zoomAroundPoint method

GMatrix zoomAroundPoint(
  1. GPoint center,
  2. double zoomFactor
)

Simple utility to zoom by zoomFactor around the point center that returns the new matrix.

Implementation

GMatrix zoomAroundPoint(GPoint center, double zoomFactor) {
  var t1 = GMatrix();
  t1.translate(-center.x, -center.y);
  var sc = GMatrix();
  sc.scale(zoomFactor, zoomFactor);
  var t2 = GMatrix();
  t2.translate(center.x, center.y);
  var zoom = GMatrix();
  zoom.concat(t1).concat(sc).concat(t2);
  return concat(zoom);
}