE


DEF FN DEG2RAD(deg) =  (deg * M_PI / 180.0)
DEF FN RAD2DEG(rad) = (rad / M_PI * 180.0)

' ===================================
FUNCTION LONDEG2LONMIN ( float lon) TYPE STRING
' ===================================

LOCAL lonmin[20] TYPE static char
LOCAL degrees TYPE int
LOCAL minutes TYPE float

degrees = (abs( (lon>0) ? floor(lon) : ceil(lon) ))
minutes = ((fabs(lon) - (float)degrees) * 60)

sprintf (lonmin,"%d°%.3f' %s",degrees,minutes,(lon>0) ? "E" : "W")

RETURN  lonmin

END FUNCTION

' =================================
FUNCTION LATDEG2LATMIN (float lat) TYPE STRING
' =================================

LOCAL  latmin[20] TYPE static char
LOCAL degrees TYPE int
LOCAL minutes TYPE float

degrees = (abs( (lat>0) ? floor(lat) : ceil(lat) ))
minutes = ((fabs(lat) - (float)degrees) * 60)

sprintf (latmin,"%d°%.3f' %s", degrees,minutes,(lat>0) ? "N" : "S")

RETURN  latmin

END FUNCTION

' =================================
FUNCTION LATDEG2LATSEC(float lat)  TYPE STRING
' =================================

LOCAL latsec[20] TYPE static char
LOCAL degrees, full_minutes TYPE int
LOCAL minutes, seconds TYPE float

degrees = abs( (lat>0) ? floor(lat) : ceil(lat) )
minutes = (fabs(lat) - (float)degrees) * 60
full_minutes = floor(minutes)
seconds = (minutes - (float)full_minutes) * 60

sprintf( latsec,"%d°%d'%.2f\" %s", degrees,full_minutes,seconds,(lat>0) ? "N" : "S")

RETURN latsec

END FUNCTION

' ==================================
FUNCTION LONDEG2LONSEC ( float lon) TYPE STRING
' ==================================

LOCAL lonmin[20] TYPE static char
LOCAL degrees, full_minutes TYPE int
LOCAL minutes, seconds TYPE float

degrees = (abs( (lon>0) ? floor(lon) : ceil(lon) ))
minutes = ((fabs(lon) - (float)degrees) * 60)
full_minutes = (floor(minutes))
seconds = ((minutes - (float)full_minutes) * 60)

sprintf(lonmin,"%d°%d'%.2f\" %s",degrees,full_minutes,seconds,(lon>0) ? "E" : "W")

RETURN lonmin

END FUNCTION

' =========================================================
FUNCTION GET_DISTANCE (double lat1, double lon1, double lat2, double lon2) TYPE float
' =========================================================

LOCAL distance = 0 TYPE float
LOCAL tmp TYPE double

tmp = sin(DEG2RAD(lat1)) * sin(DEG2RAD(lat2)) + cos(DEG2RAD(lat1)) * cos(DEG2RAD(lat2)) * cos(DEG2RAD(lon2) - DEG2RAD(lon1))

distance = 6371.0 * acos(tmp)

RETURN distance

END FUNCTION

' ========================================================
FUNCTION GET_BEARING(double lat1, double lon1, double lat2, double lon2) TYPE float
' ========================================================
LOCAL bearing, tmp  TYPE double

tmp = atan2(sin(DEG2RAD(lon2)-DEG2RAD(lon1)) * cos(DEG2RAD(lat2)), \
   cos(DEG2RAD(lat1)) * sin(DEG2RAD(lat2)) - \
   sin(DEG2RAD(lat1)) * cos(DEG2RAD(lat2)) * cos(DEG2RAD(lon2)-DEG2RAD(lon1)) )

bearing = ((tmp < 0) ? tmp + M_PI*2 : tmp)

RETURN  RAD2DEG(bearing)

END FUNCTION

LOCAL A$ TYPE STRING
A$ =  LATDEG2LATSEC(54.134938)

PRINT A$

Terminal gives

pi@raspberrypi:~/nav $ ./latlon
54°8'5.77" N

&
LOCAL A$ TYPE STRING
A$ =  LONDEG2LONSEC (-1.580320)

PRINT A$

gives
pi@raspberrypi:~/nav $ ./latlon
1°34'49.15" W

BR Alex

[alexfish]

Have Just Managed to get X11 & cairo working on RPI4

change things a bit + using new Xinput 'XIM'for the keyboard etc

so here a very simple setup , hope it shows + type something

Note Special keys like space an arrow keys should not work . may see the in the terminal

BR
Alex

OPTION PARSE FALSE


PRAGMA LDFLAGS `pkg-config   --libs x11 cairo`
PRAGMA OPTIONS `pkg-config --cflags x11 cairo`

PRAGMA INCLUDE <X11/Xlib.h>
PRAGMA INCLUDE <X11/Xutil.h>
PRAGMA INCLUDE <cairo/cairo.h>
PRAGMA INCLUDE <cairo/cairo-pdf.h>
PRAGMA INCLUDE <cairo/cairo-ps.h>
PRAGMA INCLUDE <cairo/cairo-xlib.h>

DECLARE dpy TYPE Display*
DECLARE win TYPE Window
DECLARE xim TYPE XIM
DECLARE xic TYPE XIC

DECLARE  cs TYPE cairo_surface_t *
DECLARE  wid TYPE cairo_surface_t *
DECLARE MSG$ = "OK g " TYPE STRING


SUB cairo_rgba(cairo_t * cr,char r,char g,char b,char a)
LOCAL R,G,B,A TYPE double
R = r/255.0
G = g/255.0
B = b/255.0
A = a/255.0
PRINT R , ":",G,":",B,":" ,A
cairo_set_source_rgba(cr , R ,G ,B,A)
END SUB
SUB Test(cairo_surface_t * csy, STRING txt$)

LOCAL c TYPE cairo_t *
c=cairo_create(csy)
cairo_rgba(c,0, 255,238, 255)

cairo_paint(c)
cairo_save(c)
cairo_restore(c)
cairo_set_source_rgb(c,1, 1, 1)
cairo_set_font_size(c,20.0)
cairo_set_source_rgb(c,0, 0, 0)
cairo_move_to(c, 20, 20)
cairo_show_text(c, txt$)
cairo_save(c)
cairo_restore(c)
cairo_show_page(c)
'cairo_destroy(c)

END SUB


'setlocale(LC_ALL, "")
dpy = XOpenDisplay(NULL)
screen_num = DefaultScreen(dpy)

display_width = DisplayWidth(dpy, screen_num)
display_height = DisplayHeight(dpy, screen_num)
win = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0, 600, 400, 3, BlackPixel(dpy, screen_num),WhitePixel(dpy, screen_num) )


XSetLocaleModifiers("")

xim = XOpenIM(dpy, 0, 0, 0)

IF ( NOT(xim))   THEN
' fallback to internal input method
XSetLocaleModifiers("@im=none")
xim = XOpenIM(dpy, 0, 0, 0)
PRINT "FallBack"
END IF

xic = XCreateIC(xim, \
XNInputStyle,XIMPreeditNothing | XIMStatusNothing, \
XNClientWindow, win, \
XNFocusWindow,  win, \
NULL)

XSetICFocus (xic)
XSelectInput(dpy, win, ExposureMask | KeyPressMask | KeyReleaseMask )
wm_delete_window = XInternAtom (dpy, "WM_DELETE_WINDOW", False)
XSetWMProtocols (dpy,win, &wm_delete_window, 1)
cs=cairo_xlib_surface_create(dpy, win, DefaultVisual(dpy, 0),display_width, display_height)
XMapWindow(dpy, win)
'XMapRaised(dpy, win)
'XSync(dpy , FALSE)

LOCAL prev_ev = {}, ev = {} TYPE XEvent

WHILE (1) DO

XNextEvent(dpy, &ev)

IF (XFilterEvent(&ev, None) == TRUE ) THEN

CONTINUE

END IF

SELECT ev.type



CASE Expose
PRINT "Expose :" ,ptr
INCR ptr
Test(cs,MSG$)
expo = (XExposeEvent  *)&ev

'@ when protcols are set the have to exit via the protocols if client data[0]=wm_delete_window
CASE ClientMessage

PRINT "Closing Down"


IF ((Atom)ev.xclient.data.l[0] == wm_delete_window) THEN
PRINT "EXITING"

XFlush(dpy)
XClearWindow(dpy, win)
cairo_surface_destroy(cs)
XCloseDisplay(dpy)
'DESTROY_ALL()
BREAK

END IF
CASE MapNotify
PRINT "MapNotify"

CASE KeyPress

LOCAL status TYPE Status
LOCAL keysym  TYPE KeySym
keysym = NoSymbol
LOCAL text [32]  TYPE char
memset(text,'\0',32)
LOCAL is_repeat TYPE int
LOCAL txt$ TYPE STRING

' ===========================================
is_repeat = prev_ev.type == KeyRelease && \
prev_ev.xkey.time    == ev.xkey.time && \
prev_ev.xkey.keycode == ev.xkey.keycode
' ==========================================
ev.xkey.state &= ~ControlMask

Xutf8LookupString(xic, &ev.xkey, text, sizeof(text) - 1, &keysym, &status)
' ================================================
IF (status == XBufferOverflow) THEN

' ignore
END IF

' ==================================================
IF (status == XLookupChars) THEN
txt$ = text
PRINT "Got String: " , txt$ )

END IF

' ========================================================

IF (status == XLookupBoth)  THEN
LOCAL sym_name$ TYPE STRING
txt$ = text
txt$=CHOP$(txt$)
sym_name$ = XKeysymToString(keysym)
PRINT "Have Two: ", txt$ , " : " ,  sym_name$
MSG$=MSG$ & txt$
Test(cs,MSG$)
END IF

' ================================================
IF (status == XLookupKeySym) THEN

LOCAL sym_name2$ TYPE  STRING

sym_name2$  = XKeysymToString(keysym)

PRINT "Have keysym: ",  sym_name$

END IF

' =================================================
IF (keysym == XK_Escape) THEN

END

END IF

END SELECT

WEND

[alexfish]

nearest api for what3words was based on python wrapper
https://github.com/what3words/w3w-python-wrapper
it bemoans at app key KeyError: "'W3W_API_KEY'", so puzzled

rest in popular = 'J'

BR
Alex

[vovchik]

Dear Alex,

Your keyboard code works on Pi4 and Mint. Thanks....

With kind regards,
vovchik

[alexfish]

Hi Vovchik

Thanks for testing

BR
Alex

[alexfish]

What3Words , I can sum up with what2words

git fail on V3

and followed instructions HERE
on RPI I get
res = geocoder.convert_to_3wa(what3words.Coordinates(51.484463, -0.195405))
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "build/bdist.linux-armv7l/egg/what3words/what3words.py", line 82, in convert_to_3wa
 File "build/bdist.linux-armv7l/egg/what3words/what3words.py", line 280, in _request
 File "/usr/lib/python2.7/dist-packages/requests/api.py", line 75, in get
   return request('get', url, params=params, **kwargs)
 File "/usr/lib/python2.7/dist-packages/requests/api.py", line 60, in request
   return session.request(method=method, url=url, **kwargs)
 File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 533, in request
   resp = self.send(prep, **send_kwargs)
 File "/usr/lib/python2.7/dist-packages/requests/sessions.py", line 646, in send
   r = adapter.send(request, **kwargs)
 File "/usr/lib/python2.7/dist-packages/requests/adapters.py", line 516, in send
   raise ConnectionError(e, request=request)
requests.exceptions.ConnectionError: HTTPConnectionPool(host='localhost', port=8080): Max retries exceeded with url: /v3/convert-to-3wa?key=what3words-api-key&language=en&coordinates=51.484463%2C-0.195405&format=json (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0xb5d14910>: Failed to establish a new connection: [Errno 111] Connection refused',))
>>> geocoder = what3words.Geocoder("what3words-api-key", end_point='http://localhost:8080/v3')