Initial commit

gen-icons.js

@@ -0,0 +1,126 @@
+// Generates simple PNG icons using pure Node.js (no external packages needed).
+'use strict';
+const fs   = require('fs');
+const path = require('path');
+const zlib = require('zlib');
+
+const outDir = path.join(__dirname, 'public', 'icons');
+if (!fs.existsSync(outDir)) fs.mkdirSync(outDir, { recursive: true });
+
+function writePNG(filePath, size) {
+  const channels = 4; // RGBA
+  const row = size * channels;
+  const raw = Buffer.alloc(size * row);
+
+  // Background: dark green #145228
+  const bgR = 0x14, bgG = 0x52, bgB = 0x28;
+  // Heart color: red #e53935
+  const hR = 0xe5, hG = 0x39, hB = 0x35;
+
+  // Draw pixel by pixel: background + centered heart shape
+  // Heart expressed as two overlapping circles + a downward triangle
+  const cx = size / 2;
+  const cy = size / 2 + size * 0.05;
+  const r  = size * 0.22;
+
+  // Two circle centers
+  const lx = cx - r * 0.6, ly = cy - r * 0.35;
+  const rx = cx + r * 0.6, ry = cy - r * 0.35;
+  // Triangle tip
+  const tipY = cy + r * 1.1;
+
+  for (let y = 0; y < size; y++) {
+    for (let x = 0; x < size; x++) {
+      const px = (y * size + x) * channels;
+      const nx = x + 0.5, ny = y + 0.5;
+
+      // Rounded corners (radius ~20% of size)
+      const cr = size * 0.2;
+      const inCorner = (nx < cr && ny < cr && Math.hypot(nx - cr, ny - cr) > cr) ||
+                       (nx > size - cr && ny < cr && Math.hypot(nx - (size - cr), ny - cr) > cr) ||
+                       (nx < cr && ny > size - cr && Math.hypot(nx - cr, ny - (size - cr)) > cr) ||
+                       (nx > size - cr && ny > size - cr && Math.hypot(nx - (size - cr), ny - (size - cr)) > cr);
+      if (inCorner) { raw[px+3] = 0; continue; }
+
+      // Heart: point in left circle OR right circle OR downward triangle region
+      const inL = Math.hypot(nx - lx, ny - ly) <= r;
+      const inR = Math.hypot(nx - rx, ny - ry) <= r;
+      // Triangle: below the circle union and above the tip
+      // Approximate with two lines from the outer circle edges to the tip
+      const inT = ny >= Math.min(ly, ry) && nx >= lx - r + (nx - (lx - r)) * 0 &&
+                  (ny - (cy - r * 0.35)) / (tipY - (cy - r * 0.35)) <=
+                  1 - Math.abs(nx - cx) / (r * 1.2);
+
+      const inHeart = inL || inR || inT;
+
+      if (inHeart) {
+        raw[px]   = hR;
+        raw[px+1] = hG;
+        raw[px+2] = hB;
+        raw[px+3] = 255;
+      } else {
+        raw[px]   = bgR;
+        raw[px+1] = bgG;
+        raw[px+2] = bgB;
+        raw[px+3] = 255;
+      }
+    }
+  }
+
+  // Encode to PNG
+  const chunks = [];
+
+  // PNG signature
+  chunks.push(Buffer.from([137, 80, 78, 71, 13, 10, 26, 10]));
+
+  function crc32(buf) {
+    let c = 0xffffffff;
+    const table = crc32.table || (crc32.table = (() => {
+      const t = new Uint32Array(256);
+      for (let i = 0; i < 256; i++) {
+        let v = i;
+        for (let k = 0; k < 8; k++) v = v & 1 ? 0xedb88320 ^ (v >>> 1) : v >>> 1;
+        t[i] = v;
+      }
+      return t;
+    })());
+    for (let i = 0; i < buf.length; i++) c = table[(c ^ buf[i]) & 0xff] ^ (c >>> 8);
+    return (c ^ 0xffffffff) >>> 0;
+  }
+
+  function chunk(type, data) {
+    const len = Buffer.alloc(4); len.writeUInt32BE(data.length);
+    const tp  = Buffer.from(type);
+    const crc = Buffer.alloc(4);
+    crc.writeUInt32BE(crc32(Buffer.concat([tp, data])));
+    return Buffer.concat([len, tp, data, crc]);
+  }
+
+  // IHDR
+  const ihdr = Buffer.alloc(13);
+  ihdr.writeUInt32BE(size, 0);
+  ihdr.writeUInt32BE(size, 4);
+  ihdr[8]  = 8;  // bit depth
+  ihdr[9]  = 6;  // RGBA
+  ihdr[10] = 0; ihdr[11] = 0; ihdr[12] = 0;
+  chunks.push(chunk('IHDR', ihdr));
+
+  // IDAT: add filter byte (0) before each row
+  const filtered = Buffer.alloc(size * (row + 1));
+  for (let y = 0; y < size; y++) {
+    filtered[y * (row + 1)] = 0; // None filter
+    raw.copy(filtered, y * (row + 1) + 1, y * row, (y + 1) * row);
+  }
+  const compressed = zlib.deflateSync(filtered);
+  chunks.push(chunk('IDAT', compressed));
+
+  // IEND
+  chunks.push(chunk('IEND', Buffer.alloc(0)));
+
+  fs.writeFileSync(filePath, Buffer.concat(chunks));
+  console.log(`${path.basename(filePath)} written (${size}×${size})`);
+}
+
+writePNG(path.join(outDir, 'icon-192.png'), 192);
+writePNG(path.join(outDir, 'icon-512.png'), 512);
+console.log('Icons generated.');