Wall drags at 45° lay slopes; diagonal tubes drawn as one pipe; no side arrow on drag ghosts (t35, t36)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/DESIGN.md

@@ -372,6 +372,10 @@ above, including:
   also fills one cell past its corner so a diagonal run is sealed (grains move diagonally and
   would otherwise slip through where two pieces meet). Square walls placed diagonally still
   touch only at corners and leak there, like any square blocks.
+  Later the same day the owner asked for the Wall piece itself to work diagonally, the way tubes
+  do, so the separate Sloped wall piece left the build menu: a wall drag at about 45° lays slopes
+  (solid side below, T flips it during the drag), straight drags and clicks lay squares, and for a
+  single block T cycles square and the four corners. Slope ids are unchanged, so saves still load.
 
 - **Diagonal screw tubes (t35, 2026-10-25).** Tubes run in eight directions. A drag at about 45°
   lays a diagonal run pointing along the drag, and R cycles all eight for a single tube. Diagonal

docs/PROJECT_MAP.md

@@ -205,7 +205,7 @@ Material definitions: ids, properties and metal families. ids, and drill/tank ti
 Material tables: typed properties, casting groups, flags, parts and tool tiers. Typed property tables
 - variables: PH, DENS, KC, ICAP, CASTMETAL, METAL_TIER, SOLIDMETAL, F_NAT, F_CAST, F_BURN, P_NONE, P_TU, P_TD, P_TL, P_TR, P_GRATE, P_GOPEN, P_WHEEL, P_INTAKE, P_FILTER, P_PIPE, P_TUR, P_TDR, P_TDL, P_TUL, TUBE_PARTS, TUBE_DIRS, IS_TUBE, TDX, TDY, BIT_TIERS, TANK_TIERS, REACH
 
-### src/sim/pieces.js (158 lines)
+### src/sim/pieces.js (156 lines)
 Everything the player can build (PIECES): blocks, machines and molds, with costs and descriptions; filter settings; wall materials and their cost.
 - functions: isSlope, isWall, slopeCell, slopeCode, isPipeCode, filterable, cleanFilterCfg, filterRec, filterPassAt, filterInfo, sameFilter, wallCost
 - variables: BS, BP_WALL, BP_BELT, BP_TUBE, BP_SHAFT, BP_GRATE, BP_GATE, BP_FILTER, BP_PIPE, BP_PUMP, BP_OUTLET, BP_GRIND, BP_SAW, BP_PRESS, BP_RACK, BP_SLOPE_BL, BP_SLOPE_BR, BP_SLOPE_TL, BP_SLOPE_TR, filterCfg, WALL_OF, WALL_LIST, BAR_OF, GRAINS_PER_BAR, POWER_FREE, CASH, PIECES, PIECE_BY_ID, PIECE_BY_CODE, BELT_POWER, TUBE_POWER, FAN_POWER, WHEEL_K, ENGINE_K, MOLDS
@@ -356,9 +356,9 @@ Drawing (src/render/): browser only. This file: the renderer state R, colour tab
 Propagated coloured light from glowing and burning cells.
 - functions: builtForLight, looseForLight, computeLight
 
-### src/render/world.js (332 lines)
+### src/render/world.js (361 lines)
 Scale colour without changing the smooth-look class.
-- functions: fogColor, drawWorld
+- functions: fogColor, diagonalTubeBlock, drawWorld
 - variables: TUBE_CLASS
 
 ### src/render/machines.js (242 lines)
@@ -374,7 +374,7 @@ Smooth look: WebGL setup, texture uploads, drawing and adaptive resolution.
 - functions: smCompile, smoothAvailable, smUpload, smoothDraw, smoothPace
 - variables: SM, smBytes
 
-### src/render/smooth-shaders.js (342 lines)
+### src/render/smooth-shaders.js (348 lines)
 Smooth shaders: vertex and fragment programs for the rounded world look.
 - variables: SM_VS, SM_FS
 
@@ -430,12 +430,12 @@ Notebook blueprints: starter designs, saved library and code sharing.
 The tool hotbar and what is selected.
 - functions: renderHotbar, toolId, steering, modShift, grainAt, selectTool, bagMaterials, blowList, blowAllList, blowingAll, piece
 
-### src/ui/build-menu.js (105 lines)
+### src/ui/build-menu.js (109 lines)
 The build menu along the bottom: categories, piece tiles and their icons.
 - functions: pieceIcon, catOf, selectBuildCat, cycleBuildCat, buildVariantChips, renderBuildBar, setupBuildBar
 - variables: BUILD_CATS, BUILD_ORDER, PIECE_ICONS, lastBuildKey, lastBuildMenu
 
-### src/ui/selection.js (107 lines)
+### src/ui/selection.js (112 lines)
 Tool selection: cycling, drill tuning, piece variants and costs.
 - functions: pieceSize, pieceUsesWall, setDrillWidth, tuneUnderCursor, cycleItem, cycleWall, rotate, toggleBlow, pickFilterUnderCursor, toggleFilterMat, setBrush, pieceV, pieceExtra, filterBlockAt, chipCost, pieceCostNow, pieceCode, turnSlope
 
@@ -467,7 +467,7 @@ Gamepad input.
 - functions: padPressed, pollPad
 - variables: PAD
 
-### src/ui/previews.js (203 lines)
+### src/ui/previews.js (199 lines)
 Cursor previews: shared grid helpers, air streaks and tool preview dispatch.
 - functions: blockRectPx, drawGrid, previewColor, drawAirStreaks, drawReachCircle, drawPreviews, previewBlock
 

docs/agent-log.md

@@ -4,6 +4,18 @@ What agents have done, newest first. Add an entry for every piece of work: the d
 note or request it was for, what changed, the files touched, the tests run, and anything left
 open or not verified. Keep each entry short; the git history has the details.
 
+## 2026-10-25: t35/t36 follow-ups: wall drags make slopes, diagonal tube art (Claude Code, Codex)
+
+- Wall piece: a diagonal drag lays slopes (`pieceCode`/`turnSlope` in `src/ui/selection.js`), T flips
+  a drag or cycles square and four corners for one block; the Sloped wall piece is gone from the
+  menu, slope codes map to the wall piece (`src/sim/pieces.js`); old slope saves load
+  (`test/fixtures/slopes-v2.json.gz`).
+- Diagonal tubes draw as one continuous 45° pipe in both looks, overhanging empty cells at joints
+  (`src/render/world.js`, `smooth-shaders.js`). Drag ghosts lost the long side arrow; each ghost
+  block keeps its own chevron (`src/ui/previews.js`). The owner found the diagonal still meets
+  straight tubes off-centre; an elbow fix follows.
+- `test/t_slopes.js`, `t_diag_tubes.js`, `play.py`; `run_all.py --browser` ALL PASSED.
+
 ## 2026-10-25: t37 follow-up: grains on built things cast no shadows (Claude Code, Codex)
 
 - The owner saw a flickering shadow under a grinder fed by a stream: grains resting on its