[flutter_svg] Update README with an example to scale images

third_party/packages/flutter_svg/README.md

@@ -127,6 +127,43 @@ import 'dart:ui' as ui;
   pictureInfo.picture.dispose();
 ```
 
+or if you want to scale it, you can do something like:
+
+<?code-excerpt "example/lib/readme_excerpts.dart (OutputScaling)"?>
+```dart
+import 'dart:ui' as ui;
+
+// ···
+  const rawSvg = '''<svg ...>...</svg>''';
+  final PictureInfo pictureInfo = await vg.loadPicture(
+    const SvgStringLoader(rawSvg),
+    null,
+  );
+
+  // You can convert the picture to a scaled image:
+  const double targetWidth = 512;
+  const double targetHeight = 512;
+  final pictureRecorder = ui.PictureRecorder();
+  final canvas = Canvas(
+    pictureRecorder,
+    Rect.fromPoints(
+      Offset.zero,
+      const Offset(targetWidth, targetHeight),
+    ),
+  );
+  canvas.scale(
+    targetWidth / pictureInfo.size.width,
+    targetHeight / pictureInfo.size.height,
+  );
+  canvas.drawPicture(pictureInfo.picture);
+  final ui.Image scaledImage = await pictureRecorder.endRecording().toImage(
+    targetWidth.ceil(),
+    targetHeight.ceil(),
+  );
+
+  pictureInfo.picture.dispose();
+```
+
 The `SvgPicture` helps to automate this logic, and it provides some convenience
 wrappers for getting assets from multiple sources.
 

third_party/packages/flutter_svg/example/lib/readme_excerpts.dart

@@ -6,9 +6,11 @@
 // intended for use as an actual example application.
 
 // #docregion OutputConversion
+// #docregion OutputScaling
 import 'dart:ui' as ui;
 
 // #enddocregion OutputConversion
+// #enddocregion OutputScaling
 
 import 'package:flutter/material.dart';
 import 'package:flutter_svg/flutter_svg.dart';
@@ -101,6 +103,41 @@ Future<ui.Image> convertSvgOutput() async {
   return image;
 }
 
+/// Demonstrates scaling SVG to a larger image
+Future<ui.Image> scaleSvgOutput() async {
+  // #docregion OutputScaling
+  const rawSvg = '''<svg ...>...</svg>''';
+  final PictureInfo pictureInfo = await vg.loadPicture(
+    const SvgStringLoader(rawSvg),
+    null,
+  );
+
+  // You can convert the picture to a scaled image:
+  const double targetWidth = 512;
+  const double targetHeight = 512;
+  final pictureRecorder = ui.PictureRecorder();
+  final canvas = Canvas(
+    pictureRecorder,
+    Rect.fromPoints(
+      Offset.zero,
+      const Offset(targetWidth, targetHeight),
+    ),
+  );
+  canvas.scale(
+    targetWidth / pictureInfo.size.width,
+    targetHeight / pictureInfo.size.height,
+  );
+  canvas.drawPicture(pictureInfo.picture);
+  final ui.Image scaledImage = await pictureRecorder.endRecording().toImage(
+    targetWidth.ceil(),
+    targetHeight.ceil(),
+  );
+
+  pictureInfo.picture.dispose();
+  // #enddocregion OutputScaling
+  return scaledImage;
+}
+
 // #docregion ColorMapper
 class _MyColorMapper extends ColorMapper {
   const _MyColorMapper();