* 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; }
+/**
+ *
+ * @private
+ */
DygraphCanvasRenderer.prototype._drawStyledLine = function(
ctx, i, setName, color, strokeWidth, strokePattern, drawPoints,
drawPointCallback, pointSize) {
}
var drawGapPoints = this.dygraph_.attr_('drawGapEdgePoints', setName);
- ctx.save();
-
var iter = Dygraph.createIterator(points, firstIndexInSet, setLength,
- DygraphCanvasRenderer._getIteratorPredicate(this.attr_("connectSeparatedPoints")));
+ DygraphCanvasRenderer._getIteratorPredicate(
+ this.attr_("connectSeparatedPoints")));
- 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);
+
+ 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 = this._drawSeries(ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints, stepPlot, color);
+ this._drawPointsOnLine(ctx, pointsOnLine, drawPointCallback, setName, 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) {
DygraphCanvasRenderer.prototype._drawSeries = function(
ctx, iter, strokeWidth, pointSize, drawPoints, drawGapPoints,
- stepPlot, strategy) {
+ 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();
+ ctx.beginPath();
+ ctx.strokeStyle = color;
+ ctx.lineWidth = strokeWidth;
- while(iter.hasNext) {
+ 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(prevX, prevY);
+ ctx.lineTo(point.canvasx, prevY);
}
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?
+ // 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) {
}
}
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);
+ ctx.moveTo(prevCanvasX, prevCanvasY);
+ ctx.lineTo(point.canvasx, prevCanvasY);
prevCanvasX = point.canvasx;
}
- strategy.drawLine(prevCanvasX, prevCanvasY, point.canvasx, point.canvasy);
- strategy.endSegment();
+ ctx.moveTo(prevCanvasX, prevCanvasY);
+ ctx.lineTo(point.canvasx, point.canvasy);
}
}
if (drawPoints || isIsolated) {
}
first = false;
}
- strategy.finish();
+ ctx.stroke();
return pointsOnLine;
};
ctx.fill();
}
};
-
-/**
- * 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;
- }
-
- // 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