*/
/*jshint globalstrict: true */
-/*global Dygraph:false,RGBColor:false */
+/*global Dygraph:false,RGBColorParser:false */
"use strict";
* The chart canvas has already been created by the Dygraph object. The
* renderer simply gets a drawing context.
*
- * @param {Dyraph} dygraph The chart to which this renderer belongs.
- * @param {Canvas} element The <canvas> DOM element on which to draw.
+ * @param {Dygraph} dygraph The chart to which this renderer belongs.
+ * @param {HTMLCanvasElement} element The <canvas> DOM element on which to draw.
* @param {CanvasRenderingContext2D} elementContext The drawing context.
* @param {DygraphLayout} layout The chart's DygraphLayout object.
*
this.width = this.element.width;
// --- check whether everything is ok before we return
+ // NOTE(konigsberg): isIE is never defined in this object. Bug of some sort.
if (!this.isIE && !(DygraphCanvasRenderer.isSupported(this.element)))
throw "Canvas is not supported.";
}
};
-DygraphCanvasRenderer.prototype.attr_ = function(x) {
- return this.dygraph_.attr_(x);
+/**
+ * This just forwards to dygraph.attr_.
+ * TODO(danvk): remove this?
+ * @private
+ */
+DygraphCanvasRenderer.prototype.attr_ = function(name, opt_seriesName) {
+ return this.dygraph_.attr_(name, opt_seriesName);
};
/**
};
/**
- * @param { [String] } colors Array of color strings. Should have one entry for
- * each series to be rendered.
- */
-DygraphCanvasRenderer.prototype.setColors = function(colors) {
- this.colorScheme_ = colors;
-};
-
-/**
* This method is responsible for drawing everything on the chart, including
* lines, error bars, fills and axes.
* It is called immediately after clear() on every frame, including during pans
* @private
*/
DygraphCanvasRenderer.prototype.render = function() {
- // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to
- // half-integers. This prevents them from drawing in two rows/cols.
- var ctx = this.elementContext;
- function halfUp(x) { return Math.round(x) + 0.5; }
- function halfDown(y){ return Math.round(y) - 0.5; }
-
- if (this.attr_('underlayCallback')) {
- // NOTE: we pass the dygraph object to this callback twice to avoid breaking
- // users who expect a deprecated form of this callback.
- this.attr_('underlayCallback')(ctx, this.area, this.dygraph_, this.dygraph_);
- }
+ // attaches point.canvas{x,y}
+ this._updatePoints();
- // Do the ordinary rendering, as before
+ // actually draws the chart.
this._renderLineChart();
};
* skip over points with missing yVals.
*/
DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) {
- return connectSeparatedPoints ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : null;
-}
+ return connectSeparatedPoints ?
+ DygraphCanvasRenderer._predicateThatSkipsEmptyPoints :
+ null;
+};
DygraphCanvasRenderer._predicateThatSkipsEmptyPoints =
- function(array, idx) { return array[idx].yval !== null; }
+ function(array, idx) {
+ return array[idx].yval !== null;
+};
-DygraphCanvasRenderer.prototype._drawStyledLine = function(
- ctx, i, setName, color, strokeWidth, strokePattern, drawPoints,
+/**
+ * Draws a line with the styles passed in and calls all the drawPointCallbacks.
+ * @param {Object} e The dictionary passed to the plotter function.
+ * @private
+ */
+DygraphCanvasRenderer._drawStyledLine = function(e,
+ color, strokeWidth, strokePattern, drawPoints,
drawPointCallback, pointSize) {
+ var g = e.dygraph;
// TODO(konigsberg): Compute attributes outside this method call.
- var stepPlot = this.attr_("stepPlot");
- var firstIndexInSet = this.layout.setPointsOffsets[i];
- var setLength = this.layout.setPointsLengths[i];
- var points = this.layout.points;
+ var stepPlot = g.getOption("stepPlot", e.setName);
+
if (!Dygraph.isArrayLike(strokePattern)) {
strokePattern = null;
}
- var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName);
- ctx.save();
+ var drawGapPoints = g.getOption('drawGapEdgePoints', e.setName);
- var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
- DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
+ var points = e.points;
+ var iter = Dygraph.createIterator(points, 0, points.length,
+ DygraphCanvasRenderer._getIteratorPredicate(
+ g.getOption("connectSeparatedPoints"))); // TODO(danvk): per-series?
- var pointsOnLine;
- var strategy;
- if (!strokePattern || strokePattern.length <= 1) {
- strategy = trivialStrategy(ctx, color, strokeWidth);
- } else {
- strategy = nonTrivialStrategy(this, ctx, color, strokeWidth, strokePattern);
+ var stroking = strokePattern && (strokePattern.length >= 2);
+
+ var ctx = e.drawingContext;
+ ctx.save();
+ if (stroking) {
+ ctx.installPattern(strokePattern);
}
- pointsOnLine = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, strategy);
- this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize);
- ctx.restore();
-};
+ var pointsOnLine = DygraphCanvasRenderer._drawSeries(
+ e, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color);
+ DygraphCanvasRenderer._drawPointsOnLine(
+ e, pointsOnLine, drawPointCallback, color, pointSize);
-var nonTrivialStrategy = function(renderer, ctx, color, strokeWidth, strokePattern) {
- return new function() {
- this.init = function() { };
- this.finish = function() { };
- this.startSegment = function() {
- ctx.beginPath();
- ctx.strokeStyle = color;
- ctx.lineWidth = strokeWidth;
- };
- this.endSegment = function() {
- ctx.stroke(); // should this include closePath?
- };
- this.drawLine = function(x1, y1, x2, y2) {
- renderer._dashedLine(ctx, x1, y1, x2, y2, strokePattern);
- };
- this.skipPixel = function(prevX, prevY, curX, curY) {
- // TODO(konigsberg): optimize with http://jsperf.com/math-round-vs-hack/6 ?
- return (Math.round(prevX) == Math.round(curX) &&
- Math.round(prevY) == Math.round(curY));
- };
- };
-};
+ if (stroking) {
+ ctx.uninstallPattern();
+ }
-var trivialStrategy = function(ctx, color, strokeWidth) {
- return new function() {
- this.init = function() {
- ctx.beginPath();
- ctx.strokeStyle = color;
- ctx.lineWidth = strokeWidth;
- };
- this.finish = function() {
- ctx.stroke(); // should this include closePath?
- };
- this.startSegment = function() { };
- this.endSegment = function() { };
- this.drawLine = function(x1, y1, x2, y2) {
- ctx.moveTo(x1, y1);
- ctx.lineTo(x2, y2);
- };
- // don't skip pixels.
- this.skipPixel = function() {
- return false;
- };
- };
+ ctx.restore();
};
-DygraphCanvasRenderer.prototype._drawPointsOnLine = function(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize) {
- for (var idx = 0; idx < pointsOnLine.length; idx++) {
- var cb = pointsOnLine[idx];
- ctx.save();
- drawPointCallback(
- this.dygraph_, setName, ctx, cb[0], cb[1], color, pointSize);
- ctx.restore();
- }
-}
-
-DygraphCanvasRenderer.prototype._drawSeries = function(
- ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints,
- stepPlot, strategy) {
+/**
+ * This does the actual drawing of lines on the canvas, for just one series.
+ * Returns a list of [canvasx, canvasy] pairs for points for which a
+ * drawPointCallback should be fired. These include isolated points, or all
+ * points if drawPoints=true.
+ * @param {Object} e The dictionary passed to the plotter function.
+ * @private
+ */
+DygraphCanvasRenderer._drawSeries = function(e,
+ iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color) {
var prevCanvasX = null;
var prevCanvasY = null;
var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
var first = true; // the first cycle through the while loop
- strategy.init();
+ var ctx = e.drawingContext;
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
+
+ // NOTE: we break the iterator's encapsulation here for about a 25% speedup.
+ var arr = iter.array_;
+ var limit = iter.end_;
+ var predicate = iter.predicate_;
+
+ for (var i = iter.start_; i < limit; i++) {
+ point = arr[i];
+ if (predicate) {
+ while (i < limit && !predicate(arr, i)) {
+ i++;
+ }
+ if (i == limit) break;
+ point = arr[i];
+ }
- while(iter.hasNext()) {
- point = iter.next();
if (point.canvasy === null || point.canvasy != point.canvasy) {
if (stepPlot && prevCanvasX !== null) {
// Draw a horizontal line to the start of the missing data
- strategy.startSegment();
- strategy.drawLine(prevX, prevY, point.canvasx, prevY);
- strategy.endSegment();
+ ctx.moveTo(prevCanvasX, prevCanvasY);
+ ctx.lineTo(point.canvasx, prevCanvasY);
}
prevCanvasX = prevCanvasY = null;
} else {
- nextCanvasY = iter.hasNext() ? iter.peek().canvasy : null;
- // TODO: we calculate isNullOrNaN for this point, and the next, and then, when
- // we iterate, test for isNullOrNaN again. Why bother?
- var isNextCanvasYNullOrNaN = nextCanvasY === null || nextCanvasY != nextCanvasY;
- isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN);
- if (drawGapPoints) {
- // Also consider a point to be "isolated" if it's adjacent to a
- // null point, excluding the graph edges.
- if ((!first && !prevCanvasX) ||
- (iter.hasNext() && isNextCanvasYNullOrNaN)) {
- isIsolated = true;
+ isIsolated = false;
+ if (drawGapPoints || !prevCanvasX) {
+ iter.nextIdx_ = i;
+ iter.next();
+ nextCanvasY = iter.hasNext ? iter.peek.canvasy : null;
+
+ var isNextCanvasYNullOrNaN = nextCanvasY === null ||
+ nextCanvasY != nextCanvasY;
+ isIsolated = (!prevCanvasX && isNextCanvasYNullOrNaN);
+ if (drawGapPoints) {
+ // Also consider a point to be "isolated" if it's adjacent to a
+ // null point, excluding the graph edges.
+ if ((!first && !prevCanvasX) ||
+ (iter.hasNext && isNextCanvasYNullOrNaN)) {
+ isIsolated = true;
+ }
}
}
+
if (prevCanvasX !== null) {
- if (strategy.skipPixel(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy)) {
- continue;
- }
if (strokeWidth) {
- strategy.startSegment();
if (stepPlot) {
- strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, prevCanvasY);
- prevCanvasX = point.canvasx;
+ ctx.moveTo(prevCanvasX, prevCanvasY);
+ ctx.lineTo(point.canvasx, prevCanvasY);
}
- strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy);
- strategy.endSegment();
+
+ ctx.lineTo(point.canvasx, point.canvasy);
}
+ } else {
+ ctx.moveTo(point.canvasx, point.canvasy);
}
if (drawPoints || isIsolated) {
- pointsOnLine.push([point.canvasx, point.canvasy]);
+ pointsOnLine.push([point.canvasx, point.canvasy, point.idx]);
}
prevCanvasX = point.canvasx;
prevCanvasY = point.canvasy;
}
first = false;
}
- strategy.finish();
+ ctx.stroke();
return pointsOnLine;
};
-DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) {
- var setNames = this.layout.setNames;
- var setName = setNames[i];
-
- var strokeWidth = this.dygraph_.attr_("strokeWidth", setName);
- var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName);
- var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) ||
- Dygraph.Circles.DEFAULT;
-
- if (borderWidth && strokeWidth) {
- this._drawStyledLine(ctx, i, setName,
- this.dygraph_.attr_("strokeBorderColor", setName),
- strokeWidth + 2 * borderWidth,
- this.dygraph_.attr_("strokePattern", setName),
- this.dygraph_.attr_("drawPoints", setName),
- drawPointCallback,
- this.dygraph_.attr_("pointSize", setName));
+/**
+ * This fires the drawPointCallback functions, which draw dots on the points by
+ * default. This gets used when the "drawPoints" option is set, or when there
+ * are isolated points.
+ * @param {Object} e The dictionary passed to the plotter function.
+ * @private
+ */
+DygraphCanvasRenderer._drawPointsOnLine = function(
+ e, pointsOnLine, drawPointCallback, color, pointSize) {
+ var ctx = e.drawingContext;
+ for (var idx = 0; idx < pointsOnLine.length; idx++) {
+ var cb = pointsOnLine[idx];
+ ctx.save();
+ drawPointCallback(
+ e.dygraph, e.setName, ctx, cb[0], cb[1], color, pointSize, cb[2]);
+ ctx.restore();
}
-
- this._drawStyledLine(ctx, i, setName,
- this.colors[setName],
- strokeWidth,
- this.dygraph_.attr_("strokePattern", setName),
- this.dygraph_.attr_("drawPoints", setName),
- drawPointCallback,
- this.dygraph_.attr_("pointSize", setName));
};
/**
- * Actually draw the lines chart, including error bars.
- * TODO(danvk): split this into several smaller functions.
+ * Attaches canvas coordinates to the points array.
* @private
*/
-DygraphCanvasRenderer.prototype._renderLineChart = function() {
- // TODO(danvk): use this.attr_ for many of these.
- var ctx = this.elementContext;
- var fillAlpha = this.attr_('fillAlpha');
- var errorBars = this.attr_("errorBars") || this.attr_("customBars");
- var fillGraph = this.attr_("fillGraph");
- var stackedGraph = this.attr_("stackedGraph");
- var stepPlot = this.attr_("stepPlot");
- var points = this.layout.points;
- var pointsLength = points.length;
- var point, i, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis;
-
- var setNames = this.layout.setNames;
- var setCount = setNames.length;
-
- this.colors = this.dygraph_.colorsMap_;
-
+DygraphCanvasRenderer.prototype._updatePoints = function() {
// Update Points
// TODO(danvk): here
//
// TODO(bhs): this loop is a hot-spot for high-point-count charts. These
// transformations can be pushed into the canvas via linear transformation
// matrices.
- for (i = pointsLength; i--;) {
- point = points[i];
- point.canvasx = this.area.w * point.x + this.area.x;
- point.canvasy = this.area.h * point.y + this.area.y;
+ // NOTE(danvk): this is trickier than it sounds at first. The transformation
+ // needs to be done before the .moveTo() and .lineTo() calls, but must be
+ // undone before the .stroke() call to ensure that the stroke width is
+ // unaffected. An alternative is to reduce the stroke width in the
+ // transformed coordinate space, but you can't specify different values for
+ // each dimension (as you can with .scale()). The speedup here is ~12%.
+ var sets = this.layout.points;
+ for (var i = sets.length; i--;) {
+ var points = sets[i];
+ for (var j = points.length; j--;) {
+ var point = points[j];
+ point.canvasx = this.area.w * point.x + this.area.x;
+ point.canvasy = this.area.h * point.y + this.area.y;
+ }
}
+};
- // create paths
- if (errorBars) {
- ctx.save();
- if (fillGraph) {
- this.dygraph_.warn("Can't use fillGraph option with error bars");
- }
+/**
+ * Add canvas Actually draw the lines chart, including error bars.
+ *
+ * This function can only be called if DygraphLayout's points array has been
+ * updated with canvas{x,y} attributes, i.e. by
+ * DygraphCanvasRenderer._updatePoints.
+ *
+ * @param {string=} opt_seriesName when specified, only that series will
+ * be drawn. (This is used for expedited redrawing with highlightSeriesOpts)
+ * @param {CanvasRenderingContext2D} opt_ctx when specified, the drawing
+ * context. However, lines are typically drawn on the object's
+ * elementContext.
+ * @private
+ */
+DygraphCanvasRenderer.prototype._renderLineChart = function(opt_seriesName, opt_ctx) {
+ var ctx = opt_ctx || this.elementContext;
+ var i;
- for (i = 0; i < setCount; i++) {
- setName = setNames[i];
- axis = this.dygraph_.axisPropertiesForSeries(setName);
- color = this.colors[setName];
+ var sets = this.layout.points;
+ var setNames = this.layout.setNames;
+ var setName;
- var firstIndexInSet = this.layout.setPointsOffsets[i];
- var setLength = this.layout.setPointsLengths[i];
+ this.colors = this.dygraph_.colorsMap_;
- var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
- DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
+ // Determine which series have specialized plotters.
+ var plotter_attr = this.attr_("plotter");
+ var plotters = plotter_attr;
+ if (!Dygraph.isArrayLike(plotters)) {
+ plotters = [plotters];
+ }
- // setup graphics context
- prevX = NaN;
- prevY = NaN;
- prevYs = [-1, -1];
- yscale = axis.yscale;
- // should be same color as the lines but only 15% opaque.
- rgb = new RGBColor(color);
- err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' +
- fillAlpha + ')';
- ctx.fillStyle = err_color;
- ctx.beginPath();
- while (iter.hasNext()) {
- point = iter.next();
- if (point.name == setName) { // TODO(klausw): this is always true
- if (!Dygraph.isOK(point.y)) {
- prevX = NaN;
- continue;
- }
+ var setPlotters = {}; // series name -> plotter fn.
+ for (i = 0; i < setNames.length; i++) {
+ setName = setNames[i];
+ var setPlotter = this.attr_("plotter", setName);
+ if (setPlotter == plotter_attr) continue; // not specialized.
- // TODO(danvk): here
- if (stepPlot) {
- newYs = [ point.y_bottom, point.y_top ];
- prevY = point.y;
- } else {
- newYs = [ point.y_bottom, point.y_top ];
- }
- newYs[0] = this.area.h * newYs[0] + this.area.y;
- newYs[1] = this.area.h * newYs[1] + this.area.y;
- if (!isNaN(prevX)) {
- if (stepPlot) {
- ctx.moveTo(prevX, newYs[0]);
- } else {
- ctx.moveTo(prevX, prevYs[0]);
- }
- ctx.lineTo(point.canvasx, newYs[0]);
- ctx.lineTo(point.canvasx, newYs[1]);
- if (stepPlot) {
- ctx.lineTo(prevX, newYs[1]);
- } else {
- ctx.lineTo(prevX, prevYs[1]);
- }
- ctx.closePath();
- }
- prevYs = newYs;
- prevX = point.canvasx;
- }
- }
- ctx.fill();
- }
- ctx.restore();
- } else if (fillGraph) {
- ctx.save();
- var baseline = {}; // for stacked graphs: baseline for filling
- var currBaseline;
-
- // process sets in reverse order (needed for stacked graphs)
- for (i = setCount - 1; i >= 0; i--) {
- setName = setNames[i];
- color = this.colors[setName];
- axis = this.dygraph_.axisPropertiesForSeries(setName);
- var axisY = 1.0 + axis.minyval * axis.yscale;
- if (axisY < 0.0) axisY = 0.0;
- else if (axisY > 1.0) axisY = 1.0;
- axisY = this.area.h * axisY + this.area.y;
- var firstIndexInSet = this.layout.setPointsOffsets[i];
- var setLength = this.layout.setPointsLengths[i];
-
- var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
- DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
-
- // setup graphics context
- prevX = NaN;
- prevYs = [-1, -1];
- yscale = axis.yscale;
- // should be same color as the lines but only 15% opaque.
- rgb = new RGBColor(color);
- err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' +
- fillAlpha + ')';
- ctx.fillStyle = err_color;
- ctx.beginPath();
- while(iter.hasNext()) {
- point = iter.next();
- if (point.name == setName) { // TODO(klausw): this is always true
- if (!Dygraph.isOK(point.y)) {
- prevX = NaN;
- continue;
- }
- if (stackedGraph) {
- currBaseline = baseline[point.canvasx];
- var lastY;
- if (currBaseline === undefined) {
- lastY = axisY;
- } else {
- if(stepPlot) {
- lastY = currBaseline[0];
- } else {
- lastY = currBaseline;
- }
- }
- newYs = [ point.canvasy, lastY ];
-
- if(stepPlot) {
- // Step plots must keep track of the top and bottom of
- // the baseline at each point.
- if(prevYs[0] === -1) {
- baseline[point.canvasx] = [ point.canvasy, axisY ];
- } else {
- baseline[point.canvasx] = [ point.canvasy, prevYs[0] ];
- }
- } else {
- baseline[point.canvasx] = point.canvasy;
- }
+ setPlotters[setName] = setPlotter;
+ }
- } else {
- newYs = [ point.canvasy, axisY ];
- }
- if (!isNaN(prevX)) {
- ctx.moveTo(prevX, prevYs[0]);
-
- if (stepPlot) {
- ctx.lineTo(point.canvasx, prevYs[0]);
- if(currBaseline) {
- // Draw to the bottom of the baseline
- ctx.lineTo(point.canvasx, currBaseline[1]);
- } else {
- ctx.lineTo(point.canvasx, newYs[1]);
- }
- } else {
- ctx.lineTo(point.canvasx, newYs[0]);
- ctx.lineTo(point.canvasx, newYs[1]);
- }
-
- ctx.lineTo(prevX, prevYs[1]);
- ctx.closePath();
- }
- prevYs = newYs;
- prevX = point.canvasx;
+ for (i = 0; i < plotters.length; i++) {
+ var plotter = plotters[i];
+ var is_last = (i == plotters.length - 1);
+
+ for (var j = 0; j < sets.length; j++) {
+ setName = setNames[j];
+ if (opt_seriesName && setName != opt_seriesName) continue;
+
+ var points = sets[j];
+
+ // Only throw in the specialized plotters on the last iteration.
+ var p = plotter;
+ if (setName in setPlotters) {
+ if (is_last) {
+ p = setPlotters[setName];
+ } else {
+ // Don't use the standard plotters in this case.
+ continue;
}
}
- ctx.fill();
+
+ var color = this.colors[setName];
+ var strokeWidth = this.dygraph_.getOption("strokeWidth", setName);
+
+ ctx.save();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
+ p({
+ points: points,
+ setName: setName,
+ drawingContext: ctx,
+ color: color,
+ strokeWidth: strokeWidth,
+ dygraph: this.dygraph_,
+ axis: this.dygraph_.axisPropertiesForSeries(setName),
+ plotArea: this.area,
+ seriesIndex: j,
+ seriesCount: sets.length,
+ singleSeriesName: opt_seriesName,
+ allSeriesPoints: sets
+ });
+ ctx.restore();
}
- ctx.restore();
}
+};
+
+/**
+ * Standard plotters. These may be used by clients via Dygraph.Plotters.
+ * See comments there for more details.
+ */
+DygraphCanvasRenderer._Plotters = {
+ linePlotter: function(e) {
+ DygraphCanvasRenderer._linePlotter(e);
+ },
+
+ fillPlotter: function(e) {
+ DygraphCanvasRenderer._fillPlotter(e);
+ },
- // Drawing the lines.
- for (i = 0; i < setCount; i += 1) {
- this._drawLine(ctx, i);
+ errorPlotter: function(e) {
+ DygraphCanvasRenderer._errorPlotter(e);
}
};
/**
- * This does dashed lines onto a canvas for a given pattern. You must call
- * ctx.stroke() after to actually draw it, much line ctx.lineTo(). It remembers
- * the state of the line in regards to where we left off on drawing the pattern.
- * You can draw a dashed line in several function calls and the pattern will be
- * continous as long as you didn't call this function with a different pattern
- * in between.
- * @param ctx The canvas 2d context to draw on.
- * @param x The start of the line's x coordinate.
- * @param y The start of the line's y coordinate.
- * @param x2 The end of the line's x coordinate.
- * @param y2 The end of the line's y coordinate.
- * @param pattern The dash pattern to draw, an array of integers where even
- * index is drawn and odd index is not drawn (Ex. [10, 2, 5, 2], 10 is drawn 5
- * is drawn, 2 is the space between.). A null pattern, array of length one, or
- * empty array will do just a solid line.
+ * Plotter which draws the central lines for a series.
* @private
*/
-DygraphCanvasRenderer.prototype._dashedLine = function(ctx, x, y, x2, y2, pattern) {
- // Original version http://stackoverflow.com/questions/4576724/dotted-stroke-in-canvas
- // Modified by Russell Valentine to keep line history and continue the pattern
- // where it left off.
- var dx, dy, len, rot, patternIndex, segment;
-
- // If we don't have a pattern or it is an empty array or of size one just
- // do a solid line.
- if (!pattern || pattern.length <= 1) {
- ctx.moveTo(x, y);
- ctx.lineTo(x2, y2);
- return;
+DygraphCanvasRenderer._linePlotter = function(e) {
+ var g = e.dygraph;
+ var setName = e.setName;
+ var strokeWidth = e.strokeWidth;
+
+ // TODO(danvk): Check if there's any performance impact of just calling
+ // getOption() inside of _drawStyledLine. Passing in so many parameters makes
+ // this code a bit nasty.
+ var borderWidth = g.getOption("strokeBorderWidth", setName);
+ var drawPointCallback = g.getOption("drawPointCallback", setName) ||
+ Dygraph.Circles.DEFAULT;
+ var strokePattern = g.getOption("strokePattern", setName);
+ var drawPoints = g.getOption("drawPoints", setName);
+ var pointSize = g.getOption("pointSize", setName);
+
+ if (borderWidth && strokeWidth) {
+ DygraphCanvasRenderer._drawStyledLine(e,
+ g.getOption("strokeBorderColor", setName),
+ strokeWidth + 2 * borderWidth,
+ strokePattern,
+ drawPoints,
+ drawPointCallback,
+ pointSize
+ );
}
- // If we have a different dash pattern than the last time this was called we
- // reset our dash history and start the pattern from the begging
- // regardless of state of the last pattern.
- if (!Dygraph.compareArrays(pattern, this._dashedLineToHistoryPattern)) {
- this._dashedLineToHistoryPattern = pattern;
- this._dashedLineToHistory = [0, 0];
+ DygraphCanvasRenderer._drawStyledLine(e,
+ e.color,
+ strokeWidth,
+ strokePattern,
+ drawPoints,
+ drawPointCallback,
+ pointSize
+ );
+};
+
+/**
+ * Draws the shaded error bars/confidence intervals for each series.
+ * This happens before the center lines are drawn, since the center lines
+ * need to be drawn on top of the error bars for all series.
+ * @private
+ */
+DygraphCanvasRenderer._errorPlotter = function(e) {
+ var g = e.dygraph;
+ var setName = e.setName;
+ var errorBars = g.getOption("errorBars") || g.getOption("customBars");
+ if (!errorBars) return;
+
+ var fillGraph = g.getOption("fillGraph", setName);
+ if (fillGraph) {
+ g.warn("Can't use fillGraph option with error bars");
}
- ctx.save();
- // Calculate transformation parameters
- dx = (x2-x);
- dy = (y2-y);
- len = Math.sqrt(dx*dx + dy*dy);
- rot = Math.atan2(dy, dx);
-
- // Set transformation
- ctx.translate(x, y);
- ctx.moveTo(0, 0);
- ctx.rotate(rot);
-
- // Set last pattern index we used for this pattern.
- patternIndex = this._dashedLineToHistory[0];
- x = 0;
- while (len > x) {
- // Get the length of the pattern segment we are dealing with.
- segment = pattern[patternIndex];
- // If our last draw didn't complete the pattern segment all the way we
- // will try to finish it. Otherwise we will try to do the whole segment.
- if (this._dashedLineToHistory[1]) {
- x += this._dashedLineToHistory[1];
- } else {
- x += segment;
+ var ctx = e.drawingContext;
+ var color = e.color;
+ var fillAlpha = g.getOption('fillAlpha', setName);
+ var stepPlot = g.getOption("stepPlot", setName);
+ var points = e.points;
+
+ var iter = Dygraph.createIterator(points, 0, points.length,
+ DygraphCanvasRenderer._getIteratorPredicate(
+ g.getOption("connectSeparatedPoints")));
+
+ var newYs;
+
+ // setup graphics context
+ var prevX = NaN;
+ var prevY = NaN;
+ var prevYs = [-1, -1];
+ // should be same color as the lines but only 15% opaque.
+ var rgb = new RGBColorParser(color);
+ var err_color =
+ 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')';
+ ctx.fillStyle = err_color;
+ ctx.beginPath();
+
+ var isNullUndefinedOrNaN = function(x) {
+ return (x === null ||
+ x === undefined ||
+ isNaN(x));
+ };
+
+ while (iter.hasNext) {
+ var point = iter.next();
+ if ((!stepPlot && isNullUndefinedOrNaN(point.y)) ||
+ (stepPlot && !isNaN(prevY) && isNullUndefinedOrNaN(prevY))) {
+ prevX = NaN;
+ continue;
}
- if (x > len) {
- // We were unable to complete this pattern index all the way, keep
- // where we are the history so our next draw continues where we left off
- // in the pattern.
- this._dashedLineToHistory = [patternIndex, x-len];
- x = len;
+
+ if (stepPlot) {
+ newYs = [ point.y_bottom, point.y_top ];
+ prevY = point.y;
} else {
- // We completed this patternIndex, we put in the history that we are on
- // the beginning of the next segment.
- this._dashedLineToHistory = [(patternIndex+1)%pattern.length, 0];
+ newYs = [ point.y_bottom, point.y_top ];
}
+ newYs[0] = e.plotArea.h * newYs[0] + e.plotArea.y;
+ newYs[1] = e.plotArea.h * newYs[1] + e.plotArea.y;
+ if (!isNaN(prevX)) {
+ if (stepPlot) {
+ ctx.moveTo(prevX, prevYs[0]);
+ ctx.lineTo(point.canvasx, prevYs[0]);
+ ctx.lineTo(point.canvasx, prevYs[1]);
+ } else {
+ ctx.moveTo(prevX, prevYs[0]);
+ ctx.lineTo(point.canvasx, newYs[0]);
+ ctx.lineTo(point.canvasx, newYs[1]);
+ }
+ ctx.lineTo(prevX, prevYs[1]);
+ ctx.closePath();
+ }
+ prevYs = newYs;
+ prevX = point.canvasx;
+ }
+ ctx.fill();
+};
- // We do a line on a even pattern index and just move on a odd pattern index.
- // The move is the empty space in the dash.
- if(patternIndex % 2 === 0) {
- ctx.lineTo(x, 0);
- } else {
- ctx.moveTo(x, 0);
+/**
+ * Draws the shaded regions when "fillGraph" is set. Not to be confused with
+ * error bars.
+ *
+ * For stacked charts, it's more convenient to handle all the series
+ * simultaneously. So this plotter plots all the points on the first series
+ * it's asked to draw, then ignores all the other series.
+ *
+ * @private
+ */
+DygraphCanvasRenderer._fillPlotter = function(e) {
+ // Skip if we're drawing a single series for interactive highlight overlay.
+ if (e.singleSeriesName) return;
+
+ // We'll handle all the series at once, not one-by-one.
+ if (e.seriesIndex !== 0) return;
+
+ var g = e.dygraph;
+ var setNames = g.getLabels().slice(1); // remove x-axis
+
+ // getLabels() includes names for invisible series, which are not included in
+ // allSeriesPoints. We remove those to make the two match.
+ // TODO(danvk): provide a simpler way to get this information.
+ for (var i = setNames.length; i >= 0; i--) {
+ if (!g.visibility()[i]) setNames.splice(i, 1);
+ }
+
+ var anySeriesFilled = (function() {
+ for (var i = 0; i < setNames.length; i++) {
+ if (g.getOption("fillGraph", setNames[i])) return true;
}
- // If we are not done, next loop process the next pattern segment, or the
- // first segment again if we are at the end of the pattern.
- patternIndex = (patternIndex+1) % pattern.length;
+ return false;
+ })();
+
+ if (!anySeriesFilled) return;
+
+ var ctx = e.drawingContext;
+ var area = e.plotArea;
+ var sets = e.allSeriesPoints;
+ var setCount = sets.length;
+
+ var fillAlpha = g.getOption('fillAlpha');
+ var stackedGraph = g.getOption("stackedGraph");
+ var colors = g.getColors();
+
+ // For stacked graphs, track the baseline for filling.
+ //
+ // The filled areas below graph lines are trapezoids with two
+ // vertical edges. The top edge is the line segment being drawn, and
+ // the baseline is the bottom edge. Each baseline corresponds to the
+ // top line segment from the previous stacked line. In the case of
+ // step plots, the trapezoids are rectangles.
+ var baseline = {};
+ var currBaseline;
+ var prevStepPlot; // for different line drawing modes (line/step) per series
+
+ // process sets in reverse order (needed for stacked graphs)
+ for (var setIdx = setCount - 1; setIdx >= 0; setIdx--) {
+ var setName = setNames[setIdx];
+ if (!g.getOption('fillGraph', setName)) continue;
+
+ var stepPlot = g.getOption('stepPlot', setName);
+ var color = colors[setIdx];
+ var axis = g.axisPropertiesForSeries(setName);
+ var axisY = 1.0 + axis.minyval * axis.yscale;
+ if (axisY < 0.0) axisY = 0.0;
+ else if (axisY > 1.0) axisY = 1.0;
+ axisY = area.h * axisY + area.y;
+
+ var points = sets[setIdx];
+ var iter = Dygraph.createIterator(points, 0, points.length,
+ DygraphCanvasRenderer._getIteratorPredicate(
+ g.getOption("connectSeparatedPoints")));
+
+ // setup graphics context
+ var prevX = NaN;
+ var prevYs = [-1, -1];
+ var newYs;
+ // should be same color as the lines but only 15% opaque.
+ var rgb = new RGBColorParser(color);
+ var err_color =
+ 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' + fillAlpha + ')';
+ ctx.fillStyle = err_color;
+ ctx.beginPath();
+ var last_x, is_first = true;
+ while (iter.hasNext) {
+ var point = iter.next();
+ if (!Dygraph.isOK(point.y)) {
+ prevX = NaN;
+ if (point.y_stacked !== null && !isNaN(point.y_stacked)) {
+ baseline[point.canvasx] = area.h * point.y_stacked + area.y;
+ }
+ continue;
+ }
+ if (stackedGraph) {
+ if (!is_first && last_x == point.xval) {
+ continue;
+ } else {
+ is_first = false;
+ last_x = point.xval;
+ }
+
+ currBaseline = baseline[point.canvasx];
+ var lastY;
+ if (currBaseline === undefined) {
+ lastY = axisY;
+ } else {
+ if(prevStepPlot) {
+ lastY = currBaseline[0];
+ } else {
+ lastY = currBaseline;
+ }
+ }
+ newYs = [ point.canvasy, lastY ];
+
+ if(stepPlot) {
+ // Step plots must keep track of the top and bottom of
+ // the baseline at each point.
+ if(prevYs[0] === -1) {
+ baseline[point.canvasx] = [ point.canvasy, axisY ];
+ } else {
+ baseline[point.canvasx] = [ point.canvasy, prevYs[0] ];
+ }
+ } else {
+ baseline[point.canvasx] = point.canvasy;
+ }
+
+ } else {
+ newYs = [ point.canvasy, axisY ];
+ }
+ if (!isNaN(prevX)) {
+ ctx.moveTo(prevX, prevYs[0]);
+
+ // Move to top fill point
+ if (stepPlot) {
+ ctx.lineTo(point.canvasx, prevYs[0]);
+ } else {
+ ctx.lineTo(point.canvasx, newYs[0]);
+ }
+ // Move to bottom fill point
+ if (prevStepPlot && currBaseline) {
+ // Draw to the bottom of the baseline
+ ctx.lineTo(point.canvasx, currBaseline[1]);
+ } else {
+ ctx.lineTo(point.canvasx, newYs[1]);
+ }
+
+ ctx.lineTo(prevX, prevYs[1]);
+ ctx.closePath();
+ }
+ prevYs = newYs;
+ prevX = point.canvasx;
+ }
+ prevStepPlot = stepPlot;
+ ctx.fill();
}
- ctx.restore();
};