public void StartPinchToZoom(float x0, float y0, float x1, float y1)
{
_previousDist = LineUtil.Distance(x0, y0, x1, y1);
if (_previousDist > _minPinchToZoomDistance)
{
_savedMatrix.Set(_matrix);
LineUtil.Middle(ref _middle, x0, y0, x1, y1);
}
}
public void PinchToZoom(float x0, float y0, float x1, float y1)
{
float currentDist = LineUtil.Distance(x0, y0, x1, y1);
if (currentDist > _minPinchToZoomDistance)
{
float scale = currentDist / _previousDist;
_matrix.Set(_savedMatrix);
_matrix.PostScale(scale, scale, _middle.X, _middle.Y);
_matrix.GetValues(_matrixValues);
Zoom = _matrixValues[Matrix.MscaleX];
PanX = _matrixValues[Matrix.MtransX];
PanY = _matrixValues[Matrix.MtransY];
}
}