chore(map-editor): bump to v0.3.1; cheatsheet + README sync

Bumps the module version to v0.3.1 (lib-core.maps dep pin was
already bumped to 0.5.7 in CT6 to allow the editor to load).
Updates the file header, startup banner, cheatsheet Tab entry
(now mentions all three modes), and appends a Cell-Tile Mode
subsection to the README.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -131,3 +131,25 @@ future engine + lib slice.
 All previous hotkeys (Tab, S, E, R, H, 0, D, G, I, Esc) continue to
 work; their bindings are documented in the items where applicable
 and in the in-editor Cheatsheet modal.
+
+## Cell-Tile Mode (v0.3.1)
+
+Third painting mechanic alongside Auto-Tile and Direct. LMB paints a
+per-cell material flag at the cursor cell; RMB clears it. The
+renderer uses the classical 47-blob 8-neighbour bitmask for
+cell-tile cells, unlocking the 9 atlas slots that Auto-Tile's
+dual-grid 4-corner rule structurally cannot reach (isolated, end,
+corner_open, straight, tee_open, tee_half, cross_open, cross_q1,
+cross_q2adj).
+
+Auto-Tile (vertex-paint, 5 reachable slots, dual-grid look) and
+Direct (manual override placement, all 14 slots via explicit pick)
+are unchanged. Tab cycles through all three modes.
+
+For clean visuals, use a single painting mode per layer. Mixing
+Vertex-Tile and Cell-Tile material in the same layer is allowed but
+produces an asymmetric seam at the boundary because vertex-tile
+cells are structurally blind to their cell-tile neighbours.
+
+See `sporel-meta/docs/superpowers/specs/2026-06-01-map-editor-cell-tile-mode-design.md`
+for the full design rationale and the Boris-taxonomy background.

init.lua

@@ -1,4 +1,4 @@
--- sporel-module-map-editor v0.3.0
+-- sporel-module-map-editor v0.3.1
 -- Interactive map editor — Rev 4 UX architecture (see design paper
 -- 2026-05-28-autotile-blob-styles-design.md §11 + plan stub
 -- 2026-05-28-map-editor-blob-v2.md). 0.2.0b adds the bottom palette
@@ -133,13 +133,23 @@ local state = (function()
     function M.is_picker_open()        return state.picker_open end
 
     -- 0.2.0a: binary mode switch (Auto-Tile vs Direct).
+    -- CT6: extended to three-way cycle (auto-tile / cell-tile / direct).
     function M.get_mode()              return state.mode end
     function M.set_mode(m)
-        if m == "auto-tile" or m == "direct" then state.mode = m end
+        if m == "auto-tile" or m == "cell-tile" or m == "direct" then state.mode = m end
     end
-    function M.toggle_mode()
-        state.mode = (state.mode == "auto-tile") and "direct" or "auto-tile"
+    function M.cycle_mode()
+        if state.mode == "auto-tile" then
+            state.mode = "cell-tile"
+        elseif state.mode == "cell-tile" then
+            state.mode = "direct"
+        else
+            state.mode = "auto-tile"
+        end
     end
+    -- Backwards-compat alias (still called by the input binding and the
+    -- toolbar mode toggle in older code paths; both now cycle 3 modes).
+    M.toggle_mode = M.cycle_mode
 
     function M.is_modal_open(id)
         if id == nil then return state.modal_open ~= nil end
@@ -295,6 +305,19 @@ local actions = (function()
         state.mark_dirty()
     end
 
+    -- 0.3.1: Cell-Tile mode paint actions. Write the per-cell material
+    -- flag via lib-core.maps; the renderer's 47-blob branch picks the
+    -- slot.
+    function M.paint_cell_material_at(cell_x, cell_y)
+        maps.set_cell_material(state.get_active_layer(), cell_x, cell_y, true)
+        state.mark_dirty()
+    end
+
+    function M.erase_cell_material_at(cell_x, cell_y)
+        maps.set_cell_material(state.get_active_layer(), cell_x, cell_y, false)
+        state.mark_dirty()
+    end
+
     -- =====================================================================
     -- Hotkey-driven actions
     -- =====================================================================
@@ -377,7 +400,7 @@ local ui = (function()
     -- Menu bar
     local MENU_BAR_H           = 24
     local MENU_LABEL_PAD_X     = 12
-    local MODE_PILL_W          = 130
+    local MODE_PILL_W          = 195
     local MODE_PILL_H          = 18
     local MODE_PILL_SEG_W      = 65
     local MODE_PILL_MARGIN     = 4
@@ -548,6 +571,9 @@ local ui = (function()
             { type = "toggle", label = "Auto-Tile",
               is_on = function() return mode_is("auto-tile") end,
               fire  = function() actions.set_mode("auto-tile") end },
+            { type = "toggle", label = "Cell-Tile",
+              is_on = function() return mode_is("cell-tile") end,
+              fire  = function() actions.set_mode("cell-tile") end },
             { type = "toggle", label = "Direct", hotkey = "Tab",
               is_on = function() return mode_is("direct") end,
               fire  = function() actions.set_mode("direct") end },
@@ -587,7 +613,7 @@ local ui = (function()
 
     -- Cheatsheet content (rendered into the modal).
     local CHEATSHEET = {
-        { key="Tab",   action="Toggle mode (Auto-Tile / Direct)" },
+        { key="Tab",   action="Cycle mode (Auto-Tile / Cell-Tile / Direct)" },
         { key="I",     action="Show / hide this cheatsheet" },
         { key="S",     action="Save current map to work.map.json" },
         { key="E",     action="Erase tile at mouse cell" },
@@ -655,21 +681,26 @@ local ui = (function()
         local y = (MENU_BAR_H - MODE_PILL_H) / 2
         return {
             x = x, y = y,
-            auto   = { x = x,                    y = y, w = MODE_PILL_SEG_W, h = MODE_PILL_H, mode = "auto-tile" },
-            direct = { x = x + MODE_PILL_SEG_W,  y = y, w = MODE_PILL_SEG_W, h = MODE_PILL_H, mode = "direct" },
+            auto   = { x = x,                       y = y, w = MODE_PILL_SEG_W, h = MODE_PILL_H, mode = "auto-tile" },
+            cell   = { x = x + MODE_PILL_SEG_W,     y = y, w = MODE_PILL_SEG_W, h = MODE_PILL_H, mode = "cell-tile" },
+            direct = { x = x + MODE_PILL_SEG_W * 2, y = y, w = MODE_PILL_SEG_W, h = MODE_PILL_H, mode = "direct" },
         }
     end
 
     local function draw_mode_pill()
         local lay = mode_pill_layout()
         local current = state.get_mode()
-        for _, seg in ipairs({ lay.auto, lay.direct }) do
+        for _, seg in ipairs({ lay.auto, lay.cell, lay.direct }) do
             local active = (current == seg.mode)
             local bg     = active and COL_BUTTON_BG_ACTIVE or COL_BUTTON_BG
             local fg     = active and COL_TEXT_ACTIVE      or COL_TEXT
             engine.render.draw_rect(seg.x, seg.y, seg.w, seg.h, rgba(bg, 0xFF))
             engine.render.draw_rect_lines(seg.x, seg.y, seg.w, seg.h, rgba(COL_BUTTON_BORDER, 0x40))
-            local label = (seg.mode == "auto-tile") and "Auto-Tile" or "Direct"
+            local label
+            if     seg.mode == "auto-tile" then label = "Auto-Tile"
+            elseif seg.mode == "cell-tile" then label = "Cell-Tile"
+            else                                label = "Direct"
+            end
             engine.render.draw_text(label, seg.x + 8, seg.y + 3, 11, rgba(fg, 0xFF))
         end
     end
@@ -1274,6 +1305,22 @@ local ui = (function()
                 engine.render.draw_rect_lines(px - 6, py - 6, 12, 12,
                     rgba(COL_VERTEX_SNAP, 0xFF))
             end
+        elseif mode == "cell-tile" then
+            -- Cell-tile mode: faint render-cell grid (same density as Direct).
+            local grid_col = rgba(COL_VERTEX_GRID, 0x40)
+            for x = 0, map_w do
+                engine.render.draw_line(x * t_size, 0, x * t_size, map_h * t_size, grid_col)
+            end
+            for y = 0, map_h do
+                engine.render.draw_line(0, y * t_size, map_w * t_size, y * t_size, grid_col)
+            end
+            -- Hover-cell highlight: 1-px outline around the cursor cell.
+            local c = state.get_mouse_cell()
+            if c then
+                engine.render.draw_rect_lines(
+                    c.x * t_size, c.y * t_size, t_size, t_size,
+                    rgba(COL_VERTEX_SNAP, 0xFF))
+            end
         else
             -- Direct mode: subtle render-cell grid only — that's the
             -- grid LMB strokes write to.
@@ -1297,7 +1344,7 @@ local ui = (function()
 
         -- Mode-pill
         local pill = mode_pill_layout()
-        for _, seg in ipairs({ pill.auto, pill.direct }) do
+        for _, seg in ipairs({ pill.auto, pill.cell, pill.direct }) do
             if in_rect(mx, my, seg.x, seg.y, seg.w, seg.h) then
                 if button == "left" then
                     actions.set_mode(seg.mode)
@@ -1431,6 +1478,8 @@ local ui = (function()
     M._VIEW_ITEMS      = VIEW_ITEMS
     M._EDIT_ITEMS      = EDIT_ITEMS
     M._LAYER_PANEL_ROWS = LAYER_PANEL_ROWS
+    M._mode_pill_layout = mode_pill_layout
+    M._MODE_PILL_SEG_W  = MODE_PILL_SEG_W
 
     return M
 end)()
@@ -1464,7 +1513,7 @@ input.bind("reset_transform",   { "0" })     -- 0.2.0c
 input.bind("toggle_debug_overlay", { "d" })  -- 0.2.0c.3
 input.bind("toggle_world_overlay", { "g" })  -- 0.2.0c.4
 
-engine.print("map-editor v0.3.0: ready. Tab=mode, I=help, G=grid, D=debug, S=save, E=erase, R=rotate, H=flip, 0=reset, ESC=quit / close")
+engine.print("map-editor v0.3.1: ready. Tab=cycle mode (Auto/Cell/Direct), I=help, G=grid, D=debug, S=save, E=erase, R=rotate, H=flip, 0=reset, ESC=quit / close")
 
 -- =====================================================================
 -- 0.3.0: self-tests (Spec §7.1). Run once on the first CI frame.
@@ -1541,6 +1590,85 @@ local function self_test()
     engine.test.equals(state.is_layer_visible(lname), not vis_before,
         "t7: layer visibility flipped via state.toggle_layer_visible")
     state.toggle_layer_visible(lname)
+
+    -- t8: state.set_mode accepts "cell-tile"
+    state.set_mode("cell-tile")
+    engine.test.equals(state.get_mode(), "cell-tile",
+        "t8: set_mode('cell-tile') sets mode")
+
+    -- t9: mode_pill_layout returns 3 segments at consecutive x positions
+    local pill = ui._mode_pill_layout and ui._mode_pill_layout() or nil
+    engine.test.assert(pill ~= nil,
+        "t9: mode_pill_layout accessible from self_test")
+    engine.test.assert(pill.cell ~= nil and pill.direct ~= nil,
+        "t9: pill has all three segments (auto, cell, direct)")
+    engine.test.equals(pill.cell.x - pill.auto.x, ui._MODE_PILL_SEG_W,
+        "t9: cell segment sits one SEG_W right of auto")
+    engine.test.equals(pill.direct.x - pill.cell.x, ui._MODE_PILL_SEG_W,
+        "t9: direct segment sits one SEG_W right of cell")
+
+    -- t12: cycle_mode cycles auto -> cell -> direct -> auto
+    state.set_mode("auto-tile")
+    state.cycle_mode()
+    engine.test.equals(state.get_mode(), "cell-tile", "t12: cycle auto -> cell")
+    state.cycle_mode()
+    engine.test.equals(state.get_mode(), "direct", "t12: cycle cell -> direct")
+    state.cycle_mode()
+    engine.test.equals(state.get_mode(), "auto-tile", "t12: cycle direct -> auto")
+
+    -- t10: paint_cell_material_at writes the flag readable by
+    -- maps.get_cell_material; cell-tile mode dispatches LMB to it.
+    state.set_mode("cell-tile")
+    local layer = state.get_active_layer()
+    -- Clear first to avoid pollution from earlier tests
+    if maps.get_cell_material(layer, 5, 5) then
+        maps.set_cell_material(layer, 5, 5, false)
+    end
+    actions.paint_cell_material_at(5, 5)
+    engine.test.equals(maps.get_cell_material(layer, 5, 5), true,
+        "t10: paint_cell_material_at sets the flag")
+    actions.erase_cell_material_at(5, 5)
+    engine.test.equals(maps.get_cell_material(layer, 5, 5), false,
+        "t10: erase_cell_material_at clears the flag")
+
+    -- t11: Cycle Rotation / Toggle Flip / Reset Transform are disabled
+    -- in both auto-tile AND cell-tile modes; enabled only in direct.
+    local target_labels = { "Cycle Rotation", "Toggle Flip", "Reset Transform" }
+    for _, label in ipairs(target_labels) do
+        state.set_mode("auto-tile")
+        for _, it in ipairs(ui._EDIT_ITEMS) do
+            if it.label == label then
+                local d = it.disabled
+                local is_disabled = (type(d) == "function") and d() or (d == true)
+                engine.test.equals(is_disabled, true,
+                    "t11: " .. label .. " disabled in auto-tile mode")
+                break
+            end
+        end
+        state.set_mode("cell-tile")
+        for _, it in ipairs(ui._EDIT_ITEMS) do
+            if it.label == label then
+                local d = it.disabled
+                local is_disabled = (type(d) == "function") and d() or (d == true)
+                engine.test.equals(is_disabled, true,
+                    "t11: " .. label .. " disabled in cell-tile mode")
+                break
+            end
+        end
+        state.set_mode("direct")
+        for _, it in ipairs(ui._EDIT_ITEMS) do
+            if it.label == label then
+                local d = it.disabled
+                local is_disabled = (type(d) == "function") and d() or (d == true)
+                engine.test.equals(is_disabled, false,
+                    "t11: " .. label .. " enabled in direct mode")
+                break
+            end
+        end
+    end
+
+    -- t11 teardown: restore auto-tile so we don't leave state in direct
+    state.set_mode("auto-tile")
 end
 
 -- =====================================================================
@@ -1678,6 +1806,15 @@ function update(ctx, dt)
                 if snap then
                     actions.paint_vertex_at(snap.vx, snap.vy, dp == "paint")
                 end
+            elseif state.get_mode() == "cell-tile" then
+                local cell = state.get_mouse_cell()
+                if cell then
+                    if dp == "paint" then
+                        actions.paint_cell_material_at(cell.x, cell.y)
+                    else
+                        actions.erase_cell_material_at(cell.x, cell.y)
+                    end
+                end
             else
                 local cell = state.get_mouse_cell()
                 if cell then

manifest.module

@@ -1,6 +1,6 @@
 {
     "id": "map-editor",
-    "version": "0.3.0",
+    "version": "0.3.1",
     "kind": "module",
     "api": "^0.1",
     "ci_frames": 30,
@@ -9,7 +9,7 @@
         "blob_rect_stone": "lib-asset.prototype-blob-geom"
     },
     "deps": [
-        {"id":"lib-core.maps","version":"0.5.6"},
+        {"id":"lib-core.maps","version":"0.5.7"},
         {"id":"lib-core.render","version":"0.1.0"},
         {"id":"lib-core.camera","version":"0.3.0"},
         {"id":"lib-core.input","version":"0.4.0"},