sclass TradingCandlePainter {
  settable L<TradingCandle> candles;
  
  settable int w = 600;
  settable int h = 400;
  int horizontalMargin = 10;
  int verticalMargin = 10;
  int spikeWidth = 1;
  Color shortColor = java.awt.Color.blue;
  Color longColor = java.awt.Color.yellow;
  
  L<TradingPosition> positions;
  
  // how many lines are drawn to indicate percent changes
  settable double percentLineDistance = 0.05;
  
  BufferedImage render() {
    var run = new TradingRun(candles);
    var verticalRange = doubleRange(run.min(), run.max());
    var horizontalRange = doubleRange(run.startTime().unixDate(), run.endTime().unixDate());
    var xRange = doubleRange(horizontalMargin, w-horizontalMargin);
    var yRange = doubleRange(h-verticalMargin, verticalMargin);
    
    // Make black image
    var img = blackImage(w, h);
    var g = img.createGraphics();
    
    // Draw percent lines
    double percentStep = center(verticalRange)*percentLineDistance/100;
    for (double y = verticalRange.start; y <= verticalRange.end; y += percentStep) {
      var yy = iround(transformBetweenDoubleRanges(y, verticalRange, yRange));
      drawLine(g, 0, yy, w-1, yy, Color.gray);
    }
    
    // Draw candles
    
    var nCandles = l(candles);
    
    for i to nCandles: {
      var candle = candles.get(i);
        //x1 <- transformBetweenDoubleRanges (candle startTime) horizontalRange xRange
      var x1 = xRange.start()+doubleRatio(i, nCandles)*xRange.length();
      var x2 = xRange.start()+doubleRatio(i+1, nCandles)*xRange.length();
      x2 = blend(x1, x2, 0.75);
      var xCenter = avg(x1, x2);
      var y1 = transformBetweenDoubleRanges(candle.max(), verticalRange, yRange);
      var y2 = transformBetweenDoubleRanges(candle.min(), verticalRange, yRange);
      var yStart = transformBetweenDoubleRanges(candle.start(), verticalRange, yRange);
      var yEnd = transformBetweenDoubleRanges(candle.end(), verticalRange, yRange);
      
        // draw "spikes"
      var r = doubleRectFromPoints(xCenter, y1, xCenter+spikeWidth, y2);
      fillRect(g, growRectBottom(1, toRect_round(r)), candle.color());
      
        // draw candle body
      r = doubleRectFromPoints(x1, min(yStart, yEnd), x2, max(yStart, yEnd));
      fillRect(g, growRectBottom(1, toRect_round(r)), candle.color());
    
    };
    
    for (position : positions) {
      var time = position.openingTime();
      var price = position.openingPrice();
      var x = transformBetweenDoubleRanges(time, horizontalRange, xRange);
      var y = transformBetweenDoubleRanges(price, verticalRange, yRange);
      
      var color = colorFromHex(position.relativeValue() > 0 ? "1da2b4" : "f1493f");
      
      // Mark opening point
      fillRect(g, rectAroundPt(iround(x), iround(y), 10), color);
          
      if (not(position.isOpen())) {
        time = position.closingTime();
        price = position.closingPrice();
        var x2 = transformBetweenDoubleRanges(time, horizontalRange, xRange);
        var y2 = transformBetweenDoubleRanges(price, verticalRange, yRange);
        drawArrowBetweenPoints(g, toPt_round(doublePt(x, y)), toPt_round(doublePt(x2, y2)), color);
      }
    }
    
    ret img;
  }
}