Randomize steel wall layouts

src/game.js

@@ -97,20 +97,83 @@
   let particles = [];
   let lastTime = 0;
 
-  const walls = [
+  // Static brick layout (kept stable across games). Steel walls are randomized
-    ...brickWall(120, 80, TILE, TILE * 3),
+  // on every reset, so they are added separately in resetGame via regenerateWalls.
-    ...brickWall(240, 120, TILE * 4, TILE),
+  const BRICK_LAYOUT = [
-    ...steelWall(520, 80, TILE, TILE * 3),
+    [120, 80, TILE, TILE * 3],
-    ...brickWall(640, 160, TILE * 2, TILE),
+    [240, 120, TILE * 4, TILE],
-    ...brickWall(80, 320, TILE * 3, TILE),
+    [640, 160, TILE * 2, TILE],
-    ...brickWall(280, 280, TILE, TILE * 3),
+    [80, 320, TILE * 3, TILE],
-    ...brickWall(400, 360, TILE * 4, TILE),
+    [280, 280, TILE, TILE * 3],
-    ...steelWall(640, 360, TILE, TILE * 3),
+    [400, 360, TILE * 4, TILE],
-    ...steelWall(560, 240, TILE * 2, TILE),
+    [160, 480, TILE * 2, TILE],
-    ...brickWall(160, 480, TILE * 2, TILE),
+    [480, 500, TILE * 3, TILE],
-    ...brickWall(480, 500, TILE * 3, TILE),
   ];
 
+  // Rectangles that steel walls must avoid so spawns are not blocked or boxed in.
+  // Each entry is padded around a player/enemy starting position.
+  const SPAWN_KEEPOUTS = [
+    spawnKeepout(384, 536), // player
+    spawnKeepout(84, 64),
+    spawnKeepout(384, 64),
+    spawnKeepout(684, 64),
+    spawnKeepout(84, 220),
+    spawnKeepout(684, 260),
+  ];
+
+  let walls = [];
+
+  function spawnKeepout(x, y) {
+    // Generous margin (1.5 tiles) around the spawn keeps lanes open so tanks
+    // are never immediately boxed in by randomized steel.
+    const margin = TILE * 1.5;
+    return {
+      x: x - margin,
+      y: y - margin,
+      w: TANK_SIZE + margin * 2,
+      h: TANK_SIZE + margin * 2,
+    };
+  }
+
+  function buildBrickWalls() {
+    const pieces = [];
+    for (const [x, y, w, h] of BRICK_LAYOUT) {
+      pieces.push(...brickWall(x, y, w, h));
+    }
+    return pieces;
+  }
+
+  function randomSteelWalls(occupied) {
+    // Generate a handful of vertical/horizontal steel segments at random tile
+    // positions, skipping any that overlap a spawn keep-out zone.
+    const pieces = [];
+    const count = 3 + Math.floor(Math.random() * 3); // 3-5 steel walls
+    const cols = Math.floor(WIDTH / TILE);
+    const rows = Math.floor(HEIGHT / TILE);
+    let attempts = 0;
+    while (pieces.length < count && attempts < count * 20) {
+      attempts += 1;
+      const vertical = Math.random() < 0.5;
+      const length = (2 + Math.floor(Math.random() * 2)) * TILE; // 2-3 tiles long
+      const x = Math.floor(Math.random() * cols) * TILE;
+      const y = Math.floor(Math.random() * rows) * TILE;
+      const w = vertical ? TILE : length;
+      const h = vertical ? length : TILE;
+      const candidate = { x, y, w, h };
+      if (x + w > WIDTH || y + h > HEIGHT) continue;
+      if (SPAWN_KEEPOUTS.some((zone) => intersects(candidate, zone))) continue;
+      if (occupied.some((area) => intersects(candidate, area))) continue;
+      pieces.push(...steelWall(x, y, w, h));
+      occupied.push(candidate);
+    }
+    return pieces;
+  }
+
+  function regenerateWalls() {
+    const bricks = buildBrickWalls();
+    walls = [...bricks, ...randomSteelWalls([...bricks])];
+  }
+
   function rect(x, y, w, h, type = "brick") {
     return { x, y, w, h, type, destructible: type === "brick" };
   }
@@ -153,6 +216,7 @@
     lives = 3;
     bullets = [];
     particles = [];
+    regenerateWalls();
     player = tank(384, 536, "#77b255", "up", "player");
     enemies = [
       tank(84, 64, "#db5a42", "down"),
@@ -565,6 +629,7 @@
   if (stopAction) stopAction.addEventListener("click", endGame);
   if (endAction) endAction.addEventListener("click", endGame);
 
+  regenerateWalls();
   player = tank(384, 536, "#77b255", "up", "player");
   updateHud();
   setState("menu");