Hot loads: visible melt damage, rebuild-over repair, warning glow (t69)

src/render/screw-heat.js

@@ -0,0 +1,29 @@
+// Persistent scorch and broken casing, or a warning before the 1000°C limit, in both looks.
+function drawScrewHeat() {
+  const ctx = R.ctx, zp = R.zp, v = viewCells(), s = BS * zp;
+  const x0 = Math.max(0, Math.floor(R.camX / BS)), x1 = Math.min(BW - 1, Math.floor((R.camX + v.w) / BS));
+  const y0 = Math.max(0, Math.floor(R.camY / BS)), y1 = Math.min(BH - 1, Math.floor((R.camY + v.h) / BS));
+  ctx.save();
+  for (let by = y0; by <= y1; by++) for (let bx = x0; bx <= x1; bx++) {
+    const b = by * BW + bx;
+    if (blockP[b] !== BP_SCREW || (SET.fog && fogSeen(bx * BS + 2, by * BS + 2) < 64)) continue;
+    const damage = screwDamageMask(b);
+    if (!damage && screwLoadHeat(b) < 900) continue;
+    const p = worldToScreenPx(bx * BS, by * BS);
+    if (damage) {
+      ctx.fillStyle = 'rgba(32,19,17,0.65)'; ctx.fillRect(p.x, p.y, s, s);
+      // Keep the actual holes visible beneath a jagged fracture, even after cooling.
+      ctx.strokeStyle = '#f18b68'; ctx.lineWidth = Math.max(1, zp * 0.3);
+      ctx.beginPath(); ctx.moveTo(p.x, p.y + s * 0.65);
+      ctx.lineTo(p.x + s * 0.4, p.y + s * 0.4); ctx.lineTo(p.x + s * 0.6, p.y + s * 0.65);
+      ctx.lineTo(p.x + s, p.y + s * 0.3); ctx.stroke();
+      ctx.setLineDash([zp, zp]); ctx.strokeRect(p.x, p.y, s, s); ctx.setLineDash([]);
+    } else {
+      ctx.fillStyle = 'rgba(255,126,38,0.3)'; ctx.fillRect(p.x, p.y, s, s);
+      ctx.strokeStyle = '#ffb54f'; ctx.lineWidth = Math.max(1, zp * 0.3); ctx.strokeRect(p.x, p.y, s, s);
+      ctx.fillStyle = '#ffdc85'; ctx.fillRect(p.x + s * 0.45, p.y + s * 0.15, zp * 0.4, s * 0.4);
+      ctx.fillRect(p.x + s * 0.45, p.y + s * 0.7, zp * 0.4, zp * 0.4);
+    }
+  }
+  ctx.restore();
+}