42b55d1446
longer-term (many/all) of these should probably move to the crossbarexamples repository but that hasn't happened yet.
291 lines
11 KiB
JavaScript
291 lines
11 KiB
JavaScript
// MIT License:
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//
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// Copyright (c) 2010-2011, Joe Walnes
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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/**
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* Smoothie Charts - http://smoothiecharts.org/
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* (c) 2010, Joe Walnes
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*
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* v1.0: Main charting library, by Joe Walnes
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* v1.1: Auto scaling of axis, by Neil Dunn
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* v1.2: fps (frames per second) option, by Mathias Petterson
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* v1.3: Fix for divide by zero, by Paul Nikitochkin
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* v1.4: Set minimum, top-scale padding, remove timeseries, add optional timer to reset bounds, by Kelley Reynolds
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* v1.5: Set default frames per second to 50... smoother.
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* .start(), .stop() methods for conserving CPU, by Dmitry Vyal
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* options.interpolation = 'bezier' or 'line', by Dmitry Vyal
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* options.maxValue to fix scale, by Dmitry Vyal
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*/
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function TimeSeries(options) {
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options = options || {};
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options.resetBoundsInterval = options.resetBoundsInterval || 3000; // Reset the max/min bounds after this many milliseconds
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options.resetBounds = options.resetBounds || true; // Enable or disable the resetBounds timer
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this.options = options;
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this.data = [];
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this.maxValue = Number.NaN; // The maximum value ever seen in this time series.
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this.minValue = Number.NaN; // The minimum value ever seen in this time series.
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// Start a resetBounds Interval timer desired
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if (options.resetBounds) {
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this.boundsTimer = setInterval(function(thisObj) { thisObj.resetBounds(); }, options.resetBoundsInterval, this);
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}
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}
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// Reset the min and max for this timeseries so the graph rescales itself
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TimeSeries.prototype.resetBounds = function() {
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this.maxValue = Number.NaN;
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this.minValue = Number.NaN;
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for (var i = 0; i < this.data.length; i++) {
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this.maxValue = !isNaN(this.maxValue) ? Math.max(this.maxValue, this.data[i][1]) : this.data[i][1];
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this.minValue = !isNaN(this.minValue) ? Math.min(this.minValue, this.data[i][1]) : this.data[i][1];
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}
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};
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TimeSeries.prototype.append = function(timestamp, value) {
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this.data.push([timestamp, value]);
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this.maxValue = !isNaN(this.maxValue) ? Math.max(this.maxValue, value) : value;
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this.minValue = !isNaN(this.minValue) ? Math.min(this.minValue, value) : value;
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};
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function SmoothieChart(options) {
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// Defaults
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options = options || {};
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options.grid = options.grid || { fillStyle:'#000000', strokeStyle: '#777777', lineWidth: 1, millisPerLine: 1000, verticalSections: 2 };
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options.millisPerPixel = options.millisPerPixel || 20;
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options.fps = options.fps || 50;
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options.maxValueScale = options.maxValueScale || 1;
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options.minValue = options.minValue;
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options.maxValue = options.maxValue;
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options.labels = options.labels || { fillStyle:'#ffffff' };
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options.interpolation = options.interpolation || "bezier";
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this.options = options;
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this.seriesSet = [];
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}
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SmoothieChart.prototype.addTimeSeries = function(timeSeries, options) {
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this.seriesSet.push({timeSeries: timeSeries, options: options || {}});
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};
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SmoothieChart.prototype.removeTimeSeries = function(timeSeries) {
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this.seriesSet.splice(this.seriesSet.indexOf(timeSeries), 1);
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};
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SmoothieChart.prototype.streamTo = function(canvas, delay) {
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var self = this;
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this.render_on_tick = function() {
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self.render(canvas, new Date().getTime() - (delay || 0));
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};
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this.start();
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};
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SmoothieChart.prototype.start = function() {
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if (!this.timer)
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this.timer = setInterval(this.render_on_tick, 1000/this.options.fps);
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};
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SmoothieChart.prototype.stop = function() {
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if (this.timer) {
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clearInterval(this.timer);
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this.timer = undefined;
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}
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};
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SmoothieChart.prototype.render = function(canvas, time) {
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var canvasContext = canvas.getContext("2d");
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var options = this.options;
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var dimensions = {top: 0, left: 0, width: canvas.clientWidth, height: canvas.clientHeight};
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// Save the state of the canvas context, any transformations applied in this method
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// will get removed from the stack at the end of this method when .restore() is called.
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canvasContext.save();
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// Round time down to pixel granularity, so motion appears smoother.
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time = time - time % options.millisPerPixel;
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// Move the origin.
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canvasContext.translate(dimensions.left, dimensions.top);
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// Create a clipped rectangle - anything we draw will be constrained to this rectangle.
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// This prevents the occasional pixels from curves near the edges overrunning and creating
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// screen cheese (that phrase should need no explanation).
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canvasContext.beginPath();
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canvasContext.rect(0, 0, dimensions.width, dimensions.height);
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canvasContext.clip();
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// Clear the working area.
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canvasContext.save();
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canvasContext.fillStyle = options.grid.fillStyle;
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canvasContext.fillRect(0, 0, dimensions.width, dimensions.height);
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canvasContext.restore();
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// Grid lines....
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canvasContext.save();
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canvasContext.lineWidth = options.grid.lineWidth || 1;
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canvasContext.strokeStyle = options.grid.strokeStyle || '#ffffff';
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// Vertical (time) dividers.
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if (options.grid.millisPerLine > 0) {
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for (var t = time - (time % options.grid.millisPerLine); t >= time - (dimensions.width * options.millisPerPixel); t -= options.grid.millisPerLine) {
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canvasContext.beginPath();
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var gx = Math.round(dimensions.width - ((time - t) / options.millisPerPixel));
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canvasContext.moveTo(gx, 0);
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canvasContext.lineTo(gx, dimensions.height);
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canvasContext.stroke();
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canvasContext.closePath();
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}
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}
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// Horizontal (value) dividers.
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for (var v = 1; v < options.grid.verticalSections; v++) {
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var gy = Math.round(v * dimensions.height / options.grid.verticalSections);
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canvasContext.beginPath();
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canvasContext.moveTo(0, gy);
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canvasContext.lineTo(dimensions.width, gy);
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canvasContext.stroke();
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canvasContext.closePath();
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}
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// Bounding rectangle.
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canvasContext.beginPath();
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canvasContext.strokeRect(0, 0, dimensions.width, dimensions.height);
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canvasContext.closePath();
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canvasContext.restore();
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// Calculate the current scale of the chart, from all time series.
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var maxValue = Number.NaN;
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var minValue = Number.NaN;
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for (var d = 0; d < this.seriesSet.length; d++) {
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// TODO(ndunn): We could calculate / track these values as they stream in.
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var timeSeries = this.seriesSet[d].timeSeries;
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if (!isNaN(timeSeries.maxValue)) {
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maxValue = !isNaN(maxValue) ? Math.max(maxValue, timeSeries.maxValue) : timeSeries.maxValue;
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}
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if (!isNaN(timeSeries.minValue)) {
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minValue = !isNaN(minValue) ? Math.min(minValue, timeSeries.minValue) : timeSeries.minValue;
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}
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}
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if (isNaN(maxValue) && isNaN(minValue)) {
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return;
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}
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// Scale the maxValue to add padding at the top if required
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if (options.maxValue != null)
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maxValue = options.maxValue;
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else
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maxValue = maxValue * options.maxValueScale;
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// Set the minimum if we've specified one
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if (options.minValue != null)
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minValue = options.minValue;
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var valueRange = maxValue - minValue;
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// For each data set...
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for (var d = 0; d < this.seriesSet.length; d++) {
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canvasContext.save();
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var timeSeries = this.seriesSet[d].timeSeries;
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var dataSet = timeSeries.data;
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var seriesOptions = this.seriesSet[d].options;
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// Delete old data that's moved off the left of the chart.
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// We must always keep the last expired data point as we need this to draw the
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// line that comes into the chart, but any points prior to that can be removed.
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while (dataSet.length >= 2 && dataSet[1][0] < time - (dimensions.width * options.millisPerPixel)) {
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dataSet.splice(0, 1);
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}
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// Set style for this dataSet.
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canvasContext.lineWidth = seriesOptions.lineWidth || 1;
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canvasContext.fillStyle = seriesOptions.fillStyle;
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canvasContext.strokeStyle = seriesOptions.strokeStyle || '#ffffff';
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// Draw the line...
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canvasContext.beginPath();
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// Retain lastX, lastY for calculating the control points of bezier curves.
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var firstX = 0, lastX = 0, lastY = 0;
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for (var i = 0; i < dataSet.length; i++) {
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// TODO: Deal with dataSet.length < 2.
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var x = Math.round(dimensions.width - ((time - dataSet[i][0]) / options.millisPerPixel));
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var value = dataSet[i][1];
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var offset = maxValue - value;
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var scaledValue = valueRange ? Math.round((offset / valueRange) * dimensions.height) : 0;
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var y = Math.max(Math.min(scaledValue, dimensions.height - 1), 1); // Ensure line is always on chart.
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if (i == 0) {
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firstX = x;
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canvasContext.moveTo(x, y);
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}
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// Great explanation of Bezier curves: http://en.wikipedia.org/wiki/B<>zier_curve#Quadratic_curves
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//
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// Assuming A was the last point in the line plotted and B is the new point,
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// we draw a curve with control points P and Q as below.
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//
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// A---P
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// |
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// |
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// |
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// Q---B
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//
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// Importantly, A and P are at the same y coordinate, as are B and Q. This is
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// so adjacent curves appear to flow as one.
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//
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else {
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switch (options.interpolation) {
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case "line":
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canvasContext.lineTo(x,y);
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break;
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case "bezier":
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default:
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canvasContext.bezierCurveTo( // startPoint (A) is implicit from last iteration of loop
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Math.round((lastX + x) / 2), lastY, // controlPoint1 (P)
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Math.round((lastX + x)) / 2, y, // controlPoint2 (Q)
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x, y); // endPoint (B)
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break;
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}
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}
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lastX = x, lastY = y;
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}
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if (dataSet.length > 0 && seriesOptions.fillStyle) {
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// Close up the fill region.
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canvasContext.lineTo(dimensions.width + seriesOptions.lineWidth + 1, lastY);
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canvasContext.lineTo(dimensions.width + seriesOptions.lineWidth + 1, dimensions.height + seriesOptions.lineWidth + 1);
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canvasContext.lineTo(firstX, dimensions.height + seriesOptions.lineWidth);
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canvasContext.fill();
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}
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canvasContext.stroke();
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canvasContext.closePath();
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canvasContext.restore();
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}
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// Draw the axis values on the chart.
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if (!options.labels.disabled) {
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canvasContext.fillStyle = options.labels.fillStyle;
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var maxValueString = maxValue.toFixed(2);
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var minValueString = minValue.toFixed(2);
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canvasContext.fillText(maxValueString, dimensions.width - canvasContext.measureText(maxValueString).width - 2, 10);
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canvasContext.fillText(minValueString, dimensions.width - canvasContext.measureText(minValueString).width - 2, dimensions.height - 2);
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}
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canvasContext.restore(); // See .save() above.
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}
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