From 7543e775e5cca09663c13b697418f4728ec13750 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Tue, 10 Jun 2025 13:12:19 +0100
Subject: [PATCH] repaint on orientation changes, rotate road names

this is still not correct, but it's closer
---
 pkgs/maps/main.fnl | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/pkgs/maps/main.fnl b/pkgs/maps/main.fnl
index 2a1183f..c725ee6 100644
--- a/pkgs/maps/main.fnl
+++ b/pkgs/maps/main.fnl
@@ -66,7 +66,7 @@ label.readout {
             :lon 0
             :zoom 17
             :course 0 ; direction of travel
-            :orientation 0 ; map rotation angle from north
+            :orientation {:target 0 :actual 0} ; map rotation angle from north
             :tiles {}
             }
  )
@@ -186,8 +186,10 @@ label.readout {
         (set biggest-n (- i 1)))))
   (let [[x y] (. points biggest-n)
         [nx ny] (. points (+ 1 biggest-n))
-        angle (math.atan (- ny y) (- nx x))]
-    (if (> nx x)
+        angle (math.atan (- ny y) (- nx x))
+        screen-angle (- angle
+                        (/ (* app-state.orientation.target math.pi) 180))]
+    (if (< (math.abs screen-angle) (/ math.pi 2))
         (values
          (* tile-size (- x bounds.min.x))
          (* tile-size (- y bounds.min.y))
@@ -271,7 +273,7 @@ label.readout {
                (draw-onto-map-surface bounds app-state.zoom)))))
 
     (g:translate (+ (/ viewport-width 2))  (+ (/ viewport-height 2)))
-    (g:rotate (* (/ (- 360 app-state.orientation) 180) math.pi))
+    (g:rotate (* (/ (- 360 app-state.orientation.actual) 180) math.pi))
     (g:translate (- (/ viewport-width 2))  (- (/ viewport-height 2)))
 
     (g:set_source_surface map-surface (- offset-x) (- offset-y))
@@ -322,9 +324,15 @@ label.readout {
       (when (not (bounds= old-bounds bounds))
         (fetch-tiles bounds app-state.tiles app-state.zoom)
         (set map-surface nil)))
-    (set app-state.orientation
-         (+ app-state.orientation
-            (* 0.05 (- app-state.course app-state.orientation))))
+    (when (> (math.abs (- app-state.orientation.target app-state.course)) 20)
+      (set app-state.orientation.target app-state.course)
+      (set map-surface nil))
+
+    (when (not (= app-state.orientation.target app-state.orientation.actual))
+      (set app-state.orientation.actual 
+           (+ app-state.orientation.actual
+              (* 0.05 (- app-state.orientation.target app-state.orientation.actual)))))
+    
     (each [name widget (pairs state-widgets)]
       (case name
         :speed (widget:set_label
@@ -359,7 +367,7 @@ label.readout {
                  (fn [self g]
                    (g:set_source_rgb 0.4 0.0 0.1)
                    (g:translate (// height 2) (// height 2))
-                   (g:rotate (* (/ (- app-state.course app-state.orientation)
+                   (g:rotate (* (/ (- app-state.course app-state.orientation.actual)
                                    180) math.pi))
                    (g:translate (// height -2) (// height -2))
                    (g:set_line_width 4)