Remember artillery and target positions across reloads per map

js/core/core.js

@@ -46,6 +46,9 @@ const SAVED_TARGETS_KEY =
 const SAVE_ARTILLERY_KEY =
     'wardogs-save-artillery-position';
 
+const MAP_POINTS_KEY =
+    'wardogs-map-points';
+
 
 /* =========================
    ZOOM

js/events.js

@@ -46,6 +46,13 @@ function bindEvents() {
                     'custom';
             }
 
+            if (
+                typeof loadMapPoints ===
+                'function'
+            ) {
+                loadMapPoints();
+            }
+
             clamp(
                 S.origin
             );

js/features/saved-targets.js

@@ -164,6 +164,163 @@ function persistSavedTargets() {
     );
 }
 
+/* =========================
+   ARTILLERY / TARGET POSITIONS
+   ========================= */
+
+/*
+ * Where the two points sit is worth keeping across a reload: coming back
+ * to a gun laid on the wrong side of the map means placing it again every
+ * single time.
+ *
+ * Every map keeps its own entry, keyed by map id, because the coordinates
+ * are meaningless on a different map. Switching maps restores that map's
+ * pair and leaves the others untouched.
+ */
+const MAP_POINTS_WRITE_DELAY_MS = 300;
+
+let mapPointsWriteTimer = null;
+
+function persistMapPoints() {
+
+    /*
+     * inputs() runs on every frame of a drag, so the write trails the
+     * gesture instead of hitting localStorage a hundred times across it.
+     */
+    if (mapPointsWriteTimer) {
+        return;
+    }
+
+    mapPointsWriteTimer = setTimeout(
+        () => {
+            mapPointsWriteTimer = null;
+            writeMapPoints();
+        },
+        MAP_POINTS_WRITE_DELAY_MS
+    );
+}
+
+function readMapPointsStore() {
+
+    const raw =
+        localStorage.getItem(
+            MAP_POINTS_KEY
+        );
+
+    if (!raw) {
+        return {};
+    }
+
+    let parsed = null;
+
+    try {
+        parsed =
+            JSON.parse(raw);
+    } catch (error) {
+        return {};
+    }
+
+    if (
+        !parsed ||
+        typeof parsed !== 'object'
+    ) {
+        return {};
+    }
+
+    /*
+     * The first release stored a single { map, origin, target } object;
+     * fold that lone map into the keyed shape instead of dropping it.
+     */
+    if (
+        typeof parsed.map === 'string'
+    ) {
+
+        return {
+            [parsed.map]: {
+                origin: parsed.origin,
+                target: parsed.target
+            }
+        };
+    }
+
+    return parsed;
+}
+
+function writeMapPoints() {
+
+    try {
+        const store =
+            readMapPointsStore();
+
+        store[S.map] = {
+            origin: {
+                x: S.origin.x,
+                y: S.origin.y
+            },
+            target: {
+                x: S.target.x,
+                y: S.target.y
+            }
+        };
+
+        localStorage.setItem(
+            MAP_POINTS_KEY,
+            JSON.stringify(store)
+        );
+    } catch (error) {
+        console.warn(
+            'Failed to save map points:',
+            error
+        );
+    }
+}
+
+function readStoredPoint(value) {
+
+    return (
+        value &&
+        Number.isFinite(Number(value.x)) &&
+        Number.isFinite(Number(value.y))
+    )
+        ? {
+            x: Number(value.x),
+            y: Number(value.y)
+        }
+        : null;
+}
+
+function loadMapPoints() {
+
+    try {
+        const stored =
+            readMapPointsStore()[S.map];
+
+        if (!stored) {
+            return;
+        }
+
+        const origin =
+            readStoredPoint(stored.origin);
+
+        const target =
+            readStoredPoint(stored.target);
+
+        if (origin) {
+            S.origin = origin;
+        }
+
+        if (target) {
+            S.target = target;
+        }
+
+    } catch (error) {
+        console.warn(
+            'Failed to load map points:',
+            error
+        );
+    }
+}
+
 function getSaveArtilleryPreference() {
 
     return (

js/main.js

@@ -207,6 +207,12 @@ async function init() {
 
         initLayout();
 
+        /*
+         * Before the clamp below, so points restored from a previous
+         * visit are pulled inside the map's bounds like any other.
+         */
+        loadMapPoints();
+
         /*
          * Sync initial state with the
          * selected preset map after the

js/ui/inputs.js

@@ -24,6 +24,19 @@ function inputs() {
     $('h').value =
         S.h;
 
+    /*
+     * Origin and target are written from six different places (map drags,
+     * the coordinate inputs, saved-target restore, undo, coordinate
+     * search). They all land here, so one throttled write covers them all
+     * instead of a hook at each site.
+     */
+    if (
+        typeof persistMapPoints ===
+        'function'
+    ) {
+        persistMapPoints();
+    }
+
     /*
      * The saved-target highlight is derived from where the target sits,
      * so every writer of S.target refreshes it by arriving here.