README

@@ -79,6 +79,9 @@ elapsed time: what should it actually show? moving time, I guess
 
 should we rename bearing as course in nmea?
 
+perhaps we need a server-side component for route planning
+
+
 7) think about how to use nfc tags or something for profiles so that
 it can recognise when it's attached to bicycle or motorbike
 
@@ -107,30 +110,40 @@ cover more than 1/16th the length of the tile"
 
 d) render ways according to their type (road/cycleway/path/etc)
 
+e) label the ways
+
+f) async tile fetching
+
+we don't want everything to stop when it's time to fetch a new
+row of tiles, what are our options? lua-http is built on cqueues
+which is async enough to make my head hurt, but we also need
+to make it coexist with the gtk event loop
+
+assumptions:
+1) gtk stuff has to happen in the main thread (whatever that is...)
+so we can't control it from cqueues because that has its own
+threading stuff
+2) there will be lots of fds from lua-http, do we really want the
+housekeeping of making GLib.io_add_watch for each of them? it looks
+like adding a glib source from lgi is not currently practical
+https://github.com/lgi-devs/lgi/issues/111
+
+3) if we put http calls inside cq:wrap, that make them background
+provided that we call (cq:step 0)
+periodically. we could do that in a glib idle function, perhaps.
+
+- The tile fetcher would need to know where to write the data when
+  eventually it comes back
+- need some say to not fetch the same tile 18 times if there's more than
+  one request for it while a previous request is in progress
+
+
+---- 
 
 https://git.syndicate-lang.org/tonyg/squeak-phone/raw/commit/474960ddc665ed445a1f5afb0164fe39057720f9/devices/pine64-pinephone/modem-docs/80545ST10798A_LM940_QMI_Command_Reference_Guide_r3.pdf
 
 ----
 
-... sod, forgot to push latest changes from noetbook
-
-we need to extend to multiple tiles'-worth of map
-
-* get tile for curent lat/long and request overpass data for enough
-  surrounding tiles to fill the screen
-
-* I think a way is served with all its nodes whether or not they're in
-the bbox, so we can just store the ids of ways we've seen and skip
-them if the come up again
-
-* render all the polylines into the widget (some day also the labels etc)
-
-* to get it centred on the cyclist, take the tile fractional part *
-  256, and translate the canvas up and left by that amount
 
 
 
-and offset
-by 
-
-

pkgs/maps/main.fnl

@@ -119,47 +119,11 @@ label.readout {
 
 (local cq (cqueues.new))
 
-(fn cairo-roads-path [g lines bounds]
+(var map-surface nil)
-  (each [_ line (pairs lines)]
-    (case line.points
-      [[sx sy] & more]
-      (do
-        (g:save)
-        (g:move_to (* tile-size (- sx bounds.min.x))
-                   (* tile-size (- sy bounds.min.y)))
-        (each [_ [x y] (ipairs more)]
-          (let [x1 (* tile-size (- x bounds.min.x))
-                y1 (* tile-size (- y bounds.min.y))]
-            (g:line_to x1 y1)))
-        (g:stroke)
-        (g:restore)))))
-
-(fn label-coords [{ : points } bounds]
-  (var biggest 0)
-  (var biggest-n 0)
-
-  (for [i 2 (# points)]
-    (let [[x1 y1] (. points (- i 1))
-          [x2 y2]  (. points i)
-          dist
-          (+ (* (- x2 x1)  (- x2 x1))
-             (* (- y2 y1)  (- y2 y1)))]
-      (when (>= dist biggest)
-        (set biggest dist)
-        (set biggest-n (- i 1)))))
-  (let [[x y] (. points biggest-n)
-        [nx ny] (. points (+ 1 biggest-n))
-        angle (math.atan (- ny y) (- nx x))]
-    (values
-     (* tile-size (- x bounds.min.x))
-     (* tile-size (- y bounds.min.y))
-     angle)))
-
 
 (fn cairo-the-map [window]
   (let [{ : lat : lon : zoom } app-state
         { : num-tiles-x : num-tiles-y &as bounds } (map-bounds lat lon zoom)
-        road-width 14
         lines []]
 
     (for [x bounds.min.x bounds.max.x]
@@ -175,31 +139,23 @@ label.readout {
            (* tile-size num-tiles-y))
           g (cairo.Context.create map-surface)]
 
-      (g:set_source_rgb 0.7 0.8 0.8)
+      (g:set_source_rgb 1 1 1)
       (g:rectangle 0 0 (* tile-size num-tiles-x) (* tile-size num-tiles-y))
       (g:fill)
 
-      (g:set_source_rgb 0 0 0)
+      (g:set_source_rgb 0.2 0.2 0.6)
-      (g:set_line_width road-width)
+      (g:set_line_width 2)
-      (cairo-roads-path g lines bounds)
-      (g:set_source_rgb 1 1 1)
-      (g:set_line_width (- road-width 2))
-      (cairo-roads-path g lines bounds)
-
-      (g:set_source_rgb 0.2 0.2 0.2)
-      (g:set_font_size (- road-width 3))
       (each [_ line (pairs lines)]
-        (case line.name
+        (case line
-          n (let [(x y angle) (label-coords line bounds)]
+          [[sx sy] & more]
-              (when (and x y)
+          (do
-                (g:save)
+            (g:move_to (* tile-size (- sx bounds.min.x))
-                (g:move_to x y)
+                       (* tile-size (- sy bounds.min.y)))
-                (g:rotate angle)
+            (each [_ [x y] (ipairs more)]
-                (g:rel_move_to 0 3)
+              (let [x1 (* tile-size (- x bounds.min.x))
-                (g:text_path n)
+                    y1 (* tile-size (- y bounds.min.y))]
-                (g:fill)
+                (g:line_to x1 y1))))))
-                (g:restore)))))
+      (g:stroke)
-
       map-surface)))
 
 

pkgs/maps/tiles.fnl

@@ -60,7 +60,7 @@
       ]
      (table.concat  "\n"))))
 
-(fn canvas [elements zoom]
+(fn canvas [elements]
   (let [nodes {}
         lines {}]
     (each [_ e (ipairs elements)]
@@ -70,15 +70,11 @@
         (tset
          lines
          e.id
-         {
-          :name (?. e :tags :name)
-          :points
          (icollect [_ nd (ipairs e.nodes)]
            (let [node (. nodes nd)
-                  (tx ty) (latlon->tile node.lat node.lon zoom)]
+                 (tx ty) (latlon->tile node.lat node.lon 17)]
              ;;(print e.tags.name e.id e.name node.lat node.lon)
-              [ tx ty  ]))
+             [ tx ty  ])))))
-          })))
     lines))
 
 
@@ -116,7 +112,7 @@
         (let [data (with-open [i (io.open pathname :r)] (i:read "*a"))]
           (if (= data "")
               []
-              (canvas (. (json.decode data) :elements) zoom)))
+              (canvas (. (json.decode data) :elements))))
         (let [out (io.open pathname :w)]
           (cq:wrap (fn []
                      (print "getting " k)