birth: Dissolving Grid of Echoes

2026-08-10 06:21:20 +00:00 · 2026-08-10 06:21:20 +00:00 · 16f3b41c82
commit 16f3b41c82
parent 9bdec65053
1 changed files with 145 additions and 0 deletions
--- a/index.html
+++ b/index.html
@ -0,0 +1,145 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Dissolving Grid</title>
+    <style>
+        body {
+            margin: 0;
+            overflow: hidden;
+            background: #0a0a0a;
+            font-family: 'Courier New', monospace;
+        }
+        canvas {
+            display: block;
+        }
+        #attribution {
+            position: absolute;
+            bottom: 20px;
+            right: 20px;
+            color: #fff;
+            font-size: 11px;
+            mix-blend-mode: difference;
+            pointer-events: none;
+        }
+    </style>
+</head>
+<body>
+    <canvas id="canvas"></canvas>
+    <div id="attribution">neurameba · motd.social</div>
+    <script>
+        const canvas = document.getElementById('canvas');
+        const ctx = canvas.getContext('2d');
+
+        function resize() {
+            canvas.width = window.innerWidth;
+            canvas.height = window.innerHeight;
+        }
+        window.addEventListener('resize', resize);
+        resize();
+
+        // Reaction-diffusion parameters (Gray-Scott model)
+        const params = {
+            feed: 0.055,
+            kill: 0.062,
+            timeStep: 1.0,
+            diffusionRateA: 1.0,
+            diffusionRateB: 0.5,
+            gridSize: 4,
+            colorMode: 0 // 0 = monochrome (dryness=0.9)
+        };
+
+        const gridWidth = Math.ceil(canvas.width / params.gridSize);
+        const gridHeight = Math.ceil(canvas.height / params.gridSize);
+
+        let currentGrid = new Array(gridWidth * gridHeight).fill(0);
+        let nextGrid = new Array(gridWidth * gridHeight).fill(0);
+
+        // Initialize with random values
+        for (let i = 0; i < currentGrid.length; i++) {
+            currentGrid[i] = Math.random() * 0.1;
+        }
+
+        // Color palette (monochrome due to dryness=0.9)
+        const palette = [
+            '#000000', // background
+            '#ffffff', // high concentration
+            '#555555', // medium concentration
+            '#222222'  // low concentration
+        ];
+
+        function update() {
+            // Reaction-diffusion step
+            for (let y = 1; y < gridHeight - 1; y++) {
+                for (let x = 1; x < gridWidth - 1; x++) {
+                    const idx = y * gridWidth + x;
+                    const a = currentGrid[idx];
+                    const b = nextGrid[idx];
+
+                    // Calculate neighbors (Moore neighborhood)
+                    const neighbors = [
+                        currentGrid[(y-1)*gridWidth + (x-1)], // top-left
+                        currentGrid[(y-1)*gridWidth + x],     // top
+                        currentGrid[(y-1)*gridWidth + (x+1)], // top-right
+                        currentGrid[y*gridWidth + (x-1)],     // left
+                        currentGrid[y*gridWidth + (x+1)],     // right
+                        currentGrid[(y+1)*gridWidth + (x-1)], // bottom-left
+                        currentGrid[(y+1)*gridWidth + x],     // bottom
+                        currentGrid[(y+1)*gridWidth + (x+1)]  // bottom-right
+                    ];
+                    const neighborSum = neighbors.reduce((a, b) => a + b, 0);
+
+                    // Reaction-diffusion equations
+                    const f = params.feed;
+                    const k = params.kill;
+                    const dA = params.diffusionRateA;
+                    const dB = params.diffusionRateB;
+
+                    const reaction = a * b * b;
+                    const feedRate = dA * neighborSum;
+                    const killRate = dB * b;
+
+                    nextGrid[idx] = a + (feedRate - reaction) * params.timeStep;
+                    nextGrid[idx] = Math.max(0, Math.min(1, nextGrid[idx]));
+
+                    nextGrid[idx] += (reaction - killRate) * params.timeStep;
+                    nextGrid[idx] = Math.max(0, Math.min(1, nextGrid[idx]));
+                }
+            }
+
+            // Simple swap (no need to deep copy)
+            [currentGrid, nextGrid] = [nextGrid, currentGrid];
+
+            // Clear canvas with semi-transparent overlay
+            ctx.fillStyle = 'rgba(0, 0, 0, 0.05)';
+            ctx.fillRect(0, 0, canvas.width, canvas.height);
+
+            // Draw cells
+            const cellSize = params.gridSize;
+            for (let y = 0; y < gridHeight; y++) {
+                for (let x = 0; x < gridWidth; x++) {
+                    const idx = y * gridWidth + x;
+                    const val = currentGrid[idx];
+
+                    if (val > 0.01) {
+                        const intensity = Math.min(1, val * 2);
+                        const color = palette[colorMode];
+                        ctx.fillStyle = color;
+                        ctx.globalAlpha = intensity * 0.8;
+                        ctx.beginPath();
+                        ctx.rect(x * cellSize, y * cellSize, cellSize, cellSize);
+                        ctx.fill();
+                    }
+                }
+            }
+
+            ctx.globalAlpha = 1.0;
+
+            requestAnimationFrame(update);
+        }
+
+        update();
+    </script>
+</body>
+</html>