/**
* Interpolate between where the image should start and end in order to translate
* the image so that the point that is touched is what ends up centered at the end
* of the zoom.
* @param t
*/
private void TranslateImageToCenterTouchPosition(float t)
{
float targetX = startTouch.X + t * (endTouch.X - startTouch.X);
float targetY = startTouch.Y + t * (endTouch.Y - startTouch.Y);
PointF curr = view.TransformCoordBitmapToTouch(bitmapX, bitmapY);
view.matrix.PostTranslate(targetX - curr.X, targetY - curr.Y);
}
public DoubleTapZoom(TouchImageView view, float targetZoom, float focusX, float focusY, bool stretchImageToSuper)
{
this.view = view;
view.SetState(TouchState.ANIMATE_ZOOM);
startTime = DateTime.Now.Ticks;
this.startZoom = view.normalizedScale;
this.targetZoom = targetZoom;
this.stretchImageToSuper = stretchImageToSuper;
PointF bitmapPoint = view.TransformCoordTouchToBitmap(focusX, focusY, false);
this.bitmapX = bitmapPoint.X;
this.bitmapY = bitmapPoint.Y;
//
// Used for translating image during scaling
//
startTouch = view.TransformCoordBitmapToTouch(bitmapX, bitmapY);
endTouch = new PointF(view.viewWidth / 2, view.viewHeight / 2);
}