Tilemaps: Fill, Pick and holding Alt (#133); check total 1038

Development.md

@@ -12,7 +12,7 @@ npm run check        # typecheck + lint + format:check + tests, the gate CI runs
                      #   code is lost (tail's is reported), so a red run reads as green
 npm run build        # writes dist/ and regenerates index.html
 ./build.sh           # the same under `set -o pipefail`, for callers that pipe the output
-node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1034 editor checks, screenshots in /tmp/gm-e2e-*.png
+node tools/seed-e2e.mjs && node tools/e2e.mjs                 # 1038 editor checks, screenshots in /tmp/gm-e2e-*.png
 GM_STEPS=20 node tools/e2e.mjs                                # or 1-12, or 6,20 — a subset while working on one step
 ./e2e.sh start [GM_STEPS]                                     # the same run detached, see below
 ./e2e.sh status                                               # live progress, or the last run's result

Tilemaps.md

@@ -49,11 +49,20 @@ the Columns, Rows and Tile size rows.
   pointer was reported at.
 - **Erase** clears cells the same way.
 - **Rect** fills the box a drag spans; while dragging, that box is outlined.
+- **Fill** (#133) fills, from the cell clicked, every cell of the active layer that holds the same
+  tile — or is empty, if that one is — and is reached through the four edge neighbours. Diagonals do
+  not count, so a fill does not leak through the gap between two corners. The grid is the border.
+  Filling a cell with the tile it already holds does nothing.
+- **Pick** takes the tile of the cell clicked on the **active layer** and hands it straight to the
+  painting tool used before Pick (Brush, Rect or Fill; from Select or Erase it is the Brush). An
+  empty cell says so in the console and changes nothing.
+- **Holding Alt** is Pick for as long as it is held, from any tool; letting go brings the tool
+  back. Choosing another tool while Alt is down keeps that one.
 
-While any of the three is chosen, the map shows its cell grid, so one does not paint blind.
+While any painting tool is chosen, the map shows its cell grid, so one does not paint blind.
 Shift-drag still pans the view, whatever the tool.
 
-**One stroke is one undo step** — a line of twenty cells comes back with one Ctrl+Z, and a stroke
+**One stroke is one undo step**, and so is one fill — a line of twenty cells comes back with one Ctrl+Z, and a stroke
 painted over another tile puts *that* one back, not merely emptiness.
 
 Under **TILES** stands every tile of the project as a grid of pictures with its name below
@@ -138,4 +147,3 @@ the next save.
 
 - No trigger tiles: a tile that only reports an overlap (water that fires an event) is not there
   yet — a tile blocks or it does not.
-- Nothing fills an area by flooding it, and there is no picking up a tile off the map.