docs: private void anchorAtThisPositionAndScale() {
          if (DEBUG)
              Log.i("MulitTouch", "anchorAtThisPositionAndScale()");
  		if (selectedObject == null)
  			return;
  
  		// Get selected object's current position and scale
  		objectCanvas.getPositionAndScale(selectedObject, mCurrXform);
  
  		// Figure out the object coords of the drag start point's screen coords.
  		// All stretching should be around this point in object-coord-space.
  		// Also figure out out ratio between object scale factor and multitouch
  		// diameter at beginning of drag; same for angle and optional anisotropic
  		// scale.
  		float currScaleInv = 1.0f / (!mCurrXform.updateScale ? 1.0f : mCurrXform.scale == 0.0f ? 1.0f : mCurrXform.scale);
  		extractCurrPtInfo();
  		startPosX = (mCurrPtX - mCurrXform.xOff) * currScaleInv;
  		startPosY = (mCurrPtY - mCurrXform.yOff) * currScaleInv;
  		startScaleOverPinchDiam = mCurrXform.scale / mCurrPtDiam;
  		startScaleXOverPinchWidth = mCurrXform.scaleX / mCurrPtWidth;
  		startScaleYOverPinchHeight = mCurrXform.scaleY / mCurrPtHeight;
  		startAngleMinusPinchAngle = mCurrXform.angle - mCurrPtAng;
  	}