peity.alarmline.js

  $.fn.peity.register('alarmline', $.extend({},$.fn.peity.defaults.line,{
    alarmColour: '#a00'
  }), function (opts) {
    $.fn.peity.graphers.line.apply(this, [opts]);
    var values = this.values();
    if (values.length == 1) values.push(values[0]);
    var min = Math.min.apply(Math, values.concat([opts.min]));
    var max = Math.max.apply(Math, values.concat([opts.max]));

    var canvas = this.canvas;
    var context = this.context;
    var width = canvas.width;
    var height = canvas.height - opts.strokeWidth;
    var yQuotient = height / (max - min);

    if (opts.alarm) {
      context.beginPath();
      var alarm_y = height - (yQuotient * (opts.alarm - min)) + opts.strokeWidth / 2;
      context.moveTo(0, alarm_y);
      context.lineTo(width, alarm_y);
      context.lineWidth = opts.strokeWidth * (window.devicePixelRatio||1);
      context.strokeStyle = opts.alarmColour;
      context.stroke();
    }
  });