Avoid the overhead of instantiating a generator in paintImage (#28736)
This function is called frequently with non-repeating images during many
animations
diff --git a/packages/flutter/lib/src/painting/decoration_image.dart b/packages/flutter/lib/src/painting/decoration_image.dart
index b3bdc09..96a8b82 100644
--- a/packages/flutter/lib/src/painting/decoration_image.dart
+++ b/packages/flutter/lib/src/painting/decoration_image.dart
@@ -438,22 +438,25 @@
final Rect sourceRect = alignment.inscribe(
sourceSize, Offset.zero & inputSize,
);
- for (Rect tileRect in _generateImageTileRects(rect, destinationRect, repeat))
- canvas.drawImageRect(image, sourceRect, tileRect, paint);
+ if (repeat == ImageRepeat.noRepeat) {
+ canvas.drawImageRect(image, sourceRect, destinationRect, paint);
+ } else {
+ for (Rect tileRect in _generateImageTileRects(rect, destinationRect, repeat))
+ canvas.drawImageRect(image, sourceRect, tileRect, paint);
+ }
} else {
- for (Rect tileRect in _generateImageTileRects(rect, destinationRect, repeat))
- canvas.drawImageNine(image, centerSlice, tileRect, paint);
+ if (repeat == ImageRepeat.noRepeat) {
+ canvas.drawImageNine(image, centerSlice, destinationRect, paint);
+ } else {
+ for (Rect tileRect in _generateImageTileRects(rect, destinationRect, repeat))
+ canvas.drawImageNine(image, centerSlice, tileRect, paint);
+ }
}
if (needSave)
canvas.restore();
}
Iterable<Rect> _generateImageTileRects(Rect outputRect, Rect fundamentalRect, ImageRepeat repeat) sync* {
- if (repeat == ImageRepeat.noRepeat) {
- yield fundamentalRect;
- return;
- }
-
int startX = 0;
int startY = 0;
int stopX = 0;
