fix(flutter): scale the remote cursor with its image

flutter/lib/desktop/pages/remote_page.dart

@@ -1413,26 +1413,25 @@ class CursorPaint extends StatelessWidget {
       }
     }
 
-    double x = m.x * c.scale + cx - hotx;
-    double y = m.y * c.scale + cy - hoty;
-    double scale = 1.0;
-    final isViewOriginal = c.viewStyle.style == kRemoteViewStyleOriginal;
-    if (zoomCursor.value || isViewOriginal) {
-      x = m.x - hotx + cx / c.scale;
-      y = m.y - hoty + cy / c.scale;
-      scale = c.scale;
-    } else if (isLinux || isMacOS) {
-      scale = 1.0 / MediaQuery.devicePixelRatioOf(context);
-      x = (m.x * c.scale + cx) / scale - hotx;
-      y = (m.y * c.scale + cy) / scale - hoty;
+    final image = m.image ?? preDefaultCursor.image;
+    final nativePixels = isWindows ? MediaQuery.devicePixelRatioOf(context) : 1.0;
+    double scale = c.scale;
+    if (image != null && scale * nativePixels != 1.0) {
+      final sx = kMinCursorSize / (image.width * nativePixels);
+      final sy = kMinCursorSize / (image.height * nativePixels);
+      final minimumScale = sx > sy ? sx : sy;
+      if (scale < minimumScale) scale = minimumScale;
     }
+    final x = (m.x * c.scale + cx) / scale - hotx;
+    final y = (m.y * c.scale + cy) / scale - hoty;
 
     return CustomPaint(
       painter: ImagePainter(
-        image: m.image ?? preDefaultCursor.image,
+        image: image,
         x: x,
         y: y,
         scale: scale,
+        useIntegerPosition: false,
       ),
     );
   }

flutter/lib/utils/image.dart

@@ -96,12 +96,14 @@ class ImagePainter extends CustomPainter {
     required this.x,
     required this.y,
     required this.scale,
+    this.useIntegerPosition = true,
   });
 
   ui.Image? image;
   double x;
   double y;
   double scale;
+  final bool useIntegerPosition;
 
   @override
   void paint(Canvas canvas, Size size) {
@@ -122,8 +124,10 @@ class ImagePainter extends CustomPainter {
     if (isWeb) {
       paint.filterQuality = FilterQuality.high;
     }
-    canvas.drawImage(
-        image!, Offset(x.toInt().toDouble(), y.toInt().toDouble()), paint);
+    final position = useIntegerPosition
+        ? Offset(x.toInt().toDouble(), y.toInt().toDouble())
+        : Offset(x, y);
+    canvas.drawImage(image!, position, paint);
   }
 
   @override

flutter/test/cursor_paint_scale_test.dart

@@ -11,9 +11,8 @@ import 'package:get/get.dart';
 import 'package:provider/provider.dart';
 
 const _hotspot = Offset(4, 9);
-const _remotePosition = Offset(100, 80);
-const _canvasOffset = Offset(15, 10);
-const _canvasScale = 0.5;
+const _remotePosition = Offset(100.25, 80.75);
+const _canvasOffset = Offset(15.125, 10.25);
 const _viewport = Size(200, 160);
 
 class _CursorModel extends ChangeNotifier implements CursorModel {
@@ -35,7 +34,7 @@ class _CursorModel extends ChangeNotifier implements CursorModel {
 }
 
 class _CanvasModel extends ChangeNotifier implements CanvasModel {
-  _CanvasModel(String style)
+  _CanvasModel(String style, this.scale)
       : viewStyle = ViewStyle(
           style: style,
           width: _viewport.width,
@@ -51,7 +50,7 @@ class _CanvasModel extends ChangeNotifier implements CanvasModel {
   @override
   double get y => _canvasOffset.dy;
   @override
-  double get scale => _canvasScale;
+  final double scale;
   @override
   ScrollStyle get scrollStyle => ScrollStyle.scrollauto;
 
@@ -59,17 +58,48 @@ class _CanvasModel extends ChangeNotifier implements CanvasModel {
   dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
+class _Canvas extends Fake implements Canvas {
+  double factor = 1;
+  Offset? position;
+
+  @override
+  void scale(double sx, [double? sy]) => factor *= sx;
+
+  @override
+  void drawImage(ui.Image image, Offset offset, Paint paint) {
+    position = offset * factor;
+  }
+}
+
 void main() {
-  for (final (style, zoom, dpr, scale) in [
-    (kRemoteViewStyleAdaptive, false, 2.0, 0.5),
-    (kRemoteViewStyleAdaptive, false, 3.0, 1 / 3),
-    (kRemoteViewStyleAdaptive, true, 3.0, _canvasScale),
-    (kRemoteViewStyleOriginal, false, 2.0, _canvasScale),
+  for (final (style, zoom, dpr, source, canvasScale, scale) in [
+    (kRemoteViewStyleAdaptive, false, 2.0, (48, 64), 0.375, 0.375),
+    (kRemoteViewStyleAdaptive, false, 3.0, (48, 64), 0.25, 0.25),
+    (kRemoteViewStyleAdaptive, true, 3.0, (48, 64), 0.375, 0.375),
+    (kRemoteViewStyleOriginal, false, 2.0, (48, 64), 0.5, 0.5),
+    (kRemoteViewStyleOriginal, true, 2.0, (48, 64), 0.5, 0.5),
+    (
+      kRemoteViewStyleAdaptive,
+      false,
+      2.0,
+      (9, 18),
+      0.1,
+      Platform.isWindows ? 2 / 3 : 4 / 3
+    ),
+    (
+      kRemoteViewStyleAdaptive,
+      true,
+      2.0,
+      (9, 18),
+      0.1,
+      Platform.isWindows ? 2 / 3 : 4 / 3
+    ),
   ]) {
-    testWidgets('$style zoom=$zoom dpr=$dpr keeps cursor scale and hotspot',
+    testWidgets(
+        '$style zoom=$zoom dpr=$dpr source=$source keeps remote geometry',
         (tester) async {
-      final image =
-          (await tester.runAsync(() => createTestImage(width: 9, height: 18)))!;
+      final image = (await tester.runAsync(
+          () => createTestImage(width: source.$1, height: source.$2)))!;
       addTearDown(image.dispose);
       await tester.pumpWidget(MediaQuery(
         data: MediaQueryData(devicePixelRatio: dpr),
@@ -78,7 +108,7 @@ void main() {
             ChangeNotifierProvider<CursorModel>(
                 create: (_) => _CursorModel(image)),
             ChangeNotifierProvider<CanvasModel>(
-                create: (_) => _CanvasModel(style)),
+                create: (_) => _CanvasModel(style, canvasScale)),
           ],
           child: CursorPaint(id: 'cursor-test', zoomCursor: zoom.obs),
         ),
@@ -90,7 +120,13 @@ void main() {
       expect(painter.image, same(image));
       expect(painter.scale, scale);
       expect((Offset(painter.x, painter.y) + _hotspot) * scale,
-          _remotePosition * _canvasScale + _canvasOffset);
-    }, skip: Platform.isWindows && style == kRemoteViewStyleAdaptive && !zoom);
+          _remotePosition * canvasScale + _canvasOffset);
+      final canvas = _Canvas();
+      painter.paint(canvas, _viewport);
+      final position = canvas.position! + _hotspot * canvas.factor;
+      final target = _remotePosition * canvasScale + _canvasOffset;
+      expect(position.dx, closeTo(target.dx, 1e-9));
+      expect(position.dy, closeTo(target.dy, 1e-9));
+    });
   }
 }