icon minification

tools/minify-icon-font.js

@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2022 StApps
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/* eslint-disable @typescript-eslint/no-non-null-assertion */
+import {openSync} from "fontkit"
+import {exec} from "child_process"
+import config from "../icons.config.js"
+import {statSync, existsSync} from "fs"
+
+/**
+ * @param command {string[] | string}
+ * @returns {Promise<string>}
+ */
+async function run(command) {
+  const fullCommand = Array.isArray(command) ? command.join(" ") : command
+  console.log(`>> ${fullCommand}`)
+
+  return new Promise((resolve, reject) => {
+    exec(fullCommand, (error, stdout, stderr) => {
+      if (error) {
+        reject(error)
+      } else if (stderr) {
+        reject(stderr)
+      } else {
+        resolve(stdout.trim())
+      }
+    })
+  })
+}
+
+/** @type {Set<string>} */
+const icons = new Set(config.icons)
+
+console.log("Icons used:", [...icons.values()].sort())
+const font = openSync(config.inputPath)
+
+const glyphs = ["5f-7a", "30-39"]
+for (const icon of icons) {
+  const iconGlyphs = font.layout(icon).glyphs
+  if (iconGlyphs.length === 0) {
+    console.error(`${icon} not found in font. Typo?`)
+    process.exit(-1)
+  }
+
+  const codePoints = iconGlyphs
+    .flatMap(it => font.stringsForGlyph(it.id))
+    .flatMap(it => [...it])
+    .map(it => it.codePointAt(0).toString(16))
+
+  if (codePoints.length === 0) {
+    if (config.codePoints?.[icon]) {
+      glyphs.push(config.codePoints[icon])
+    } else {
+      console.log()
+      console.error(`${icon} code point could not be determined. Add it to config.codePoints.`)
+      process.exit(-1)
+    }
+  }
+
+  glyphs.push(...codePoints)
+}
+glyphs.sort()
+
+const pythonPath = "./venv/bin/python"
+if (!existsSync(pythonPath)) {
+  throw new Error(`Expected a python virtual environment at ${pythonPath}`)
+}
+console.log(await run(`${pythonPath} --version`))
+console.log(
+  await run([
+    pythonPath,
+    "-m fontTools.subset",
+    `"${config.inputPath}"`,
+    `--unicodes=${glyphs.join(",")}`,
+    "--no-layout-closure",
+    `--output-file="${config.outputPath}"`,
+    "--flavor=woff2",
+  ]),
+)
+
+console.log(`${glyphs.length} Used Icons Total`)
+console.log(`Minified font saved to ${config.outputPath}`)
+const result = statSync(config.outputPath).size
+const before = statSync(config.inputPath).size
+
+console.log(
+  `${toByteUnit(before)} > ${toByteUnit(result)} (${(((before - result) / before) * 100).toFixed(
+    2,
+  )}% Reduction)`,
+)
+
+/**
+ * Bytes to respective units
+ *
+ * @param value {number}
+ * @returns {string}
+ */
+function toByteUnit(value) {
+  if (value < 1024) {
+    return `${value}B`
+  } else if (value < 1024 * 1024) {
+    return `${(value / 1024).toFixed(2)}KB`
+  } else {
+    return `${(value / 1024 / 1024).toFixed(2)}MB`
+  }
+}