Build range follows the screen; out-of-range replace ghosts replace (t64)

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

src/ui/actions.js

@@ -131,7 +131,7 @@ function primaryPress(shift) {
     else {
       const { bw, bh } = pieceSize(P);
       const { bx, by } = stampOrigin(bw, bh);
-      if (!inReach(bx * BS + bw * BS / 2, by * BS + bh * BS / 2)) { setStatus('Out of reach.'); playSfx('error'); return; }
+      if (!inBuildRange(bx * BS + bw * BS / 2, by * BS + bh * BS / 2)) { setStatus('Out of reach.'); playSfx('error'); return; }
       const place = () => P.kind === 'mold' ? placeMoldAt(P.mold, bx, by, GAME.wallMat) : placeMachineAt(P.id, GAME.pieceDir[P.id] || 0, bx, by);
       const check = () => P.kind === 'mold' ? canPlaceMold(P.mold, bx, by) : canPlaceMachine(P.id, bx, by);
       let err = '';
@@ -178,7 +178,8 @@ function primaryRelease(shift) {
       for (const [bx, by] of far) {
         const b = by * BW + bx;
         if (bx < 0 || by < 0 || bx >= BW || by >= BH || blockIs(b, code, v, ex) || ghostBlocks.has(b)) continue;
-        ghostBlocks.set(b, ex ? [code, v, ex] : [code, v]); g.blocks.push([bx, by, code]); ghosts++;
+        // held G over a different piece: the ghost replaces it when the bot comes in range
+        ghostBlocks.set(b, GAME.replace && blockP[b] ? [code, v, ex, 1] : ex ? [code, v, ex] : [code, v]); g.blocks.push([bx, by, code]); ghosts++;
       }
       if (ghosts) undoNote(g);
       return res;
@@ -230,7 +231,7 @@ function toolTick() {
       if (r.placed) { playSfx('blow'); hudDirty = true; } else if (r.status) setStatus(r.status);
     } else if (t === 'build') {
       const key = `${(ax / BS) | 0},${(ay / BS) | 0}`;
-      if (!GAME.rmbSeen.has(key) && inReach(ax, ay)) {
+      if (!GAME.rmbSeen.has(key) && inBuildRange(ax, ay)) {
         GAME.rmbSeen.add(key);
         const keep = undoRec; undoRec = GAME.rmbRec;
         const msg = removePieceAt(ax, ay);

src/ui/info.js

@@ -158,7 +158,7 @@ function hoverInfo(ax, ay) {
     const hint = furnaceJunkHint(mo).trim(); if (hint) t2.push(hint);
     if (player.lens) t2.push(fmtT(temp[i]));
   }
-  const reachOk = toolId() === 'drill' || inReach(ax, ay);
+  const reachOk = toolId() === 'drill' || (toolId() === 'build' ? inBuildRange(ax, ay) : inReach(ax, ay));
   if (!reachOk) { t2.push('out of reach'); warn = 'out of reach'; }
   // what it does, unless the cursor is on a machine or mold, which have their own details
   const what = bar ? bar.m : !mo && !id && !(p && p !== P_GRATE && p !== P_PIPE) && m !== BELTL && m !== BELTR && m !== PIPE ? (m === EMPTY && bgm[i] ? bgm[i] : m) : 0;

src/ui/loop.js

@@ -54,6 +54,7 @@ function frame(now) {
   // grid under the cursor does not slide around mid-line.
   if (GAME.drag) { lookX = GAME.lookHold.x; lookY = GAME.lookHold.y; } else { GAME.lookHold.x = lookX; GAME.lookHold.y = lookY; }
   if (!GAME.drag || Math.hypot(bot.vx, bot.vy) > 0.08) updateCamera(dt, lookX, lookY);
+  { const v = viewCells(); setBuildRange(R.camX + v.w / 2, R.camY + v.h / 2, v.w, v.h); }
   R.frame++;
   drawWorld();
   drawCracks();

src/ui/previews.js

@@ -67,7 +67,7 @@ function drawPreviews() {
   ctx.save();
   const reachOk = inReach(ax, ay);
   const sel = GAME.selDrag ? GAME.selDrag.mode : selModeHeld(), pasting = !sel && GAME.paste && GAME.clip;
-  if (!reachOk && t !== 'drill' && !sel) {
+  if (!reachOk && t !== 'drill' && t !== 'build' && !sel) {
     drawReachCircle(REACH, 0.35);
   }
   drawDrillPulses();
@@ -143,7 +143,7 @@ function drawPreviews() {
       const { bx, by } = stampOrigin(bw, bh);
       const err = P.kind === 'mold' ? canPlaceMold(P.mold, bx, by) : canPlaceMachine(P.id, bx, by);
       const swap = !!err && GAME.replace && /already/.test(err) && !footprintBlocker(bx, by, bw, bh);
-      const ok = (!err || swap) && inReach(bx * BS + bw * BS / 2, by * BS + bh * BS / 2) && canAfford(pieceCostNow(P), 1);
+      const ok = (!err || swap) && inBuildRange(bx * BS + bw * BS / 2, by * BS + bh * BS / 2) && canAfford(pieceCostNow(P), 1);
       const [x, y, w, h] = blockRectPx(bx, by, bw, bh);
       if (swap && ok) { ctx.fillStyle = 'rgba(255,190,90,0.35)'; ctx.fillRect(x, y, w, h); }
       if (P.kind === 'mold') {