X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=3b2979e69269d7713cae2bc2d0c0409dea3121fb;hb=5108eb2029afe739872ebfb58f9fb826cef9ea13;hp=971a038199634630973725313d79c754fd081ccf;hpb=74a5af31a87b245b89337037bc33a0e900153eae;p=dygraphs.git diff --git a/dygraph-canvas.js b/dygraph-canvas.js index 971a038..3b2979e 100644 --- a/dygraph-canvas.js +++ b/dygraph-canvas.js @@ -1,5 +1,5 @@ // Copyright 2006 Dan Vanderkam (danvdk@gmail.com) -// All Rights Reserved. +// MIT-licensed (http://opensource.org/licenses/MIT) /** * @fileoverview Based on PlotKit.CanvasRenderer, but modified to meet the @@ -12,12 +12,8 @@ */ /** - * This class determines the charting area (in pixel coordinates), maps the - * percentage coordinates in the DygraphLayout to pixels and draws them. - * It's also responsible for creating chart DOM elements, i.e. annotations, - * tick mark labels, the title and the x/y-axis labels. - * This class is based on PlotKit.CanvasRenderer. - * + * The DygraphCanvasRenderer class does the actual rendering of the chart onto + * a canvas. It's based on PlotKit.CanvasRenderer. * @param {Object} element The canvas to attach to * @param {Object} elementContext The 2d context of the canvas (injected so it * can be mocked for testing.) @@ -264,7 +260,7 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { // height: this.attr_('axisLabelFontSize') + 2 + "px", overflow: "hidden" }; - var makeDiv = function(txt, axis) { + var makeDiv = function(txt, axis, prec_axis) { var div = document.createElement("div"); for (var name in labelStyle) { if (labelStyle.hasOwnProperty(name)) { @@ -272,8 +268,9 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { } } var inner_div = document.createElement("div"); - // TODO(danvk): separate class for secondary y-axis - inner_div.className = 'dygraph-axis-label dygraph-axis-label-' + axis; + inner_div.className = 'dygraph-axis-label' + + ' dygraph-axis-label-' + axis + + (prec_axis ? ' dygraph-axis-label-' + prec_axis : ''); inner_div.appendChild(document.createTextNode(txt)); div.appendChild(inner_div); return div; @@ -286,14 +283,17 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { if (this.attr_('drawYAxis')) { if (this.layout.yticks && this.layout.yticks.length > 0) { + var num_axes = this.dygraph_.numAxes(); for (var i = 0; i < this.layout.yticks.length; i++) { var tick = this.layout.yticks[i]; if (typeof(tick) == "function") return; var x = this.area.x; var sgn = 1; + var prec_axis = 'y1'; if (tick[0] == 1) { // right-side y-axis x = this.area.x + this.area.w; sgn = -1; + prec_axis = 'y2'; } var y = this.area.y + tick[1] * this.area.h; context.beginPath(); @@ -302,7 +302,7 @@ DygraphCanvasRenderer.prototype._renderAxis = function() { context.closePath(); context.stroke(); - var label = makeDiv(tick[2], 'y'); + var label = makeDiv(tick[2], 'y', num_axes == 2 ? prec_axis : null); var top = (y - this.attr_('axisLabelFontSize') / 2); if (top < 0) top = 0; @@ -596,6 +596,10 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() { * Overrides the CanvasRenderer method to draw error bars */ 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 fillAlpha = this.attr_('fillAlpha'); @@ -603,6 +607,8 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { 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 setNames = []; for (var name in this.layout.datasets) { @@ -620,8 +626,8 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { // Update Points // TODO(danvk): here - for (var i = 0; i < this.layout.points.length; i++) { - var point = this.layout.points[i]; + for (var i = pointsLength; i--;) { + var point = points[i]; point.canvasx = this.area.w * point.x + this.area.x; point.canvasy = this.area.h * point.y + this.area.y; } @@ -650,8 +656,8 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { fillAlpha + ')'; ctx.fillStyle = err_color; ctx.beginPath(); - for (var j = 0; j < this.layout.points.length; j++) { - var point = this.layout.points[j]; + for (var j = 0; j < pointsLength; j++) { + var point = points[j]; if (point.name == setName) { if (!Dygraph.isOK(point.y)) { prevX = NaN; @@ -660,12 +666,10 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { // TODO(danvk): here if (stepPlot) { - var newYs = [ prevY - point.errorPlus * yscale, - prevY + point.errorMinus * yscale ]; + var newYs = [ point.y_bottom, point.y_top ]; prevY = point.y; } else { - var newYs = [ point.y - point.errorPlus * yscale, - point.y + point.errorMinus * yscale ]; + var 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; @@ -714,8 +718,8 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { fillAlpha + ')'; ctx.fillStyle = err_color; ctx.beginPath(); - for (var j = 0; j < this.layout.points.length; j++) { - var point = this.layout.points[j]; + for (var j = 0; j < pointsLength; j++) { + var point = points[j]; if (point.name == setName) { if (!Dygraph.isOK(point.y)) { prevX = NaN; @@ -749,73 +753,78 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() { } } - var isNullOrNaN = function(x) { - return (x === null || isNaN(x)); - }; - - for (var i = 0; i < setCount; i++) { + // Drawing the lines. + var firstIndexInSet = 0; + var afterLastIndexInSet = 0; + var setLength = 0; + for (var i = 0; i < setCount; i += 1) { + setLength = this.layout.setPointsLengths[i]; + afterLastIndexInSet += setLength; var setName = setNames[i]; var color = this.colors[setName]; var strokeWidth = this.dygraph_.attr_("strokeWidth", setName); // setup graphics context context.save(); - var point = this.layout.points[0]; var pointSize = this.dygraph_.attr_("pointSize", setName); var prevX = null, prevY = null; var drawPoints = this.dygraph_.attr_("drawPoints", setName); - var points = this.layout.points; - for (var j = 0; j < points.length; j++) { + for (var j = firstIndexInSet; j < afterLastIndexInSet; j++) { var point = points[j]; - if (point.name == setName) { - if (isNullOrNaN(point.canvasy)) { - if (stepPlot && prevX != null) { - // Draw a horizontal line to the start of the missing data + 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 = this.attr_('strokeWidth'); + ctx.lineWidth = 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) { + if (stepPlot) { + ctx.lineTo(point.canvasx, prevY); + } prevX = point.canvasx; prevY = point.canvasy; - } else { - // TODO(danvk): figure out why this conditional is necessary. - 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(); - } + ctx.lineTo(prevX, prevY); + ctx.stroke(); } + } - if (drawPoints || isIsolated) { - ctx.beginPath(); - ctx.fillStyle = color; - ctx.arc(point.canvasx, point.canvasy, pointSize, - 0, 2 * Math.PI, false); - ctx.fill(); - } + if (drawPoints || isIsolated) { + ctx.beginPath(); + ctx.fillStyle = color; + ctx.arc(point.canvasx, point.canvasy, pointSize, + 0, 2 * Math.PI, false); + ctx.fill(); } } } + firstIndexInSet = afterLastIndexInSet; } context.restore();