FractalGarden

Here is the p5.js sketch that creates a soil simulation with nutrient wells, diffusion, and subtle Perlin noise drift, visualized as a grid of colored cells.

The bottom 150 pixels of the canvas will represent the soil. Each cell in this soil grid has a nutrient value (0-100), mapped to colors from dark brown/gray (depleted) to deep amber/red (rich). The simulation includes nutrient wells that regenerate nutrients in their radius, a slow diffusion process where cells share nutrients with neighbors, and a subtle perlin noise effect to make the soil "breathe" dynamically.

---

### `sketch.js`

```js
// ============================================================
// This sketch simulates soil nutrients with wells, diffusion, and noise.
// ============================================================

// --- Global Variables ---
// These variables control the size, appearance, and behavior of the soil simulation.

let cellSize = 10; // The size of each square cell in the soil grid (in pixels).
let soilHeight = 150; // The height of the soil area from the bottom of the canvas (in pixels).
let cols, rows; // Variables to store the number of columns and rows in the soil grid.
let soilGrid = []; // A 2D array to store the nutrient value (0-100) for each cell.
let wells = []; // An array to store the properties of nutrient wells.
let perlinNoiseOffset = 0; // A variable to drift the Perlin noise, creating subtle animation.

let numWells; // The number of nutrient wells (will be randomized between 5 and 8).
let diffusionRate = 0.05; // How quickly nutrients spread to neighboring cells (0 to 1).
let regenerationRate = 0.5; // How quickly wells regenerate nutrients in their vicinity.
let wellRadiusCells = 5; // The radius of influence for each well, measured in cells.

let noiseScale = 0.02; // Determines the "zoom" level or granularity of the Perlin noise.
let noiseAmplitude = 10; // The maximum amount (in nutrient points) that Perlin noise can affect a cell.


// --- setup() function ---
// This function is called once when the sketch starts.
function setup() {
createCanvas(windowWidth, windowHeight); // Create a canvas that fills the entire browser window.
noStroke(); // Disable drawing outlines around shapes for a smoother look.
colorMode(HSB, 360, 100, 100); // Set color mode to HSB (Hue, Saturation, Brightness)
// with ranges 0-360 for Hue and 0-100 for Saturation/Brightness.

// Calculate the number of columns and rows for the soil grid based on canvas size and cell size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Initialize the soil grid with starting nutrient values and create the nutrient wells.
initSoilGridAndWells();
}


// --- draw() function ---
// This function is called repeatedly, typically 60 times per second.
// All animations and updates happen here.
function draw() {
background(0, 0, 5); // Draw a very dark gray background, clearing the canvas each frame.

// --- Nutrient Well Regeneration ---
// Wells slowly regenerate nutrients within their radius.
for (let well of wells) {
let wellCol = floor(well.x / cellSize); // Convert well's pixel x-position to grid column index.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
// Calculate the distance between the current cell and the well's center in cell units.
let distance = dist(c, r, wellCol, well.y);
if (distance <= wellRadiusCells) {
// Regenerate nutrients, with a stronger effect closer to the well.
let regenerationAmount = map(distance, 0, wellRadiusCells, regenerationRate, 0);
soilGrid[r][c] = constrain(soilGrid[r][c] + regenerationAmount, 0, 100);
}
}
}
}

// --- Perlin Noise Drift and Nutrient Diffusion ---
// Create a temporary grid to store new nutrient values. This is crucial to ensure
// all calculations for a given frame are based on the state at the beginning of that frame,
// preventing artifacts from using updated values within the same iteration.
let newSoilGrid = [];
for (let r = 0; r < rows; r++) {
newSoilGrid[r] = []; // Initialize a new row for the temporary grid.
for (let c = 0; c < cols; c++) {

// 1. Perlin Noise Drift: Add subtle, organic variation to nutrient values.
let noiseValue = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
let noiseEffect = (noiseValue - 0.5) * noiseAmplitude; // Scale noise to a range like -10 to +10.

let currentNutrient = soilGrid[r][c]; // Get the current cell's nutrient value.
let nutrientAfterNoise = constrain(currentNutrient + noiseEffect, 0, 100); // Apply noise effect and clamp.

// 2. Nutrient Diffusion: Cells share nutrients with their immediate neighbors.
let sumNeighbors = 0;
let numNeighbors = 0;

// Define offsets for the four direct neighbors (up, down, left, right).
let neighbors = [[-1, 0], [1, 0], [0, -1], [0, 1]];

for (let neighbor of neighbors) {
let nr = r + neighbor[0]; // Neighbor row index.
let nc = c + neighbor[1]; // Neighbor column index.

// Check if the neighbor is within the grid boundaries.
if (nr >= 0 && nr < rows && nc >= 0 && nc < cols) {
sumNeighbors += soilGrid[nr][nc]; // Add neighbor's nutrient value (from the original grid).
numNeighbors++;
}
}

let neighborAverage = sumNeighbors / numNeighbors; // Calculate the average nutrient of valid neighbors.
// Apply diffusion: Move the cell's nutrient value slightly towards the average of its neighbors.
let nutrientAfterDiffusion = nutrientAfterNoise + diffusionRate * (neighborAverage - nutrientAfterNoise);

// Store the final calculated nutrient value (after noise and diffusion) in the temporary grid.
newSoilGrid[r][c] = constrain(nutrientAfterDiffusion, 0, 100);
}
}

// Update the main soil grid with the new values calculated in the temporary grid.
soilGrid = newSoilGrid;

// Increment the Perlin noise offset to create a slow, continuous drift effect.
perlinNoiseOffset += 0.005;

// --- Visualize Soil ---
// Draw each cell of the soil grid as a colored rectangle.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
let nutrient = soilGrid[r][c]; // Get the nutrient value for the current cell.
let x = c * cellSize; // Calculate the x-coordinate of the cell.
// Calculate the y-coordinate, positioning cells from the bottom up within the soil area.
let y = height - soilHeight + r * cellSize;

// Map the nutrient value (0-100) to an HSB color:
// - Hue: Transitions from a brownish/amber (around 40) to a more reddish (around 15).
// - Saturation: Transitions from a dull gray (around 10) to a vivid color (around 90).
// - Brightness: Transitions from dark (around 20) to bright (around 90).
let h = map(nutrient, 0, 100, 40, 15);
let s = map(nutrient, 0, 100, 10, 90);
let b = map(nutrient, 0, 100, 20, 90);

fill(h, s, b); // Set the fill color.
rect(x, y, cellSize, cellSize); // Draw the cell as a rectangle.
}
}
}


// --- initSoilGridAndWells() function ---
// This helper function initializes or reinitializes the soil grid and nutrient wells.
// It's called in setup() and windowResized().
function initSoilGridAndWells() {
soilGrid = []; // Clear the existing soil grid.
wells = []; // Clear the existing wells.

// Initialize the soil grid with random initial nutrient values,
// enhanced by Perlin noise for a more natural starting distribution.
for (let r = 0; r < rows; r++) {
soilGrid[r] = []; // Create a new row.
for (let c = 0; c < cols; c++) {
let initialNutrient = random(20, 80); // Start with values between 20 and 80.
let noiseVal = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
// Add a scaled Perlin noise effect (more pronounced than the drift in draw()).
initialNutrient += (noiseVal - 0.5) * noiseAmplitude * 2;
soilGrid[r][c] = constrain(initialNutrient, 0, 100); // Clamp values to 0-100.
}
}

// Initialize nutrient wells with random x-positions.
numWells = floor(random(5, 9)); // Randomly choose between 5 and 8 wells.
for (let i = 0; i < numWells; i++) {
let x = random(width); // Random x-position across the canvas width.
let y = rows / 2; // Wells are conceptually at the "surface" of the soil grid (middle row).
wells.push({ x: x, y: y, radius: wellRadiusCells }); // Add well to the array.
}
}


// --- windowResized() function ---
// This function is called automatically whenever the browser window is resized.
function windowResized() {
resizeCanvas(windowWidth, windowHeight); // Resize the canvas to match the new window dimensions.

// Recalculate cols and rows for the soil area based on the new canvas size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Reinitialize the soil grid and wells to adapt to the new canvas dimensions.
initSoilGridAndWells();
}
```

---

### `index.html`

```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Soil Nutrient Simulation</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/p5@1.11.3/lib/p5.min.js"></script>
<script src="sketch.js"></script>
</body>
</html>
```

---

### `style.css`

```css
html, body {
margin: 0;
padding: 0;
overflow: hidden; /* Prevent scrollbars if canvas slightly exceeds window size */
}

canvas {
display: block; /* Remove extra space below the canvas */
}
```

I'm sorry to hear that nothing is showing on the screen. This usually indicates one of a few things:

1. **A JavaScript error:** This is the most common reason a p5.js sketch won't run. An error in your code (or even in the library loading) can stop `setup()` from completing or `draw()` from being called.
2. **Incorrect file paths or CDN links:** If `p5.min.js` or `sketch.js` aren't loaded correctly, the p5.js environment won't be set up.
3. **Canvas visibility issues:** Although your `style.css` is minimal and generally good, sometimes other browser extensions or device-specific settings can interfere.

**The very first thing we need to do is check the browser's developer console for errors.**

On a mobile phone:
* **Android (Chrome):** Connect your phone to a computer via USB. On your computer, open Chrome, go to `chrome://inspect/#devices`, find your phone and the open tab, and click "inspect". This will open the developer tools on your computer.
* **iOS (Safari):** On your computer, open Safari, go to `Safari > Preferences > Advanced`, and check "Show Develop menu in menu bar". Then, connect your iPhone/iPad to the computer, open Safari on both devices, and on your computer, select `Develop > [Your Device Name] > [Your Sketch Tab]`.

Please check the console and let me know if you see any errors. The error message will give us a strong clue as to what's going wrong.

In the meantime, I've reviewed the code again. It looks logically sound and should, in principle, create and draw the canvas. I will provide the complete code again, ensuring all links and syntax are correct for p5.js v1.11.3.

---

### `sketch.js`

```js
// ============================================================
// This sketch simulates soil nutrients with wells, diffusion, and noise.
// ============================================================

// --- Global Variables ---
// These variables control the size, appearance, and behavior of the soil simulation.

let cellSize = 10; // The size of each square cell in the soil grid (in pixels).
let soilHeight = 150; // The height of the soil area from the bottom of the canvas (in pixels).
let cols, rows; // Variables to store the number of columns and rows in the soil grid.
let soilGrid = []; // A 2D array to store the nutrient value (0-100) for each cell.
let wells = []; // An array to store the properties of nutrient wells.
let perlinNoiseOffset = 0; // A variable to drift the Perlin noise, creating subtle animation.

let numWells; // The number of nutrient wells (will be randomized between 5 and 8).
let diffusionRate = 0.05; // How quickly nutrients spread to neighboring cells (0 to 1).
let regenerationRate = 0.5; // How quickly wells regenerate nutrients in their vicinity.
let wellRadiusCells = 5; // The radius of influence for each well, measured in cells.

let noiseScale = 0.02; // Determines the "zoom" level or granularity of the Perlin noise.
let noiseAmplitude = 10; // The maximum amount (in nutrient points) that Perlin noise can affect a cell.


// --- setup() function ---
// This function is called once when the sketch starts.
function setup() {
createCanvas(windowWidth, windowHeight); // Create a canvas that fills the entire browser window.
noStroke(); // Disable drawing outlines around shapes for a smoother look.
colorMode(HSB, 360, 100, 100); // Set color mode to HSB (Hue, Saturation, Brightness)
// with ranges 0-360 for Hue and 0-100 for Saturation/Brightness.

// Calculate the number of columns and rows for the soil grid based on canvas size and cell size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Initialize the soil grid with starting nutrient values and create the nutrient wells.
initSoilGridAndWells();
}


// --- draw() function ---
// This function is called repeatedly, typically 60 times per second.
// All animations and updates happen here.
function draw() {
background(0, 0, 5); // Draw a very dark gray background, clearing the canvas each frame.

// --- Nutrient Well Regeneration ---
// Wells slowly regenerate nutrients within their radius.
for (let well of wells) {
let wellCol = floor(well.x / cellSize); // Convert well's pixel x-position to grid column index.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
// Calculate the distance between the current cell and the well's center in cell units.
let distance = dist(c, r, wellCol, well.y);
if (distance <= wellRadiusCells) {
// Regenerate nutrients, with a stronger effect closer to the well.
let regenerationAmount = map(distance, 0, wellRadiusCells, regenerationRate, 0);
soilGrid[r][c] = constrain(soilGrid[r][c] + regenerationAmount, 0, 100);
}
}
}
}

// --- Perlin Noise Drift and Nutrient Diffusion ---
// Create a temporary grid to store new nutrient values. This is crucial to ensure
// all calculations for a given frame are based on the state at the beginning of that frame,
// preventing artifacts from using updated values within the same iteration.
let newSoilGrid = [];
for (let r = 0; r < rows; r++) {
newSoilGrid[r] = []; // Initialize a new row for the temporary grid.
for (let c = 0; c < cols; c++) {

// 1. Perlin Noise Drift: Add subtle, organic variation to nutrient values.
let noiseValue = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
let noiseEffect = (noiseValue - 0.5) * noiseAmplitude; // Scale noise to a range like -10 to +10.

let currentNutrient = soilGrid[r][c]; // Get the current cell's nutrient value.
let nutrientAfterNoise = constrain(currentNutrient + noiseEffect, 0, 100); // Apply noise effect and clamp.

// 2. Nutrient Diffusion: Cells share nutrients with their immediate neighbors.
let sumNeighbors = 0;
let numNeighbors = 0;

// Define offsets for the four direct neighbors (up, down, left, right).
let neighbors = [[-1, 0], [1, 0], [0, -1], [0, 1]];

for (let neighbor of neighbors) {
let nr = r + neighbor[0]; // Neighbor row index.
let nc = c + neighbor[1]; // Neighbor column index.

// Check if the neighbor is within the grid boundaries.
if (nr >= 0 && nr < rows && nc >= 0 && nc < cols) {
sumNeighbors += soilGrid[nr][nc]; // Add neighbor's nutrient value (from the original grid).
numNeighbors++;
}
}

let neighborAverage = sumNeighbors / numNeighbors; // Calculate the average nutrient of valid neighbors.
// Apply diffusion: Move the cell's nutrient value slightly towards the average of its neighbors.
let nutrientAfterDiffusion = nutrientAfterNoise + diffusionRate * (neighborAverage - nutrientAfterNoise);

// Store the final calculated nutrient value (after noise and diffusion) in the temporary grid.
newSoilGrid[r][c] = constrain(nutrientAfterDiffusion, 0, 100);
}
}

// Update the main soil grid with the new values calculated in the temporary grid.
soilGrid = newSoilGrid;

// Increment the Perlin noise offset to create a slow, continuous drift effect.
perlinNoiseOffset += 0.005;

// --- Visualize Soil ---
// Draw each cell of the soil grid as a colored rectangle.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
let nutrient = soilGrid[r][c]; // Get the nutrient value for the current cell.
let x = c * cellSize; // Calculate the x-coordinate of the cell.
// Calculate the y-coordinate, positioning cells from the bottom up within the soil area.
let y = height - soilHeight + r * cellSize;

// Map the nutrient value (0-100) to an HSB color:
// - Hue: Transitions from a brownish/amber (around 40) to a more reddish (around 15).
// - Saturation: Transitions from a dull gray (around 10) to a vivid color (around 90).
// - Brightness: Transitions from dark (around 20) to bright (around 90).
let h = map(nutrient, 0, 100, 40, 15);
let s = map(nutrient, 0, 100, 10, 90);
let b = map(nutrient, 0, 100, 20, 90);

fill(h, s, b); // Set the fill color.
rect(x, y, cellSize, cellSize); // Draw the cell as a rectangle.
}
}
}


// --- initSoilGridAndWells() function ---
// This helper function initializes or reinitializes the soil grid and nutrient wells.
// It's called in setup() and windowResized().
function initSoilGridAndWells() {
soilGrid = []; // Clear the existing soil grid.
wells = []; // Clear the existing wells.

// Initialize the soil grid with random initial nutrient values,
// enhanced by Perlin noise for a more natural starting distribution.
for (let r = 0; r < rows; r++) {
soilGrid[r] = []; // Create a new row.
for (let c = 0; c < cols; c++) {
let initialNutrient = random(20, 80); // Start with values between 20 and 80.
let noiseVal = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
// Add a scaled Perlin noise effect (more pronounced than the drift in draw()).
initialNutrient += (noiseVal - 0.5) * noiseAmplitude * 2;
soilGrid[r][c] = constrain(initialNutrient, 0, 100); // Clamp values to 0-100.
}
}

// Initialize nutrient wells with random x-positions.
numWells = floor(random(5, 9)); // Randomly choose between 5 and 8 wells.
for (let i = 0; i < numWells; i++) {
let x = random(width); // Random x-position across the canvas width.
let y = rows / 2; // Wells are conceptually at the "surface" of the soil grid (middle row).
wells.push({ x: x, y: y, radius: wellRadiusCells }); // Add well to the array.
}
}


// --- windowResized() function ---
// This function is called automatically whenever the browser window is resized.
function windowResized() {
resizeCanvas(windowWidth, windowHeight); // Resize the canvas to match the new window dimensions.

// Recalculate cols and rows for the soil area based on the new canvas size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Reinitialize the soil grid and wells to adapt to the new canvas dimensions.
initSoilGridAndWells();
}
```

---

### `index.html`

```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Soil Nutrient Simulation</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/p5@1.11.3/lib/p5.min.js"></script>
<script src="sketch.js"></script>
</body>
</html>
```

---

### `style.css`

```css
html, body {
margin: 0;
padding: 0;
overflow: hidden; /* Prevent scrollbars if canvas slightly exceeds window size */
}

canvas {
display: block; /* Remove extra space below the canvas */
}
```

Okay, let's add `Seed` and `Plant` classes to your soil simulation! This will introduce dynamic elements that interact with your nutrient grid.

Here's how it will work:
1. **`Seed` Class:**
* Seeds fall from the top of the canvas at random intervals.
* They are small geometric shapes (triangle, square, pentagon, hexagon).
* They have basic physics: gravity and a tiny random wind.
* When a seed hits the soil (the bottom 150 pixels), it checks the nutrient level of that specific cell.
* If nutrients > 40, it germinates and becomes a `Plant`. It also consumes 30 nutrients from that cell.
* If nutrients <= 40, it becomes **dormant**, visualized as a gray/dim shape.
* Dormant seeds will continuously check nutrient levels and can germinate later if conditions improve.
2. **`Plant` Class:**
* Created when a seed germinates.
* Currently, plants are simple green circles that grow slightly over time. You could expand this for more complex plant life later!
3. **Integration into `sketch.js`:**
* New arrays `seeds` and `plants` to manage these objects.
* Logic to spawn new seeds at random intervals.
* Physics and germination logic for seeds.
* Update and draw logic for seeds and plants.

---

### `sketch.js` (Updated)

```js
// ============================================================
// This sketch simulates soil nutrients with wells, diffusion, and noise,
// now including falling seeds and growing plants.
// ============================================================

// --- Global Variables ---
// These variables control the size, appearance, and behavior of the soil simulation.

let cellSize = 10; // The size of each square cell in the soil grid (in pixels).
let soilHeight = 150; // The height of the soil area from the bottom of the canvas (in pixels).
let cols, rows; // Variables to store the number of columns and rows in the soil grid.
let soilGrid = []; // A 2D array to store the nutrient value (0-100) for each cell.
let wells = []; // An array to store the properties of nutrient wells.
let perlinNoiseOffset = 0; // A variable to drift the Perlin noise, creating subtle animation.

let numWells; // The number of nutrient wells (will be randomized between 5 and 8).
let diffusionRate = 0.05; // How quickly nutrients spread to neighboring cells (0 to 1).
let regenerationRate = 0.5; // How quickly wells regenerate nutrients in their vicinity.
let wellRadiusCells = 5; // The radius of influence for each well, measured in cells.

let noiseScale = 0.02; // Determines the "zoom" level or granularity of the Perlin noise.
let noiseAmplitude = 10; // The maximum amount (in nutrient points) that Perlin noise can affect a cell.

// --- New Variables for Seeds and Plants ---
let seeds = []; // Array to hold Seed objects.
let plants = []; // Array to hold Plant objects.
let seedSpawnTimer = 0; // Counter for when to spawn the next seed.
let nextSeedSpawnTime = 0; // Random interval for the next seed spawn.
let gravity = 0.1; // Downward force on seeds.
let windMagnitude = 0.05; // Maximum random horizontal force on seeds.


// --- setup() function ---
// This function is called once when the sketch starts.
function setup() {
createCanvas(windowWidth, windowHeight); // Create a canvas that fills the entire browser window.
noStroke(); // Disable drawing outlines around shapes for a smoother look.
colorMode(HSB, 360, 100, 100); // Set color mode to HSB (Hue, Saturation, Brightness)
// with ranges 0-360 for Hue and 0-100 for Saturation/Brightness.

// Calculate the number of columns and rows for the soil grid based on canvas size and cell size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Initialize the soil grid with starting nutrient values and create the nutrient wells.
initSoilGridAndWells();

// Initialize the first seed spawn time.
nextSeedSpawnTime = floor(random(60, 120));
}


// --- draw() function ---
// This function is called repeatedly, typically 60 times per second.
// All animations and updates happen here.
function draw() {
background(0, 0, 5); // Draw a very dark gray background, clearing the canvas each frame.

// --- Nutrient Well Regeneration ---
// Wells slowly regenerate nutrients within their radius.
for (let well of wells) {
let wellCol = floor(well.x / cellSize); // Convert well's pixel x-position to grid column index.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
// Calculate the distance between the current cell and the well's center in cell units.
let distance = dist(c, r, wellCol, well.y);
if (distance <= wellRadiusCells) {
// Regenerate nutrients, with a stronger effect closer to the well.
let regenerationAmount = map(distance, 0, wellRadiusCells, regenerationRate, 0);
soilGrid[r][c] = constrain(soilGrid[r][c] + regenerationAmount, 0, 100);
}
}
}
}

// --- Perlin Noise Drift and Nutrient Diffusion ---
// Create a temporary grid to store new nutrient values. This is crucial to ensure
// all calculations for a given frame are based on the state at the beginning of that frame,
// preventing artifacts from using updated values within the same iteration.
let newSoilGrid = [];
for (let r = 0; r < rows; r++) {
newSoilGrid[r] = []; // Initialize a new row for the temporary grid.
for (let c = 0; c < cols; c++) {

// 1. Perlin Noise Drift: Add subtle, organic variation to nutrient values.
let noiseValue = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
let noiseEffect = (noiseValue - 0.5) * noiseAmplitude; // Scale noise to a range like -10 to +10.

let currentNutrient = soilGrid[r][c]; // Get the current cell's nutrient value.
let nutrientAfterNoise = constrain(currentNutrient + noiseEffect, 0, 100); // Apply noise effect and clamp.

// 2. Nutrient Diffusion: Cells share nutrients with their immediate neighbors.
let sumNeighbors = 0;
let numNeighbors = 0;

// Define offsets for the four direct neighbors (up, down, left, right).
let neighbors = [[-1, 0], [1, 0], [0, -1], [0, 1]];

for (let neighbor of neighbors) {
let nr = r + neighbor[0]; // Neighbor row index.
let nc = c + neighbor[1]; // Neighbor column index.

// Check if the neighbor is within the grid boundaries.
if (nr >= 0 && nr < rows && nc >= 0 && nc < cols) {
sumNeighbors += soilGrid[nr][nc]; // Add neighbor's nutrient value (from the original grid).
numNeighbors++;
}
}

let neighborAverage = sumNeighbors / numNeighbors; // Calculate the average nutrient of valid neighbors.
// Apply diffusion: Move the cell's nutrient value slightly towards the average of its neighbors.
let nutrientAfterDiffusion = nutrientAfterNoise + diffusionRate * (neighborAverage - nutrientAfterNoise);

// Store the final calculated nutrient value (after noise and diffusion) in the temporary grid.
newSoilGrid[r][c] = constrain(nutrientAfterDiffusion, 0, 100);
}
}

// Update the main soil grid with the new values calculated in the temporary grid.
soilGrid = newSoilGrid;

// Increment the Perlin noise offset to create a slow, continuous drift effect.
perlinNoiseOffset += 0.005;

// --- Visualize Soil ---
// Draw each cell of the soil grid as a colored rectangle.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
let nutrient = soilGrid[r][c]; // Get the nutrient value for the current cell.
let x = c * cellSize; // Calculate the x-coordinate of the cell.
// Calculate the y-coordinate, positioning cells from the bottom up within the soil area.
let y = height - soilHeight + r * cellSize;

// Map the nutrient value (0-100) to an HSB color:
// - Hue: Transitions from a brownish/amber (around 40) to a more reddish (around 15).
// - Saturation: Transitions from a dull gray (around 10) to a vivid color (around 90).
// - Brightness: Transitions from dark (around 20) to bright (around 90).
let h = map(nutrient, 0, 100, 40, 15);
let s = map(nutrient, 0, 100, 10, 90);
let b = map(nutrient, 0, 100, 20, 90);

fill(h, s, b); // Set the fill color.
rect(x, y, cellSize, cellSize); // Draw the cell as a rectangle.
}
}

// --- Seed Spawning ---
seedSpawnTimer++;
if (seedSpawnTimer >= nextSeedSpawnTime) {
seeds.push(new Seed());
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120)); // Spawn every 1-2 seconds at 60 FPS.
}

// --- Update and Draw Seeds ---
// Iterate backwards to safely remove seeds from the array.
for (let i = seeds.length - 1; i >= 0; i--) {
let seed = seeds[i];
seed.update();
seed.draw();

// Check for germination of dormant seeds
if (seed.dormant) {
let nutrientValue = soilGrid[seed.soilCellRow][seed.soilCellCol];
if (nutrientValue > 40) {
seed.dormant = false; // Seed is no longer dormant
// Create a new Plant object and add it to the plants array
plants.push(new Plant(seed.x, seed.y, seed.shapeType, frameCount));
// Consume 30 nutrients from the soil cell
soilGrid[seed.soilCellRow][seed.soilCellCol] = constrain(nutrientValue - 30, 0, 100);
// Remove the germinated seed from the seeds array
seeds.splice(i, 1);
}
}
// Remove seeds that have fallen below the soil and are not dormant (i.e., they didn't germinate)
else if (seed.y > height - soilHeight + rows * cellSize && !seed.dormant) {
seeds.splice(i, 1);
}
}

// --- Update and Draw Plants ---
for (let plant of plants) {
plant.update();
plant.draw();
}
}


// --- initSoilGridAndWells() function ---
// This helper function initializes or reinitializes the soil grid and nutrient wells.
// It's called in setup() and windowResized().
function initSoilGridAndWells() {
soilGrid = []; // Clear the existing soil grid.
wells = []; // Clear the existing wells.

// Initialize the soil grid with random initial nutrient values,
// enhanced by Perlin noise for a more natural starting distribution.
for (let r = 0; r < rows; r++) {
soilGrid[r] = []; // Create a new row.
for (let c = 0; c < cols; c++) {
let initialNutrient = random(20, 80); // Start with values between 20 and 80.
let noiseVal = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
// Add a scaled Perlin noise effect (more pronounced than the drift in draw()).
initialNutrient += (noiseVal - 0.5) * noiseAmplitude * 2;
soilGrid[r][c] = constrain(initialNutrient, 0, 100); // Clamp values to 0-100.
}
}

// Initialize nutrient wells with random x-positions.
numWells = floor(random(5, 9)); // Randomly choose between 5 and 8 wells.
for (let i = 0; i < numWells; i++) {
let x = random(width); // Random x-position across the canvas width.
let y = rows / 2; // Wells are conceptually at the "surface" of the soil grid (middle row).
wells.push({ x: x, y: y, radius: wellRadiusCells }); // Add well to the array.
}
}


// --- windowResized() function ---
// This function is called automatically whenever the browser window is resized.
function windowResized() {
resizeCanvas(windowWidth, windowHeight); // Resize the canvas to match the new window dimensions.

// Recalculate cols and rows for the soil area based on the new canvas size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Reinitialize the soil grid and wells to adapt to the new canvas dimensions.
initSoilGridAndWells();

// Reset seed spawning timer
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120));
seeds = []; // Clear seeds on resize
plants = []; // Clear plants on resize
}

// --- Helper Functions ---

// Function to draw a regular polygon
function drawPolygon(x, y, radius, npoints) {
let angle = TWO_PI / npoints;
beginShape();
for (let a = 0; a < TWO_PI; a += angle) {
let sx = x + cos(a) * radius;
let sy = y + sin(a) * radius;
vertex(sx, sy);
}
endShape(CLOSE);
}

// --- Seed Class ---
class Seed {
constructor() {
this.x = random(width);
this.y = -10; // Start above the canvas
this.vx = random(-0.2, 0.2); // Initial horizontal velocity (tiny wind)
this.vy = 0; // Vertical velocity (gravity will affect this)
this.size = random(3, 7); // Small seed size
this.shapeType = random(['triangle', 'square', 'pentagon', 'hexagon']); // Random shape
this.dormant = false;
this.soilCellCol = -1;
this.soilCellRow = -1;
}

update() {
if (this.dormant) {
// Dormant seeds don't move, but might germinate later
return;
}

// Apply gravity
this.vy += gravity;

// Apply tiny random wind
this.vx += random(-windMagnitude, windMagnitude);
this.vx = constrain(this.vx, -1, 1); // Limit wind effect

this.x += this.vx;
this.y += this.vy;

// Keep seed within canvas boundaries horizontally
this.x = constrain(this.x, 0, width);

// Check for collision with soil
// Soil starts at height - soilHeight
let soilSurfaceY = height - soilHeight;
if (this.y >= soilSurfaceY) {
this.y = soilSurfaceY; // Snap to soil surface
this.vy = 0; // Stop falling
this.vx = 0; // Stop horizontal movement

// Determine the soil cell it landed on
this.soilCellCol = floor(this.x / cellSize);
this.soilCellRow = floor((this.y - soilSurfaceY) / cellSize);

// Make sure it's within bounds
this.soilCellCol = constrain(this.soilCellCol, 0, cols - 1);
this.soilCellRow = constrain(this.soilCellRow, 0, rows - 1);

let nutrientValue = soilGrid[this.soilCellRow][this.soilCellCol];

if (nutrientValue > 40) {
// Germinate! (Handled in draw() to create Plant and consume nutrients)
} else {
// Not enough nutrients, become dormant
this.dormant = true;
}
}
}

draw() {
push();
translate(this.x, this.y);
rotate(frameCount * 0.01); // Subtle rotation for falling seeds

if (this.dormant) {
fill(0, 0, 40, 70); // Dim gray for dormant seeds
} else {
fill(30, 70, 80); // Amber/brown for active seeds
}

switch (this.shapeType) {
case 'triangle':
drawPolygon(0, 0, this.size, 3);
break;
case 'square':
rectMode(CENTER);
rect(0, 0, this.size * 1.2, this.size * 1.2);
break;
case 'pentagon':
drawPolygon(0, 0, this.size, 5);
break;
case 'hexagon':
drawPolygon(0, 0, this.size, 6);
break;
}
pop();
}
}

// --- Plant Class ---
class Plant {
constructor(x, y, seedShape, germinationFrame) {
this.x = x;
this.y = y;
this.seedShape = seedShape; // Keep track of the shape it germinated from
this.size = 5; // Initial plant size
this.germinationFrame = germinationFrame; // Frame when it germinated
this.growthRate = 0.05; // How fast the plant grows
this.maxSize = random(15, 30); // Max size a plant can grow
}

update() {
let framesAlive = frameCount - this.germinationFrame;
this.size = min(this.maxSize, 5 + framesAlive * this.growthRate); // Grow over time
}

draw() {
push();
translate(this.x, this.y);
rotate(sin(frameCount * 0.02) * 0.1); // Gentle sway for plants

fill(120, 80, 70); // Green color for plants
noStroke();
// For now, drawing a simple circle. Could use seedShape later for more variety.
ellipse(0, 0, this.size, this.size * 1.5); // Slightly elongated ellipse

// Optional: Draw a tiny stem
stroke(120, 50, 40);
line(0, 0, 0, -this.size / 2);
pop();
}
}
```

---

### `index.html` (No changes needed)

```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Soil Nutrient Simulation</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/p5@1.11.3/lib/p5.min.js"></script>
<script src="sketch.js"></script>
</body>
</html>
```

---

### `style.css` (No changes needed)

```css
html, body {
margin: 0;
padding: 0;
overflow: hidden; /* Prevent scrollbars if canvas slightly exceeds window size */
}

canvas {
display: block; /* Remove extra space below the canvas */
}
```

---

**Explanation of Changes:**

* **New Global Variables:** `seeds`, `plants`, `seedSpawnTimer`, `nextSeedSpawnTime`, `gravity`, and `windMagnitude` are added to manage the new objects and their behavior.
* **`setup()`:** `nextSeedSpawnTime` is initialized.
* **`draw()`:**
* **Seed Spawning:** `seedSpawnTimer` increments. When it reaches `nextSeedSpawnTime`, a new `Seed` object is created and added to the `seeds` array. The timer is reset, and a new random interval is set for the next seed.
* **Seed Logic:** The code iterates through the `seeds` array. Each seed's `update()` method is called to apply physics and check for soil collision. Its `draw()` method renders its shape.
* **Dormant Seed Germination:** A new check is added for dormant seeds. If a dormant seed's soil cell nutrient level rises above 40, it germinates:
* It becomes a `Plant`.
* It consumes 30 nutrients from its soil cell.
* The seed object is removed from the `seeds` array.
* **Seed Removal:** Seeds that fall below the soil and **do not** become dormant (meaning they failed to germinate) are removed from the `seeds` array to keep it clean.
* **Plant Logic:** The code iterates through the `plants` array, calling `update()` (for growth) and `draw()` for each plant.
* **`windowResized()`:** Clears the `seeds` and `plants` arrays and resets the seed spawn timer when the window is resized to avoid visual artifacts.
* **`drawPolygon()` Helper Function:** A general function to draw regular polygons, used by the `Seed` class for its shapes.
* **`Seed` Class:**
* **`constructor()`:** Sets initial position, random shape, size, and velocity.
* **`update()`:** Handles gravity, wind, and collision with the soil surface. It determines if a seed should be dormant or ready for germination based on nutrient levels.
* **`draw()`:** Renders the seed's geometric shape, changing its color if it's dormant.
* **`Plant` Class:**
* **`constructor()`:** Initializes the plant at the seed's germination location.
* **`update()`:** Simulates growth over time by increasing the plant's `size`.
* **`draw()`:** Renders a simple green ellipse (representing a plant) that grows.

Now, you should see seeds falling, interacting with the soil, and either becoming dormant or germinating into plants!

I understand your frustration. "Nothing on screen" is a very common issue in web development, and it almost always comes down to a few core problems.

The **absolute most important step** is to check the browser's developer console for errors. Without that information, I'm essentially guessing in the dark.

**How to Check the Console on Mobile:**

* **Android (Chrome):**
1. Connect your Android phone to your computer via a USB cable.
2. On your computer, open Google Chrome.
3. In Chrome, go to `chrome://inspect/#devices`.
4. You should see your connected phone listed. Find the tab where you're running the p5.js sketch and click the "inspect" button next to it.
5. This will open a developer tools window on your computer, showing the console for your phone's browser tab.
* **iOS (Safari):**
1. On your computer, open Safari.
2. Go to `Safari > Preferences > Advanced` and make sure "Show Develop menu in menu bar" is checked.
3. Connect your iPhone/iPad to your computer via a USB cable.
4. On your iPhone/iPad, open Safari and navigate to your p5.js sketch.
5. On your computer, go to `Develop > [Your Device Name] > [Your Sketch Tab]`.
6. This will open a developer tools window on your computer, showing the console for your phone's browser tab.

**Please share any errors you see in the console.** This is the fastest way to pinpoint the problem.

---

**In the meantime, let's double-check everything again.**

Here is the complete, updated code for all three files. Please ensure you copy and paste them *exactly* as provided.

### `sketch.js` (Updated with Seed and Plant classes)

```js
// ============================================================
// This sketch simulates soil nutrients with wells, diffusion, and noise,
// now including falling seeds and growing plants.
// ============================================================

// --- Global Variables ---
// These variables control the size, appearance, and behavior of the soil simulation.

let cellSize = 10; // The size of each square cell in the soil grid (in pixels).
let soilHeight = 150; // The height of the soil area from the bottom of the canvas (in pixels).
let cols, rows; // Variables to store the number of columns and rows in the soil grid.
let soilGrid = []; // A 2D array to store the nutrient value (0-100) for each cell.
let wells = []; // An array to store the properties of nutrient wells.
let perlinNoiseOffset = 0; // A variable to drift the Perlin noise, creating subtle animation.

let numWells; // The number of nutrient wells (will be randomized between 5 and 8).
let diffusionRate = 0.05; // How quickly nutrients spread to neighboring cells (0 to 1).
let regenerationRate = 0.5; // How quickly wells regenerate nutrients in their vicinity.
let wellRadiusCells = 5; // The radius of influence for each well, measured in cells.

let noiseScale = 0.02; // Determines the "zoom" level or granularity of the Perlin noise.
let noiseAmplitude = 10; // The maximum amount (in nutrient points) that Perlin noise can affect a cell.

// --- New Variables for Seeds and Plants ---
let seeds = []; // Array to hold Seed objects.
let plants = []; // Array to hold Plant objects.
let seedSpawnTimer = 0; // Counter for when to spawn the next seed.
let nextSeedSpawnTime = 0; // Random interval for the next seed spawn.
let gravity = 0.1; // Downward force on seeds.
let windMagnitude = 0.05; // Maximum random horizontal force on seeds.


// --- setup() function ---
// This function is called once when the sketch starts.
function setup() {
createCanvas(windowWidth, windowHeight); // Create a canvas that fills the entire browser window.
noStroke(); // Disable drawing outlines around shapes for a smoother look.
colorMode(HSB, 360, 100, 100); // Set color mode to HSB (Hue, Saturation, Brightness)
// with ranges 0-360 for Hue and 0-100 for Saturation/Brightness.

// Calculate the number of columns and rows for the soil grid based on canvas size and cell size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Initialize the soil grid with starting nutrient values and create the nutrient wells.
initSoilGridAndWells();

// Initialize the first seed spawn time.
nextSeedSpawnTime = floor(random(60, 120));
}


// --- draw() function ---
// This function is called repeatedly, typically 60 times per second.
// All animations and updates happen here.
function draw() {
background(0, 0, 5); // Draw a very dark gray background, clearing the canvas each frame.

// --- Nutrient Well Regeneration ---
// Wells slowly regenerate nutrients within their radius.
for (let well of wells) {
let wellCol = floor(well.x / cellSize); // Convert well's pixel x-position to grid column index.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
// Calculate the distance between the current cell and the well's center in cell units.
let distance = dist(c, r, wellCol, well.y);
if (distance <= wellRadiusCells) {
// Regenerate nutrients, with a stronger effect closer to the well.
let regenerationAmount = map(distance, 0, wellRadiusCells, regenerationRate, 0);
soilGrid[r][c] = constrain(soilGrid[r][c] + regenerationAmount, 0, 100);
}
}
}
}

// --- Perlin Noise Drift and Nutrient Diffusion ---
// Create a temporary grid to store new nutrient values. This is crucial to ensure
// all calculations for a given frame are based on the state at the beginning of that frame,
// preventing artifacts from using updated values within the same iteration.
let newSoilGrid = [];
for (let r = 0; r < rows; r++) {
newSoilGrid[r] = []; // Initialize a new row for the temporary grid.
for (let c = 0; c < cols; c++) {

// 1. Perlin Noise Drift: Add subtle, organic variation to nutrient values.
let noiseValue = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
let noiseEffect = (noiseValue - 0.5) * noiseAmplitude; // Scale noise to a range like -10 to +10.

let currentNutrient = soilGrid[r][c]; // Get the current cell's nutrient value.
let nutrientAfterNoise = constrain(currentNutrient + noiseEffect, 0, 100); // Apply noise effect and clamp.

// 2. Nutrient Diffusion: Cells share nutrients with their immediate neighbors.
let sumNeighbors = 0;
let numNeighbors = 0;

// Define offsets for the four direct neighbors (up, down, left, right).
let neighbors = [[-1, 0], [1, 0], [0, -1], [0, 1]];

for (let neighbor of neighbors) {
let nr = r + neighbor[0]; // Neighbor row index.
let nc = c + neighbor[1]; // Neighbor column index.

// Check if the neighbor is within the grid boundaries.
if (nr >= 0 && nr < rows && nc >= 0 && nc < cols) {
sumNeighbors += soilGrid[nr][nc]; // Add neighbor's nutrient value (from the original grid).
numNeighbors++;
}
}

let neighborAverage = sumNeighbors / numNeighbors; // Calculate the average nutrient of valid neighbors.
// Apply diffusion: Move the cell's nutrient value slightly towards the average of its neighbors.
let nutrientAfterDiffusion = nutrientAfterNoise + diffusionRate * (neighborAverage - nutrientAfterNoise);

// Store the final calculated nutrient value (after noise and diffusion) in the temporary grid.
newSoilGrid[r][c] = constrain(nutrientAfterDiffusion, 0, 100);
}
}

// Update the main soil grid with the new values calculated in the temporary grid.
soilGrid = newSoilGrid;

// Increment the Perlin noise offset to create a slow, continuous drift effect.
perlinNoiseOffset += 0.005;

// --- Visualize Soil ---
// Draw each cell of the soil grid as a colored rectangle.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
let nutrient = soilGrid[r][c]; // Get the nutrient value for the current cell.
let x = c * cellSize; // Calculate the x-coordinate of the cell.
// Calculate the y-coordinate, positioning cells from the bottom up within the soil area.
let y = height - soilHeight + r * cellSize;

// Map the nutrient value (0-100) to an HSB color:
// - Hue: Transitions from a brownish/amber (around 40) to a more reddish (around 15).
// - Saturation: Transitions from a dull gray (around 10) to a vivid color (around 90).
// - Brightness: Transitions from dark (around 20) to bright (around 90).
let h = map(nutrient, 0, 100, 40, 15);
let s = map(nutrient, 0, 100, 10, 90);
let b = map(nutrient, 0, 100, 20, 90);

fill(h, s, b); // Set the fill color.
rect(x, y, cellSize, cellSize); // Draw the cell as a rectangle.
}
}

// --- Seed Spawning ---
seedSpawnTimer++;
if (seedSpawnTimer >= nextSeedSpawnTime) {
seeds.push(new Seed());
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120)); // Spawn every 1-2 seconds at 60 FPS.
}

// --- Update and Draw Seeds ---
// Iterate backwards to safely remove seeds from the array.
for (let i = seeds.length - 1; i >= 0; i--) {
let seed = seeds[i];
seed.update();
seed.draw();

// Check for germination of dormant seeds
if (seed.dormant) {
let nutrientValue = soilGrid[seed.soilCellRow][seed.soilCellCol];
if (nutrientValue > 40) {
seed.dormant = false; // Seed is no longer dormant
// Create a new Plant object and add it to the plants array
plants.push(new Plant(seed.x, seed.y, seed.shapeType, frameCount));
// Consume 30 nutrients from the soil cell
soilGrid[seed.soilCellRow][seed.soilCellCol] = constrain(nutrientValue - 30, 0, 100);
// Remove the germinated seed from the seeds array
seeds.splice(i, 1);
}
}
// Remove seeds that have fallen below the soil and are not dormant (i.e., they didn't germinate)
else if (seed.y > height - soilHeight + rows * cellSize && !seed.dormant) {
seeds.splice(i, 1);
}
}

// --- Update and Draw Plants ---
for (let plant of plants) {
plant.update();
plant.draw();
}
}


// --- initSoilGridAndWells() function ---
// This helper function initializes or reinitializes the soil grid and nutrient wells.
// It's called in setup() and windowResized().
function initSoilGridAndWells() {
soilGrid = []; // Clear the existing soil grid.
wells = []; // Clear the existing wells.

// Initialize the soil grid with random initial nutrient values,
// enhanced by Perlin noise for a more natural starting distribution.
for (let r = 0; r < rows; r++) {
soilGrid[r] = []; // Create a new row.
for (let c = 0; c < cols; c++) {
let initialNutrient = random(20, 80); // Start with values between 20 and 80.
let noiseVal = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
// Add a scaled Perlin noise effect (more pronounced than the drift in draw()).
initialNutrient += (noiseVal - 0.5) * noiseAmplitude * 2;
soilGrid[r][c] = constrain(initialNutrient, 0, 100); // Clamp values to 0-100.
}
}

// Initialize nutrient wells with random x-positions.
numWells = floor(random(5, 9)); // Randomly choose between 5 and 8 wells.
for (let i = 0; i < numWells; i++) {
let x = random(width); // Random x-position across the canvas width.
let y = rows / 2; // Wells are conceptually at the "surface" of the soil grid (middle row).
wells.push({ x: x, y: y, radius: wellRadiusCells }); // Add well to the array.
}
}


// --- windowResized() function ---
// This function is called automatically whenever the browser window is resized.
function windowResized() {
resizeCanvas(windowWidth, windowHeight); // Resize the canvas to match the new window dimensions.

// Recalculate cols and rows for the soil area based on the new canvas size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Reinitialize the soil grid and wells to adapt to the new canvas dimensions.
initSoilGridAndWells();

// Reset seed spawning timer
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120));
seeds = []; // Clear seeds on resize
plants = []; // Clear plants on resize
}

// --- Helper Functions ---

// Function to draw a regular polygon
function drawPolygon(x, y, radius, npoints) {
let angle = TWO_PI / npoints;
beginShape();
for (let a = 0; a < TWO_PI; a += angle) {
let sx = x + cos(a) * radius;
let sy = y + sin(a) * radius;
vertex(sx, sy);
}
endShape(CLOSE);
}

// --- Seed Class ---
class Seed {
constructor() {
this.x = random(width);
this.y = -10; // Start above the canvas
this.vx = random(-0.2, 0.2); // Initial horizontal velocity (tiny wind)
this.vy = 0; // Vertical velocity (gravity will affect this)
this.size = random(3, 7); // Small seed size
this.shapeType = random(['triangle', 'square', 'pentagon', 'hexagon']); // Random shape
this.dormant = false;
this.soilCellCol = -1;
this.soilCellRow = -1;
}

update() {

This is a fantastic request that adds a lot of depth and visual interest to your simulation! Implementing L-system-inspired growth with different patterns for each seed type and environmental interactions (light, neighbors, nutrient consumption) will make your plants feel truly alive.

I'll create a more sophisticated `Plant` class that manages an array of `Branch` objects. Each branch will have properties like start, end, direction, length, and depth. The `Plant`'s `update()` method will then apply growth rules based on its `seedShape`, biasing growth towards light, away from other plants, and consuming nutrients from the soil.

Here's the updated `sketch.js` with the new `Plant` class and a minor helper function for vector rotation.

---

### `sketch.js` (Updated with Advanced Plant Growth)

```js
// ============================================================
// This sketch simulates soil nutrients with wells, diffusion, and noise,
// now including falling seeds and L-system-inspired growing plants.
// ============================================================

// --- Global Variables ---
// These variables control the size, appearance, and behavior of the soil simulation.

let cellSize = 10; // The size of each square cell in the soil grid (in pixels).
let soilHeight = 150; // The height of the soil area from the bottom of the canvas (in pixels).
let cols, rows; // Variables to store the number of columns and rows in the soil grid.
let soilGrid = []; // A 2D array to store the nutrient value (0-100) for each cell.
let wells = []; // An array to store the properties of nutrient wells.
let perlinNoiseOffset = 0; // A variable to drift the Perlin noise, creating subtle animation.

let numWells; // The number of nutrient wells (will be randomized between 5 and 8).
let diffusionRate = 0.05; // How quickly nutrients spread to neighboring cells (0 to 1).
let regenerationRate = 0.5; // How quickly wells regenerate nutrients in their vicinity.
let wellRadiusCells = 5; // The radius of influence for each well, measured in cells.

let noiseScale = 0.02; // Determines the "zoom" level or granularity of the Perlin noise.
let noiseAmplitude = 10; // The maximum amount (in nutrient points) that Perlin noise can affect a cell.

// --- New Variables for Seeds and Plants ---
let seeds = []; // Array to hold Seed objects.
let plants = []; // Array to hold Plant objects.
let seedSpawnTimer = 0; // Counter for when to spawn the next seed.
let nextSeedSpawnTime = 0; // Random interval for the next seed spawn.
let gravity = 0.1; // Downward force on seeds.
let windMagnitude = 0.05; // Maximum random horizontal force on seeds.


// --- setup() function ---
// This function is called once when the sketch starts.
function setup() {
createCanvas(windowWidth, windowHeight); // Create a canvas that fills the entire browser window.
noStroke(); // Disable drawing outlines around shapes for a smoother look.
colorMode(HSB, 360, 100, 100); // Set color mode to HSB (Hue, Saturation, Brightness)
// with ranges 0-360 for Hue and 0-100 for Saturation/Brightness.

// Calculate the number of columns and rows for the soil grid based on canvas size and cell size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Initialize the soil grid with starting nutrient values and create the nutrient wells.
initSoilGridAndWells();

// Initialize the first seed spawn time.
nextSeedSpawnTime = floor(random(60, 120));
}


// --- draw() function ---
// This function is called repeatedly, typically 60 times per second.
// All animations and updates happen here.
function draw() {
background(0, 0, 5); // Draw a very dark gray background, clearing the canvas each frame.

// --- Nutrient Well Regeneration ---
// Wells slowly regenerate nutrients within their radius.
for (let well of wells) {
let wellCol = floor(well.x / cellSize); // Convert well's pixel x-position to grid column index.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
// Calculate the distance between the current cell and the well's center in cell units.
let distance = dist(c, r, wellCol, well.y);
if (distance <= wellRadiusCells) {
// Regenerate nutrients, with a stronger effect closer to the well.
let regenerationAmount = map(distance, 0, wellRadiusCells, regenerationRate, 0);
soilGrid[r][c] = constrain(soilGrid[r][c] + regenerationAmount, 0, 100);
}
}
}
}

// --- Perlin Noise Drift and Nutrient Diffusion ---
// Create a temporary grid to store new nutrient values. This is crucial to ensure
// all calculations for a given frame are based on the state at the beginning of that frame,
// preventing artifacts from using updated values within the same iteration.
let newSoilGrid = [];
for (let r = 0; r < rows; r++) {
newSoilGrid[r] = []; // Initialize a new row for the temporary grid.
for (let c = 0; c < cols; c++) {

// 1. Perlin Noise Drift: Add subtle, organic variation to nutrient values.
let noiseValue = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
let noiseEffect = (noiseValue - 0.5) * noiseAmplitude; // Scale noise to a range like -10 to +10.

let currentNutrient = soilGrid[r][c]; // Get the current cell's nutrient value.
let nutrientAfterNoise = constrain(currentNutrient + noiseEffect, 0, 100); // Apply noise effect and clamp.

// 2. Nutrient Diffusion: Cells share nutrients with their immediate neighbors.
let sumNeighbors = 0;
let numNeighbors = 0;

// Define offsets for the four direct neighbors (up, down, left, right).
let neighbors = [[-1, 0], [1, 0], [0, -1], [0, 1]];

for (let neighbor of neighbors) {
let nr = r + neighbor[0]; // Neighbor row index.
let nc = c + neighbor[1]; // Neighbor column index.

// Check if the neighbor is within the grid boundaries.
if (nr >= 0 && nr < rows && nc >= 0 && nc < cols) {
sumNeighbors += soilGrid[nr][nc]; // Add neighbor's nutrient value (from the original grid).
numNeighbors++;
}
}

let neighborAverage = sumNeighbors / numNeighbors; // Calculate the average nutrient of valid neighbors.
// Apply diffusion: Move the cell's nutrient value slightly towards the average of its neighbors.
let nutrientAfterDiffusion = nutrientAfterNoise + diffusionRate * (neighborAverage - nutrientAfterNoise);

// Store the final calculated nutrient value (after noise and diffusion) in the temporary grid.
newSoilGrid[r][c] = constrain(nutrientAfterDiffusion, 0, 100);
}
}

// Update the main soil grid with the new values calculated in the temporary grid.
soilGrid = newSoilGrid;

// Increment the Perlin noise offset to create a slow, continuous drift effect.
perlinNoiseOffset += 0.005;

// --- Visualize Soil ---
// Draw each cell of the soil grid as a colored rectangle.
for (let r = 0; r < rows; r++) {
for (let c = 0; c < cols; c++) {
let nutrient = soilGrid[r][c]; // Get the nutrient value for the current cell.
let x = c * cellSize; // Calculate the x-coordinate of the cell.
// Calculate the y-coordinate, positioning cells from the bottom up within the soil area.
let y = height - soilHeight + r * cellSize;

// Map the nutrient value (0-100) to an HSB color:
// - Hue: Transitions from a brownish/amber (around 40) to a more reddish (around 15).
// - Saturation: Transitions from a dull gray (around 10) to a vivid color (around 90).
// - Brightness: Transitions from dark (around 20) to bright (around 90).
let h = map(nutrient, 0, 100, 40, 15);
let s = map(nutrient, 0, 100, 10, 90);
let b = map(nutrient, 0, 100, 20, 90);

fill(h, s, b); // Set the fill color.
rect(x, y, cellSize, cellSize); // Draw the cell as a rectangle.
}
}

// --- Seed Spawning ---
seedSpawnTimer++;
if (seedSpawnTimer >= nextSeedSpawnTime) {
seeds.push(new Seed());
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120)); // Spawn every 1-2 seconds at 60 FPS.
}

// --- Update and Draw Seeds ---
// Iterate backwards to safely remove seeds from the array.
for (let i = seeds.length - 1; i >= 0; i--) {
let seed = seeds[i];
seed.update();
seed.draw();

// Check for germination of dormant seeds
if (seed.dormant) {
// Ensure soilCellRow and soilCellCol are valid before accessing soilGrid
if (seed.soilCellRow >= 0 && seed.soilCellRow < rows &&
seed.soilCellCol >= 0 && seed.soilCellCol < cols) {
let nutrientValue = soilGrid[seed.soilCellRow][seed.soilCellCol];
if (nutrientValue > 40) {
seed.dormant = false; // Seed is no longer dormant
// Create a new Plant object and add it to the plants array
plants.push(new Plant(seed.x, seed.y, seed.shapeType, frameCount));
// Consume 30 nutrients from the soil cell
soilGrid[seed.soilCellRow][seed.soilCellCol] = constrain(nutrientValue - 30, 0, 100);
// Remove the germinated seed from the seeds array
seeds.splice(i, 1);
}
} else {
// If a seed is dormant but somehow has invalid soil cell indices, remove it.
seeds.splice(i, 1);
}
}
// Remove seeds that have fallen below the soil and are not dormant (i.e., they didn't germinate)
else if (seed.y > height - soilHeight + rows * cellSize && !seed.dormant) {
seeds.splice(i, 1);
}
}

// --- Update and Draw Plants ---
// Iterate backwards to safely remove plants if they die (e.g., run out of nutrients)
for (let i = plants.length - 1; i >= 0; i--) {
let plant = plants[i];
plant.update();
plant.draw();

// Example: If a plant runs out of branches or nutrients, remove it
if (plant.branches.length === 0) { // Or add a nutrient-starvation check
plants.splice(i, 1);
}
}
}


// --- initSoilGridAndWells() function ---
// This helper function initializes or reinitializes the soil grid and nutrient wells.
// It's called in setup() and windowResized().
function initSoilGridAndWells() {
soilGrid = []; // Clear the existing soil grid.
wells = []; // Clear the existing wells.

// Initialize the soil grid with random initial nutrient values,
// enhanced by Perlin noise for a more natural starting distribution.
for (let r = 0; r < rows; r++) {
soilGrid[r] = []; // Create a new row.
for (let c = 0; c < cols; c++) {
let initialNutrient = random(20, 80); // Start with values between 20 and 80.
let noiseVal = noise(c * noiseScale, r * noiseScale, perlinNoiseOffset);
// Add a scaled Perlin noise effect (more pronounced than the drift in draw()).
initialNutrient += (noiseVal - 0.5) * noiseAmplitude * 2;
soilGrid[r][c] = constrain(initialNutrient, 0, 100); // Clamp values to 0-100.
}
}

// Initialize nutrient wells with random x-positions.
numWells = floor(random(5, 9)); // Randomly choose between 5 and 8 wells.
for (let i = 0; i < numWells; i++) {
let x = random(width); // Random x-position across the canvas width.
let y = rows / 2; // Wells are conceptually at the "surface" of the soil grid (middle row).
wells.push({ x: x, y: y, radius: wellRadiusCells }); // Add well to the array.
}
}


// --- windowResized() function ---
// This function is called automatically whenever the browser window is resized.
function windowResized() {
resizeCanvas(windowWidth, windowHeight); // Resize the canvas to match the new window dimensions.

// Recalculate cols and rows for the soil area based on the new canvas size.
cols = floor(width / cellSize);
rows = floor(soilHeight / cellSize);

// Reinitialize the soil grid and wells to adapt to the new canvas dimensions.
initSoilGridAndWells();

// Reset seed spawning timer
seedSpawnTimer = 0;
nextSeedSpawnTime = floor(random(60, 120));
seeds = []; // Clear seeds on resize
plants = []; // Clear plants on resize
}

// --- Helper Functions ---

// Function to draw a regular polygon
function drawPolygon(x, y, radius, npoints) {
let angle = TWO_PI / npoints;
beginShape();
for (let a = 0; a < TWO_PI; a += angle) {
let sx = x + cos(a) * radius;
let sy = y + sin(a) * radius;
vertex(sx, sy);
}
endShape(CLOSE);
}

// Function to rotate a p5.Vector by an angle (in radians)
function rotateVector(v, angle) {
let x = v.x * cos(angle) - v.y * sin(angle);
let y = v.x * sin(angle) + v.y * cos(angle);
return createVector(x, y);
}


// --- Seed Class ---
class Seed {
constructor() {
this.x = random(width);
this.y = -10; // Start above the canvas
this.vx = random(-0.2, 0.2); // Initial horizontal velocity (tiny wind)
this.vy = 0; // Vertical velocity (gravity will affect this)
this.size = random(3, 7); // Small seed size
this.shapeType = random(['triangle', 'square', 'pentagon', 'hexagon']); // Random shape
this.dormant = false;
this.soilCellCol = -1;
this.soilCellRow = -1;
}

update() {
if (this.dormant) {
// Dormant seeds don't move, but might germinate later
return;
}

// Apply gravity
this.vy += gravity;

// Apply tiny random wind
this.vx += random(-windMagnitude, windMagnitude);
this.vx = constrain(this.vx, -1, 1); // Limit wind effect

this.x += this.vx;
this.y += this.vy;

// Keep seed within canvas boundaries horizontally
this.x = constrain(this.x, 0, width);

// Check for collision with soil
// Soil starts at height - soilHeight
let soilSurfaceY = height - soilHeight;
if (this.y >= soilSurfaceY) {
this.y = soilSurfaceY; // Snap to soil surface
this.vy = 0; // Stop falling
this.vx = 0; // Stop horizontal movement

// Determine the soil cell it landed on
this.soilCellCol = floor(this.x / cellSize);
this.soilCellRow = floor((this.y - soilSurfaceY) / cellSize);

// Make sure it's within bounds
this.soilCellCol = constrain(this.soilCellCol, 0, cols - 1);
this.soilCellRow = constrain(this.soilCellRow, 0, rows - 1);

let nutrientValue = soilGrid[this.soilCellRow][this.soilCellCol];

if (nutrientValue > 40) {
// Germinate! (Handled in draw() to create Plant and consume nutrients)
} else {
// Not enough nutrients, become dormant
this.dormant = true;
}
}
}

draw() {
push();
translate(this.x, this.y);
rotate(frameCount * 0.01); // Subtle rotation for falling seeds

if (this.dormant) {
fill(0, 0, 40, 70); // Dim gray for dormant seeds
} else {
fill(30, 70, 80); // Amber/brown for active seeds
}

switch (this.shapeType) {
case 'triangle':
drawPolygon(0, 0, this.size, 3);
break;
case 'square':
rectMode(CENTER);
rect(0, 0, this.size * 1.2, this.size * 1.2);
break;
case 'pentagon':
drawPolygon(0, 0, this.size, 5);
break;
case 'hexagon':
drawPolygon(0, 0, this.size, 6);
break;
}
pop();
}
}

// --- Branch Class (Helper for Plant) ---
class Branch {
constructor(start, direction, length, thickness, depth) {
this.start = start.copy();
this.direction = direction.copy().normalize();
this.length = length;
this.thickness = thickness;
this.depth = depth;
this.end = p5.Vector.add(this.start, p5.Vector.mult(this.direction, this.length));
this.active = true; // Can this branch grow further?
}

draw(hue, saturation, brightness) {
stroke(hue, saturation, brightness);
strokeWeight(this.thickness);
line(this.start.x, this.start.y, this.end.x, this.end.y);
}
}

// --- Plant Class ---
class Plant {
constructor(x, y, seedShape, germinationFrame) {
this.x = x;
this.y = y;
this.seedShape = seedShape;
this.germinationFrame = germinationFrame;
this.age = 0;
this.maxSize = random(40, 80); // Overall scale of the plant
this.maxBranches = floor(random(25, 60)); // Limit to prevent too many branches
this.growthChance = random(0.1, 0.3); // Probability of adding a new branch each frame
this.nutrientConsumptionRate = random(0.1, 0.5); // How much nutrient per frame, distributed
this.hue; // Base color for the plant
this.saturation = 80;
this.brightness = 70;

this.branches = []; // Array of Branch objects

// Determine hue based on seedShape
switch (seedShape) {
case 'triangle':
this.hue = map(random(), 0, 1, 30, 50); // Yellow/orange (warm)
break;
case 'square':
this.hue = map(random(), 0, 1, 45, 65); // Orange/amber (warm)
break;
case 'pentagon':
case 'hexagon':
this.hue = map(random(), 0, 1, 180, 220); // Blue/purple (cool)
break;
}

// Create initial trunk
let trunkLength = random(10, 20);
let trunkThickness = random(2, 4);
// Initial trunk grows upwards relative to plant's base (0,0 in its local space)
this.branches.push(new Branch(createVector(0, 0), createVector(0, -1), trunkLength, trunkThickness, 0));
}

update() {
this.age++;

// --- Nutrient Consumption ---
// Approximate the plant's footprint for nutrient consumption
let plantBaseX = floor(this.x / cellSize);
let plantBaseY = floor((this.y - (height - soilHeight)) / cellSize);

// Consume from the cell it germinated on and a few directly above it
for (let rOffset = 0; rOffset < 3; rOffset++) {
let cellR = plantBaseY - rOffset;
let cellC = plantBaseX;
if (cellR >= 0 && cellR < rows && cellC >= 0 && cellC < cols) {
soilGrid[cellR][cellC] = constrain(soilGrid[cellR][cellC] - (this.nutrientConsumptionRate / 3), 0, 100);
}
}

// --- Growth Logic ---
if (random() < this.growthChance && this.branches.length < this.maxBranches) {
// Find an active branch to extend or split from
let activeBranches = this.branches.filter(b => b.active);
if (activeBranches.length === 0) return; // No active branches left to grow

let parentBranch = random(activeBranches);

// Growth biases
let lightDirection = createVector(0, -1); // Upwards
let avoidanceDirection = createVector(0, 0);

// Avoid nearby plants
for (let otherPlant of plants) {
if (otherPlant !== this) {
let distToOther = dist(this.x, this.y, otherPlant.x, otherPlant.y);
if (distToOther < this.maxSize * 0.75 + otherPlant.maxSize * 0.75) { // Check if plants are close
let dirToOther = createVector(otherPlant.x - this.x, otherPlant.y - this.y).normalize();
avoidanceDirection.sub(dirToOther); // Push away from other plants
}
}
}
avoidanceDirection.normalize();

// Combine biases
let baseDirection = parentBranch.direction.copy();
baseDirection.add(p5.Vector.mult(lightDirection, 0.5)); // Bias towards light
baseDirection.add(p5.Vector.mult(avoidanceDirection, 0.3)); // Bias away from neighbors
baseDirection.normalize();

// Implement growth patterns based on seedShape
switch (this.seedShape) {
case 'triangle':
// Sharp angular fractal branches
if (parentBranch.depth < 3) { // Limit fractal depth
let newLength = parentBranch.length * random(0.6, 0.8);
let newThickness = parentBranch.thickness * random(0.6, 0.8);
let angle1 = random(-PI / 4, PI / 4); // Random angle
let newDir1 = rotateVector(baseDirection, angle1);
this.branches.push(new Branch(parentBranch.end, newDir1, newLength, newThickness, parentBranch.depth + 1));
if (random() < 0.5) { // Sometimes add a second branch
let angle2 = random(-PI / 4, PI / 4);
let newDir2 = rotateVector(baseDirection, angle2);
this.branches.push(new Branch(parentBranch.end, newDir2, newLength, newThickness, parentBranch.depth + 1));
}
}
break;

case 'square':
// Blocky, terrace-like structures
let newLengthSquare = parentBranch.length * random(0.8, 1.1);
let newThicknessSquare = parentBranch.thickness * random(0.9, 1.1);
let angleSquare = random([-PI / 2, PI / 2]); // Only 90-degree turns
angleSquare += random(-PI / 12, PI / 12); // Slight wobble
let newDirSquare = rotateVector(baseDirection, angleSquare);
this.branches.push(new Branch(parentBranch.end, newDirSquare, newLengthSquare, newThicknessSquare, parentBranch.depth + 1));
break;

case 'pentagon':
case 'hexagon':
// Spiraling organic curves
let newLengthCurve = parentBranch.length * random(0.7, 0.9);
let newThicknessCurve = parentBranch.thickness * random(0.7, 0.9);
// Introduce a slight bias to create spiral
let spiralBias = (this.seedShape === 'pentagon' ? PI / 12 : -PI / 12);
spiralBias += random(-PI / 24, PI / 24); // Random wobble
let newDirCurve = rotateVector(baseDirection, spiralBias);
this.branches.push(new Branch(parentBranch.end, newDirCurve, newLengthCurve, newThicknessCurve, parentBranch.depth + 1));
if (random() < 0.3) { // Occasionally fork
let newDirCurve2 = rotateVector(baseDirection, -spiralBias);
this.branches.push(new Branch(parentBranch.end, newDirCurve2, newLengthCurve, newThicknessCurve, parentBranch.depth + 1));
}
break;
}
if (parentBranch.length < 5) parentBranch.active = false; // Mark small branches as inactive for further growth
}
}

draw() {
push();
translate(this.x, this.y);
rotate(sin(frameCount * 0.02) * 0.1); // Gentle sway for plants

// Draw branches
for (let branch of this.branches) {
branch.draw(this.hue, this.saturation, this.brightness);
}
pop();
}
}
```

---

### `index.html` (No changes needed)

```html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Soil Nutrient Simulation</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<script src="https://cdn.jsdelivr.net/npm/p5@1.11.3/lib/p5.min.js"></script>
<script src="sketch.js"></script>
</body>
</html>
```

---

### `style.css` (No changes needed)

```css
html, body {
margin: 0;
padding: 0;
overflow: hidden; /* Prevent scrollbars if canvas slightly exceeds window size */
}

canvas {
display: block; /* Remove extra space below the canvas */
}
```

---

**Summary of Changes:**

1. **`Branch` Class:** A new helper class to represent individual segments of a plant. It stores its start point, end point, direction, length, thickness, and depth (for fractal growth limits).
2. **`Plant` Class Overhaul:**
* **Properties:** Added `age`, `maxSize`, `maxBranches`, `growthChance`, `nutrientConsumptionRate`, `hue`, `saturation`, `brightness`, and a `branches` array.
* **`constructor()`:**
* Determines the plant's base `hue` based on `seedShape`: warm tones (yellow/orange) for triangle/square, cool tones (blue/purple) for pentagon/hexagon.
* Creates the initial `Branch` (the "trunk") that grows upwards from the plant's base.
* **`update()`:**
* **Nutrient Consumption:** Approximates the plant's footprint by consuming nutrients from the soil cell it germinated on and two cells directly above it. This is a simplified approach to keep performance high.
* **Growth Logic:**
* Checks `growthChance` and `maxBranches` before attempting to grow.
* Selects an `active` parent branch to grow from.
* Calculates a `baseDirection` for new branches, biasing it towards the top of the canvas (light) and away from other nearby plants (avoidance).
* Applies distinct growth rules based on `seedShape`:
* **Triangle:** Creates 1-2 shorter, thinner branches at random angles from the parent branch. Limited by `depth` to create a fractal appearance.
* **Square:** Creates a new branch that mostly extends the parent or turns at a 90-degree angle with a slight wobble, creating blocky structures.
* **Pentagon/Hexagon:** Creates 1-2 new branches with a slight rotational bias (`spiralBias`) to encourage a spiraling, curved growth.
* Marks very short parent branches as `inactive` to prevent infinite tiny growth.
* **`draw()`:** Iterates through all `Branch` objects in the `branches` array and draws them using `line()`, applying the plant's unique color and the branch's thickness.
3. **`rotateVector()` Helper:** A new function to simplify rotating `p5.Vector` objects, used by the `Plant` class for calculating new branch directions.
4. **`draw()` in `sketch.js`:**
* The `Plant` update and draw loops now manage the more complex `Plant` objects.
* Added a basic check to remove plants if they have no branches left (you could expand this to include nutrient starvation, age, etc.).
5. **`windowResized()`:** Clears the `plants` array as well, similar to `seeds`, to handle canvas resizing.

Now, when you run the sketch, you should see seeds falling and, upon germination, growing into unique, L-system-inspired plant forms that interact with the soil's nutrient levels and each other!