public void ZoomByScaleFactor(SKPoint point, float scaleFactor)
{
var currentScale = GetScale();
currentScale *= scaleFactor;
if (currentScale < MinScale || currentScale > MaxScale)
{
return;
}
if (!CenterBoundary.IsEmpty)
{
var center = GetCenter();
if (!CenterBoundary.Contains(center))
{
return;
}
}
SKMatrix.PreConcat(ref Matrix, SKMatrix.MakeScale(scaleFactor, scaleFactor, point.X, point.Y));
}
public void MoveByVector(SKPoint vector)
{
SKMatrix invertedMatrix;
if (!Matrix.TryInvert(out invertedMatrix))
{
return;
}
var resultPoint = invertedMatrix.MapVector(vector.X, vector.Y);
SKMatrix.PreConcat(ref Matrix, SKMatrix.MakeTranslation(resultPoint.X, resultPoint.Y));
if (CenterBoundary.IsEmpty)
{
return;
}
var center = GetCenter();
if (!CenterBoundary.Contains(center))
{
//rollback
SKMatrix.PreConcat(ref Matrix, SKMatrix.MakeTranslation(-resultPoint.X, -resultPoint.Y));
}
}