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thingsboard-flot/src/plugins/jquery.flot.symbol.js

73 lines
2.6 KiB
JavaScript

/* Flot plugin that adds some extra symbols for plotting points.
Copyright (c) 2007-2013 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) {
// 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) {
// 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) {
// 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)),
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) {
// 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);
}
},
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);