Aquarium breach · step-3.5-flash

The user wants me to build an interactive 2D aquarium-breach simulation on a canvas. Let me break down the requirements:

1. **Initial state**: An intact glass tank containing water, fish, rocks, plants, and a floating toy.
2. **User interaction**: User can drag a visible crack vertically on one side below the initial waterline, then press a "Breach" button. There should also be a "Reset" button.
3. **Breach simulation**:
   - Show panel breaking around the selected opening
   - Water exits in a gravity-curved jet
   - Waterline falls continuously
   - Outflow weakens as water level approaches the opening
   - Outflow stops when water no longer reaches it
4. **Escaped water**: Forms a spreading puddle constrained by floor and room walls
5. **Physics for objects**:
   - Rocks: sink
   - Toy: float
   - Plants: bend or drift
   - Fish: initially swim against current, some swept through breach
   - Movable objects that fit opening can be carried out by flow
   - Objects leaving water transition to gravity-driven motion and collide with floor
   - Glass fragments: rotate, collide, experience resistance in water
6. **Simplified physics** is fine, no need for CFD

I need to create a single self-contained HTML file with all CSS and JavaScript inline. No external resources.

Let me think about the architecture:

- Canvas for rendering
- Physics simulation loop
- Water simulation: I'll need to model water as particles or a height field. For outflow, I can use particle-based water.
- Object types: Water particles, Fish, Rocks, Plants (maybe as segments), Floating toy, Glass fragments
- Water jet: Particles that exit through breach follow a curved path under gravity
- Puddle: Water particles that land on floor coalesce/slow down

Let me design a simplified but convincing physics model:

**Water particles**:
- Each water droplet has position, velocity, and state (in_tank, in_jet, in_puddle)
- In tank: constrained by tank walls, apply pressure/flow through breach
- Jet: particles exit with initial velocity, affected by gravity (curve downward), air resistance
- Puddle: particles on floor spread, slow down due to friction, coalesce visually

**Fish**:
- Position, velocity, state (in_water, swept, escaped)
- Swim behavior: move using periodic motion, can be influenced by current
- If in current region near breach, may get swept out

**Rocks**:
- Sink to bottom, affected by water drag if submerged
- Collide with tank bottom and walls
- If in breach flow, may be carried out

**Toy**:
- Floats on water surface, follows water motion
- Can be carried out by strong flow

**Plants**:
- Bend based on water velocity at their position
- Animate as they sway

**Glass fragments**:
- Created when breach occurs
- Rotate and collide, with water resistance

**Simplified water level**:
- I can track water level height as a value that decreases over time based on outflow
- Draw water surface as a horizontal line inside tank
- But for jet, need particles anyway

Actually, for better visuals and simulation, I'll use a particle system for water:
- Tank water: array of particles with positions (x,y) inside tank
- Each frame, move particles according to flow field toward breach
- Some particles exit and become jet particles
- Jet particles affected by gravity, draw as curved stream
- When they land, become puddle particles on floor

The water level can be computed from average y of tank water particles or tracked separately.

Let me implement:

**Setup**:
- Canvas fullscreen or centered with fixed size
- Tank: rect with glass walls
- Initial water fills from bottom up to some level
- Fish swimming in water (use simple shapes: fish = ellipse with triangle tail)
- Rocks: gray circles/rocks at bottom
- Plants: green curves from bottom
- Toy: rubber duck shape on surface

**Breach selection**:
- User drags on tank wall to define vertical crack segment
- Visual feedback: highlight red crack line
- Press Breach button: create opening, trigger simulation

**Breach event**:
- Remove glass segment (draw opening gap)
- Spawn glass fragments (small pieces with rotation)
- Start water outflow: tank water particles move toward opening and exit

**Physics loop**:
- Update fish positions: swim normally, but near breach add current velocity
- Update rock positions: sink (increase y), water drag
- Update toy: float on surface, follow water motion if near breach
- Update plants: bend angle based on water velocity
- Update glass fragments: gravity + rotation + collisions

**Water**:
- Tank water: many particles. Each frame, move toward breach by a flow velocity.
- When particle reaches breach, convert to jet particle with initial velocity.
- Jet particles: position += velocity; velocity.y += gravity; some horizontal spread
- When jet particle hits floor (y >= floor), become puddle particle (stop or spread slowly)
- puddle particles: very slow, accumulate, draw as wet area

**Simplified approach**: Instead of individual water particles everywhere, use:
- Water surface line that lowers
- Jet: a stream of particles emitted from breach opening
- Puddle: grows on floor as water lands

But we need objects to respond to current. So we need flow velocity field in the breach region and some spread in tank.

Better: simulate water as particles, but fewer for performance: maybe 200-300 particles. That's enough visually.

Let's plan classes:

- `WaterParticle`: pos, vel, life (for jet), state ('tank','jet','puddle')
- `Fish`: pos, vel, direction (left/right), state ('normal','swept','escaped'), timer for swimming
- `Rock`: pos, vel, radius, inTank boolean
- `Toy`: pos, vel (buoyant)
- `Plant`: base position, segments, bending angle
- `GlassFragment`: pos, vel, angle, angVel, polygon points

Maintain arrays: waterParticles, fish, rocks, plants, toy, fragments, puddleParticles (optional)

**Breach crack**:
- User drags from one wall point to another vertically. We'll allow dragging on the left or right wall.
- Record startY and endY (vertical range). The crack is centered horizontally on that wall (thickness small).
- On breach: create opening: remove that portion of wall from rendering, and allow water to exit.

**Flow physics**:
- Inside tank: water particles are initially spread filling tank up to waterline.
- Each frame, for each tank water particle, if it is within a distance to breach opening, apply a flow velocity toward the opening. Or simpler: all particles have a tendency to move toward breach based on their x position: the closer to the wall, the stronger the pull toward breach. But need to avoid pushing particles from the other side of tank too much. Actually water flows due to pressure difference; water level decreases uniformly. So we can apply a velocity toward breach that increases as water level is above breach opening. Simpler: if particle.y < waterLevel and particle.y >= breachTop and particle.y <= breachBottom and particle is on the side of the breach wall, push toward breach. But particles need to find the opening. Let's define the breach as a rectangle hole on the wall. Water particles that are close to the wall and within the vertical range will exit.

Implementation: For each water particle in tank state, if it is near the wall (distance < some threshold) and its y is within [breachY1, breachY2], move it toward the wall at flow speed. If it passes the wall, convert to jet particle with initial velocity having outward horizontal component and small upward component (maybe slight upward from water pressure) and gravity.

**Jet physics**:
- Jet particles have position just outside tank, velocity pointing outward and slightly upward or horizontal? Realistic: water exiting horizontally from a hole at the bottom of a tank has high pressure, but as it exits it arcs due to gravity. The breach is below waterline, so water exits with some pressure. We'll give initial velocity outward (horizontal away from tank) and maybe slight upward if breach not at very bottom. But we can do: initial velocity = (sign * sqrt(2*g*h), 0) from Torricelli's law, where h is water depth above center of opening. But we'll simplify: constant initial speed proportional to water pressure = constant * (waterLevel - openingCenter). But we can adjust for visuals.
- Each frame: apply gravity to jet particles, update position.
- When jet particle hits floor, convert to puddle (or remove and increase puddle size).

**Puddle**:
- We can draw a growing puddle region: a polygon filling the floor area where water accumulates. Water particles in puddle state can be drawn as small droplets merging into a pool.

**Fish behavior**:
- Fish swim back and forth horizontally with some vertical wandering.
- If fish is close to breach area and water is flowing, current adds velocity toward breach, can sweep fish out.
- Once fish leaves tank (passes breach), becomes escaped, then falls with gravity and lands on floor, flops around.

**Rocks**:
- Affected by gravity and water drag. If submerged and near current, may be pushed toward breach.
- If they reach breach, they can be pushed out if they fit (size < opening width). Then they fall outside.

**Toy**:
- Floats at water surface. Follows water motion (if water moving, toy moves with flow). Can be carried out.

**Plants**:
- Draw as curved lines from seabed. At each frame, apply bend based on water velocity at that x.

**Glass fragments**:
- When breach occurs, generate many small triangles/polygons from the broken wall section. They initially have some outward velocity, then gravity and rotation, collide with each other? We'll simplify: they fly outward, then fall and land on floor inside tank or outside? Actually glass from the wall would fall into tank or out. But we can have them inside, scatter.

**Water level**:
- The waterline in tank falls because water is lost. We'll compute effective waterLevel = initialWaterLevel - (totalWaterLost / tankArea). But easier: track a waterLevel variable that decreases each frame based on outflow rate. Outflow rate = area of opening * flow speed * density (proportional). So waterLevel decreases proportionally to flow speed * time.

Simplify: waterLevel -= outflowRate * dt; outflowRate = openingArea * flowVelocity; flowVelocity depends on waterHeight above opening center. But for visual, we can just have waterLevel drop at a constant rate or slowly decreasing.

**Rendering**:
- Draw tank: glass walls with transparency
- Draw water: fill tank with blue up to waterLevel, but with varying alpha to show depth? Could also draw water particles as small circles for detail.
- Draw fish, rocks, plants, toy
- Draw breach gap: dark opening
- Draw jet: stream of particles
- Draw puddle: on floor outside tank, growing shape filled with water color
- Draw glass fragments: rotating polygons

**User interaction**:
- Mouse down on tank wall: start crack selection, set startY
- Mouse move while down: update crack endY
- Mouse up: finalize crack vertical line (drawn as red line)
- Breach button: read crack range, validate (within wall, below waterlevel), trigger breach
- Reset button: reload initial state (we can store initial configuration and reset arrays)

Let's implement. I'll create the HTML structure with a canvas and buttons. All CSS and JS inline.

I'll use requestAnimationFrame for the simulation loop.

I'll need to decide tank dimensions relative to canvas. Let's set fixed logical coordinate system: tank from x=100 to 700, y=50 to 550 (height 500). Water initial level at y=400 (so 100 deep from top? Actually water level measured from bottom? Let's define bottom at y=550, top of tank at y=50. Water surface at y=400 means water depth 150 from bottom (550-400=150). Breach will be on right wall at x=700. Opening vertical range maybe y=450 to 500 (so below waterline). That seems fine.

We'll have floor area outside tank: canvas extends to maybe x=100 to 1200, y=0 to 800. Tank left wall at x=100, right wall at x=700, bottom at y=550. Water puddle will accumulate on floor y=550 and spread to right (since breach on right side) and maybe left if wall broken on left.

I'll handle both left and right wall breach? Requirement says "drag a visible crack vertically on one side". So we choose either left or right. I'll allow both sides by checking which wall the user clicks near.

Simplify: crack always on the right wall? But could be either. I'll detect if mouse is within 20px of left or right wall, then start crack. But for simplicity in code I can restrict to right wall only. The requirement says "on one side" so either is fine. I'll implement detection.

Let's start coding.

Plan for JS:

- Classes: Fish, Rock, Plant, Toy, WaterParticle, GlassFragment.
- Arrays: fishes, rocks, plants, toy (single), waterParticles (tank state), jetParticles, puddleParticles?, glassFragments.
- State: waterLevel, isBreached, breachY1, breachY2, breachSide ('right' or 'left'), crackSelection (startY, endY), crackLineVisible.

- Init function: create objects, fill waterParticles (grid or random).
- Update function: if breached, update water outflow, jet, puddle, fish, rocks, etc.
- Draw function: render everything.
- Event listeners: mousedown, mousemove, mouseup on canvas; buttons.

Let's start writing the HTML structure with inline CSS and JS.

We've built the simulation. Now we need to verify: position the crack, trigger a breach, and check that the jet curves downward, waterline falls, objects respond. Also test Reset.

I'll use the browser tool to load the page and then interact with it. Steps:
1. Load index.html
2. Check that initial scene is intact: tank with water, fish, rocks, plants, toy.
3. Drag on right wall to create a crack below waterline.
4. Click Breach.
5. Observe: panel breaking (rectangular hole), water exits in jet that curves downward, waterline falls, fish respond (some swept), toy drifts toward breach, rocks may roll, plants bend.
6. Click Reset and verify scene returns.

Let's do it.

There's a JavaScript error: "left is not defined". I need to fix this. The error likely comes from somewhere in the code where I use `left` as a variable without defining it in some scope. Let me search the code.

Looking at the code, I see `left` used in various places within functions that should define it. For example in `drawTank`:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
```
This looks okay. But I also see in `Fish.update`:
```
if (this.x < tank.x + 20) { this.x = tank.x+20; this.dir = 1; }
```
That's fine.

Wait, maybe the error occurs in the `GlassFragment` update? I see:
```
// Collision with bottom
    if (this.y >= tank.bottomY) {
      this.y = tank.bottomY;
      this.vy = -this.vy * 0.3;
      this.vx *= 0.8;
      this.angVel *= 0.8;
    }
```

That seems okay.

Perhaps the error occurs when updating fish state for left/right wall? Actually in Fish.update, they use `tank.x` and `tank.width`. But what about `left`? Actually in Rock.update:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
```
That is inside the update function, so it should be fine.

The error might be from something else: maybe I used `left` in a loop where I had a variable `left` from another scope? Let's search for standalone `left`. I see in `Fish.update`:
```
if (this.x < tank.x + 20) { this.x = tank.x+20; ... }
```
That's fine.

In `drawWaterParticles`:
```
for (let p of waterParticles) p.draw(ctx);
for (let p of jetParticles) p.draw(ctx);
```
No `left`.

Maybe the error occurs in `drawTank`:
```
const left = tank.x + tank.glassThickness;
...
if (this.x - this.r < left) { this.x = left + this.r; this.vx = -this.vx * 0.5; }
```
Okay.

Wait, I see in the `GlassFragment` class there is no use of `left`.

Maybe the error occurs when processing puddle? In `drawPuddle`, they use `puddleParticles`, but the error says "left is not defined". Could it be from the `update` function when checking water level and computing exit?

Actually, I see in `WaterParticle.update`:
```
const wallX = breachSide === 'right' ? tank.rightWallX : tank.leftWallX;
```
So `rightWallX` and `leftWallX` are properties of `tank`. That should be fine.

Maybe the error is from `Rock.update`:
```
if (this.x - this.r < left) { this.x = left + this.r; this.vx = -this.vx * 0.5; }
```
But `left` is defined within that method just before.

But wait: In `Rock.update`, I have:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
```
I used `left` and `right` later for boundary checks. That's fine.

Maybe the error occurs before `init` is called? But we call `init` before `requestAnimationFrame(loop)`.

I should re-read the console message: "error: left is not defined". The error is likely from a scope where `left` is used without `const`. Could be in the `Fish` class where I use `left`? Actually I see:

```
if (this.state === 'normal') {
...
if (this.x < tank.x + 20) { this.x = tank.x+20; this.dir = 1; }
if (this.x > tank.x+tank.width - 20) { this.x = tank.x+tank.width-20; this.dir = -1; }
if (this.y < tank.y + 10) { this.y = tank.y+10; this.wanderAngle = 0; this.vy = 0; }
if (this.y > waterLevel - 15) { this.y = waterLevel - 15; this.wanderAngle = Math.PI; this.vy = 0; }
}
```
No left there.

Maybe the error occurs in the `GlassFragment` update? No.

What about the `Toy` class? It doesn't use left.

Wait, maybe it's from the `Plant` draw method? They use `x` and `y` but no left.

Let's search for any `left` that is not declared within a function. I see in the global scope: we have `let tank = { x: 100, y: 50, width: 600, height: 500, glassThickness: 8, bottomY: 550, leftWallX: 100, rightWallX: 700 };` So `leftWallX` is defined. Not `left`.

Maybe in the `triggerBreach` or `drawTank` there is a use of `left` that might be confused with a global? Actually in `drawTank`, I define `const left = tank.x + tank.glassThickness;` and then later `const currentWaterLevel = isBreached ? (waterLevel - totalWaterLost*0.1) : waterLevel;` and then use `left`. That seems fine.

Maybe the error occurs when I call `drawWaterParticles`? No.

Maybe it's from the `WaterParticle.update` method: somewhere I used `left`? No.

Actually, I suspect the error is from something like `left` being referenced in a closure where it's not defined. Could be in the `draw` function inside `drawWaterParticles`? But I call methods on particles.

Let's try to run the code in a debug environment mentally. The error appears immediately after reload, according to the console error screenshot? The console said: "error: left is not defined". And there was also a warning about iframe sandbox. That's not important.

The script might have a syntax error that prevented initialization. Possibly the error is from the `GlassFragment` class? I see:
```
this.color = `rgba(200, 230, 255, 0.6)`;
```
That's fine.

Wait: In the `init` function, I set `totalWaterLost = 0;` but I also have a variable `totalWaterLost` used in `update` to compute water level. That's defined globally.

Maybe the error is in the initialization of waterParticles: I use `right-left` inside loop. That should be okay.

Let's search for any occurrence of the word `left` that is not part of a property access (like `leftWallX`). I'll scan:

- In the tank object: leftWallX
- In `drawTank`: `const left = tank.x + tank.glassThickness;`
- In `drawTank` later: `ctx.fillRect(left, waterLevel, right-left, bottom - waterLevel);` That's okay.
- In `drawTank` for crack: `const wallX = crackSelection.side === 'right' ? tank.rightWallX : tank.leftWallX;` No left.
- In `WaterParticle.update`: `const wallX = breachSide === 'right' ? tank.rightWallX : tank.leftWallX;` That's okay.
- In `Fish.update` none.
- In `Rock.update`: `const left = tank.x + tank.glassThickness;` used later.
- In `Rock.update`: `if (this.x - this.r < left) { this.x = left + this.r; this.vx = -this.vx * 0.5; }`
- In `Rock.update`: `if (this.x + this.r > right) { this.x = right - this.r; this.vx = -this.vx * 0.5; }`
- In `Plant` none.
- In `Toy` none.
- In `GlassFragment` none.

All these use `left` as a local variable declared with `const`. So why "left is not defined"?

Maybe the error occurs in the `drawTank` function when `isBreached` is true and we compute `currentWaterLevel`. That is inside `drawTank` and uses `left` from the earlier const.

Wait: In `drawTank`, I have:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
const bottom = tank.bottomY;
...
ctx.fillRect(left, waterLevel, right-left, bottom - waterLevel);
```
But inside the else block for breached, I recompute:
```
const currentWaterLevel = isBreached ? (waterLevel - totalWaterLost*0.1) : waterLevel;
ctx.fillStyle = 'rgba(30, 144, 255, 0.2)';
ctx.fillRect(left, currentWaterLevel, right-left, bottom - currentWaterLevel);
```
That still uses `left` and `right` declared above.

I also see that `drawTank` is called from the main draw loop. So `left` should be defined.

But maybe the error occurs earlier, during initialization? Possibly the error is that `left` is not defined in the global scope? No.

Maybe I inadvertently shadowed a variable? Not.

Maybe the code is failing to parse because of a missing bracket or parentheses causing the scope to be wrong. Let's check for any syntax errors. The code seems well-formed.

The error says "left is not defined" and the console also says "An iframe which has both allow-scripts and allow-same-origin for its sandbox attribute can escape its sandboxing." That's just a warning from the browser about the sandbox, but not fatal.

The error appears right away, before any interaction, so likely during first execution of the script. Possibly the code inside `window.onload` or IIFE had a reference error. Let's test by opening the file in a real browser? I can't, but I can simulate.

Maybe the error is from the `puddleParticles` handling? No.

Alternatively, maybe it's a simple typo: I meant `leftWallX` but wrote `left` somewhere else. Let's double-check all occurrences of the word `left` outside of string literals:

In the code:
- `leftWallX` (tank property)
- `const left = ...` (declared)
- `if (this.x - this.r < left) ...`
- `if (this.x < tank.x + 20) ...`
- `if (this.x < left) ...` in Rock.update
- In Fish.update, no `left` variable.
- In WaterParticle.update: not.
- In `drawTank`: multiple uses.
- In `Rock.update`: uses `left` as const defined.
- In `GlassFragment`: none.

So maybe I have a `left` used in a place where it should be `leftWallX`? Not seeing it.

Maybe the error occurs in the `init` function? In `init`, I have:
```
for (let i=0; i<WATER_FILL_PARTICLES; i++) {
      const x = randomRange(left, right);
      const y = randomRange(waterLevel, bottom - 2);
      waterParticles.push(new WaterParticle(x, y));
    }
```
Here, `left` and `right` are not defined! Indeed, inside `init`, I didn't define `left` and `right` before using them. I used `left` and `right` in the water particle generation but they aren't defined in that scope. That's the error! The similar code in `drawTank` has `const left = tank.x + tank.glassThickness;` but `init` does not have that. So we need to define `left` and `right` inside `init` as well.

Yes, that's the bug. Let's fix it. Also maybe `bottom` is used without definition? In that loop I used `bottom - 2`, but `bottom` is not defined either. I should use `tank.bottomY` or compute bottom as `tank.bottomY`. So `init` has:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
const bottom = tank.bottomY;
```
Then use those variables.

I'll edit the file to fix `init`.

Let me read the file to see the exact content and indentation.

Let me search for the specific part where the error occurs. The error says "left is not defined". I need to find the init function and see where left, right, bottom are referenced without being defined in that scope.

Based on my earlier reading, in the init function I do define left, right, bottom locally. So the error might be somewhere else.

The console error is: "error: left is not defined". This likely refers to a JavaScript ReferenceError where a variable `left` is used before declaration. I should look for places where I use variables like left, right, bottom without defining them.

Let me search systematically.

Looking at the code, many methods reference `tank` properties and also compute left/right on the fly. I also have a function `drawTank` that uses:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
```
That's fine.

In update methods for various classes, they often compute left/right boundaries. For example, in Rock.update:
```
const left = tank.x + tank.glassThickness;
const right = tank.x + tank.width - tank.glassThickness;
```
That's inside a method and should work because `tank` is a global variable (in closure). So that's okay.

In Fish.update, I have:
```
if (this.x < tank.x + 20) ...
```
No left.

In Plant, no left.

In WaterParticle.update, I have:
```
const wallX = breachSide === 'right' ? tank.rightWallX : tank.leftWallX;
```
That's fine.

Maybe the error is from something else: I see in the console also a warning about iframe sandbox.

Let me re-run and capture full console output.

The error "left is not defined" is happening. Let me find the exact location where `left` is used without definition. It's likely in the `init` function or in other places like `drawTank` or update. I'll search for the exact problematic line by checking the code around the `init` function. I need to read more of the file to locate the issue.