private void prepareLinePaint(final Line line) {
        linePaint.setStrokeWidth(ChartUtils.dp2px(density, line.getStrokeWidth()));
        linePaint.setColor(line.getColor());
        linePaint.setPathEffect(line.getPathEffect());
        linePaint.setShader(null);
    }
Draws lines, uses path for drawing filled area on software canvas. Line is drawn with canvas.drawLines() method.
hellocharts-library/src/lecho/lib/hellocharts/renderer/LineChartRenderer.java