Add mem free printing (I need it to verify a suspicion relating to a bug)

node_modules/lv_font_conv/lib/writers/dump.js

@@ -0,0 +1,68 @@
+// Write font data into png images
+
+'use strict';
+
+
+const path     = require('path');
+const { PNG }  = require('pngjs');
+const AppError = require('../app_error');
+const utils    = require('../utils');
+
+const normal_color  = [ 255, 255, 255 ];
+const outside_color = [ 255, 127, 184 ];
+
+
+module.exports = function write_images(args, font) {
+  if (!args.output) throw new AppError('Output is required for "dump" writer');
+
+  let files = {};
+
+  let glyphs = font.glyphs.map(glyph => utils.set_depth(glyph, args.bpp));
+
+  for (let glyph of glyphs) {
+    let { code, advanceWidth, bbox, pixels } = glyph;
+
+    advanceWidth = Math.round(advanceWidth);
+
+    let minX = bbox.x;
+    let maxX = Math.max(bbox.x + bbox.width - 1, bbox.x);
+    let minY = Math.min(bbox.y, font.typoDescent);
+    let maxY = Math.max(bbox.y + bbox.height - 1, font.typoAscent);
+
+    let png = new PNG({ width: maxX - minX + 1, height: maxY - minY + 1 });
+
+    /* eslint-disable max-depth */
+    for (let pos = 0, y = maxY; y >= minY; y--) {
+      for (let x = minX; x <= maxX; x++) {
+        let value = 0;
+
+        if (x >= bbox.x && x < bbox.x + bbox.width && y >= bbox.y && y < bbox.y + bbox.height) {
+          value = pixels[bbox.height - (y - bbox.y) - 1][x - bbox.x];
+        }
+
+        let r, g, b;
+
+        if (x < 0 || x >= advanceWidth || y < font.typoDescent || y > font.typoAscent) {
+          [ r, g, b ] = outside_color;
+        } else {
+          [ r, g, b ] = normal_color;
+        }
+
+        png.data[pos++] = (255 - value) * r / 255;
+        png.data[pos++] = (255 - value) * g / 255;
+        png.data[pos++] = (255 - value) * b / 255;
+        png.data[pos++] = 255;
+      }
+    }
+
+
+    files[path.join(args.output, `${code.toString(16)}.png`)]  = PNG.sync.write(png);
+  }
+
+  files[path.join(args.output, 'font_info.json')] = JSON.stringify(
+    font,
+    (k, v) => (k === 'pixels' && !args.full_info ? undefined : v),
+    2);
+
+  return files;
+};