}
// draw a vertical line on the left to separate the chart from the labels.
+ var axisX;
+ if (this.attr_('drawAxesAtZero')) {
+ var r = this.dygraph_.toPercentXCoord(0);
+ if (r > 1 || r < 0) r = 0;
+ axisX = halfUp(this.area.x + r * this.area.w);
+ } else {
+ axisX = halfUp(this.area.x);
+ }
context.beginPath();
- context.moveTo(halfUp(this.area.x), halfDown(this.area.y));
- context.lineTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
+ context.moveTo(axisX, halfDown(this.area.y));
+ context.lineTo(axisX, halfDown(this.area.y + this.area.h));
context.closePath();
context.stroke();
}
context.beginPath();
- context.moveTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
- context.lineTo(halfUp(this.area.x + this.area.w), halfDown(this.area.y + this.area.h));
+ var axisY;
+ if (this.attr_('drawAxesAtZero')) {
+ var r = this.dygraph_.toPercentYCoord(0, 0);
+ if (r > 1 || r < 0) r = 1;
+ axisY = halfDown(this.area.y + r * this.area.h);
+ } else {
+ axisY = halfDown(this.area.y + this.area.h);
+ }
+ context.moveTo(halfUp(this.area.x), axisY);
+ context.lineTo(halfUp(this.area.x + this.area.w), axisY);
context.closePath();
context.stroke();
}
}
};
-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 };
- }
+/**
+ * Returns a predicate to be used with an iterator, which will
+ * iterate over points appropriately, depending on whether
+ * connectSeparatedPoints is true. When it's false, the predicate will
+ * skip over points with missing yVals.
+ */
+DygraphCanvasRenderer._getIteratorPredicate = function(connectSeparatedPoints) {
+ return connectSeparatedPoints ? DygraphCanvasRenderer._predicateThatSkipsEmptyPoints : null;
+}
+
+DygraphCanvasRenderer._predicateThatSkipsEmptyPoints =
+ function(array, idx) { return array[idx].yval !== null; }
+
+DygraphCanvasRenderer.isNullOrNaN_ = function(x) {
+ return (x === null || isNaN(x));
};
DygraphCanvasRenderer.prototype._drawStyledLine = function(
ctx, i, setName, color, strokeWidth, strokePattern, drawPoints,
drawPointCallback, pointSize) {
- var isNullOrNaN = function(x) {
- return (x === null || isNaN(x));
- };
-
+ // 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 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 drawGapPoints = this.dygraph_.attr_('drawGapPoints', setName);
+ var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName);
- 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)) {
+
+ var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
+ DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
+
+ if (strokeWidth && !stepPlot && (!strokePattern || strokePattern.length <= 1)) {
+ this._drawTrivialLine(ctx, iter, setName, color, strokeWidth, drawPointCallback, pointSize, drawPoints, drawGapPoints);
+ } else {
+ this._drawNonTrivialLine(ctx, iter, setName, color, strokeWidth, strokePattern, drawPointCallback, pointSize, drawPoints, drawGapPoints, stepPlot);
+ }
+ 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._drawNonTrivialLine = function(
+ ctx, iter, setName, color, strokeWidth, strokePattern, drawPointCallback, pointSize, drawPoints, drawGapPoints, stepPlot) {
+ var prevX = null;
+ var prevY = null;
+ var nextY = null;
+ var point;
+ var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
+ var first = true;
+ while(iter.hasNext()) {
+ point = iter.next();
+ nextY = iter.hasNext() ? iter.peek().canvasy : null;
+ if (DygraphCanvasRenderer.isNullOrNaN_(point.canvasy)) {
if (stepPlot && prevX !== null) {
// Draw a horizontal line to the start of the missing data
ctx.beginPath();
} 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)));
+ var isIsolated = (!prevX && DygraphCanvasRenderer.isNullOrNaN_(nextY));
if (drawGapPoints) {
// Also consider a point to be is "isolated" if it's adjacent to a
// null point, excluding the graph edges.
- if ((j > 0 && !prevX) ||
- (j < points.length - 1 && isNullOrNaN(points[j+1].canvasy))) {
+ if ((!first && !prevX) ||
+ (iter.hasNext() && DygraphCanvasRenderer.isNullOrNaN_(nextY))) {
isIsolated = true;
}
}
pointsOnLine.push([point.canvasx, point.canvasy]);
}
}
+ first = false;
}
- 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();
+ this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize);
+};
+
+DygraphCanvasRenderer.prototype._drawTrivialLine = function(
+ ctx, iter, setName, color, strokeWidth, drawPointCallback, pointSize, drawPoints, drawGapPoints) {
+ var prevX = null;
+ var prevY = null;
+ var nextY = null;
+ var pointsOnLine = []; // Array of [canvasx, canvasy] pairs.
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
+ var first = true;
+ while(iter.hasNext()) {
+ var point = iter.next();
+ nextY = iter.hasNext() ? iter.peek().canvasy : null;
+ if (DygraphCanvasRenderer.isNullOrNaN_(point.canvasy)) {
+ prevX = prevY = null;
+ } else {
+ var isIsolated = (!prevX && DygraphCanvasRenderer.isNullOrNaN_(nextY));
+ if (drawGapPoints) {
+ // Also consider a point to be is "isolated" if it's adjacent to a
+ // null point, excluding the graph edges.
+ if ((!first && !prevX) ||
+ (iter.hasNext() && DygraphCanvasRenderer.isNullOrNaN_(nextY))) {
+ isIsolated = true;
+ }
+ }
+ if (prevX === null) {
+ prevX = point.canvasx;
+ prevY = point.canvasy;
+ ctx.moveTo(point.canvasx, point.canvasy);
+ } else {
+ ctx.lineTo(point.canvasx, point.canvasy);
+ }
+ if (drawPoints || isIsolated) {
+ pointsOnLine.push([point.canvasx, point.canvasy]);
+ }
+ }
+ first = false;
}
- ctx.restore();
+ ctx.stroke();
+ this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, color, pointSize);
};
DygraphCanvasRenderer.prototype._drawLine = function(ctx, i) {
var borderWidth = this.dygraph_.attr_("strokeBorderWidth", setName);
var drawPointCallback = this.dygraph_.attr_("drawPointCallback", setName) ||
Dygraph.Circles.DEFAULT;
+
+ // TODO(konigsberg): Turn this into one call, and then consider inlining drawStyledLine.
if (borderWidth && strokeWidth) {
this._drawStyledLine(ctx, i, setName,
this.dygraph_.attr_("strokeBorderColor", setName),
var stepPlot = this.attr_("stepPlot");
var points = this.layout.points;
var pointsLength = points.length;
- var point, i, j, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis;
+ var point, i, prevX, prevY, prevYs, color, setName, newYs, err_color, rgb, yscale, axis;
var setNames = this.layout.setNames;
var setCount = setNames.length;
// 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;
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);
+ var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
+ DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
// setup graphics context
prevX = NaN;
fillAlpha + ')';
ctx.fillStyle = err_color;
ctx.beginPath();
- for (j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
- point = points[j];
+ while (iter.hasNext()) {
+ point = iter.next();
if (point.name == setName) { // TODO(klausw): this is always true
if (!Dygraph.isOK(point.y)) {
prevX = NaN;
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);
+ var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
+ DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
// setup graphics context
prevX = NaN;
fillAlpha + ')';
ctx.fillStyle = err_color;
ctx.beginPath();
- for (j = firstIndexInSet; j < afterLastIndexInSet; j = next(j)) {
- point = points[j];
+ while(iter.hasNext()) {
+ point = iter.next();
if (point.name == setName) { // TODO(klausw): this is always true
if (!Dygraph.isOK(point.y)) {
prevX = NaN;
}
}
newYs = [ point.canvasy, lastY ];
-
+
if(stepPlot) {
// Step plots must keep track of the top and bottom of
// the baseline at each point.
} else {
baseline[point.canvasx] = point.canvasy;
}
-
+
} else {
newYs = [ point.canvasy, axisY ];
}
if (!isNaN(prevX)) {
ctx.moveTo(prevX, prevYs[0]);
-
+
if (stepPlot) {
ctx.lineTo(point.canvasx, prevYs[0]);
if(currBaseline) {
ctx.lineTo(point.canvasx, newYs[0]);
ctx.lineTo(point.canvasx, newYs[1]);
}
-
+
ctx.lineTo(prevX, prevYs[1]);
ctx.closePath();
}