getTextSizeAsync function
GetTextSizeWithBaseline calculates the width and height of a text string including the basline of the text. It returns an image.Point with the size required to draw text using a specific font face, scale, and thickness as well as its baseline.
For further details, please see: http:///docs.opencv.org/master/d6/d6e/group__imgproc__draw.html#ga3d2abfcb995fd2db908c8288199dba82
Implementation
Future<(Size size, int baseline)> getTextSizeAsync(
String text,
int fontFace,
double fontScale,
int thickness,
) async {
final ctext = text.toNativeUtf8().cast<ffi.Char>();
final ret = cvRunAsync2<(Size, int)>(
(callback) => cimgproc.GetTextSizeWithBaseline_Async(ctext, fontFace, fontScale, thickness, callback),
(completer, p, p1) {
final size = Size.fromPointer(p.cast<cimgproc.Size>());
final baseline = p1.cast<ffi.Int>().value;
calloc.free(p1);
completer.complete((size, baseline));
});
calloc.free(ctext);
return ret;
}