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88e95c46 DV |
1 | /** |
2 | * @license | |
3 | * Copyright 2006 Dan Vanderkam (danvdk@gmail.com) | |
4 | * MIT-licensed (http://opensource.org/licenses/MIT) | |
5 | */ | |
6a1aa64f DV |
6 | |
7 | /** | |
74a5af31 DV |
8 | * @fileoverview Based on PlotKit.CanvasRenderer, but modified to meet the |
9 | * needs of dygraphs. | |
10 | * | |
3df0ccf0 | 11 | * In particular, support for: |
0abfbd7e | 12 | * - grid overlays |
3df0ccf0 DV |
13 | * - error bars |
14 | * - dygraphs attribute system | |
6a1aa64f DV |
15 | */ |
16 | ||
6a1aa64f | 17 | /** |
423f5ed3 DV |
18 | * The DygraphCanvasRenderer class does the actual rendering of the chart onto |
19 | * a canvas. It's based on PlotKit.CanvasRenderer. | |
6a1aa64f | 20 | * @param {Object} element The canvas to attach to |
2cf95fff RK |
21 | * @param {Object} elementContext The 2d context of the canvas (injected so it |
22 | * can be mocked for testing.) | |
285a6bda | 23 | * @param {Layout} layout The DygraphLayout object for this graph. |
74a5af31 | 24 | * @constructor |
6a1aa64f | 25 | */ |
c0f54d4f | 26 | |
464b5f50 | 27 | /*global Dygraph:false */ |
c0f54d4f DV |
28 | "use strict"; |
29 | ||
6ecc0739 | 30 | import * as utils from './dygraph-utils'; |
e8c70e4e | 31 | import Dygraph from './dygraph'; |
6ecc0739 | 32 | |
79253bd0 | 33 | |
8cfe592f DV |
34 | /** |
35 | * @constructor | |
36 | * | |
37 | * This gets called when there are "new points" to chart. This is generally the | |
38 | * case when the underlying data being charted has changed. It is _not_ called | |
39 | * in the common case that the user has zoomed or is panning the view. | |
40 | * | |
41 | * The chart canvas has already been created by the Dygraph object. The | |
42 | * renderer simply gets a drawing context. | |
43 | * | |
7b00a3cd | 44 | * @param {Dygraph} dygraph The chart to which this renderer belongs. |
48fc4786 | 45 | * @param {HTMLCanvasElement} element The <canvas> DOM element on which to draw. |
8cfe592f DV |
46 | * @param {CanvasRenderingContext2D} elementContext The drawing context. |
47 | * @param {DygraphLayout} layout The chart's DygraphLayout object. | |
48 | * | |
49 | * TODO(danvk): remove the elementContext property. | |
50 | */ | |
c0f54d4f | 51 | var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) { |
9317362d | 52 | this.dygraph_ = dygraph; |
fbe31dc8 | 53 | |
fbe31dc8 | 54 | this.layout = layout; |
b0c3b730 | 55 | this.element = element; |
2cf95fff | 56 | this.elementContext = elementContext; |
fbe31dc8 | 57 | |
7c39bb3a DV |
58 | this.height = dygraph.height_; |
59 | this.width = dygraph.width_; | |
fbe31dc8 DV |
60 | |
61 | // --- check whether everything is ok before we return | |
6ecc0739 | 62 | if (!utils.isCanvasSupported(this.element)) { |
9901b0c1 DV |
63 | throw "Canvas is not supported."; |
64 | } | |
fbe31dc8 DV |
65 | |
66 | // internal state | |
70be5ed1 | 67 | this.area = layout.getPlotArea(); |
423f5ed3 DV |
68 | |
69 | // Set up a clipping area for the canvas (and the interaction canvas). | |
70 | // This ensures that we don't overdraw. | |
9901b0c1 DV |
71 | // on Android 3 and 4, setting a clipping area on a canvas prevents it from |
72 | // displaying anything. | |
6ecc0739 | 73 | if (!utils.isAndroid()) { |
9901b0c1 DV |
74 | var ctx = this.dygraph_.canvas_ctx_; |
75 | ctx.beginPath(); | |
76 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); | |
77 | ctx.clip(); | |
78 | ||
79 | ctx = this.dygraph_.hidden_ctx_; | |
80 | ctx.beginPath(); | |
81 | ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h); | |
82 | ctx.clip(); | |
920208fb | 83 | } |
423f5ed3 DV |
84 | }; |
85 | ||
38e3d209 | 86 | /** |
8cfe592f DV |
87 | * Clears out all chart content and DOM elements. |
88 | * This is called immediately before render() on every frame, including | |
89 | * during zooms and pans. | |
90 | * @private | |
91 | */ | |
fbe31dc8 | 92 | DygraphCanvasRenderer.prototype.clear = function() { |
9901b0c1 | 93 | this.elementContext.clearRect(0, 0, this.width, this.height); |
fbe31dc8 DV |
94 | }; |
95 | ||
8cfe592f | 96 | /** |
8cfe592f DV |
97 | * This method is responsible for drawing everything on the chart, including |
98 | * lines, error bars, fills and axes. | |
99 | * It is called immediately after clear() on every frame, including during pans | |
100 | * and zooms. | |
101 | * @private | |
6a1aa64f | 102 | */ |
285a6bda | 103 | DygraphCanvasRenderer.prototype.render = function() { |
38e3d209 DV |
104 | // attaches point.canvas{x,y} |
105 | this._updatePoints(); | |
106 | ||
107 | // actually draws the chart. | |
2ce09b19 | 108 | this._renderLineChart(); |
fbe31dc8 DV |
109 | }; |
110 | ||
ccb0001c | 111 | /** |
8722284b RK |
112 | * Returns a predicate to be used with an iterator, which will |
113 | * iterate over points appropriately, depending on whether | |
114 | * connectSeparatedPoints is true. When it's false, the predicate will | |
115 | * skip over points with missing yVals. | |
ccb0001c | 116 | */ |
8722284b | 117 | DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) { |
42a9ebb8 DV |
118 | return connectSeparatedPoints ? |
119 | DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : | |
120 | null; | |
0f20de1c | 121 | }; |
8722284b RK |
122 | |
123 | DygraphCanvasRenderer._predicateThatSkipsEmptyPoints = | |
0f20de1c DV |
124 | function(array, idx) { |
125 | return array[idx].yval !== null; | |
126 | }; | |
04c104d7 | 127 | |
9f6db80e | 128 | /** |
38e3d209 DV |
129 | * Draws a line with the styles passed in and calls all the drawPointCallbacks. |
130 | * @param {Object} e The dictionary passed to the plotter function. | |
9f6db80e DV |
131 | * @private |
132 | */ | |
38e3d209 DV |
133 | DygraphCanvasRenderer._drawStyledLine = function(e, |
134 | color, strokeWidth, strokePattern, drawPoints, | |
5469113b | 135 | drawPointCallback, pointSize) { |
38e3d209 | 136 | var g = e.dygraph; |
99a77a04 | 137 | // TODO(konigsberg): Compute attributes outside this method call. |
0e85a437 | 138 | var stepPlot = g.getBooleanOption("stepPlot", e.setName); |
2f56cd46 | 139 | |
6ecc0739 | 140 | if (!utils.isArrayLike(strokePattern)) { |
857a6931 KW |
141 | strokePattern = null; |
142 | } | |
143 | ||
0e85a437 | 144 | var drawGapPoints = g.getBooleanOption('drawGapEdgePoints', e.setName); |
38e3d209 DV |
145 | |
146 | var points = e.points; | |
b85358e2 | 147 | var setName = e.setName; |
6ecc0739 | 148 | var iter = utils.createIterator(points, 0, points.length, |
9f6db80e | 149 | DygraphCanvasRenderer._getIteratorPredicate( |
0e85a437 | 150 | g.getBooleanOption("connectSeparatedPoints", setName))); |
7d1afbb9 | 151 | |
fb63bf1b DV |
152 | var stroking = strokePattern && (strokePattern.length >= 2); |
153 | ||
38e3d209 | 154 | var ctx = e.drawingContext; |
0140347d | 155 | ctx.save(); |
fb63bf1b | 156 | if (stroking) { |
e8c70e4e | 157 | if (ctx.setLineDash) ctx.setLineDash(strokePattern); |
b843b52c | 158 | } |
fb63bf1b | 159 | |
38e3d209 DV |
160 | var pointsOnLine = DygraphCanvasRenderer._drawSeries( |
161 | e, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color); | |
162 | DygraphCanvasRenderer._drawPointsOnLine( | |
163 | e, pointsOnLine, drawPointCallback, color, pointSize); | |
31f8e58b | 164 | |
fb63bf1b | 165 | if (stroking) { |
e8c70e4e | 166 | if (ctx.setLineDash) ctx.setLineDash([]); |
fb63bf1b | 167 | } |
b843b52c | 168 | |
fb63bf1b | 169 | ctx.restore(); |
31f8e58b RK |
170 | }; |
171 | ||
38e3d209 DV |
172 | /** |
173 | * This does the actual drawing of lines on the canvas, for just one series. | |
174 | * Returns a list of [canvasx, canvasy] pairs for points for which a | |
175 | * drawPointCallback should be fired. These include isolated points, or all | |
176 | * points if drawPoints=true. | |
177 | * @param {Object} e The dictionary passed to the plotter function. | |
178 | * @private | |
179 | */ | |
180 | DygraphCanvasRenderer._drawSeries = function(e, | |
181 | iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color) { | |
31f8e58b | 182 | |
31f8e58b RK |
183 | var prevCanvasX = null; |
184 | var prevCanvasY = null; | |
185 | var nextCanvasY = null; | |
186 | var isIsolated; // true if this point is isolated (no line segments) | |
187 | var point; // the point being processed in the while loop | |
b843b52c | 188 | var pointsOnLine = []; // Array of [canvasx, canvasy] pairs. |
31f8e58b RK |
189 | var first = true; // the first cycle through the while loop |
190 | ||
38e3d209 | 191 | var ctx = e.drawingContext; |
0140347d DV |
192 | ctx.beginPath(); |
193 | ctx.strokeStyle = color; | |
194 | ctx.lineWidth = strokeWidth; | |
31f8e58b | 195 | |
239454e2 | 196 | // NOTE: we break the iterator's encapsulation here for about a 25% speedup. |
c560c848 DV |
197 | var arr = iter.array_; |
198 | var limit = iter.end_; | |
199 | var predicate = iter.predicate_; | |
200 | ||
201 | for (var i = iter.start_; i < limit; i++) { | |
202 | point = arr[i]; | |
203 | if (predicate) { | |
204 | while (i < limit && !predicate(arr, i)) { | |
0f20de1c DV |
205 | i++; |
206 | } | |
c560c848 DV |
207 | if (i == limit) break; |
208 | point = arr[i]; | |
0f20de1c DV |
209 | } |
210 | ||
b7ec6c55 PH |
211 | // FIXME: The 'canvasy != canvasy' test here catches NaN values but the test |
212 | // doesn't catch Infinity values. Could change this to | |
213 | // !isFinite(point.canvasy), but I assume it avoids isNaN for performance? | |
a02978e2 | 214 | if (point.canvasy === null || point.canvasy != point.canvasy) { |
31f8e58b | 215 | if (stepPlot && prevCanvasX !== null) { |
857a6931 | 216 | // Draw a horizontal line to the start of the missing data |
42a9ebb8 DV |
217 | ctx.moveTo(prevCanvasX, prevCanvasY); |
218 | ctx.lineTo(point.canvasx, prevCanvasY); | |
857a6931 | 219 | } |
31f8e58b | 220 | prevCanvasX = prevCanvasY = null; |
857a6931 | 221 | } else { |
0f20de1c DV |
222 | isIsolated = false; |
223 | if (drawGapPoints || !prevCanvasX) { | |
0f20de1c | 224 | iter.nextIdx_ = i; |
0cd1ad15 | 225 | iter.next(); |
82f9b10f | 226 | nextCanvasY = iter.hasNext ? iter.peek.canvasy : null; |
0f20de1c | 227 | |
0f20de1c DV |
228 | var isNextCanvasYNullOrNaN = nextCanvasY === null || |
229 | nextCanvasY != nextCanvasY; | |
230 | isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN); | |
231 | if (drawGapPoints) { | |
232 | // Also consider a point to be "isolated" if it's adjacent to a | |
233 | // null point, excluding the graph edges. | |
234 | if ((!first && !prevCanvasX) || | |
235 | (iter.hasNext && isNextCanvasYNullOrNaN)) { | |
236 | isIsolated = true; | |
237 | } | |
19b84fe7 KW |
238 | } |
239 | } | |
0f20de1c | 240 | |
31f8e58b | 241 | if (prevCanvasX !== null) { |
857a6931 | 242 | if (strokeWidth) { |
857a6931 | 243 | if (stepPlot) { |
0140347d DV |
244 | ctx.moveTo(prevCanvasX, prevCanvasY); |
245 | ctx.lineTo(point.canvasx, prevCanvasY); | |
857a6931 | 246 | } |
239454e2 | 247 | |
0140347d | 248 | ctx.lineTo(point.canvasx, point.canvasy); |
b843b52c | 249 | } |
9f636500 DV |
250 | } else { |
251 | ctx.moveTo(point.canvasx, point.canvasy); | |
b843b52c | 252 | } |
b843b52c | 253 | if (drawPoints || isIsolated) { |
b616fad1 | 254 | pointsOnLine.push([point.canvasx, point.canvasy, point.idx]); |
b843b52c | 255 | } |
31f8e58b RK |
256 | prevCanvasX = point.canvasx; |
257 | prevCanvasY = point.canvasy; | |
b843b52c | 258 | } |
7d1afbb9 | 259 | first = false; |
b843b52c | 260 | } |
0140347d | 261 | ctx.stroke(); |
31f8e58b | 262 | return pointsOnLine; |
857a6931 KW |
263 | }; |
264 | ||
38e3d209 DV |
265 | /** |
266 | * This fires the drawPointCallback functions, which draw dots on the points by | |
267 | * default. This gets used when the "drawPoints" option is set, or when there | |
268 | * are isolated points. | |
269 | * @param {Object} e The dictionary passed to the plotter function. | |
270 | * @private | |
271 | */ | |
272 | DygraphCanvasRenderer._drawPointsOnLine = function( | |
273 | e, pointsOnLine, drawPointCallback, color, pointSize) { | |
274 | var ctx = e.drawingContext; | |
275 | for (var idx = 0; idx < pointsOnLine.length; idx++) { | |
276 | var cb = pointsOnLine[idx]; | |
277 | ctx.save(); | |
4ee251cb | 278 | drawPointCallback.call(e.dygraph, |
ba697462 | 279 | e.dygraph, e.setName, ctx, cb[0], cb[1], color, pointSize, cb[2]); |
38e3d209 | 280 | ctx.restore(); |
857a6931 | 281 | } |
42a9ebb8 | 282 | }; |
ce49c2fa | 283 | |
6a1aa64f | 284 | /** |
38e3d209 | 285 | * Attaches canvas coordinates to the points array. |
758a629f | 286 | * @private |
6a1aa64f | 287 | */ |
38e3d209 | 288 | DygraphCanvasRenderer.prototype._updatePoints = function() { |
ff00d3e2 DV |
289 | // Update Points |
290 | // TODO(danvk): here | |
b843b52c RK |
291 | // |
292 | // TODO(bhs): this loop is a hot-spot for high-point-count charts. These | |
293 | // transformations can be pushed into the canvas via linear transformation | |
294 | // matrices. | |
e60234cd DV |
295 | // NOTE(danvk): this is trickier than it sounds at first. The transformation |
296 | // needs to be done before the .moveTo() and .lineTo() calls, but must be | |
297 | // undone before the .stroke() call to ensure that the stroke width is | |
298 | // unaffected. An alternative is to reduce the stroke width in the | |
299 | // transformed coordinate space, but you can't specify different values for | |
300 | // each dimension (as you can with .scale()). The speedup here is ~12%. | |
a12a78ae | 301 | var sets = this.layout.points; |
38e3d209 | 302 | for (var i = sets.length; i--;) { |
a12a78ae DV |
303 | var points = sets[i]; |
304 | for (var j = points.length; j--;) { | |
305 | var point = points[j]; | |
306 | point.canvasx = this.area.w * point.x + this.area.x; | |
307 | point.canvasy = this.area.h * point.y + this.area.y; | |
308 | } | |
6a1aa64f | 309 | } |
38e3d209 | 310 | }; |
6a1aa64f | 311 | |
38e3d209 DV |
312 | /** |
313 | * Add canvas Actually draw the lines chart, including error bars. | |
38e3d209 DV |
314 | * |
315 | * This function can only be called if DygraphLayout's points array has been | |
316 | * updated with canvas{x,y} attributes, i.e. by | |
317 | * DygraphCanvasRenderer._updatePoints. | |
48fc4786 RK |
318 | * |
319 | * @param {string=} opt_seriesName when specified, only that series will | |
34655aba RK |
320 | * be drawn. (This is used for expedited redrawing with highlightSeriesOpts) |
321 | * @param {CanvasRenderingContext2D} opt_ctx when specified, the drawing | |
322 | * context. However, lines are typically drawn on the object's | |
323 | * elementContext. | |
38e3d209 DV |
324 | * @private |
325 | */ | |
326 | DygraphCanvasRenderer.prototype._renderLineChart = function(opt_seriesName, opt_ctx) { | |
327 | var ctx = opt_ctx || this.elementContext; | |
38e3d209 | 328 | var i; |
6a834bbb | 329 | |
38e3d209 DV |
330 | var sets = this.layout.points; |
331 | var setNames = this.layout.setNames; | |
42a9ebb8 | 332 | var setName; |
38e3d209 DV |
333 | |
334 | this.colors = this.dygraph_.colorsMap_; | |
335 | ||
336 | // Determine which series have specialized plotters. | |
0e85a437 | 337 | var plotter_attr = this.dygraph_.getOption("plotter"); |
38e3d209 | 338 | var plotters = plotter_attr; |
6ecc0739 | 339 | if (!utils.isArrayLike(plotters)) { |
38e3d209 | 340 | plotters = [plotters]; |
80aaae18 DV |
341 | } |
342 | ||
38e3d209 DV |
343 | var setPlotters = {}; // series name -> plotter fn. |
344 | for (i = 0; i < setNames.length; i++) { | |
42a9ebb8 | 345 | setName = setNames[i]; |
0e85a437 | 346 | var setPlotter = this.dygraph_.getOption("plotter", setName); |
38e3d209 DV |
347 | if (setPlotter == plotter_attr) continue; // not specialized. |
348 | ||
349 | setPlotters[setName] = setPlotter; | |
350 | } | |
351 | ||
352 | for (i = 0; i < plotters.length; i++) { | |
353 | var plotter = plotters[i]; | |
354 | var is_last = (i == plotters.length - 1); | |
355 | ||
356 | for (var j = 0; j < sets.length; j++) { | |
42a9ebb8 | 357 | setName = setNames[j]; |
4b2e41a4 | 358 | if (opt_seriesName && setName != opt_seriesName) continue; |
38e3d209 DV |
359 | |
360 | var points = sets[j]; | |
361 | ||
362 | // Only throw in the specialized plotters on the last iteration. | |
363 | var p = plotter; | |
364 | if (setName in setPlotters) { | |
365 | if (is_last) { | |
366 | p = setPlotters[setName]; | |
367 | } else { | |
368 | // Don't use the standard plotters in this case. | |
369 | continue; | |
370 | } | |
371 | } | |
372 | ||
373 | var color = this.colors[setName]; | |
374 | var strokeWidth = this.dygraph_.getOption("strokeWidth", setName); | |
375 | ||
376 | ctx.save(); | |
377 | ctx.strokeStyle = color; | |
378 | ctx.lineWidth = strokeWidth; | |
379 | p({ | |
380 | points: points, | |
381 | setName: setName, | |
382 | drawingContext: ctx, | |
383 | color: color, | |
384 | strokeWidth: strokeWidth, | |
385 | dygraph: this.dygraph_, | |
386 | axis: this.dygraph_.axisPropertiesForSeries(setName), | |
387 | plotArea: this.area, | |
388 | seriesIndex: j, | |
389 | seriesCount: sets.length, | |
3c080cd0 | 390 | singleSeriesName: opt_seriesName, |
38e3d209 DV |
391 | allSeriesPoints: sets |
392 | }); | |
393 | ctx.restore(); | |
394 | } | |
395 | } | |
396 | }; | |
397 | ||
398 | /** | |
399 | * Standard plotters. These may be used by clients via Dygraph.Plotters. | |
400 | * See comments there for more details. | |
401 | */ | |
402 | DygraphCanvasRenderer._Plotters = { | |
403 | linePlotter: function(e) { | |
404 | DygraphCanvasRenderer._linePlotter(e); | |
405 | }, | |
406 | ||
407 | fillPlotter: function(e) { | |
408 | DygraphCanvasRenderer._fillPlotter(e); | |
409 | }, | |
410 | ||
411 | errorPlotter: function(e) { | |
412 | DygraphCanvasRenderer._errorPlotter(e); | |
80aaae18 | 413 | } |
6a1aa64f | 414 | }; |
79253bd0 | 415 | |
01a14b85 | 416 | /** |
38e3d209 DV |
417 | * Plotter which draws the central lines for a series. |
418 | * @private | |
419 | */ | |
420 | DygraphCanvasRenderer._linePlotter = function(e) { | |
421 | var g = e.dygraph; | |
422 | var setName = e.setName; | |
423 | var strokeWidth = e.strokeWidth; | |
424 | ||
425 | // TODO(danvk): Check if there's any performance impact of just calling | |
426 | // getOption() inside of _drawStyledLine. Passing in so many parameters makes | |
427 | // this code a bit nasty. | |
0e85a437 | 428 | var borderWidth = g.getNumericOption("strokeBorderWidth", setName); |
38e3d209 | 429 | var drawPointCallback = g.getOption("drawPointCallback", setName) || |
6ecc0739 | 430 | utils.Circles.DEFAULT; |
38e3d209 | 431 | var strokePattern = g.getOption("strokePattern", setName); |
0e85a437 DV |
432 | var drawPoints = g.getBooleanOption("drawPoints", setName); |
433 | var pointSize = g.getNumericOption("pointSize", setName); | |
38e3d209 DV |
434 | |
435 | if (borderWidth && strokeWidth) { | |
436 | DygraphCanvasRenderer._drawStyledLine(e, | |
437 | g.getOption("strokeBorderColor", setName), | |
438 | strokeWidth + 2 * borderWidth, | |
439 | strokePattern, | |
440 | drawPoints, | |
441 | drawPointCallback, | |
442 | pointSize | |
443 | ); | |
444 | } | |
445 | ||
446 | DygraphCanvasRenderer._drawStyledLine(e, | |
447 | e.color, | |
448 | strokeWidth, | |
449 | strokePattern, | |
450 | drawPoints, | |
451 | drawPointCallback, | |
452 | pointSize | |
453 | ); | |
42a9ebb8 | 454 | }; |
38e3d209 DV |
455 | |
456 | /** | |
01a14b85 DV |
457 | * Draws the shaded error bars/confidence intervals for each series. |
458 | * This happens before the center lines are drawn, since the center lines | |
459 | * need to be drawn on top of the error bars for all series. | |
01a14b85 DV |
460 | * @private |
461 | */ | |
38e3d209 DV |
462 | DygraphCanvasRenderer._errorPlotter = function(e) { |
463 | var g = e.dygraph; | |
e2d8db3a | 464 | var setName = e.setName; |
0e85a437 DV |
465 | var errorBars = g.getBooleanOption("errorBars") || |
466 | g.getBooleanOption("customBars"); | |
38e3d209 DV |
467 | if (!errorBars) return; |
468 | ||
0e85a437 | 469 | var fillGraph = g.getBooleanOption("fillGraph", setName); |
38e3d209 | 470 | if (fillGraph) { |
8a68db7d | 471 | console.warn("Can't use fillGraph option with error bars"); |
38e3d209 | 472 | } |
6a6439da | 473 | |
38e3d209 DV |
474 | var ctx = e.drawingContext; |
475 | var color = e.color; | |
0e85a437 DV |
476 | var fillAlpha = g.getNumericOption('fillAlpha', setName); |
477 | var stepPlot = g.getBooleanOption("stepPlot", setName); | |
38e3d209 | 478 | var points = e.points; |
6a6439da | 479 | |
6ecc0739 | 480 | var iter = utils.createIterator(points, 0, points.length, |
38e3d209 | 481 | DygraphCanvasRenderer._getIteratorPredicate( |
0e85a437 | 482 | g.getBooleanOption("connectSeparatedPoints", setName))); |
6a6439da | 483 | |
38e3d209 | 484 | var newYs; |
6a6439da | 485 | |
38e3d209 DV |
486 | // setup graphics context |
487 | var prevX = NaN; | |
488 | var prevY = NaN; | |
489 | var prevYs = [-1, -1]; | |
38e3d209 | 490 | // should be same color as the lines but only 15% opaque. |
6ecc0739 | 491 | var rgb = utils.toRGB_(color); |
38e3d209 DV |
492 | var err_color = |
493 | 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; | |
494 | ctx.fillStyle = err_color; | |
495 | ctx.beginPath(); | |
cf89eeed DV |
496 | |
497 | var isNullUndefinedOrNaN = function(x) { | |
498 | return (x === null || | |
499 | x === undefined || | |
500 | isNaN(x)); | |
501 | }; | |
502 | ||
38e3d209 DV |
503 | while (iter.hasNext) { |
504 | var point = iter.next(); | |
cf89eeed DV |
505 | if ((!stepPlot && isNullUndefinedOrNaN(point.y)) || |
506 | (stepPlot && !isNaN(prevY) && isNullUndefinedOrNaN(prevY))) { | |
38e3d209 DV |
507 | prevX = NaN; |
508 | continue; | |
509 | } | |
6a6439da | 510 | |
87c5a64c | 511 | newYs = [ point.y_bottom, point.y_top ]; |
38e3d209 | 512 | if (stepPlot) { |
38e3d209 | 513 | prevY = point.y; |
38e3d209 | 514 | } |
87c5a64c DV |
515 | |
516 | // The documentation specifically disallows nulls inside the point arrays, | |
517 | // but in case it happens we should do something sensible. | |
518 | if (isNaN(newYs[0])) newYs[0] = point.y; | |
519 | if (isNaN(newYs[1])) newYs[1] = point.y; | |
520 | ||
38e3d209 DV |
521 | newYs[0] = e.plotArea.h * newYs[0] + e.plotArea.y; |
522 | newYs[1] = e.plotArea.h * newYs[1] + e.plotArea.y; | |
523 | if (!isNaN(prevX)) { | |
a5701188 | 524 | if (stepPlot) { |
38e3d209 | 525 | ctx.moveTo(prevX, prevYs[0]); |
82dd90c5 | 526 | ctx.lineTo(point.canvasx, prevYs[0]); |
527 | ctx.lineTo(point.canvasx, prevYs[1]); | |
38e3d209 | 528 | } else { |
82dd90c5 | 529 | ctx.moveTo(prevX, prevYs[0]); |
530 | ctx.lineTo(point.canvasx, newYs[0]); | |
531 | ctx.lineTo(point.canvasx, newYs[1]); | |
6a6439da | 532 | } |
82dd90c5 | 533 | ctx.lineTo(prevX, prevYs[1]); |
38e3d209 | 534 | ctx.closePath(); |
6a6439da | 535 | } |
38e3d209 DV |
536 | prevYs = newYs; |
537 | prevX = point.canvasx; | |
6a6439da | 538 | } |
38e3d209 | 539 | ctx.fill(); |
42a9ebb8 | 540 | }; |
6a6439da | 541 | |
20b87d28 DV |
542 | |
543 | /** | |
544 | * Proxy for CanvasRenderingContext2D which drops moveTo/lineTo calls which are | |
545 | * superfluous. It accumulates all movements which haven't changed the x-value | |
546 | * and only applies the two with the most extreme y-values. | |
547 | * | |
548 | * Calls to lineTo/moveTo must have non-decreasing x-values. | |
549 | */ | |
550 | DygraphCanvasRenderer._fastCanvasProxy = function(context) { | |
551 | var pendingActions = []; // array of [type, x, y] tuples | |
552 | var lastRoundedX = null; | |
c0ec1a37 | 553 | var lastFlushedX = null; |
20b87d28 DV |
554 | |
555 | var LINE_TO = 1, | |
556 | MOVE_TO = 2; | |
557 | ||
558 | var actionCount = 0; // number of moveTos and lineTos passed to context. | |
559 | ||
560 | // Drop superfluous motions | |
561 | // Assumes all pendingActions have the same (rounded) x-value. | |
562 | var compressActions = function(opt_losslessOnly) { | |
563 | if (pendingActions.length <= 1) return; | |
564 | ||
565 | // Lossless compression: drop inconsequential moveTos. | |
566 | for (var i = pendingActions.length - 1; i > 0; i--) { | |
567 | var action = pendingActions[i]; | |
568 | if (action[0] == MOVE_TO) { | |
569 | var prevAction = pendingActions[i - 1]; | |
570 | if (prevAction[1] == action[1] && prevAction[2] == action[2]) { | |
571 | pendingActions.splice(i, 1); | |
572 | } | |
573 | } | |
574 | } | |
575 | ||
576 | // Lossless compression: ... drop consecutive moveTos ... | |
577 | for (var i = 0; i < pendingActions.length - 1; /* incremented internally */) { | |
578 | var action = pendingActions[i]; | |
579 | if (action[0] == MOVE_TO && pendingActions[i + 1][0] == MOVE_TO) { | |
580 | pendingActions.splice(i, 1); | |
581 | } else { | |
582 | i++; | |
583 | } | |
584 | } | |
585 | ||
586 | // Lossy compression: ... drop all but the extreme y-values ... | |
587 | if (pendingActions.length > 2 && !opt_losslessOnly) { | |
588 | // keep an initial moveTo, but drop all others. | |
589 | var startIdx = 0; | |
590 | if (pendingActions[0][0] == MOVE_TO) startIdx++; | |
591 | var minIdx = null, maxIdx = null; | |
592 | for (var i = startIdx; i < pendingActions.length; i++) { | |
593 | var action = pendingActions[i]; | |
594 | if (action[0] != LINE_TO) continue; | |
595 | if (minIdx === null && maxIdx === null) { | |
596 | minIdx = i; | |
597 | maxIdx = i; | |
598 | } else { | |
599 | var y = action[2]; | |
600 | if (y < pendingActions[minIdx][2]) { | |
601 | minIdx = i; | |
602 | } else if (y > pendingActions[maxIdx][2]) { | |
603 | maxIdx = i; | |
604 | } | |
605 | } | |
606 | } | |
607 | var minAction = pendingActions[minIdx], | |
608 | maxAction = pendingActions[maxIdx]; | |
609 | pendingActions.splice(startIdx, pendingActions.length - startIdx); | |
610 | if (minIdx < maxIdx) { | |
611 | pendingActions.push(minAction); | |
612 | pendingActions.push(maxAction); | |
613 | } else if (minIdx > maxIdx) { | |
614 | pendingActions.push(maxAction); | |
615 | pendingActions.push(minAction); | |
616 | } else { | |
617 | pendingActions.push(minAction); | |
618 | } | |
619 | } | |
620 | }; | |
621 | ||
622 | var flushActions = function(opt_noLossyCompression) { | |
623 | compressActions(opt_noLossyCompression); | |
624 | for (var i = 0, len = pendingActions.length; i < len; i++) { | |
625 | var action = pendingActions[i]; | |
626 | if (action[0] == LINE_TO) { | |
627 | context.lineTo(action[1], action[2]); | |
628 | } else if (action[0] == MOVE_TO) { | |
629 | context.moveTo(action[1], action[2]); | |
630 | } | |
631 | } | |
c0ec1a37 DV |
632 | if (pendingActions.length) { |
633 | lastFlushedX = pendingActions[pendingActions.length - 1][1]; | |
634 | } | |
20b87d28 DV |
635 | actionCount += pendingActions.length; |
636 | pendingActions = []; | |
637 | }; | |
638 | ||
639 | var addAction = function(action, x, y) { | |
640 | var rx = Math.round(x); | |
641 | if (lastRoundedX === null || rx != lastRoundedX) { | |
c0ec1a37 DV |
642 | // if there are large gaps on the x-axis, it's essential to keep the |
643 | // first and last point as well. | |
644 | var hasGapOnLeft = (lastRoundedX - lastFlushedX > 1), | |
645 | hasGapOnRight = (rx - lastRoundedX > 1), | |
646 | hasGap = hasGapOnLeft || hasGapOnRight; | |
647 | flushActions(hasGap); | |
20b87d28 DV |
648 | lastRoundedX = rx; |
649 | } | |
650 | pendingActions.push([action, x, y]); | |
651 | }; | |
652 | ||
653 | return { | |
654 | moveTo: function(x, y) { | |
655 | addAction(MOVE_TO, x, y); | |
656 | }, | |
657 | lineTo: function(x, y) { | |
658 | addAction(LINE_TO, x, y); | |
659 | }, | |
660 | ||
661 | // for major operations like stroke/fill, we skip compression to ensure | |
662 | // that there are no artifacts at the right edge. | |
663 | stroke: function() { flushActions(true); context.stroke(); }, | |
664 | fill: function() { flushActions(true); context.fill(); }, | |
665 | beginPath: function() { flushActions(true); context.beginPath(); }, | |
666 | closePath: function() { flushActions(true); context.closePath(); }, | |
667 | ||
668 | _count: function() { return actionCount; } | |
669 | }; | |
46fd9089 | 670 | }; |
20b87d28 | 671 | |
79253bd0 | 672 | /** |
01a14b85 DV |
673 | * Draws the shaded regions when "fillGraph" is set. Not to be confused with |
674 | * error bars. | |
675 | * | |
38e3d209 DV |
676 | * For stacked charts, it's more convenient to handle all the series |
677 | * simultaneously. So this plotter plots all the points on the first series | |
678 | * it's asked to draw, then ignores all the other series. | |
679 | * | |
01a14b85 DV |
680 | * @private |
681 | */ | |
38e3d209 | 682 | DygraphCanvasRenderer._fillPlotter = function(e) { |
3c080cd0 KW |
683 | // Skip if we're drawing a single series for interactive highlight overlay. |
684 | if (e.singleSeriesName) return; | |
685 | ||
38e3d209 DV |
686 | // We'll handle all the series at once, not one-by-one. |
687 | if (e.seriesIndex !== 0) return; | |
688 | ||
e2d8db3a | 689 | var g = e.dygraph; |
38e3d209 | 690 | var setNames = g.getLabels().slice(1); // remove x-axis |
e2d8db3a | 691 | |
38e3d209 DV |
692 | // getLabels() includes names for invisible series, which are not included in |
693 | // allSeriesPoints. We remove those to make the two match. | |
694 | // TODO(danvk): provide a simpler way to get this information. | |
695 | for (var i = setNames.length; i >= 0; i--) { | |
696 | if (!g.visibility()[i]) setNames.splice(i, 1); | |
697 | } | |
698 | ||
e2d8db3a DV |
699 | var anySeriesFilled = (function() { |
700 | for (var i = 0; i < setNames.length; i++) { | |
0e85a437 | 701 | if (g.getBooleanOption("fillGraph", setNames[i])) return true; |
e2d8db3a DV |
702 | } |
703 | return false; | |
704 | })(); | |
705 | ||
706 | if (!anySeriesFilled) return; | |
707 | ||
e2d8db3a DV |
708 | var area = e.plotArea; |
709 | var sets = e.allSeriesPoints; | |
710 | var setCount = sets.length; | |
711 | ||
0e85a437 | 712 | var stackedGraph = g.getBooleanOption("stackedGraph"); |
38e3d209 | 713 | var colors = g.getColors(); |
01a14b85 | 714 | |
30a5cfc6 KW |
715 | // For stacked graphs, track the baseline for filling. |
716 | // | |
717 | // The filled areas below graph lines are trapezoids with two | |
718 | // vertical edges. The top edge is the line segment being drawn, and | |
719 | // the baseline is the bottom edge. Each baseline corresponds to the | |
720 | // top line segment from the previous stacked line. In the case of | |
721 | // step plots, the trapezoids are rectangles. | |
722 | var baseline = {}; | |
01a14b85 | 723 | var currBaseline; |
104d87c5 | 724 | var prevStepPlot; // for different line drawing modes (line/step) per series |
01a14b85 | 725 | |
46fd9089 DV |
726 | // Helper function to trace a line back along the baseline. |
727 | var traceBackPath = function(ctx, baselineX, baselineY, pathBack) { | |
728 | ctx.lineTo(baselineX, baselineY); | |
729 | if (stackedGraph) { | |
730 | for (var i = pathBack.length - 1; i >= 0; i--) { | |
731 | var pt = pathBack[i]; | |
732 | ctx.lineTo(pt[0], pt[1]); | |
733 | } | |
734 | } | |
735 | }; | |
736 | ||
01a14b85 | 737 | // process sets in reverse order (needed for stacked graphs) |
9e85a8f4 | 738 | for (var setIdx = setCount - 1; setIdx >= 0; setIdx--) { |
20b87d28 | 739 | var ctx = e.drawingContext; |
9e85a8f4 | 740 | var setName = setNames[setIdx]; |
0e85a437 | 741 | if (!g.getBooleanOption('fillGraph', setName)) continue; |
20b87d28 | 742 | |
1b464274 | 743 | var fillAlpha = g.getNumericOption('fillAlpha', setName); |
0e85a437 | 744 | var stepPlot = g.getBooleanOption('stepPlot', setName); |
38e3d209 DV |
745 | var color = colors[setIdx]; |
746 | var axis = g.axisPropertiesForSeries(setName); | |
01a14b85 DV |
747 | var axisY = 1.0 + axis.minyval * axis.yscale; |
748 | if (axisY < 0.0) axisY = 0.0; | |
749 | else if (axisY > 1.0) axisY = 1.0; | |
38e3d209 | 750 | axisY = area.h * axisY + area.y; |
01a14b85 | 751 | |
38e3d209 | 752 | var points = sets[setIdx]; |
6ecc0739 | 753 | var iter = utils.createIterator(points, 0, points.length, |
01a14b85 | 754 | DygraphCanvasRenderer._getIteratorPredicate( |
0e85a437 | 755 | g.getBooleanOption("connectSeparatedPoints", setName))); |
01a14b85 DV |
756 | |
757 | // setup graphics context | |
758 | var prevX = NaN; | |
759 | var prevYs = [-1, -1]; | |
760 | var newYs; | |
01a14b85 | 761 | // should be same color as the lines but only 15% opaque. |
6ecc0739 | 762 | var rgb = utils.toRGB_(color); |
01a14b85 DV |
763 | var err_color = |
764 | 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')'; | |
765 | ctx.fillStyle = err_color; | |
766 | ctx.beginPath(); | |
12b879f4 | 767 | var last_x, is_first = true; |
20b87d28 DV |
768 | |
769 | // If the point density is high enough, dropping segments on their way to | |
770 | // the canvas justifies the overhead of doing so. | |
c0ec1a37 | 771 | if (points.length > 2 * g.width_ || Dygraph.FORCE_FAST_PROXY) { |
20b87d28 DV |
772 | ctx = DygraphCanvasRenderer._fastCanvasProxy(ctx); |
773 | } | |
774 | ||
775 | // For filled charts, we draw points from left to right, then back along | |
776 | // the x-axis to complete a shape for filling. | |
777 | // For stacked plots, this "back path" is a more complex shape. This array | |
778 | // stores the [x, y] values needed to trace that shape. | |
779 | var pathBack = []; | |
780 | ||
20b87d28 DV |
781 | // TODO(danvk): there are a lot of options at play in this loop. |
782 | // The logic would be much clearer if some (e.g. stackGraph and | |
783 | // stepPlot) were split off into separate sub-plotters. | |
46fd9089 | 784 | var point; |
12b879f4 | 785 | while (iter.hasNext) { |
46fd9089 | 786 | point = iter.next(); |
6ecc0739 | 787 | if (!utils.isOK(point.y) && !stepPlot) { |
46fd9089 DV |
788 | traceBackPath(ctx, prevX, prevYs[1], pathBack); |
789 | pathBack = []; | |
16febe6b | 790 | prevX = NaN; |
30a5cfc6 KW |
791 | if (point.y_stacked !== null && !isNaN(point.y_stacked)) { |
792 | baseline[point.canvasx] = area.h * point.y_stacked + area.y; | |
793 | } | |
16febe6b DV |
794 | continue; |
795 | } | |
796 | if (stackedGraph) { | |
12b879f4 DV |
797 | if (!is_first && last_x == point.xval) { |
798 | continue; | |
799 | } else { | |
800 | is_first = false; | |
801 | last_x = point.xval; | |
802 | } | |
803 | ||
16febe6b DV |
804 | currBaseline = baseline[point.canvasx]; |
805 | var lastY; | |
806 | if (currBaseline === undefined) { | |
807 | lastY = axisY; | |
808 | } else { | |
104d87c5 | 809 | if(prevStepPlot) { |
16febe6b | 810 | lastY = currBaseline[0]; |
01a14b85 | 811 | } else { |
16febe6b | 812 | lastY = currBaseline; |
01a14b85 | 813 | } |
16febe6b DV |
814 | } |
815 | newYs = [ point.canvasy, lastY ]; | |
01a14b85 | 816 | |
20b87d28 | 817 | if (stepPlot) { |
16febe6b DV |
818 | // Step plots must keep track of the top and bottom of |
819 | // the baseline at each point. | |
20b87d28 | 820 | if (prevYs[0] === -1) { |
16febe6b | 821 | baseline[point.canvasx] = [ point.canvasy, axisY ]; |
01a14b85 | 822 | } else { |
16febe6b | 823 | baseline[point.canvasx] = [ point.canvasy, prevYs[0] ]; |
01a14b85 | 824 | } |
01a14b85 | 825 | } else { |
16febe6b | 826 | baseline[point.canvasx] = point.canvasy; |
01a14b85 | 827 | } |
01a14b85 | 828 | |
16febe6b | 829 | } else { |
8c31c7db | 830 | if (isNaN(point.canvasy) && stepPlot) { |
e988d192 | 831 | newYs = [ area.y + area.h, axisY ]; |
8c31c7db | 832 | } else { |
e988d192 BB |
833 | newYs = [ point.canvasy, axisY ]; |
834 | } | |
16febe6b DV |
835 | } |
836 | if (!isNaN(prevX)) { | |
104d87c5 | 837 | // Move to top fill point |
16febe6b DV |
838 | if (stepPlot) { |
839 | ctx.lineTo(point.canvasx, prevYs[0]); | |
16febe6b | 840 | ctx.lineTo(point.canvasx, newYs[0]); |
104d87c5 | 841 | } else { |
20b87d28 | 842 | ctx.lineTo(point.canvasx, newYs[0]); |
01a14b85 | 843 | } |
16febe6b | 844 | |
20b87d28 DV |
845 | // Record the baseline for the reverse path. |
846 | if (stackedGraph) { | |
847 | pathBack.push([prevX, prevYs[1]]); | |
848 | if (prevStepPlot && currBaseline) { | |
849 | // Draw to the bottom of the baseline | |
850 | pathBack.push([point.canvasx, currBaseline[1]]); | |
851 | } else { | |
852 | pathBack.push([point.canvasx, newYs[1]]); | |
853 | } | |
854 | } | |
855 | } else { | |
856 | ctx.moveTo(point.canvasx, newYs[1]); | |
857 | ctx.lineTo(point.canvasx, newYs[0]); | |
01a14b85 | 858 | } |
16febe6b DV |
859 | prevYs = newYs; |
860 | prevX = point.canvasx; | |
01a14b85 | 861 | } |
104d87c5 | 862 | prevStepPlot = stepPlot; |
46fd9089 DV |
863 | if (newYs && point) { |
864 | traceBackPath(ctx, point.canvasx, newYs[1], pathBack); | |
865 | pathBack = []; | |
20b87d28 | 866 | } |
01a14b85 DV |
867 | ctx.fill(); |
868 | } | |
869 | }; | |
3ce712e6 | 870 | |
6ecc0739 | 871 | export default DygraphCanvasRenderer; |