DankCodeJunk

<div class="page-width">
  <h1 class="small--text-center">{{ page.title }}</h1>
  <div class="content-block">
    <div class="rte rte--indented-images">
      {{ page.content }}

      <h3 id="test">IBO Speed</h3>
      <h5>(feet per second)</h5>
      <input type="text" id="ibospeed" />
      <h3>Draw Weight</h3>
      <h5>(pounds)</h5>
      <input type="text" id="drawweight" />
      <h3>Draw Length</h3>
      <h5>(inches)</h5>
      <input type="text" id="drawlength" />
      <h3>Arrow Weight</h3>
      <h5>(grains)</h5>
      <input type="text" id="arrowweight" />
      <br><br>
      <button onclick="calc()">Calculate</button>

      <h2>Calculated Arrow Speed</h2>
      <label id="result">Calculation here.</label>

    </div>
  </div>

  {% section 'featured-products-subsection' %}
</div>

<script>
  function calc() {


    //Bring the values from the text boxes into variables.
    //The parseFloat will take the first number/decimal it finds as long as
    //the variable starts with a numeric character.
    var ibo = parseFloat(document.getElementById("ibospeed").value);
    var drw = parseFloat(document.getElementById("drawweight").value);
    var drl = parseFloat(document.getElementById("drawlength").value);
    var arw = parseFloat(document.getElementById("ibospeed").value);
    var flag = false;

    //If any of the text boxes weren't a valid number, then the variables value
    //would become NaN. If there is a number greater than 1 in an if() statement
    //it will evaluate to true, and if it is NaN its false. We want to change the flag
    //if it is NaN though so the value checked is flipped with !.
    if(!ibo) {
      flag = true;
    }
    else if(!drw) {
      flag = true;
    }
    else if(!drl) {
      flag = true;
    }
    else if(!arw) {
      flag = true;
    }

    //If the flag was set, display a message and hope that the user fixes it.
    //Otherwise, start performing calculations.
    if(flag) {
      document.getElementById("result").innerHTML = "Please make sure everything is a number, then hit the calculate again!";
    }
    else {

      var dla = 0;
      var dwa = 0;
      var kezero = 0;
      var awdw = (arw/drw).toPrecision(10);
      var keone = 0;

      //dla
      switch(drl) {
        //case ((drl >= 18) && (drl <= 28)):
        case 1:
          dla = (-8 * drl) + 244;
          break;
        case (drl <= 32):
          dla = (-10 * drl) + 300;
          break;
        default:
          document.getElementById("result").innerHTML = "Sorry, Draw Length needs to be between 18 and 32 for the calculation to work.";
          return;
      };

      //dwa
      switch(drw) {
        case ((drw >= 14.75) && (drw <= 50)):
          dwa = ((-28.2 * drw) / 35.25) + (2079.75 / 35.25);
          break;
        case (drw <= 60):
          dwa = ((-9 * drw) / 10) + 64;
          break;
        case (drw <= 70):
          dwa = (-drw) + 70;
          break;
        case (drw <= 80):
          dwa = ((-9 * drw) / 10) + 63;
          break;
        case (drw <= 90):
          dwa = ((-8 * drw) / 10) + 55;
          break;
        default:
          document.getElementById("result").innerHTML = "Sorry, Draw Weight needs to be between 14.75 and 90 for the calculation to work.";
          return;
      };

      //ke0
      kezero = (drw * 5) * (((ibo-dla-dwa)^2)/450800).toPrecision(10);

      //ke1
      switch(awdw) {
        case ((awdw >= 4) && (awdw <= 5.9)):
          keone = kezero + 0;
          break;
        case (awdw <= 12):
          keone = kezero + ((5.4 * awdw) / 6) - (31.86 / 6);
          break;
        case (awdw <= 18):
          keone = kezero + ((2.2 * awdw) / 5.9) + (6.066 / 5.9);
          break;
        case (awdw <= 68):
          keone = kezero + 0;
          break;
        default:
          document.getElementById("result").innerHTML = "Sorry, something went wrong with the calculation, please contact Robert!";
          return;

      }

      document.getElementById("result").innerHTML = keone;
    }

};
</script>