L-system tree · deepseek-v4.1-flash

Let me build the L-system tree. Let me first check the directory.

Let me build the L-system tree. I'll write a self-contained index.html using p5.js global.

Design:
- Axiom: "X"
- Rules: X -> F[-X][+X]FX? Let me think about a classic bracketed L-system tree.
- Use turtle graphics with branching.

Let me define:
- Axiom: "F"
- Rule: F -> "FF+[+F-F-F]-[-F+F+F]"
- angle 22.5

That's a classic fractal plant. But for tree look with trunk and branches, maybe:
- Axiom: "X"
- X -> "F[-X][+X]FX" ... hmm.

A common tree:
- axiom: "X"
- X → "F[-X]FX[+X]" or "F[+X][-X]FX"

Let me use:
- Variables: X (bud), F (draw forward)
- Axiom: X
- Rule: X -> F[+X][-X]FX  (actually X -> F[+X]F[-X]+X is classic)

Classic "fractal plant":
axiom: X
X -> F+[[X]-X]-F[-FX]+X
F -> FF
angle 25

That's complex. Let me use a simpler one with good tree shape:
axiom: F
F -> FF+[+F-F-F]-[-F+F+F]
angle 22.5
Generation 1-5. Generation 5 gives 2^? large but bounded. Length grows. We need to scale so tree fits. We can compute total length and scale branch length so whole fits.

But for leaves and child attachments, better to build segment list with parent pointers.

I'll parse the string, maintaining turtle state stack. For each "F" draw segment from current pos to new pos, record it with parent (the current branch parent). Use "[" push state including current segment index as parent; "]" pop. Also track for sway: each segment should have a sway offset that propagates. To keep children attached, compute each segment's endpoints each frame from its parent plus the local angle plus sway. Better: store tree as nodes with parent pointer and local angle. Then compute world transform recursively each frame, applying wind based on depth and time. That ensures attachment.

Let me design node structure:
- Each node is a branch segment: {parent, localAngle (relative to parent's absolute direction), length, depth}
- The root localAngle = -90 deg (pointing up).
- Actually turtle: each F goes forward with current heading. Bracket changes heading by ±angle. When we push state, we save heading and parent node. So children's localAngle = heading - parentHeading. For root, parentHeading assumed 0? Let's just store absolute heading at creation for base and compute local relative.

Simpler: store for each segment its heading relative to parent's heading. At render time, absolute heading = parentAbs + localAngle + swayInfluence. Sway: add wind rotation to each node based on depth and a phase, but to keep connection, we compute recursively from parent position and absolute angle.

Let's compute recursively:
drawNode(node, startX, startY, parentAbsAngle):
  abs = parentAbsAngle + node.localAngle + wind
  endX = startX + cos(abs)*len; endY = startY + sin(abs)*len
  store computed end for this frame
  recurse children.

For wind, add something like sin(time + depth*0.5)* windStrength * depth factor. But if each node adds wind to its abs angle, cumulative. That's fine — deeper branches sway more.

But recomputing all nodes each frame for gen 5 could be expensive. Let's count segments. Rule F->FF+[+F-F-F]-[-F+F+F]: each F replaced by 8 F's (count: F F + [ + F - F - F ] - [ - F + F + F ] => F count = 2 + 3 + 3 = 8). Generation 5 => 8^4 * initial? Axiom F is generation 0 = 1 F. gen1=8, gen2=64, gen3=512, gen4=4096, gen5=32768 segments. Plus branches. 32768 segments recursion per frame at 60fps could be heavy but doable? JS recursion with ~33000 nodes per frame maybe ~ a few ms to tens of ms. Could be okay but pushing 60fps maybe heavy. Let's cap at gen 5 and it's fine. Actually 8^5 = 32768 for gen5. Hmm.

Maybe reduce branching factor. Use rule F -> F[+F][-F]F? count = F, F, F, F = 4 F's. gen5 = 4^5 = 1024. Too sparse? Actually 1->4->16->64->256->1024. Good size. Let's use more interesting: F -> F[+F]F[-F]F  -> F count = 1 +1 +1 +1 = 4? "F[+F]F[-F]F" = F, F, F, F = 4. That gives nice binary tree. angle ~ 25.

Or F -> F[+F][-F]F? Similar.

To make richer tree, use F -> FF[+F][-F]? count=4. Fine.

Let me use rule: F → "FF[+F][-F]" count 4. Actually order matters for look. Classic.

I'll use X-style with flowers/leaves. Let's keep it simple: axiom "F", rule "F -> FF+[+F-F-F]-[-F+F+F]" is iconic and tree-like but 8^5=32768. That may be too dense/slow. Let's instead do F -> "F[+F]F[-F]F" angle 25. 1024 at gen5 — a nice tree.

Hmm but that produces a somewhat narrow tree. Let's do a moderate: F → "F[+F]F[-F][F]" count 5. gen5 = 5^5=3125, wait gen0=1, gen1=5, gen2=25, gen3=125, gen4=625, gen5=3125. Good.

I want good visual. Let's use two rules maybe include leaves. Keep it clean.

Actually let's use the well-known:
axiom: F
rule: F → "F[+F]F[-F]F"
angle: 25°
Generations 1..5. At gen5 = 1024 F segments (4^5). Good and fits.

For leaves at tips: any F node with no children gets leaves/buds. But in this rule, every F has children except last F of each expansion? Some F's are terminal. We can add leaf at terminal nodes and maybe at shallow. That gives leaves spread.

Scaling: Need whole tree visible at every generation. Compute tree with unit length, find bounding box across all nodes for the static (unswayed) configuration, then compute a global scale and offset to fit canvas with margin. Compute after growth complete? But growth animates progressively; if we scale based on final, all good as it grows within bounds. Recompute bounding box for current fully-expanded tree (the target), scale accordingly, and as segments grow they're within.

Actually progressive growth: we animate a "growthProgress" from 0 to 1 over time; each segment has an appearance order (its index in creation order / total). Draw segment length scaled by min(1, (progress*total - index)/something). That makes growth from trunk outward since creation order is depth-first from root. Good.

But nodes have varying lengths? Let's assign length per depth: maybe base length / something. Simpler all segments equal unit length 1, then scale. For finer look, multiply by depth factor? Let's make segment length = 1 * (0.85^depth)? That yields tapering and bounded. Hmm but bounding box computation handles.

Actually a natural tree: constant unit length per segment, and each generation adds more segments. Trunk length stays 1 unit. That's fine.

But for thickness styling, strokeWeight by depth: trunk thick, tips thin.

Let me structure:

Grammar class:
axiom, rules {F: replacement}, angleDeg.

expand(gen): start with axiom, apply rules gen times, but cap string length to avoid blowup (e.g., 200000). gen max 5 fine.

parse into nodes:
- nodes array, each {id, parent, localAngle, depth}. Root node created maybe as first F.
- turtle: x,y,heading, parentStack.
- For each char:
  - 'F' or 'G': create node with parent = current parent, localAngle = heading - parentHeading (parentHeading = parent's absolute? easier store heading at parent creation). Let's store per-node its absolute heading at build. localAngle = heading - parentAbsHeading. Root parentAbsHeading = -PI/2 (up) so localAngle=0. Actually set initial heading = -PI/2. Root's localAngle relative to a virtual parent with heading = -PI/2, so localAngle 0. Then absolute heading of node = -PI/2 at build time.
  - push turtle state: save {heading, parentId}. On '[': push heading and parent. On ']': pop heading and parent.
  - '+'/'-': heading ± angle. Also could have 'X' ignored / treated as branch marker.
  
Wait, need parent tracking. When we create a node, current parent is the last created node (the F we're extending). Actually in turtle, "F" draws from current position forward; the current position becomes end of new segment. The parent for a new F is the previous F (the node whose end is current position). So maintain currentParentId. Initially null. On F: new node parent=currentParentId; currentParentId = new node id. On [: push {heading, currentParentId} (and also maybe lengthScale). On ]: pop, restore heading and currentParentId. That's the correct parent linkage: when you return to a branching point, subsequent F attaches to the same parent as the branching node's parent (i.e., the node at the branch point). Yes because we pushed currentParentId before branching.

Good.

Then children arrays built from parent references.

Rendering recursively compute positions. Wind adds sway. Leaves at terminal nodes.

Growth: order nodes by creation index (matches depth-first order). Each node has "appear" = index / total. duration per node maybe 1/total. progress p in [0,1]; visible fraction for node = clamp((p - appear)/nodeGrowth, 0,1). Simpler: node grows over a window.

Compute positions of full tree each frame with sway, then for each node draw from its start (parent computed end) to lerp toward end based on fraction. Since parent may not be fully grown, child start attaches to parent's current end (so attached). 

Approach: recursive function computes start for node (parent's current end), then end = start + dir*len*frac. Draw line. This keeps attachment.

Bounding/scale: compute final full-tree positions without sway; get min/max. scale = min(width/rangeX, height/rangeY)*0.85. offset center. Also account for strokeWeight. Apply scale in the drawing transform (translate offset, scale).

World coordinates: root start at (0,0)? Let's set trunk base at origin then bounding box min y will be negative (up). Compute all, then translate so tree centered and base near bottom.

For sway, we add per-node wind angle based on time and depth. windAngle = 0.04 * sin(t*1.2 + node.depth*0.6 + node.id*0.01) * (depth+1)? If we add each node's wind relative, cumulative gives big sway at tips. Let's make absolute angle for node = parentAbs + localAngle + windAmount where windAmount = windStrength * sin(...) * (0.3 + depth*0.15). Because it's added at each level, cumulative. Could get large. Keep small: 0.01 rad * depth.

Better: sway should bend the whole branch. Cumulative is natural.

Let me also add gravity-free.

Generation control: HTML range input 1-5 and Regrow button. p5 canvas full window. Use DOM elements.

On generation change: rebuild and restart growth. Regrow: same generation restart.

Let's write code.

Colors: trunk brown (#6b4a2b), branches gradient to green, leaves green circles at tips. Draw branches first, then leaves.

Leaves: for terminal nodes (no children) draw a small ellipse at node end when fully grown. Also maybe small leaves on depth>=3 nodes. Keep it performant: leaves only terminal.

Number of terminal nodes ~ 3^5? In rule F->F[+F]F[-F]F, number of F's 4, branching. Terminal count maybe ~ (4^5 - something). Let's just draw.

Let me be careful with performance at gen 5: 1024 nodes, trivial.

Wait 4^5 = 1024 yes. Good.

But maybe tree looks sparse. Let's make rule produce more: F -> "FF[+F]F[-F]F"? count 5, gen5=3125. Fine. Let's test visual.

Actually I'll use a richer known grammar with leaves symbol maybe. Let's keep F only rule: 
F -> "F[+F]F[-F]F" gives 4. I'll go with it and angle 25. It's the classic binary tree, looks good.

Hmm, to make trunk longer, maybe multiplication F->"FF" for trunk. Could use two rules: X and F. Classic:
axiom: X
X -> F[-X][+X]FX? Let's not overcomplicate.

I'll do: axiom "F", rule "F -> FF[+F][-F]" (count 4). This makes straight runs (FF) and branches. angle 28. Looks tree-like.

Let me now think about length variation. Constant length per F segment. With generation, number of trunk segments between branches grows. At gen1: FF[+F][-F] => trunk of 2 segments then two branches. Good.

Scale bounding box.

Actually the straight FF means trunk extends each generation by factor? Bounding box grows, scale shrinks to fit, so tree stays visible and trunk thins. Good.

Let me implement.

Node depth for thickness: thickness = max(1, 14 * pow(0.72, depth)) maybe. At gen5 depths up to ~10. pow(0.72,10)=0.037*14=0.5. min 0.6.

Now code.

For position recursion I need children arrays. Build nodes list.

Let me write parse:

function buildTree(gen){
  const rule = s => s.replace(/F/g, 'FF[+F][-F]'); // careful replace
  let s='F';
  for(let i=0;i<gen;i++){ s=s.replace(/F/g, ()=>'FF[+F][-F]'); if(s.length>1e6) break;}
  ...
}

Wait gen: generations 1..5. If gen=1 we apply once: FF[+F][-F]. Good. gen=0 would be just F but range starts 1.

Parse:
nodes=[]; 
let heading=-Math.PI/2, parent=null;
stack=[];
let curX=0, curY=0; // not needed; positions computed later from parent relationships but heading stored.
for ch of s:
  if(ch==='F'){ nodes.push({id:nodes.length,parent,localAngle:0,depth:parent?nodes[parent].depth+1:0}); parent=nodes.length-1; }
  else if(ch==='+') heading += ang;
  else if(ch==='-') heading -= ang;
  else if(ch==='['){ stack.push({heading,parent}); }
  else if(ch===']'){ const st=stack.pop(); heading=st.heading; parent=st.parent; }

But localAngle must be computed relative to parent heading, which we know at creation time. Store parent's absolute heading at build. Let's store each node's buildHeading. localAngle = heading - (parent!=null? nodes[parent].buildHeading : heading) => root localAngle 0. For child, localAngle = heading - nodes[parent].buildHeading.

So node: {parent, localAngle, depth, buildHeading:heading}.

Set localAngle accordingly.

Then children built.

Render recursion: 
function drawNode(node, sx, sy, parentAbs, t){
  const sway = windStrength * Math.sin(t*1.3 + node.depth*0.7 + node.id*0.05) * (0.15+node.depth*0.08);
  const abs = parentAbs + node.localAngle + sway;
  const len = unitLen * growthFrac(node);
  const ex = sx + Math.cos(abs)*len*scale? ... 

Actually apply global scale via p5 transform: translate(cx,cy); scale(s); then draw in world units. Then strokeWeight must be divided by scale maybe. Simpler draw in screen coords by multiplying positions. I'll apply scale transform and set strokeWeight(worldThickness) — p5 scales stroke weight too under scale()? Yes, scale affects stroke. Actually p5 scale() does affect stroke weight. We want consistent screen thickness. Alternatively compute screen positions manually: X = cx + (x - minx)*scale. Let's just do transform and set weight accordingly: weight in world units = desiredPx / scale. Eh.

Simplest: compute world coords, then map: sx = offsetX + x*scale, sy = offsetY + y*scale. Draw with strokeWeight in pixels. That avoids transform issues.

Recursion returns nothing but draws and stores end for children. To draw leaves at terminal, after drawing line, if no children and frac>=1 draw leaf.

Growth fraction: total nodes N. Each node appearStart = id/N, appearEnd = (id+1)/N + 0.1? Let's give each node a window of 3/N. frac = clamp((p - id/N) * (N/3),0,1). With p from 0..1+ so that last nodes finish. Actually growth duration = N + 3 windows scaled. Set global progress increments; p goes 0.. (N+3)/N. Let progress grow over time: growth += dt/ growthDuration. Let growth progress raw g in seconds; compute p = g * (N/ (N+3))?? Let me define:
windowW = 3 (in node units). total span = N + windowW. g from 0..1 over growTime seconds. currentNode position = g*totalSpan. frac = clamp(currentPos - id, 0, windowW)/windowW? Wait node id position. frac = clamp((g*totalSpan - id)/windowW, 0,1). When g=1, currentPos=N+windowW, frac=1 for all id up to N (last id N-1). Good.

growTime ~ 2.5 + gen*0.5 seconds maybe. Let's set 3.5s.

Wind active after growth complete (g>=1) — but can sway always subtly. Requirement: once grown, sways. Let's sway always but amplitude ramps after grown.

Let me compute bounding box from final full positions (frac=1, no wind). Precompute at build using recursion. Then scale.

But if we scale based on full tree, while growing tree is smaller, fine and visible.

Maybe also add slight bottom margin.

Now leaves terminal: many. Draw small ellipse fill green with alpha. Since screen coords, size ~ max(2, 6*scale?) Hmm scale maybe small for gen5. Use pixel size ~ 3-6.

Let me also add flowers? Keep leaves.

Let me write the file.

Canvas: full window, recreate on resize? Keep fixed full window and center. p5 createCanvas(windowWidth, windowHeight). On windowResized, resizeCanvas and recompute scale.

But recomputing scale requires bounding box in world units (independent of canvas). bbox stored. computeScale().

I'll implement.

Let me write the HTML.

I'll keep UI overlay: title, generation slider, value, Regrow button, maybe speed.

Let me write code carefully.

function setupGrammar? Use global vars.

Code:

let nodes=[], children=[], axiom='F', rule='FF[+F][-F]', angleDeg=28;
let gen=3;
let growProgress=0, growSpan=0, growSpeed;
let windTime=0;
let bbox={minX,minY,maxX,maxY};
let scale=1, offX, offY;
let grown=false;

function setup(){
  createCanvas(windowWidth, windowHeight);
  buildTree(gen);
  slider = document.getElementById('gen'); etc.
}

buildTree(g):
  let s=axiom;
  for(let i=0;i<g;i++){ s = s.split('F').join(rule); if(s.length>2e6) break; }
  nodes=[]; let heading=-HALF_PI; let parent=null; const stack=[];
  for(const ch of s){
    if(ch==='F'){
      const bh=heading;
      const local = parent==null?0:(bh - nodes[parent].bh);
      nodes.push({id:nodes.length,parent,local,depth:parent==null?0:nodes[parent].depth+1,bh});
      parent=nodes.length-1;
    } else if(ch==='+') heading+=rad;
    else if(ch==='-') heading-=rad;
    else if(ch==='[') stack.push({heading,parent});
    else if(ch===']'){ const st=stack.pop(); heading=st.heading; parent=st.parent; }
  }
  // children
  children = nodes.map(()=>[]);
  nodes.forEach(n=>{ if(n.parent!=null) children[n.parent].push(n.id); });
  // bbox
  compute bbox by recursion with final frac.
  growProgress=0; grown=false; growSpan = nodes.length;
  updateScale();

computeExtents(id, sx, sy, parentAbs, out):
  const n=nodes[id]; const abs=parentAbs+n.local;
  const ex=sx+cos(abs), ey=sy+sin(abs); // unit length
  update out.
  for c of children[id] recurse(c, ex,ey,abs,out).

unit length = 1.

Root start (0,0). Initial parentAbs for root = -HALF_PI (so abs = -HALF_PI + 0 = up).

bbox includes all endpoints and start.

updateScale:
  width = maxX-minX, height = maxY-minY.
  const margin=60;
  scale = min((w-2*margin)/width, (h-2*margin)/height);
  center tree: offX = w/2 - (minX+maxX)/2*scale; offY = h/2 - (minY+maxY)/2*scale; maybe shift down.

Wait world y negative up; screen y down. We want tree upright: world y = sin(-90°)=-1 goes up; screen y = offY + y*scale => negative direction up. Good since screen y grows down, -1*scale moves up. So mapping sx=offX+x*scale, sy=offY+y*scale works and tree points up.

Center: offY = h/2 - (minY+maxY)/2*scale. Fine.

draw:
  background gradient maybe.
  windTime += dt.
  if(!grown){ growProgress += dt/growTime; if(growProgress>=1){growProgress=1;grown=true;} }
  drawRecursive(0, 0,0, -HALF_PI);

Need world to screen each node. I'll compute in recursion and draw directly.

drawRecursive(id, wx, wy, parentAbs){
  const n=nodes[id];
  const windAmp = grown? windStrength : windStrength*0.3;
  const sway = windAmp*Math.sin(windTime*1.4 + n.depth*0.6 + n.id*0.13)*(0.2+n.depth*0.1);
  const abs=parentAbs+n.local+sway;
  const ex=wx+Math.cos(abs); const ey=wy+Math.sin(abs);
  // growth fraction
  const t = growProgress==1?1: constrain((growProgress*growSpan - id)/windowW,0,1);
  ...
  const sx=offX+wx*scale, sy=offY+wy*scale;
  const exs=offX+(wx+(ex-wx)*t)*scale, eys=offY+(wy+(ey-wy)*t)*scale;
  strokeWeight thickness; line(sx,sy,exs,eys);
  if(t>=1) maybe leaf.
  for children recurse with (wx+(ex-wx)*t, wy+(ey-wy)*t, abs).
}

Wait growProgress spans 0..1 and growSpan=nodes.length+windowW? Let me set span = nodes.length + windowW. t = (progress*span - id)/windowW.

At progress=0, t negative ->0. At progress=1, progress*span = N+W, for id=N-1 => (N+W-(N-1))/W=(W+1)/W>1 clamp 1. Good.

Thickness: sqrt scaling? use w = constrain(trunkW*pow(0.75,depth),0.6,trunkW). trunkW maybe 12 * (canvas scale factor?). Since we draw in screen px, use base ~ 14 * (scale/ (canvasH)??). Hmm. For gen5 scale smaller, tree dense, want thinner. Let's base thickness on scale: trunkPx = constrain(18*scale/ (something)). Actually scale for gen5 maybe ~ h/(tree height). Tree height in units ~ maybe 20, so scale ~ 35 for h=800. Gen1 tree height ~3 => scale ~ 240. Difference huge. We want branch lines visible; thickness in px should be ~ proportional to world thickness so it looks consistent. Let's define world thickness and multiply by scale: weight = worldW * scale. trunk worldW = 0.08 maybe. Gen5 scale 35 => 2.8px. Gen1 scale 240 => 19px thick. Too thick. Hmm.

Alternative: keep screen thickness modest and depth-based, independent of scale, but scaled by sqrt. Let's do trunkPx = 16 * Math.pow(0.75, depth) then clamp min 1.2, but multiply by scaleFactor = scale/scaleRef where scaleRef = height/(heightUnitsRef). Ugh.

Simplest: weight = max(1, baseW * Math.pow(0.72, depth) * (scale*0.012)). With gen1 scale 240*0.012=2.88 baseW maybe 6 => up to 17. gen5 scale 35*0.012=0.42 baseW6 =>2.5. Good enough. Let's just do:
weight = constrain( (7 * Math.pow(0.7, depth)) * scale/60, 0.8, 22 ).
gen1 scale240 => 7*1*4=28 clamp22 (trunk thick) fine. Actually trunk should be thick. Gen5 scale35 => 7*0.58=4. good.

Let's use scale/70.

Leaves: for terminal node (children[id].length===0) draw leaf ellipse at end with size = constrain(scale*0.18, 2, 9). Fill color varying green, maybe with slight pink. Use random-ish based on id.

Also maybe draw leaves only when depth>=2.

Colors: branch color interpolate from brown to green by depth. brown (110,72,40) to (90,140,60).

Let me finalize.

Also progressive growth should draw trunk first. Since id order is depth-first: root F0, then F1, then branch... Actually parsing: axiom F expands to FF[+F][-F]. id0=F(first), id1=F(second), then '[' push parent=id1, '+' then F => id2 attaches to id1, ']' pop to parent=id1, '-' F => id3 attaches to id1. So growth order draws trunk first then branches. Good. Though DFS means it may draw a whole branch deep before the other branch—still progressive tip-ward. Acceptable. Could sort by depth for nicer growth. Sorting by depth would make all nodes at same depth grow together (more like full tree expanding). But then parent-child attachment ordering not needed since attachments computed from parent positions regardless. Drawing order only affects overlap of strokes, not attachment. But if parent grows after child... child start = parent's current end which may be partially grown; interpolation keeps attached. But if child drawn before parent, child might appear floating from a point. Since we draw via recursion per frame, ordering in recursion is depth-first by structure, not by grow. The growth fraction is per node independent. A deep node may reach t=1 while its parent still at t<1? Since id order DFS, parent id < child id, so parent grows earlier. For same-depth across branches, fine.

To make growth more "level by level," I could set appear based on depth. But id order already gives trunk-first growth. I'll keep id-based but maybe sort? Let's use id-based, it's fine and guarantees parent before child.

Actually a concern: DF S id order means after finishing deep branch, the next branch near trunk starts late, so tree grows lopsided. That's actually natural-ish. Fine.

Let me also add a subtle ground shadow? optional.

Wind strength: const windStrength=0.06? cumulative over depth ~10 => 0.6 rad at tips. Might be too much. Each node sway term amplitude = windStrength*(0.2+depth*0.1)*sin. At depth10 amplitude=1.2*windStrength. Summing over path gives cumulative random-ish. With windStrength 0.04, tip total could be ~0.3 rad. Reasonable.

Let me write and test.

Now DOM. Provide slider id gen, output, button regrow. Also maybe display axiom/rules.

Let me write index.html.

One more: p5 global script must load before our script. Put <script src="p5.min.js"></script> then inline script. p5 global mode auto runs setup/draw.

Let me write it.

Let me run it in the browser and inspect.

The tree is tiny! Only a tiny trunk visible at bottom center. The scale is wrong. It seems bbox is huge relative to tree, or the tree measured has weird bounds. Wait, at frame 1 (just after setup), growProgress=0 so only tiny. But scale seems like tree is tiny. Let me wait and take motion/screenshot after growth. Actually the second screenshot shows a tiny stub. Maybe scale is too small. Let me inspect __treeState after some time.

The issue: bbox computed with unit segment length over the whole tree. But `measure` root at (0,0) and heading -90°, so y goes negative. bbox minY negative, maxY 0 maybe. height in units small. Why tiny? Because offY = h/2 - center*scale. Hmm.

Wait maybe the tree is drawn but with scale such that it's ~250px tall but appears as a stub because growProgress tiny at frame 1. The tool screenshots happen immediately. Let me wait and take a motion frame. Actually the tool likely advances frames. Let me call screenshot again after some time, or motion.

Actually the second screenshot shows a small vertical line with a bend at top ~60px. That's growth in progress (trunk growing). Let me wait more.

Let me use motion action to see frames. Or just inspect state.

The tree is growing and attached, nice. But it's asymmetric — because the rule FF[+F][-F] at each generation: the first F continues straight with branches. Actually it looks like a single trunk with a couple branch clusters, quite sparse and lopsided. Gen 3 tree. It's okay but could be nicer. Also observe the wind: frames show slight sway at tips.

The tree looks a bit weak. The branches only occur sparsely because FF then two branches. At gen 3, trunk is long. Maybe use a rule producing a fuller tree. But requirement is met. Let me test generation change to 5 and check fit.

Let me change generation via the slider. Use click on slider... The slider isn't a native drag easily. I can set via JS? The browser tool has click/type. Let me click at far right of slider to set gen 5, then screenshot after growth.

Slider is at roughly x from 40 to 285, y=118. Click near x=285,y=118 sets to 5? Clicking a range input at a position sets value. Let's do click at 283,118. Then wait.

Interesting: gen 5 tree is tiny! It should be larger. Why? At gen5 scale computed from bbox. The tree apparently is very wide/large in units, so scale is small, and at growth start it's tiny. Wait the image shows tiny stump at bottom (~2px). Growth just started. But scale should make full tree fill canvas. Since growth just started only trunk tiny grows. But the trunk appears only tiny fraction. Hmm, at gen5 the trunk segment is drawn at scale. bbox height maybe 50 units, so scale ~ 660/50 = 13. Trunk first segment length 13px. That's tiny. Full tree height 50*13=650px. OK that's reasonable. The stump is one segment ~13px, but appears ~4px. Hmm.

Actually wait, at gen 5 the bbox includes lots of horizontal spread maybe, making scale limited by width. The rule FF[+F][-F] produces a narrow tree though. Let me wait for full growth and screenshot.

But there's a concern: at gen5 the trunk should be thick (weight formula: 7.5*scale/70 ~ 7.5*13/70=1.4px). So it looks thin. Not great but visible.

Let me wait and see final gen5.

The gen5 tree is off-center to the right and cut off? It seems positioned right of center and top. The tree appears to extend beyond top maybe but fits. Actually the bbox centering seems off: tree is centered around x~800 rather than 600. Why? Because the tree's bbox center in x is negative? Wait offX = w/2 - (minX+maxX)/2*scale. The rendered tree center should be screen center. But it's to the right. Hmm.

Also it looks like the tree is growing lopsided because DFS and sway? No, sway small. Actually the structure: FF[+F][-F] is asymmetric: the + branch and - branch differ because after the first branch, the second branch attaches at same parent but the '+' rotates and '-' rotates relative to parent. They should be symmetric. But the tree looks asymmetric/lopsided to the right. Why?

Ah, because the rule replaces F with FF[+F][-F]. The first F in the replacement continues along original heading, but its children are computed. Consider parent direction. The '+' branch and '-' branch should be symmetric about parent direction. So overall tree should be symmetric. But image shows big lopsided growth to upper right.

Wait, maybe wind sway accumulates and drastically bends? At tips, sway could accumulate. windTime is large after seconds; cumulative sway over depth ~ many nodes. Let's estimate: each node sway amplitude = 0.055*(0.25+depth*0.11). At depth 10 => 0.055*1.35=0.074 rad. Summed over path of ~10 nodes could be ~0.4 rad, but random signs. The windTime appears consistent phase per depth so they add coherently: sway = amp*sin(windTime*1.45 + depth*0.65 + id*0.13). Different id shifts. Could cause notable bend. But the lopsided appearance is huge—tree leans right significantly. More likely the wind bending is strong and consistent.

Actually wait, the gen3 image also leaned slightly. The gen5 tree leans right strongly. This might just be wind. But the bounding box was measured without wind, so the swayed tree could exceed bounds and get cut off. In the screenshot the top-right branches approach but maybe within. The right side almost touches edge? It's around x=960, canvas 1200, fine.

But the centering issue: the tree base is at x≈600 (bottom center), good. The canopy extends right because of wind. So it's wind sway accumulated. Actually 0.4 rad over the whole path shouldn't shift canopy that far. Hmm, the canopy top is at x~780 vs base 600, over height ~600 => lean ~0.3 rad. Plausible.

That's actually fine — it's the wind. But at gen5 the sway may push out of bounds. Let me reduce wind strength a bit and make it oscillate so it doesn't stay permanently leaned. It does oscillate with time. The screenshot is one phase. Since it's sin, it swings both ways. Fine.

Actually the accumulated sway over many depth levels with coherent phase is problematic: different depths have different phases (depth*0.65), so not fully coherent. Fine.

But the bigger issue: at gen5, the tree's branches look very thin and the structure is spindly. It's acceptable procedurally but let's improve the grammar to a fuller, more tree-like structure. Also the gen3 looked sparse. Let me consider a better grammar.

Also concern: "bound grammar expansion and keep whole tree visible at every supported generation." Wind could push beyond bounds. I should add margin and measure bbox with maximum sway accounted, or reduce wind, or include sway in bbox. Add a margin in scale (e.g., 12% extra) and compute bbox including an estimated max wind displacement. Simpler: increase margin and use a slightly larger margin for safety. Also clamp sway amplitude.

Let me improve:
- Use a nicer grammar: 
  axiom: "X"
  X -> "F[+X][-X]FX"?? Hmm.
  
Let me think of a classic tree producing good shape and leaves:
axiom: X
X -> F[+X]F[-X]+X   (branching factor ~3)
F -> FF

That grows fast (F doubling). generation counts get big. At gen 5: X count triples, F's many. Could be big.

Maybe simpler keep current rule but add an angle that makes fuller, and use rule F->"F[+F]F[-F]F" (4) giving more branches at each node (two branches per F with a continued segment). Actually current "FF[+F][-F]" gives a long trunk segment and 2 branches. The "F[+F]F[-F]F" gives branches at every segment -> fuller.

Let me try rule = "F[+F]F[-F]F", angle 25. That gives 4 F per expansion. gen5=1024 nodes. Fuller, rounder tree. Let me test quickly by editing.

Also thickness: at gen5 scale small so branches thin. Might want thicker relative. Let's increase base weight a bit and make depth-based taper gentler.

Also the leaves: current terminal leaves clustering. With fuller rule, many terminals.

Let me change RULE and ANGLE and adjust. Then test gen3 and gen5.

Also fix wind bounding: add margin factor in updateScale: use margin = max(70, 0.12*min(w,h)) and additionally measure bbox then expand by wind allowance: expand bbox by e.g. 8% width/height. Let's just multiply bw,bh by 1.15 when computing scale.

Let me also reduce WIND to 0.04.

Let me make the edits.

Now reload and test. Let me set gen 3 first (default after reload? gen=3). Reload.

This screenshot was taken right after reload at frame 1, before growth. Let me wait and take again. Also I want to see it after growth.

This tree is very narrow/spindly and leaning. The problem: rule "F[+F]F[-F]F" — the main axis continues, but branches are short. Actually at gen3, it's tall and thin. It doesn't look like a full tree. The issue is that with constant segment length, growth is dominated by the continued F axis making a tall trunk, and side branches have fewer segments (they also get expanded though). Actually each F expands the same, so branches should be as long as trunk at each generation. But visually the side branches are short because... hmm.

Wait at gen3 the tree should have side branches that themselves branch. But it looks like mostly vertical with tiny side twigs. That's because the main trunk keeps extending via the middle F's and the continuation gets longer each generation, while side branches get rotated 25° and their sub-branches turn. Over 3 generations, side branches do grow but each segment count same. Hmm.

Actually the classic rule F[+F]F[-F]F does produce a nice tree typically. But the rendering looks thin because the segments are long relative to branch count? At gen3 = 64 nodes only. The tree has 64 segments. The branches appear. It's okay but leaning strongly to the left at top — that's asymmetric due to wind? At this moment wind sway. Also the structure is inherently somewhat asymmetric due to ordering (the [-F] branch is drawn relative).

I think the tree shape is fine but sparse. Let me check gen5. But more importantly the strong lean. Let me test with wind off/steady? Actually the requirement includes sway; lean is natural.

Hmm, but the tree looks like it leans left at top substantially. Let me reconsider wind accumulation. The sway formula adds per-node with phase depending on depth and id. Over a chain, at a given instant, phases differ, causing bending. Peak cumulative could be significant. But the screenshot shows a consistent lean over whole height, suggesting the lower trunk also bends. Node depths small near trunk so amp small. At depth 1, amp=0.04*(0.36)=0.014. Tiny. So trunk shouldn't bend. The lean at top is from accumulating across many nodes with similar phase (depth increments 0.65 rad, id 0.13). Could be.

I think it's acceptable. But let me improve overall aesthetics: make the tree more balanced by using symmetric rule and perhaps reduce angle. The classic rule F[+F]F[-F]F is fine.

Actually wait — the tree looks like it's leaning and the right side branch only on one side. Because of the wind moment. Let me take a motion sample to observe sway, and test gen1 and gen5.

Let me first test gen 1 (min) and gen5 (max) for bounds.

Click slider far left for gen1.

Growth just started (only first segment). Wait for it. Actually the tree at gen1 has 4 nodes. growSeconds = 3.7s. Let me wait.

Gen1 looks correct: connected trunk, two side branches with leaves. Wait, rule F[+F]F[-F]F at gen1: torso: first F, then [+F] branch left, then middle F continues, then [-F] branch right, then last F continues. So there should be 2 branches and 3 trunk segments. But image shows trunk then a branch left and a branch right, and top continues. Looks right. Good.

But the tree at gen1 fills only ~500px tall, not the full height. Bbox for gen1: tree height maybe 3 units, width small. scale limited by width! Because width is small (~1.5 units) and canvas width 1200, margin: (1200-140)/1.5*1.18 ≈ huge; height (800-140)/3*1.12 ≈ 196. So scale ~196, tree height 3*196=588. Fits. Good.

Now gen5. Click slider right.

At gen5 the initial trunk is tiny — the tree isn't scaled to fill. Hmm. This is a bug: the tree at gen5 starts at a tiny scale, meaning the full tree will be small? No: scale is computed from full bbox. At gen5 the tree is big in units, so scale small. The first segment = 1 unit * scale tiny. But the full tree should fill canvas after growth. Let me wait. If final tree fills canvas, then this is just the first frame. But the earlier gen5 screenshot (before grammar change) showed a decent tree. Let me wait for full growth.

Actually this is the immediate frame right after click (frame 1, +0ms). Growth hasn't progressed. Wait 6s already? The screenshot was taken by the click action before sleep. The bash sleep happened after. So need another screenshot now.

The gen5 tree is small (occupies ~250px) and off-center bottom, not filling canvas. Why? Because bbox measurement includes something huge? Let me think. The bbox is measured at unit length. But at gen5, the tree in units should be tall ~? The scale is limited by width or height. But the rendered tree is only 250px for a 1200x800 canvas. That means scale*bw or bh much less than canvas. Something wrong: bbox must be much larger than actual tree — maybe because of the sway? No, measure uses no sway.

Wait, maybe the tree actually is not filling because scale computed using `width`/`height` globals before canvas fully? No, updateScale called after createCanvas. Hmm.

Actually, consider: offX = w/2 - (minX+maxX)/2*scale. If bbox center x is far from tree's visual center due to a few outlier nodes, the tree could be off. But scale itself: if bw is large (tree wide) then scale small. The rendered tree is ~250px wide and tall. So scale is small, meaning bw or bh large. Maybe bh is large because of some long segment? No, unit length each.

Wait — maybe generation 5 expansion is capped? No.

Hold on: the tree rendered is small and the trunk base at x~620,y~720, canopy top y~460, so height ~260px. With scale maybe ~? If tree height in units ~ 15, scale ~17. Then canvas height 800, so tree doesn't fill. Why would scale be 17 if bh=15? Then (800-140)/15/1.12 ≈ 39, not 17. Unless bw is huge ~ 43 units: (1200-140)/43/1.18 = 21. Hmm.

Let me actually query the bbox and scale via JS. I'll use the browser to evaluate? There's no eval tool. I can add to __treeState. Let me edit to expose scale/bbox, reload, and inspect via... the inspect only gives DOM, not JS eval. Hmm. I could write values into the DOM (e.g., document title) but easier: temporarily add a debug element. Or I can reason.

Actually wait, the tree's visual is small AND to the lower right. Notice the tree extends only up-right from base at ~(620,720). The bbox centering: offX centers bbox. If base is at bottom, center of bbox should be canvas center-ish. But tree is drawn low. The offY = h/2 - center*scale + h*0.03. If bbox height ~15, center y ~ -7.5, offY = 400 +7.5*scale... then base at world (0,0) maps to y=offY = 400+7.5*scale, near bottom. Good. Canopy top world y=-15 maps to offY-15*scale = 400+7.5s-15s=400-7.5s. For tree to fill, 7.5s ~ 400 => s~53. So scale should be ~53. But it's rendering ~17. So scale smaller than expected -> bw or bh bigger than thought.

Let me add debug text to the panel showing scale/bbox. I'll add to __treeState and also update the grammar div? Simpler: change the hint div to show state each frame. Let me add a debug span update in draw.

Actually, I realize the issue! `width` and `height` globals in p5 at updateScale during setup: after createCanvas they're set. Fine.

Wait, could bbox be including the tree measured with the initial heading but measure recursion uses children which may have cycles? No.

Let me reconsider: measure computes ext for all nodes. But it's called with ext init {minX:0,...} and root. Fine.

Hmm, maybe the problem is `bbox` measured before `children` fully? No, children built before measure.

Let me just instrument. I'll add a small on-screen debug output. Actually let me expose via title and use inspect—the DOM includes title? inspect shows body text. I'll append a div with state. Let me add to draw: document.getElementById('dbg').textContent = ... and add the div. Quick.

Actually, maybe the real issue: the rendered tree image is smaller because growProgress not finished? No, leaves all present, it's fully grown.

Let me compute expected node count for F->F[+F]F[-F]F: F count = 1+1+1+1 = 4. gen5 = 1024. Tree of 1024 unit segments. The tree is a fractal: main axis length ~ number of trunk segments. At gen5, there are 5 levels of "main axis" F? Actually each generation the middle/continuation F continues. The trunk's straight length grows ~3 per generation? Not exactly.

Regardless, let me instrument. I'll temporarily insert a debug element.

Actually, simpler idea: the tree might be limited by width because the L-system tree for this rule spreads very wide (branches keep branching at 25°). Width in units could be ~40. Then scale = (1200-140)/40/1.18 ≈ 22.5. Height ~15*22.5=340. That matches the ~260-340px. So the tree is wide and short! The rule F[+F]F[-F]F doesn't grow tall; it grows bushy. So the whole tree fits, but it's wide, so scale limited by width, leaving vertical space. That's acceptable "keep visible" but the tree looks small.

The tree looks bushy/wide indeed. To make it fill better, the aspect ratio matters. Canvas is 1200x800. A wide tree fits width. It's fine but maybe better to reduce angle or use a taller grammar so the tree is taller than wide, using full height.

Let me use a grammar that's taller/narrower: rule "F[+F][-F]F" or "FF[+F][-F]" (original). Original gave tall thin tree. Or the classic with X to make trunk longer.

Actually the wide bushy tree looks nice and tree-like, better than the spindly original. The issue is just it doesn't fill vertically. Could allow scale to fill height and let width clip? No, must keep visible. So the bounding box determines.

Maybe better: make the tree naturally taller by adding length to vertical segments. Use rule: F -> "F[+F]F[-F]F" but reduce angle to 18° so branches narrower => taller aspect. Let's try angle 18. That makes a taller tree, better fill. Also branches spread less.

Let me also consider using a rule with a longer trunk: F -> "FF[+F]F[-F]F" (5 F's) gives more vertical emphasis with straight run. Let's try RULE = "FF[+F][-F]F"? count 5. Hmm.

Let me try angle 18 with current rule and see gen5. Quick edit and reload.

Actually let me reduce angle to 20 and test.

That screenshot is frame 1 after reload (growth not started). Let me take a fresh screenshot now.

Now gen3 with angle 19: tall thin tree, but very sparse and tall — only fills ~600px of 800. It's narrow. It looks more like a tall plant. Hmm, not great either. The earlier angle 25 gen5 bushy looked nicer. 

Let me find a balance. The issue is aspect ratio. For a nice tree, we want the tree roughly as wide as tall (canvas 3:2). A bushy tree at angle 25 filled width but was short. At angle 19 it's tall and narrow.

Maybe increase angle to 22 and also make leaves bigger / branches thicker. Actually the bushy gen5 at 25° was only ~250px tall because very wide. Let me reconsider: maybe the width was not actually that large. Let me measure.

Actually the issue might be different: at gen5 with 25°, the tree was about 250px tall and 250 wide, in a 1200x800 canvas, meaning scale was determined by bbox which was much larger than the visible tree? No, visible = bbox*scale. If it fills neither dimension, scale must be limited by something else. Margin? scale = min((w-140)/bw, (h-140)/bh). For the tree to be only 250px tall, bh*scale=250. And bw*scale would be the width. The image showed the tree about 250 wide too. So neither fits w-140=1060 nor h-140=660. So scale is not determined by these! Unless bbox is wrong.

Wait, unless the tree itself is small because growProgress hadn't finished and many nodes at 0 length? At the gen5 screenshot, leaves were fully formed at tips, so grown.

Hmm. Let me actually instrument. I bet bbox has an anomaly: the measured bbox may include a stray. Let me expose debug by drawing text on canvas with scale/bbox. I'll add a temporary debug draw. Actually, I can inject a persistent debug element and inspect. Let me modify __treeState to also compute bbox, and put it in the hint div every frame. Then inspect DOM.

Let me edit: in draw, set document.getElementById('hint').textContent = 'scale='+scale.toFixed(1)+' bbox='+JSON.stringify(bbox)... But bbox is floats. Round.

Then inspect DOM. Let me do that.

I can't set window.__debugHint from the tool except by editing. Let me just always show it temporarily. Actually I'll set __debugHint = true in setup. Simpler: change condition to always true for now. But I'll remove later. Let me just always set in setup. Actually let me change the code to always display, then revert.

Let me set window.__debugHint unconditionally via editing the condition to `true`. Hmm, but I want to remove before final. I'll just leave it always and it's a harmless status line? It changes the hint text which is fine actually—could be a feature. But better to remove.

Let me set the condition to always update and check gen5. Then decide.

Actually simpler: set `window.__debugHint = true;` in setup, and I can later delete. Let me edit.

Now I have data: gen3 bbox width=6.9, height=27. scale=21.1. So tree height 27*21.1=570px. That's why it's tall. Width 6.9*21.1=145px. So the tree is very narrow! Wait but the earlier screenshot at angle 19 showed a tree wide ~200px and tall ~600. Yes.

So scale is limited by height: (800-140)/(27+1)*1.12 ≈ 660/31.4=21. Yes. Good, no bug. So at gen3 the tree is tall and narrow. Fine.

Earlier at gen5 angle25, the tree rendered ~250px. Let me check gen5 bbox. Let me set gen5.

Also note: scale formula uses bw*1.18+1 and bh*1.12+1. At gen3 bh=27 => 27*1.12+1=31.2, scale=660/31.2=21.1. Good.

For gen5 at angle25, the bbox likely huge (bushy) so scale small. Let's check with current angle 19 gen5. Let me click gen5.

Now I see the bug clearly! At gen5, bbox height=243, width=63, scale=2.4. scale = min((1200-140)/(63*1.18+1)=14.2, (800-140)/(243*1.12+1)=2.42). So height-limited => tree height = 243*2.4=583px, width=63*2.4=151px. That should be visible as a tall narrow tree ~583px. But the screenshot shows a tiny 20px tree!

Wait, spawn scale was 2.4 and the tree at gp=0.01 is tiny because just started. I need to wait for growth. The screenshot was frame1 again. bp=0.01. Let me wait and re-screenshot.

The bash sleep 8 happened before the screenshot? No: I clicked then slept 8, then the click result was frame1. The screenshot after sleep is a separate call. Let me take screenshot now.

Now it's clear: gen5 tree is a tangled blob, not tree-like. The bbox says height 243 units but rendered tree is ~200px, not 583. So something is wrong with the rendering vs measured bbox. The tree rendered occupies only ~200px, but bbox*scale = 243*2.4 = 583px. Why?

Wait — the wind sway! The tree drawn with sway, and the sway is LARGE at gen5 because depth is huge and cumulative. The measured bbox is without sway. But the rendered tree appears compressed, not expanded. Hmm.

Actually look: rendered tree is a messy tangle with no clear trunk. That's because the L-system with this rule at gen5 creates a space-filling-ish tangle (angles close to 19°, branches at various rotations). The bbox without sway spans 243 tall, but the drawn tree with accumulated wind sway has branches bending so the visual bounding box is different.

But more importantly, the drawn tree's trunk base at ~(615,720) and top ~(660,545): total height ~175px, not 583. That means the drawn coordinates are NOT bbox-scale consistent. 

OH. I see the bug. In drawNode, I recurse with `drawNode(kids[k], endWX, endWY, abs)` — endWX/endWY are the FULL unit end (I compute `endWX = wx + Math.cos(abs) * fr;`). That's correct, full length regardless of growth. Then screen mapping multiplies by scale. So final tree should span bbox. 

Unless... the wind sway makes branches bend so much that they curl back, reducing the overall extent! With gen5, depth up to ~? maybe 15. The cumulative sway could be huge, causing branches to curl. Yes! That's why it's a blob — the wind is bending branches massively at high depth, tangling everything.

The sway amplitude grows with depth: amp=0.04*(0.25+depth*0.11). At depth 15 => 0.04*1.9=0.076 rad. But cumulative sum over a path of length 15 with slowly varying phase (depth*0.65) could add to ~1 rad, curling. And the phase id*0.13 adds noise. So the wind is way too strong for gen5.

Fix: make wind not depend on depth growth, and instead apply wind at the whole-tree level plus a bounded tip sway. Better approach: sway should bend the tree, but bounded. Use a normalized depth factor based on relative depth or just a small fixed amplitude per node, and importantly make the phase coherent along a branch but bounded cumulative.

Simplest robust approach: apply sway based on absolute world-space horizontal displacement as a function of height, rather than per-node angle accumulation. i.e., each node's position gets a wind offset proportional to (depth/totalDepth)^2 and a global sway, but then children attach because we use parent's displaced position. 

A cleaner method: compute the swayed position recursively where the local angle perturbation is small and depends on time and the node's index but NOT accumulating unboundedly. The issue is accumulation. If we add a per-node angle perturbation δ_i, the cumulative angle at depth d is sum δ. Even random, over 15 levels gives large deviation.

To bound it: make δ_i = WIND * sin(...) * (depends on depth) but scale by 1/N so cumulative stays bounded? Or better: apply the wind as a displacement in the perpendicular direction that is the same coherent function of world height, added to positions.

Alternative: two-pass. First compute base (no wind) positions. Then for drawing, warp coordinates: 
wx' = wx + wind * (perpendicular offset) ... but then attachments? If we warp each node's position by a function of its base position (same function applied to all), parent-child lines remain connected because we just draw lines between warped positions of parent and child. Connectivity preserved automatically! We draw each segment between warped(parentEnd) and warped(nodeEnd). Since each segment connects warped endpoints, the tree stays connected regardless of warp function. 

So simplest: compute base positions with a recursion storing them; then apply a smooth warp to all positions: e.g.
swayAmount = WIND_PX * hard? In world units: offset = a * (something) .
We want the top to sway more than the base. Use offset proportional to (baseY)^? Actually base y is negative going up. Let h = -wy (height above base). warp x += A * sin(t + h*k) * (h * scaleFactor). This is a global function of position, smooth, so nearby points stay close, segments connected. And bounded because h bounded by tree height.

But if we warp x by function of h only, then all points at same height shift by same amount — good, tree bends like a stalk. That's natural wind.

Let me implement:
- Precompute base positions for a node at unit length: recursive, storing node.x, node.y (end positions) and start = parent's end.
- Then at draw time, define warp(x,y): 
   const h = -y; // height above base (world units)
   const sway = WIND_UNITS * Math.sin(windTime*1.5 + h*swayFreq) * h;  
   return {x: x + sway, y: y + small?}
   Only x warp. Actually should also slightly reduce height? no.
   Use a per-node height normalized: h up to say 30 units. WIND_UNITS maybe 0.06. Top sway = 0.06*30=1.8 units. With scale at gen5 ~2.4 => 4px. Too small? At gen3 scale 21 => 38px. Hmm depends. Maybe normalize by tree height: sway fraction of height. 

Better: warp in world units as fraction of total height. Let H = bbox height. swayX = 0.06*H*sin(...)*( h/H )^2? Top gets 0.06*H. At gen5 H=243 => 14.6 units * scale 2.4 = 35px. At gen3 H=27 => 1.6 units*21=34px. Nice consistent screen sway. 

Use hNorm = clamp(h/H,0,1); swayX = amp * H * sin(windTime*1.5 + hNorm*2 + nodePhase) * hNorm^1.5. But nodePhase breaks smoothness causing segments to stretch; we can use only position-based (hNorm), so all nodes at same height shift same amount => rigid bending, still connected. Add a small twist based on x maybe. Keep smooth.

Actually to add variation between branches, use sin of (x*0.1 + hNorm*2). Smooth in x too. Good.

Also add a small vertical component to make it look organic: maybe not.

Then draw each segment: base start P0 (parent's end) and P1 (node end) in world; warp both; map to screen. Since we warp endpoints independently but the function is smooth and similar over a short segment, fine. Connectivity exact because child start = parent end (same point -> same warp). 

So restructure: precompute positions at build (store x,y for each node as end coords, and root start 0,0). Then draw iterates nodes in order (parents before children since id order) and draws each segment from node.start to node.end where node.start = parent.end or origin. Leaves at terminal.

This is much simpler and avoids recursion per frame for positions. But wind warp is per frame.

But growth: node's drawn length fraction fr. We want child start = parent's current end (grown). So we can't just use static positions; we need current grown end. But if we draw in id order (parents before children), we can maintain an array of current positions computed from the warped? Hmm, warping complicates.

Alternative: keep recursion for growth but compute sway via the smooth warp applied at draw time based on the *base* (unwarped) position of the node. But the recursion's positions are already swayed if we pass swayed start to children. Instead: recurse using BASE positions for geometry, and warp only for drawing each segment. So:

drawNode(id, baseStartX, baseStartY, parentAbs):
  baseEndX = start + cos(abs0)*fr; where abs0 = parentAbs + local (no sway)
  // draw segment from warp(baseStart) to warp(baseEnd)
  // recurse child with baseStart=baseEnd, parentAbs=abs0

warp uses position (baseEnd). This keeps geometry connected in base space, and warp is a smooth function of base position, so screen endpoints connect. Growth attached.

The localAngle abs0 for geometry is static. Then warp adds the sway. This is clean.

But warp as function of base position: need H (bbox height) and base y. Use y (negative up). h = -y. hNorm = h/H. swayX = AMP*H*Math.sin(windTime*1.5 + hNorm*2.2 + x*0.15) * (hNorm*hNorm*0.9+0.05). Where x = baseX (unused maybe). This is smooth in x and y. AMP ~0.05.

Wait, using x in the phase: at same height different branches get different phase -> they move differently, but warp is smooth in x so connected segments still fine. Good.

Then map warped world coords to screen.

Also for bounding: the tree after warp could extend beyond bbox by up to AMP*H. So increase margin factor. With AMP=0.05 and padding 1.18 maybe enough if the widest points are at mid-height with hNorm~0.5 => 0.05*H*0.3=0.015H. Small. Top sway 0.05H. Padding of 1.18 adds 0.18H total (0.09 each side) > 0.05H. Good.

Let me also reconsider grammar. The gen5 tangle suggests the rule creates a space-filling shape at higher generations when angle 19. Actually the tangle was mostly due to wind. Without huge wind, the tree structure should be fine. But the rule F[+F]F[-F]F with angle 25 at gen5 gave a bushy tree earlier (looked decent). Let me revert angle to ~22 and implement the warp sway, then re-test.

Actually with correct bounded sway, the gen5 structure will be visible. But will it be a nice tree or a tangle? Let's test.

Let me choose angle 22.5 (classic). Revert debug after inspection.

Let me rewrite the relevant JS parts: drawNode to use base positions + warp. And remove windTime sway inside. Let me edit.

Current drawNode:
```
function drawNode(id, wx, wy, parentAbs) {
    var n = nodes[id];
    var amp = WIND * (0.25 + n.depth * 0.11);
    var sway = amp * Math.sin(windTime * 1.45 + n.depth * 0.65 + n.id * 0.13);
    var abs = parentAbs + n.local + sway;
    var fr = growthFrac(id);
    var endWX = wx + Math.cos(abs) * fr;
    ...
    for kids drawNode(child, endWX, endWY, abs)
}
```

New:
```
var TREE_H = 1; // set in buildTree = bbox.maxY-bbox.minY
var WIND_AMP = 0.05;

function warpPoint(x, y) {
  var h = -y;
  var hn = TREE_H > 0 ? Math.max(0, Math.min(1, h / TREE_H)) : 0;
  var bend = WIND_AMP * TREE_H * (0.08 + hn * hn) *
             Math.sin(windTime * 1.5 + hn * 2.3 + x * 0.18);
  return { x: x + bend, y: y };
}
```
Wait, phase includes x*0.18; for x range maybe ±30 => 5.4 rad variation, big but smooth.

Hmm but if we warp based on base x, then the same world point always warps same, good.

drawNode(id, wx, wy, parentAbs):
  var n=nodes[id];
  var abs0 = parentAbs + n.local;
  var fr = growthFrac(id);
  var endWX = wx + cos(abs0)*fr;
  var endWY = wy + sin(abs0)*fr;
  // warp base and end
  var a = warpPoint(wx,wy), b = warpPoint(endWX,endWY);
  screen...
  draw line
  leaf at b
  recurse child with (endWX,endWY, abs0)

This is correct.

But note leaves: for terminal, drawn at warped end. Good.

Let me also set TREE_H in buildTree.

Now updateScale padding: keep 1.18/1.12 plus maybe 1.22. Use scale = min((w-2m)/(bw+0.3*H?), ...). Simpler: after computed scale, multiply by 0.92 safety. Let's set final scale *= 0.92. Actually let's just increase padding to 1.25 width and 1.2 height, and add wind allowance. Fine.

Let me implement edits.

Now set angle to 22.5? Currently 19. Let me set to 23 for a fuller but not tangled look. Actually let me first test with 19 to see structure with bounded wind at gen5.

Reload and check gen5.

Let me click gen5 and wait full growth.

This is the click frame (gp=0.01), growth just starting. Need to take a screenshot after the sleep now.

Now the gen5 tree is a tall, narrow, coherent tree with bounded sway. It fills the height (~600px). Good — the earlier tangle is fixed.

But it's very narrow and leaves cluster to form fuzzy tips. The branches are short relative to trunk. The tree looks like a tall thin stalk with tiny branches. The rule F[+F]F[-F]F with angle 19 creates this narrow shape. Increasing angle would widen branches. Let's set angle to 26 to get a fuller crown, then check it still fits (width may grow). Since scale accounts for width, a wider tree will be scaled down overall; still visible.

Actually the ideal is a balance. Let me set angle 26 and test gen5. The tree might become bushy but that's fine.

Also the leaves are tiny relative to gen5; lsz = constrain(scale*0.16,2.2,9). scale=2.3 => 0.37 -> clamp 2.2. Fine. The fuzzy tips are tiny segments densely packed. Acceptable.

Let me set angle 26 and test. Also, I realize with angle larger, bbox width grows, scale shrinks, trunk gets very thin. The thickness formula uses scale/60, and base 8.5. At scale maybe 1.8 => 8.5*0.03=0.25 -> clamp 1.0 px. So all branches become 1px. Thin. Could bump base weight or use a different thickness approach. Maybe make trunk weight independent-ish: weight in px = max(1, baseW * pow(0.8,depth) * sqrt(scale)/something). Hmm.

Actually at high generation the whole tree is drawn small, so 1px lines are okay. But to make trunk more prominent, increase base. Let me set weight formula: constrain((10 * pow(0.8,depth)) * (scale/50), 1.2, 26). At gen5 scale 2 => 10*0.04=0.4 -> 1.2. Still thin. The trunk depth 0 => 10*2/50=0.4. Hmm because scale tiny. To keep trunk visible at gen5, multiply by a factor that grows when scale shrinks? That's counterintuitive; if tree is small on screen, trunk should be thin. It's fine, 1.2px visible.

Actually at gen5 the rendered trunk did look ~2px, fine.

Let me set angle 26, retest. Also maybe the leaves should be a bit larger for gen5 to read as foliage. lsz min 2.2; maybe min 2.5. Eh.

Let me try angle 26.

Let me wait and view gen3 final, then gen5.

Now gen3 looks like a proper tree: connected brown trunk, branches, circular leaves. Good. It's still a bit narrow/tall, but looks like a sapling. The leaves are nice circles.

Now gen5.

Again the click screenshot is at growth start. Take fresh screenshot now.

The gen5 tree looks like a tall thin stalk with leaves along it, not very tree-like. It's essentially too tall and narrow. The grammar F[+F]F[-F]F keeps the main axis growing and branches are short relative to the ever-lengthening trunk. At higher generations the trunk grows linearly in generation (each gen adds 3 continuation F's?), while branches are stunted? Actually all F's expand, so branches should also grow. But the main axis accumulates the most.

The issue: this grammar's silhouette is a central leader with short side branches. To get a fuller crown, I want more balanced branching. A better tree grammar is the classic one:
F -> F[+F]F[-F][F]  (5 F's) — adds a third branch, fuller.
Or use two symbols:
axiom: X
X -> F[-X][+X]FX

Hmm.

Actually the narrowness is fine for a tree (like a poplar). But it doesn't look great. Let me try the classic fractal plant:
axiom: X
X -> F+[[X]-X]-F[-FX]+X
F -> FF
angle 25
This produces a bushy plant. But complexity and node count grows fast (F doubles). At gen5, node count? X count roughly triples each gen? Let's estimate. gen5 could be thousands. Fine.

But bounding: FF doubling makes long segments. Let me not.

Alternative classic tree:
axiom: F
F -> FF+[+F-F-F]-[-F+F+F]  angle 22.5  (the classic "fractal tree"). This produces a fuller canopy around a central trunk. Node count 8^n but wait F count per expansion: FF (2) + 3 + 3 = 8. gen5 would be 8^5 = 32768 nodes. That's a lot but maybe okay (~33k line draws + leaves). Might be slow but probably fine at 60fps? Each frame recursion 33k plus trig. Could be ~10-20ms. Acceptable.

But scale: the classic fractal tree at gen5 is quite dense and beautiful. Let me try it with gen4 maybe. But required gen range 1-5, and at gen5 it should still be visible and perform. Let's test performance.

Actually, I worry about 32768 nodes with parameterized js object access. Let me estimate: 32768 iterations with Math.cos/sin, line(), warp (another sin) => ~100k trig calls/frame maybe. That's likely too slow (could be 30-50ms), dropping fps. Hmm.

We could precompute base positions at build time (not per frame) since geometry is static. Then per frame only warp and draw. That reduces trig to warp sin per node (~33k sin). Still a lot but better. Actually we can precompute node end positions (x,y) and start positions in build. Then per frame: for each node compute warp (one sin for bend) and draw. ~33k sin + 33k line calls. p5 line is not super fast. Might be ~20ms. Risky.

Better keep node count moderate. Current rule gives 4^gen: gen5=1024. Great performance. Let's design a fuller tree grammar with ~4-5 F per expansion but balanced.

Try F -> F[+F]F[-F][F] (5). gen5=3125. Balanced with 3 branches. Might look fuller. Let me test. Also try F -> F[+F][-F]F[+F][-F]? count 6.

Actually the narrowness comes from the "continuation" middle F's being at the center. With rule F[+F]F[-F]F there are two continuation F's (the last F and the middle one? The middle F is also continuation). So the main axis is double per expansion. To make side branches relatively longer, reduce continuation: rule F[+F][-F]F has one continuation and two branches (3 F's). gen5 = 243 nodes — sparse. Combine: F[+F]F[-F][F] has continuation plus 3 branches.

Hmm, side branch length issue: at generation g, side branch subtree depth = g-1 (since it started one generation later). Main axis depth = g. The difference of 1 level is small; side branches are nearly full length. So why does it look stalky? Because the main axis has 2 continuation F's per node along the spine, so the spine is twice as long as a branch that starts at the same level and also has 2 continuation F's... Actually a side branch from level 1 also has 2 continuations per node at subsequent levels, so its length scales similarly. But it turns away, so vertical extent less.

The rendered gen5 shows side branches but they're short and the overall is a spike. Increasing angle 26 already. Maybe the issue is that branches start only near trunk? Actually the tree's crown is narrow because at each node there are only 2 side branches, one each side, and they immediately branch. Should be full.

Maybe it's just that the canvas aspect: tree is 243 units tall and 82 wide. Very tall. So visually narrow. If I make scale based on width as well, the width-limited scale would be (1200-140)/(82+73)=6.8, giving height 243*6.8=1650 > 800, clipped. So it's naturally tall. We can't make it fill width without clipping height. So the tree is inherently tall/narrow for this grammar.

To make a rounder tree, need a grammar that spreads more. The classic FF+[+F-F-F]-[-F+F+F] spreads a lot. Let me just use the classic and cap generation 5, but precompute positions to help performance. Let me evaluate node count: 8^n. gen1=8? axiom F, gen1: replace F -> 8 F's. gen2=64, gen3=512, gen4=4096, gen5=32768. 

Let me test performance with 32768. I'll precompute positions in build to avoid per-frame recursion trig. Actually current recursion per frame does cos/sin per node plus warp sin. Precomputing base positions removes recursion and cos/sin; warp still needs sin per node. Let's precompute.

But maybe simpler: choose a grammar with a moderate count (4-5) but more spread. Let me try F -> "FF[+F][-F]F"? count 5, spreads via two branches and a long trunk. At gen5=3125. Might still be tall.

Alternatively use a stochastic-looking balanced rule: F -> "F[+F]F[-F]F" but reduce angle 22, and accept tall. Honestly the tree looks acceptable—like a young tree. The requirement doesn't demand a perfect oak. Visual styling is free.

But the gen5 image looks more like a tall weed than a tree. I'd prefer a nicer crown. Let me try the classic fractal tree with precomputed positions and see performance. If too slow, fall back.

Actually, a good middle-ground grammar with 5 F's and branch-heavy:
F -> "F[+F][-F]F[+F][-F]" count = 5? Count: F, F, F, F, F = 5. This has 4 branch pairs (two at start, two at end?) Actually: F [ +F ] [ -F ] F [ +F ] [ -F ] => that's F + 1 + 1 + 1 + 1 = 5 F, with 4 branches. Very bushy. gen5=3125. Spreads wide. Let's test that. Angle maybe 22.

Hmm, 4 branches per node at 22° could make a wide flat blob.

Let me instead test the classic rule at gen4 first to see look, and decide. Time is limited (we have ~15 min total, maybe used 10). Let me be efficient.

Let me try RULE = "FF[+F][-F]F" (5 F) with angle 24. This has two branches and 3 continuation F's (trunk long). Probably tall too.

The core issue: any rule with continuation F's makes tall trees. To get round, need branching without long continuation: F -> "F[+F][-F]F" has one continuation. Let's test that at gen5 (4^? no, 3^5=243). Sparse but round. With more branches: F -> "F[+F][-F]F[+F][-F]" (5 F, one continuation, 4 branches) => bushy round.

Let me go with F -> "F[+F][-F]F[+F][-F]" angle 28, gen5=3125. Test.

Actually wait, let me reconsider the classic rule and precompute. The classic FF+[+F-F-F]-[-F+F+F] is known to look great. Let me estimate its spread: it has 2 continuation F's (FF at start) and branches. It's tall too but with dense foliage.

Given time, let me test the bushy 5-F rule quickly.

I'll change RULE, angle 28, reload, gen3 then gen5.

That's just start. The bbox for gen3 is 8.2 wide, 14.6 tall — much rounder aspect (0.56)! scale 37 => tree ~540 tall, 300 wide. Good. Wait for growth.

This looks like a nice tree! Gen3: brown trunk, green branches, round leaves. Connected. Good.

Now gen5. Click right and wait.

Node count 7776 (5^5 = 3125? no, 5 F per expansion: 5^5=3125. But it's 7776 = 6^5? Let me count rule F[+F][-F]F[+F][-F]: F (1) + F (1) + F (1) + F (1) + F (1) = 5. Hmm 7776 = 6^5. Wait maybe count: "F[+F][-F]F[+F][-F]" -> F's: position: F, then +F (2), -F (3), F (4), +F (5), -F (6). Yes 6 F's! I miscounted. So gen5=6^5=7776. That's more but fine.

The screenshot at gp=0.02 shows a tiny sprout at bottom center — growth just started. bbox height 61, scale 9.2 => tree 560px. Good. Wait for full growth and check performance. 7776 nodes per frame — should be okay.

Take screenshot after gain.

Gen5 looks like a nice bushy tree, fully visible. Good. Performance appears fine.

Now verify:
1. Parent-child connections — visually yes.
2. Growth progressive — yes, observed.
3. Wind sway after grown — need to verify. Let me sample motion frames now (grown) to see sway.
4. Generation change restarts growth with different structure — verified gen3 vs gen5.
5. Regrow button restarts — test.

Also I should check console for errors. Earlier console empty. Let me check after all this.

Let me now test the Regrow button and wind motion. First motion frames to see sway.

Actually, let me verify wind by taking two screenshots a second apart and comparing. The motion tool gives multiple frames.

Let me call motion.

The motion frames show the tree swaying: compare frame 1 vs frame 4, the canopy shifts. Yes, wind motion is visible. The tree is connected and full. 

Now I need to remove the debug hint (or keep it? It's cluttering). Let me remove the debug output and restore the hint text. Also remove the `window.__debugHint = true` and the `if` block. But wait — maybe keeping a subtle status is fine, but it shows bbox which is ugly. Remove.

Also remove the unused `leafTrim` variable. And clean up.

Then test Regrow button and gen change one more time, and check console errors.

Let me make the cleanup edits.

Now reload and test Regrow and generation change, check console. Let me reload, set gen2 maybe, and press Regrow.

Actually let me just reload (gen3) and verify full tree, then click Regrow and see growth restart, then change gen.

Let me reload and take screenshot after growth then click regrow.

That's the frame right after reload (growth start), debug hint removed (good, hint is the normal text). Take screenshot after growth.

Gen3 final looks like a good tree with connected trunk and branches, leaves at tips. Console empty.

Now test Regrow button: click it and confirm growth restarts (tiny stage). Button at ~(156,155). Click and screenshot immediately.

Regrow restarts growth from the trunk (tiny sprout). Good.

Now test generation change to a different value, e.g., 1, and confirm different structure and growth restart. Let me click slider at x=35 (gen1) and then after growth screenshot. Actually I already tested gen5 earlier and it worked. Let me just verify gen1 quickly with the final code. Click left and wait.

That's frame 1 after generation change. Take fresh screenshot after growth.

Gen1: trunk with four branches (two pairs) and leaves. Correct grammar interpretation (F[+F][-F]F[+F][-F] at gen1: base F, two branches, then continuation F with two more branches). Connected. Good.

Everything works. Let me do a final check: verify no console errors after all interactions, and confirm the file is self-contained. Also the initial generation default is 3; slider value 3. Good.

One more consideration: p5 global mode and `window.setup`/`window.draw` assignment — worked. Console empty.

Let me do a final inspect for console and maybe verify file has no external refs.

Also check: `MAX_GEN` unused (fine). No network requests: p5.min.js local, no external fonts (using system fonts). Good.

Let me run a grep to ensure no http references.

Everything works. The tree currently at gen1, but default is gen3 on load. That's fine.

Let me reset to default gen3 state? The artifact starts at gen3 on load. The current runtime state is gen1, but the file's default is 3. Good.

Now final report. Let me summarize what I checked and unverified. 

Unverified: exact fps/performance at sustained gen5 over long time; responsiveness on window resize (code handles it but not tested); exact parent-child attachment at extreme wind (visually smooth). Also I didn't test dragging the slider continuously (only clicks at extremes and regrow). But those cover restart.

I'll report.