Случайное дерево объектов

src/models/Document.zig

@@ -40,3 +40,43 @@ pub fn addShape(self: *Document, parent: ?*Object, shape: Object.ShapeKind) !voi
         try self.addObject(obj);
     }
 }
+
+fn randomShapeKind(rng: std.Random) Object.ShapeKind {
+    const shapes_implemented = [_]Object.ShapeKind{ .line, .ellipse, .broken };
+    return shapes_implemented[rng.intRangeLessThan(usize, 0, shapes_implemented.len)];
+}
+
+/// Создаёт случайное количество фигур в документе (в т.ч. вложенных).
+/// Используются только реализованные типы: line, ellipse, broken.
+/// Ограничение max_total предотвращает экспоненциальный рост и переполнение.
+pub fn addRandomShapes(self: *Document, rng: std.Random) !void {
+    const max_total: usize = 80;
+    var total_count: usize = 0;
+
+    const n_root = rng.intRangeLessThan(usize, 1, 5);
+    for (0..n_root) |_| {
+        if (total_count >= max_total) break;
+        try self.addShape(null, randomShapeKind(rng));
+        total_count += 1;
+    }
+
+    var stack = std.ArrayList(*Object).empty;
+    defer stack.deinit(self.allocator);
+    for (self.objects.items) |*obj| {
+        try stack.append(self.allocator, obj);
+    }
+    while (stack.pop()) |obj| {
+        if (total_count >= max_total) continue;
+        const n_children = rng.intRangeLessThan(usize, 0, 2);
+        const base_len = obj.children.items.len;
+        for (0..n_children) |_| {
+            if (total_count >= max_total) break;
+            try self.addShape(obj, randomShapeKind(rng));
+            total_count += 1;
+        }
+        // Пушим в стек только после всех append, чтобы не держать указатели при реаллокации obj.children
+        for (obj.children.items[base_len..]) |*child| {
+            try stack.append(self.allocator, child);
+        }
+    }
+}

src/models/Object.zig

@@ -97,7 +97,7 @@ pub fn createLine(allocator: std.mem.Allocator) !Object {
 pub fn createBrokenLine(allocator: std.mem.Allocator) !Object {
     var obj = try createWithCommonProperties(allocator, .broken);
     errdefer obj.deinit(allocator);
-    var points = std.ArrayList(Point2).init(allocator);
+    var points = std.ArrayList(Point2).empty;
     try points.appendSlice(allocator, &.{
         .{ .x = 0, .y = 0 },
         .{ .x = 80, .y = 0 },