1 /* Flot plugin that adds some extra symbols for plotting points.

     2 

     3 Copyright (c) 2007-2014 IOLA and Ole Laursen.

     4 Licensed under the MIT license.

     5 

     6 The symbols are accessed as strings through the standard symbol options:

     7 

     8     series: {

     9         points: {

    10             symbol: "square" // or "diamond", "triangle", "cross", "plus", "ellipse", "rectangle"

    11         }

    12     }

    13 

    14 */

    15 

    16 (function ($) {

    17     // we normalize the area of each symbol so it is approximately the

    18     // same as a circle of the given radius

    19 

    20     var square = function (ctx, x, y, radius, shadow) {

    21             // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2

    22             var size = radius * Math.sqrt(Math.PI) / 2;

    23             ctx.rect(x - size, y - size, size + size, size + size);

    24         },

    25         rectangle = function (ctx, x, y, radius, shadow) {

    26             // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2

    27             var size = radius * Math.sqrt(Math.PI) / 2;

    28             ctx.rect(x - size, y - size, size + size, size + size);

    29         },

    30         diamond = function (ctx, x, y, radius, shadow) {

    31             // pi * r^2 = 2s^2  =>  s = r * sqrt(pi/2)

    32             var size = radius * Math.sqrt(Math.PI / 2);

    33             ctx.moveTo(x - size, y);

    34             ctx.lineTo(x, y - size);

    35             ctx.lineTo(x + size, y);

    36             ctx.lineTo(x, y + size);

    37             ctx.lineTo(x - size, y);

    38             ctx.lineTo(x, y - size);

    39         },

    40         triangle = function (ctx, x, y, radius, shadow) {

    41             // pi * r^2 = 1/2 * s^2 * sin (pi / 3)  =>  s = r * sqrt(2 * pi / sin(pi / 3))

    42             var size = radius * Math.sqrt(2 * Math.PI / Math.sin(Math.PI / 3));

    43             var height = size * Math.sin(Math.PI / 3);

    44             ctx.moveTo(x - size / 2, y + height / 2);

    45             ctx.lineTo(x + size / 2, y + height / 2);

    46             if (!shadow) {

    47                 ctx.lineTo(x, y - height / 2);

    48                 ctx.lineTo(x - size / 2, y + height / 2);

    49                 ctx.lineTo(x + size / 2, y + height / 2);

    50             }

    51         },

    52         cross = function (ctx, x, y, radius, shadow) {

    53             // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2

    54             var size = radius * Math.sqrt(Math.PI) / 2;

    55             ctx.moveTo(x - size, y - size);

    56             ctx.lineTo(x + size, y + size);

    57             ctx.moveTo(x - size, y + size);

    58             ctx.lineTo(x + size, y - size);

    59         },

    60         ellipse = function(ctx, x, y, radius, shadow, fill) {

    61             if (!shadow) {

    62                 ctx.moveTo(x + radius, y);

    63                 ctx.arc(x, y, radius, 0, Math.PI * 2, false);

    64             }

    65         },

    66         plus = function (ctx, x, y, radius, shadow) {

    67             var size = radius * Math.sqrt(Math.PI / 2);

    68             ctx.moveTo(x - size, y);

    69             ctx.lineTo(x + size, y);

    70             ctx.moveTo(x, y + size);

    71             ctx.lineTo(x, y - size);

    72         },

    73         handlers = {

    74             square: square,

    75             rectangle: rectangle,

    76             diamond: diamond,

    77             triangle: triangle,

    78             cross: cross,

    79             ellipse: ellipse,

    80             plus: plus

    81         };

    82 

    83     square.fill = true;

    84     rectangle.fill = true;

    85     diamond.fill = true;

    86     triangle.fill = true;

    87     ellipse.fill = true;

    88 

    89     function init(plot) {

    90         plot.drawSymbol = handlers;

    91     }

    92 

    93     $.plot.plugins.push({

    94         init: init,

    95         name: 'symbols',

    96         version: '1.0'

    97     });

    98 })(jQuery);