I have successfully achieved this effect by getting the y value of two prices and using their difference as a scale factor. And then using the yscale variable in the call to DrawRectangle
int y1 = ChartControl.GetYByValue(this, 1); int y2 = ChartControl.GetYByValue(this, 2); float yscale = (y1 - y2) * (float)tickSize;
Comment