private void UpdateChartPoints(OrderBookDataSet dataSet)
{
var fontHeight = (int)Font.GetHeight();
if (_askChartPoints.Count >= _pointsGraphCount)
{
_askChartPoints.RemoveAt(0); // Remove the first element from ask array
_bidChartPoints.RemoveAt(0); // From bid
}
if (dataSet != null)
{
_askChartPoints.Add(new Point(_chartWidth, GetY(dataSet.Ask[0].Price, fontHeight)));
_bidChartPoints.Add(new Point(_chartWidth, GetY(dataSet.Bid[0].Price, fontHeight)));
}
// Shit both arrays (bid, ask), make a visual move. Run throughout the array (all points) starting from the 1st and decrease X coordinate with the step
for (int i = 0; i < _askChartPoints.Count - 1; i++)
{
_askChartPoints[i] = new Point(_askChartPoints[i].X - _pointsGraphStep, _askChartPoints[i].Y); // ask. Shift a horisontal coordinate of the whole array with a step. This makes a move. Bigger step - faster move
_bidChartPoints[i] = new Point(_bidChartPoints[i].X - _pointsGraphStep, _bidChartPoints[i].Y); // bid
}
Invalidate();
}
// Draw a vertical stack of the prices
private void DrawPriceBar(Graphics g, OrderBookDataSet dataSet)
{
if (dataSet == null)
{
return;
}
var fontHeight = (int)Font.GetHeight();
for (var p = _priceStart; p < _priceEnd; p += _priceStep)
{
g.DrawString(p.ToString(CultureInfo.CurrentCulture), Font, Brushes.LightGray, _chartWidth, GetY(p, fontHeight) - fontHeight / 2);
}
var maxVolume = Math.Max(dataSet.Ask.Max(d => d.Volume), dataSet.Bid.Max(d => d.Volume));
// Price bar background width calculation
var priceBarBackGroundWidth = _orderBackgroundWidth + (int)g.MeasureString(maxVolume.ToString(), Font).Width;
// Render ask (uppder) part of the DOM
foreach (var record in dataSet.Ask)
{
DrawPriceBarRow(g, record, priceBarBackGroundWidth, fontHeight, Brushes.LightPink, maxVolume);
}
// Draw bid (lower) part of the DOM
foreach (var record in dataSet.Bid)
{
DrawPriceBarRow(g, record, priceBarBackGroundWidth, fontHeight, Brushes.LimeGreen, maxVolume);
}
if (ActiveOrders != null)
{
foreach (var activeOrder in ActiveOrders)
{
g.DrawRectangle(Pens.Black, _chartWidth - 2, GetY(activeOrder.Price, fontHeight) - fontHeight / 2, priceBarBackGroundWidth + 4, fontHeight - _backGroundReduction);
}
}
}
public void RaiseOrderBookReceived(OrderBookDataSet data) => OnOrderBookReceived(new EventArgs <OrderBookDataSet>(data));
