setScanRegion method
Restricts decoding to a rectangle of the preview, in normalized coordinates. Cutting the search area is the cheapest speed win there is.
Implementation
void setScanRegion(Rect? normalizedRegion) {
final UCameraSize preview = value.previewSize;
if (normalizedRegion == null || preview.width == 0) {
_config = _config.copyWith(scanOptions: _config.scanOptions.copyWith());
return;
}
_config = _config.copyWith(
scanOptions: _config.scanOptions.copyWith(
region: Rect.fromLTWH(
normalizedRegion.left * preview.width,
normalizedRegion.top * preview.height,
normalizedRegion.width * preview.width,
normalizedRegion.height * preview.height,
),
),
);
}