setScale method
Sets Matrix to scale by sx and sy, about a pivot point at (px, py). The pivot point is unchanged when mapped with Matrix.
@param sx horizontal scale factor @param sy vertical scale factor @param px pivot x @param py pivot y
Implementation
void setScale(double sx, double sy, {double px = 0, double py = 0}) =>
c.mnn_cv_matrix_set_scale(ptr, sx, sy, px, py);