Say I have a recursive algorithm, for example one that generates a random tree:

// Pseudocode
function generate_branch(angle, length, current_depth, max_depth) {
  var branch = Branch(angle); // creates a new branch
  if (current_depth == max_depth) {
    return branch;
  }
  current_depth++;
  // random_int(min, max)
  branch.subbranches[] = generate_branch(random_int(0, angle + random_int(-30, 30)),
                                         random_int(0, 20)
                                         current_depth,
                                         max_depth);
  // ^^^^ recursion
  return branch;
}

var trunk = generate_branch(0, random_int(10), 0, 5);
RenderTree(trunk);

The problem is that this will render the entire tree in one frame. If I want to animate this (i.e. grow the tree over time), how would I do that? What is the best way to do this?

The game uses a game loop.

Say I have a recursive algorithm, for example one that generates a random tree:

// Pseudocode, just a simple algorithm: it isn't perfect.
function generate_branch(angle, length, current_depth, max_depth) {
  var branch = Branch(angle, length); // creates a new branch
  if (current_depth == max_depth) {
    return branch;
  }
  current_depth++;
  // random_int(min, max)
  branch.subbranches[] = generate_branch(random_int(0, angle + random_int(-30, 30)),
                                         random_int(0, 20)
                                         current_depth,
                                         max_depth);
  // ^^^^ recursion
  return branch;
}

var trunk = generate_branch(0, random_int(10), 0, 5);
RenderTree(trunk);

The problem is that this will render the entire tree in one frame. If I want to animate this (i.e. grow the tree over time), how would I do that? What is the best way to do this?

The game uses a game loop.