/* Flot plugin that adds some extra symbols for plotting points.
  
  Copyright (c) 2007-2014 IOLA and Ole Laursen.
  Licensed under the MIT license.
  
  The symbols are accessed as strings through the standard symbol options:
  
  	series: {
  		points: {
  			symbol: "square" // or "diamond", "triangle", "cross"
  		}
  	}
  
  */
  
  (function ($) {
      function processRawData(plot, series, datapoints) {
          // we normalize the area of each symbol so it is approximately the
          // same as a circle of the given radius
  
          var handlers = {
              square: function (ctx, x, y, radius, shadow) {
                  // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2
                  var size = radius * Math.sqrt(Math.PI) / 2;
                  ctx.rect(x - size, y - size, size + size, size + size);
              },
              diamond: function (ctx, x, y, radius, shadow) {
                  // pi * r^2 = 2s^2  =>  s = r * sqrt(pi/2)
                  var size = radius * Math.sqrt(Math.PI / 2);
                  ctx.moveTo(x - size, y);
                  ctx.lineTo(x, y - size);
                  ctx.lineTo(x + size, y);
                  ctx.lineTo(x, y + size);
                  ctx.lineTo(x - size, y);
              },
              triangle: function (ctx, x, y, radius, shadow) {
                  // pi * r^2 = 1/2 * s^2 * sin (pi / 3)  =>  s = r * sqrt(2 * pi / sin(pi / 3))
                  var size = radius * Math.sqrt(2 * Math.PI / Math.sin(Math.PI / 3));
                  var height = size * Math.sin(Math.PI / 3);
                  ctx.moveTo(x - size/2, y + height/2);
                  ctx.lineTo(x + size/2, y + height/2);
                  if (!shadow) {
                      ctx.lineTo(x, y - height/2);
                      ctx.lineTo(x - size/2, y + height/2);
                  }
              },
              cross: function (ctx, x, y, radius, shadow) {
                  // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2
                  var size = radius * Math.sqrt(Math.PI) / 2;
                  ctx.moveTo(x - size, y - size);
                  ctx.lineTo(x + size, y + size);
                  ctx.moveTo(x - size, y + size);
                  ctx.lineTo(x + size, y - size);
              }
          };
  
          var s = series.points.symbol;
          if (handlers[s])
              series.points.symbol = handlers[s];
      }
      
      function init(plot) {
          plot.hooks.processDatapoints.push(processRawData);
      }
      
      $.plot.plugins.push({
          init: init,
          name: 'symbols',
          version: '1.0'
      });
  })(jQuery);