Aquarium breach · claude-sonnet-5.5

I'm sketching out the 2D side-view layout for the simulation—placing the room, floor, walls, and a tank on a stand, with a draggable crack point on the tank's side panel where the water jet will exit.

Now I'm working out the physics: using Torricelli's law for exit velocity based on depth above the crack, and modeling the drain rate so water level visibly drops over 15-30 seconds. I'm deciding the hole should grow over time once the panel bursts, expanding from the crack point both up and down (clamped to the tank bottom), with flow calculated from the hole's area and depth-based velocity.

For the escaping water, I'm planning to spawn particles at the hole with Torricelli-derived velocity, let them fall ballistically under gravity, and accumulate into a puddle on the floor. The puddle uses a simple height-field across the floor width with volume conservation, spreading between the walls as particles land and add height to local cells.

Since the raw tank area is too large for a realistic puddle depth given the floor-to-tank clearance, I'm scaling the puddle volume down by about a quarter to simulate spreading in the depth dimension, keeping max puddle depth to a reasonable ~25px, and treating the tank stand legs as thin enough to ignore for puddle blocking.

Now I'm planning the scene objects: three fish, a couple rocks, two rooted plants that sway with current (possibly uprooting under strong flow via a breakable anchor spring), and a low-density rubber duck floating at the surface. For physics, I'm setting up rigid circle bodies with position, velocity, radius, density, and angle, applying gravity plus buoyancy based on submerged fraction and drag relative to the water's flow velocity.

I'm working out the flow field inside the tank, directing water toward the drain hole with strength that falls off with distance, while objects airborne outside the tank experience just gravity and light air drag until they land in the puddle below, which has its own water level and buoyancy. I'm treating tank water and puddle water as separate regions, each computing a submerged fraction for collision and buoyancy purposes, and handling wall collisions for the tank while it's intact.

I'm now defining what happens once the tank wall bursts: the opening grows to about 130px so rocks (14-20px radius) can pass through without jamming, and I'm splitting the right wall into segments above and below the hole for circle-vs-wall collision checks, treating the tank top as always open.

For the fish, I want them actively swimming against the outflow current -- applying thrust away from the hole based on limited stamina, orienting toward their velocity, and once swept through they transition to flopping/hopping physics on the floor outside the tank with gravity only.

I'm also designing the stand as a solid table block spanning the tank's width, letting jets fall freely past its edge to the floor, while puddles spread across the floor in front of the table legs. For the glass burst, I'm spawning a batch of angular shard polygons from the crack region with outward velocity plus jet influence, set up to collide with the floor and walls.

Fragments need circular collision approximations and drag/buoyancy physics so they sink slowly once submerged in the puddle. For the panel itself, I'm drawing the remaining glass segments around the hole with a jagged crack line, letting the user drag a handle to set crack height before triggering failure, which then propagates visually over about 1.5 seconds with small leaking drips that intensify before the burst—plus a reset button and readouts for waterline, flow rate, crack height, and jet speed, with a hint that lower cracks produce stronger jets.

Now I'm working out the mechanics more precisely: the crack handle is only draggable while idle, clamped within the tank bounds, and the resulting hole grows from a small gap to a larger opening during the burst while staying clipped by the tank edges and waterline. I need to check how crack position interacts with water depth—placing the crack higher means a shallower depth above it and thus a weaker jet, which matches the intended behavior.

I'm calculating drain flow rates using Torricelli's law with a discharge coefficient and gravity constant, comparing jet velocities at different crack depths, then estimating how fast the hole would drain a chunk of the tank's water volume given the computed flux—roughly a few seconds to empty a meaningful portion.

For the visible jet, I'm planning to spawn particles from the hole based on Toricelli velocity at each wetted height, scaling particle count to match the flow rate while capping the total for performance, with each particle carrying its own area to render as a dense, merging blue stream.

Particles that hit the tank wall or land back down get absorbed into the puddle, maybe with a small splash chance for a couple of droplets to add visual interest. I also want the water inside the tank to have a gently wobbling surface, and near the hole I'm thinking of a flow field that pulls water toward the exit with velocity falling off with distance, so the draining motion feels physically grounded.

Now I'm working out how strong that current should be so a fish nearby would actually feel resistance - testing some exponent/falloff values for how fast the current moves at different distances from the hole, and considering a drag-based model where the fish's relative velocity to the current determines how hard it has to swim.

For rocks, reduced effective weight from buoyancy plus floor friction should let strong currents near the hole nudge some loose rocks toward it, so I'm giving them lower density and adding Coulomb-style friction impulses on floor contact to resist sliding unless pushed hard enough.  I'll place a sliding rock near the hole, then add fish with slight positive buoyancy and thrust, plus anchored plants that could uproot under strong enough flow.

Plants will anchor at the base and bend like fronds based on local flow, uprooting into a drifting body once flow at the base crosses a threshold for long enough — I'll put three plants, with the one near the hole uprooting. I'm also adding a floating rubber duck using a submerged-fraction buoyancy approximation tied to the waterline.

For the hole mechanic, the duck should only pass through once the waterline drops enough that the wet portion of the hole is tall enough to fit its radius, so I need to account for the hole getting clipped by the waterline when it sits high.

Each fish has a home position and wanders until the current near the hole gets strong enough to pull it, triggering it to thrust away with stamina draining as it fights the pull; once stamina runs out the thrust weakens and it gets swept toward the drain, with tail-beating speed reflecting the struggle. Fish on the floor occasionally flop with small random jumps, and I'm treating fish as circles for simple pairwise elastic collisions with each other and allowing airborne fish in the jet to follow near-ballistic trajectories with minimal drag.

For the buoyancy transition, I want objects to lose water support smoothly as they cross out of the tank rather than having it drop off abruptly at x=560 — so I'm fading the buoyancy force over a short range near the exit so it tapers off instead of cutting instantly, approximating how the jet stream would carry them out at its flow velocity.

For the puddle itself, I'm modeling it as shallow water on a grid with height and velocity arrays per cell, updating velocity from the pressure gradient and height from the flux between neighboring cells using a simple pipe-flow approximation for stability.

I'm checking CFL stability for the wave speed given gravity and depth, picking a small substep so the simulation stays stable, then updating heights from flux divergence while clamping to avoid negative depth. I also want the puddle to render correctly at reduced scale and account for solid objects like the table and tank sitting above it.

When particles land in the puddle, I'll add their volume into the local height field and spread it to neighboring cells for a smoother splash that also kicks off ripples, treating the impact point by checking where the particle's y position crosses the puddle surface. For visual polish I'm adding colored translucent particles for the water jet stream, plus small weep drips at the crack before it fully bursts.

I'm now defining the glass failure state machine: starting idle while dragging, then cracking (growing crack lines and shake effects over about 2.2 seconds, with tiny leaks beginning around 0.8s), then a burst phase where the hole rapidly expands to full size using an exponential growth curve, with the hole height transitioning from a thin crack leak to a 48px final opening.

I'm working out hole clamping against the tank's inner bottom edge so cracks near the bottom drain fully while cracks higher up only partially drain, creating a visible contrast in jet strength and water level depending on crack height, and restricting the crack's vertical range to roughly 250-480px. For the burst, I'm spawning about 16 shard polygons within the hole region as triangles and quads with varying sizes and outward velocities.

For physics, I'm applying gravity, water drag that's much stronger once shards are submerged, partial buoyancy since the glass density is roughly 2.5x water, and floor collisions where I find the deepest penetrating vertex, bounce with some energy loss and friction, and approximate rotational response from the impact.

I'm handling collisions against the room walls and the tank's inner surfaces too, since shards can land inside the water and bounce off the tank bottom or side wall, each with its own damping. Resting behavior damps velocity and spin to zero once motion gets small enough. I also still need to draw the static broken glass panel with jagged, randomized zigzag edges around the hole.

Now I'm figuring out how to render the panel's jagged edges and add a sand layer at the tank's floor, treating it as the resting ground for fallen objects separate from the glass boundary itself.

Clamping the hole's bottom edge to sit at the sand level, with water depth calculated from the interior dimensions, then setting up the room's walls, wallpaper, and floor with a canvas sized to scale properly in the viewport.

Mapping out the tank geometry further: walls and panel positions set interior width around 358px, with a hole for jets to spawn through. I'm calculating jet trajectories using projectile motion so water droplets land believably on the floor, and ensuring puddle waves reflect correctly off the room's boundaries.

Now I'm figuring out fish rendering: body shape, tail wagging, eye placement, and color variation, with orientation handled by smoothing the heading angle and mirroring the sprite when moving left so the fish always looks natural while swimming or flopping in air.

I'm also sketching simpler shapes for rocks as polygon blobs, plants as fronds, and the duck as a circle with beak and eye, plus mass calculations and body collision handling, then working out per-body physics each substep -- sampling water depth fractions for both the tank and puddle so buoyancy and submersion respond correctly near edges and holes.

Now I'm combining those submersion fractions with puddle flow velocities to push bodies, and setting up the core force equations: gravity pulling down, buoyancy scaled by submersion fraction, and drag resisting relative motion between body and fluid velocity.

I'm adding small damping and clamping the per-step acceleration factor to prevent overshoot, checking the duck and fish cases numerically to confirm stability. For fish, since their buoyancy pulls them toward slightly negative, I'm sketching thrust logic that lets them wander toward a target depth with clamped acceleration.

Now I'm working out panic behavior: when flow speed near the drain exceeds a threshold, fish flee away from the hole with thrust scaled by a stamina value that depletes over a few seconds, so nearby fish get swept quickly while distant ones resist briefly before stamina runs out. I also want fish to stay above the tank floor, so if the water level drops below a fish's body it should lose buoyancy, fall under gravity, and flop on the ground like a beached fish.

For the drain flow strength, I'm computing the exit velocity from the effective wet height above the hole (using the hole's wetted center relative to water level and a Torricelli-style formula), then setting a flow target point near the hole so the field amplitude scales naturally with how much of the hole is submerged and open.

For d2 and d1 near the water level, q comes out small for a thin crack, so I'm sanity checking the drain rate feels right by plugging in a sample depth and width to see the flow speed it implies.

The math shows the drain rate diverges as depth approaches zero, meaning the physically correct model would take infinite time to fully empty—so I'll add a minimum flow floor near the bottom to keep the animation finite and visually complete.

For particle spawning at the hole, I'm setting exit speed from Torricelli's law scaled by a factor, and accumulating fractional particle counts per frame based on flow rate so spawning stays smooth rather than jumpy, with spawn positions weighted along the wetted hole range.

I'll cap particle count around 4000 for performance, rendering them with normal alpha blending. For the puddle itself, I'll draw it as a polygon tracing the water surface height across the floor, filled blue with a white highlight line along the top edge.

For the tank, I'm rendering the glass panels with light bluish strokes and highlights, a black silicone rim at top, and the water with a gradient plus a rippling sine-wave surface line that grows more pronounced as drain time approaches. I'll add a handful of simple rising bubbles for texture rather than a full particle system.

For the crack itself, I'm drawing a branching polyline from the crack origin point, growing in length as the break progresses, rendered in white over the panel.

I'm rethinking how the crack reads in a side-view tank: since the right wall would normally be seen edge-on, I'll widen that panel visually into a thicker glass cross-section so the zigzagging crack lines can spread across its thickness and stretch up and down along it in a stylized way, with a small drag handle marker to indicate interactivity.

I also want HUD elements showing crack height, predicted jet speed, water level, flow rate, and state, plus HTML buttons for triggering the failure and resetting, along with a speed control slider.

I'm setting up pointer dragging so users can grab the crack handle on the panel to adjust its vertical position, using pointer events with touch support enabled.

Now I'm working out collision geometry, treating the tank walls as rectangular slabs so circles bouncing around can collide against them properly.

I'm separating the tank into top and bottom wall segments around the hole, and defining the ground/table surface as its own rectangle, while deciding to skip collision for the thin table legs so objects can pass through them.

For the collision logic itself, I'm planning a generic circle-rectangle routine that finds the closest point on the rect, pushes the circle out if it's overlapping, and applies restitution and friction on impact. The simulation loop order is forces, then integration, then rect collisions, then floor/wall checks, then body-body collisions, with friction handled as an impulse inside the rect collision step.

For effective gravity with buoyancy, the normal velocity per step naturally works out fine. For rotation, I'll give rocks rolling behavior tied to ground contact—spinning based on horizontal velocity while in contact, otherwise preserving angular velocity in the air, tracked via a contact flag. For beached fish, I'll add periodic flopping behavior when they're out of water and in contact with ground.

For the escaping fish, I want the swimming animation to look like they're struggling against the current—so the sprite's heading follows its thrust direction rather than its actual velocity when it's fighting the flow, making it visually read as swimming upstream even as it gets swept along.

Now I'm writing the HTML document structure with the title and base dark styling for the aquarium page...

I'm defining the hole growth logic through crack and burst phases, where the opening expands asymmetrically around the crack point, and setting up the step function to transition from cracking into the burst state with shard spawning and screen shake.

Now I'm computing water flow through the hole using an orifice equation based on how much of the hole is submerged below the waterline, calculating wetted height and using a depth-based discharge formula to determine outflow volume.

Let me enforce a minimum drain rate instead, clamping to the floor once the tank's nearly empty so it feels continuous rather than snapping. For particle spawning, I'm computing each droplet's position and velocity based on the waterline height, giving them a horizontal burst speed from gravity plus slight random vertical drift.

Now I'm handling particle physics and collision: applying gravity, updating position, and checking for landing on the puddle surface where droplets merge into puddle cells, occasionally spawning smaller splash droplets, and bouncing off tank walls. Then I'm setting up the puddle simulation grid across the floor width and computing fluid flow between adjacent cells based on height differences.

I also need to cap the flux so a cell can't drain more water than it has, then apply the update to neighboring heights with reflective boundaries at the walls. For stability I'm checking the CFL condition against the wave speed from gravity and max depth, which means I need a small enough timestep, so I'll substep accordingly.

Puddles on the floor should ripple and reflect off the room walls, and when the flow near a boundary gets strong enough I want to spawn a few splash droplets there for visual flair -- keeping that effect subtle. I'm also noting that the tank's waterline draining is a separate concern from the floor puddle simulation.

Now I'm defining a helper function to create body objects for fish and rocks, setting up three fish with slightly different radii and a buoyancy density around 1.02, and four rocks with higher density placed at specific positions including one near the hole in the floor.

I'm refining the rock placements and densities so smaller rocks near the hole are lighter and more likely to slide when flow is strong, while larger rocks further away stay anchored by higher density. I'm also setting up rooted plants that stay fixed at their base but bend with the flow, becoming uprooted if the local flow speed exceeds a threshold for long enough -- placing one plant near the hole so it's the first to get swept away when the flow picks up.

Setting duck radius at 45, then working out fish stamina mechanics: drain rate scales with nearby flow intensity, stamina regenerates when no current is present, and thrust power scales down as stamina depletes, with drag force depending on fish density and radius.

Balancing drag against thrust gives an equilibrium relative speed around 88 px/s, meaning the fish can make headway against gentler currents but gets swept along at a reduced rate once the current exceeds that threshold, creating a nice struggle dynamic at moderate distances. I'm also tuning the flow field falloff formula with distance from the vortex.

As the fish's stamina depletes its thrust weakens, which widens the radius where it gets dragged. Once it reaches the hole it should just get swept through and exit, with the flow amplitude near the hole center dominating fish speed, and I still need similar drag tuning for rocky ground terrain with its own friction coefficient and radius.

Working through the threshold where rocks start sliding based on relative velocity against gravity-scaled friction for different rock sizes — smaller rocks slide at lower speeds, larger rocks need faster flow to budge. Flow field only applies where it's active, and I should add a gentle buoyancy fade. For collisions, I'm setting up a pairwise loop between bodies using circles and mass, while excluding rooted plants from collision since they're fixed in place.

Now I'm sketching the shard physics: each shard has position, velocity, angle, local points, and density, with water drag and reduced gravity when submerged, plus a pull toward the ambient flow velocity so shards gradually match the current rather than instantly snapping to it.

For ground contact, I'm working out a groundAt(x) helper so shards resting inside the tank settle at the tank floor while those outside the tank (past the table edge) fall to the room floor, handling the messy boundary near the table panel and hole where shards spawn.

For the collision response itself, I'm finding whichever vertex penetrates deepest, pushing it back out, and reflecting its velocity with some restitution depending on impact speed. Then I'm converting that impact into a torque so hits off-center make the shard spin realistically, working through the sign convention carefully since canvas y is flipped, plus adding velocity damping to simulate friction.

Now I'm thinking about how shards settle at rest -- damping angular velocity exponentially when motion slows down so they stop wobbling, and applying similar wall collisions to each vertex. I'm also sketching out the initial setup for the shard fragments: around 18 pieces with varying sizes, positions spread near the crack point, and outward velocities derived from the impact direction.

For rendering, I'm picturing the shards as translucent light-blue polygons with white outlines, and the broken glass panel edges drawn jagged using randomized offset arrays rather than straight lines to look more realistic.

I'm also planning the water fill to pass through the broken hole so it's visible from outside, plus setting up a layered draw order: room background, table, tank, plants, then a semi-transparent water layer, objects, a front glass overlay with highlights, and finally the water surface line on top—with objects getting a second tinted water overlay so they read as submerged.

I'm figuring out the HUD readouts for water level percentage, flow rate, and jet speed, deciding to use a consistent pixel-to-meter scale (roughly 92px = 1m based on gravity) so the Torricelli velocity formula displays in sensible real-world units.

I'll also show a predicted jet speed label while dragging, based on the height difference between the crack and water line, then set up the reset logic and start writing the flow calculation code.

Writing flow field logic...

Still refining water physics...

Working out the equilibrium for a partially submerged duck confirms f=0.45 feels right, and I bump up linear drag so bobbing settles rather than oscillating forever. For fish behavior, I'm writing logic where fast-moving fish are flagged as "struggling" and wander toward randomized target points within the tank bounds, refreshing their target every few seconds.

Still writing fish AI...

Still working out collision geometry...

Working out collision response...

For fish friction I'll use mu=0.3. For rooted plants, I'm tracking an uproot timer based on flow force exceeding a threshold, transitioning them to free-floating once uprooted with velocity from the flow; otherwise they sway and bend their fronds toward the current while standing rooted at ground level.

Now I'm handling body-body collisions with simple mass-based impulse response, skipping rooted plants, then drawing each body type -- fish get an elliptical body with a flapping tail triangle whose angle depends on speed or struggle state, plus an eye and dorsal fin, while rocks are drawn as irregular polygons.

For ducks, I'm drawing a yellow circular body with a smaller head, orange beak, and eye. For plants, rooted ones draw blades curving upward from the ground with bend and sway offsets, while unrooted plants fan their blades outward trailing opposite to their velocity direction.

I'm figuring out initial fish positions and sizes near a hole, placing orange, blue-ish, and striped fish at different depths, and mapping the crack's vertical position to water level to determine jet depth and resulting ejection speed.

The hole dimensions respond to crack height with a ramp-up effect, and I'm sketching the water surface as a sinusoidal wave that gets disturbed near the hole, with a localized dip tied to exit velocity.

I'm setting up the fixed-timestep physics loop using substeps for stability, then handling pointer events so users can drag to set the crack position, including a hover cursor and a pulsing handle indicator when idle.

For the crack visual itself, I'm precomputing seven jagged branch polylines with randomized angles and lengths from a fixed origin, then scaling their endpoints by progress so the crack appears to grow outward as it worsens, clipped within the panel bounds.

Widening the crack panel to 20px and adding a bright impact star at the origin for visual punch. I'll batch all particle draws into a single fill call using one path with multiple arcs for efficiency, skip extra jet highlights, and move on to finalizing the file.

Checking the water height measurement of 168cm against the scale—using gravity to derive a pixel-to-meter ratio of roughly 91.7 px/m, so a 290px tank corresponds to about 3 meters, which seems reasonably sized for a large tank.

This works, though the droplets look a bit sparse during the seep stage -- that's acceptable for now. I should check the burst stage next.