/*global Dygraph:false,RGBColor:false */
"use strict";
+
var DygraphCanvasRenderer = function(dygraph, element, elementContext, layout) {
this.dygraph_ = dygraph;
ctx.closePath();
ctx.stroke();
}
+ ctx.restore();
}
if (this.attr_('drawXGrid')) {
ctx.closePath();
ctx.stroke();
}
+ ctx.restore();
}
// Do the ordinary rendering, as before
var points = this.layout.annotated_points;
for (var i = 0; i < points.length; i++) {
var p = points[i];
- if (p.canvasx < this.area.x || p.canvasx > this.area.x + this.area.w) {
+ if (p.canvasx < this.area.x || p.canvasx > this.area.x + this.area.w ||
+ p.canvasy < this.area.y || p.canvasy > this.area.y + this.area.h) {
continue;
}
}
};
+DygraphCanvasRenderer.makeNextPointStep_ = function(connect, points, end) {
+ if (connect) {
+ return function(j) {
+ while (++j < end) {
+ if (!(points[j].yval === null)) break;
+ }
+ return j;
+ }
+ } else {
+ return function(j) { return j + 1 };
+ }
+};
+
+DygraphCanvasRenderer.prototype._drawStyledLine = function(
+ ctx, i, setName, color, strokeWidth, strokePattern, drawPoints,
+ drawPointCallback, pointSize) {
+ var isNullOrNaN = function(x) {
+ return (x === null || isNaN(x));
+ };
+
+ var stepPlot = this.attr_("stepPlot");
+ var firstIndexInSet = this.layout.setPointsOffsets[i];
+ var setLength = this.layout.setPointsLengths[i];
+ var afterLastIndexInSet = firstIndexInSet + setLength;
+ var points = this.layout.points;
+ var prevX = null;
+ var prevY = null;
+ var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
+ if (!Dygraph.isArrayLike(strokePattern)) {
+ strokePattern = null;
+ }
+
+ var point;
+ var next = DygraphCanvasRenderer.makeNextPointStep_(
+ this.attr_('connectSeparatedPoints'), points, afterLastIndexInSet);
+ ctx.save();
+ for (var j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
+ point = points[j];
+ if (isNullOrNaN(point.canvasy)) {
+ if (stepPlot && prevX !== null) {
+ // Draw a horizontal line to the start of the missing data
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = this.attr_('strokeWidth');
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, prevY, strokePattern);
+ ctx.stroke();
+ }
+ // this will make us move to the next point, not draw a line to it.
+ prevX = prevY = null;
+ } else {
+ // A point is "isolated" if it is non-null but both the previous
+ // and next points are null.
+ var isIsolated = (!prevX && (j == points.length - 1 ||
+ isNullOrNaN(points[j+1].canvasy)));
+ if (prevX === null) {
+ prevX = point.canvasx;
+ prevY = point.canvasy;
+ } else {
+ // Skip over points that will be drawn in the same pixel.
+ if (Math.round(prevX) == Math.round(point.canvasx) &&
+ Math.round(prevY) == Math.round(point.canvasy)) {
+ continue;
+ }
+ // TODO(antrob): skip over points that lie on a line that is already
+ // going to be drawn. There is no need to have more than 2
+ // consecutive points that are collinear.
+ if (strokeWidth) {
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
+ if (stepPlot) {
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, prevY, strokePattern);
+ prevX = point.canvasx;
+ }
+ this._dashedLine(ctx, prevX, prevY, point.canvasx, point.canvasy, strokePattern);
+ prevX = point.canvasx;
+ prevY = point.canvasy;
+ ctx.stroke();
+ }
+ }
+
+ if (drawPoints || isIsolated) {
+ pointsOnLine.push([point.canvasx, point.canvasy]);
+ }
+ }
+ }
+ 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();
+ }
+ ctx.restore();
+};
+
+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._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.
* @private
*/
DygraphCanvasRenderer.prototype._renderLineChart = function() {
- var isNullOrNaN = function(x) {
- return (x === null || isNaN(x));
- };
-
// TODO(danvk): use this.attr_ for many of these.
- var context = this.elementContext;
+ var ctx = this.elementContext;
var fillAlpha = this.attr_('fillAlpha');
var errorBars = this.attr_("errorBars") || this.attr_("customBars");
var fillGraph = this.attr_("fillGraph");
var pointsLength = points.length;
var point, i, j, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis;
- var setNames = [];
- for (var name in this.layout.datasets) {
- if (this.layout.datasets.hasOwnProperty(name)) {
- setNames.push(name);
- }
- }
+ var setNames = this.layout.setNames;
var setCount = setNames.length;
// TODO(danvk): Move this mapping into Dygraph and get it out of here.
}
// create paths
- var ctx = context;
if (errorBars) {
+ ctx.save();
if (fillGraph) {
this.dygraph_.warn("Can't use fillGraph option with error bars");
}
axis = this.dygraph_.axisPropertiesForSeries(setName);
color = this.colors[setName];
+ var firstIndexInSet = this.layout.setPointsOffsets[i];
+ var setLength = this.layout.setPointsLengths[i];
+ var afterLastIndexInSet = firstIndexInSet + setLength;
+
+ var next = DygraphCanvasRenderer.makeNextPointStep_(
+ this.attr_('connectSeparatedPoints'), points,
+ afterLastIndexInSet);
+
// setup graphics context
- ctx.save();
prevX = NaN;
prevY = NaN;
prevYs = [-1, -1];
fillAlpha + ')';
ctx.fillStyle = err_color;
ctx.beginPath();
- for (j = 0; j < pointsLength; j++) {
+ for (j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
point = points[j];
- if (point.name == setName) {
+ if (point.name == setName) { // TODO(klausw): this is always true
if (!Dygraph.isOK(point.y)) {
prevX = NaN;
continue;
}
ctx.fill();
}
+ ctx.restore();
} else if (fillGraph) {
+ ctx.save();
var baseline = []; // for stacked graphs: baseline for filling
// process sets in reverse order (needed for stacked graphs)
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 afterLastIndexInSet = firstIndexInSet + setLength;
+
+ var next = DygraphCanvasRenderer.makeNextPointStep_(
+ this.attr_('connectSeparatedPoints'), points,
+ afterLastIndexInSet);
// setup graphics context
- ctx.save();
prevX = NaN;
prevYs = [-1, -1];
yscale = axis.yscale;
fillAlpha + ')';
ctx.fillStyle = err_color;
ctx.beginPath();
- for (j = 0; j < pointsLength; j++) {
+ for (j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
point = points[j];
- if (point.name == setName) {
+ if (point.name == setName) { // TODO(klausw): this is always true
if (!Dygraph.isOK(point.y)) {
prevX = NaN;
continue;
}
ctx.fill();
}
+ ctx.restore();
}
// Drawing the lines.
- var firstIndexInSet = 0;
- var afterLastIndexInSet = 0;
- var setLength = 0;
for (i = 0; i < setCount; i += 1) {
- setLength = this.layout.setPointsLengths[i];
- afterLastIndexInSet += setLength;
- setName = setNames[i];
- color = this.colors[setName];
- var strokeWidth = this.dygraph_.attr_("strokeWidth", setName);
-
- // setup graphics context
- context.save();
- var pointSize = this.dygraph_.attr_("pointSize", setName);
- prevX = null;
- prevY = null;
- var drawPoints = this.dygraph_.attr_("drawPoints", setName);
- for (j = firstIndexInSet; j < afterLastIndexInSet; j++) {
- point = points[j];
- if (isNullOrNaN(point.canvasy)) {
- if (stepPlot && prevX !== null) {
- // Draw a horizontal line to the start of the missing data
- ctx.beginPath();
- ctx.strokeStyle = color;
- ctx.lineWidth = this.attr_('strokeWidth');
- ctx.moveTo(prevX, prevY);
- ctx.lineTo(point.canvasx, prevY);
- ctx.stroke();
- }
- // this will make us move to the next point, not draw a line to it.
- prevX = prevY = null;
- } else {
- // A point is "isolated" if it is non-null but both the previous
- // and next points are null.
- var isIsolated = (!prevX && (j == points.length - 1 ||
- isNullOrNaN(points[j+1].canvasy)));
- if (prevX === null) {
- prevX = point.canvasx;
- prevY = point.canvasy;
- } else {
- // Skip over points that will be drawn in the same pixel.
- if (Math.round(prevX) == Math.round(point.canvasx) &&
- Math.round(prevY) == Math.round(point.canvasy)) {
- continue;
- }
- // TODO(antrob): skip over points that lie on a line that is already
- // going to be drawn. There is no need to have more than 2
- // consecutive points that are collinear.
- if (strokeWidth) {
- ctx.beginPath();
- ctx.strokeStyle = color;
- ctx.lineWidth = strokeWidth;
- ctx.moveTo(prevX, prevY);
- if (stepPlot) {
- ctx.lineTo(point.canvasx, prevY);
- }
- prevX = point.canvasx;
- prevY = point.canvasy;
- ctx.lineTo(prevX, prevY);
- ctx.stroke();
- }
- }
+ this._drawLine(ctx, i);
+ }
+};
- if (drawPoints || isIsolated) {
- ctx.beginPath();
- ctx.fillStyle = color;
- ctx.arc(point.canvasx, point.canvasy, pointSize,
- 0, 2 * Math.PI, false);
- ctx.fill();
- }
- }
- }
- firstIndexInSet = afterLastIndexInSet;
+/**
+ * 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.
+ * @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;
}
- context.restore();
+ // 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];
+ }
+ 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;
+ }
+ 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;
+ } 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];
+ }
+
+ // 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);
+ }
+ // 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;
+ }
+ ctx.restore();
};
projects / dygraphs.git / blobdiff