_getBrush: function() {
var brushCanvas = this._brushCanvas || (this._brushCanvas = zrUtil.createCanvas());
// set brush size
var r = BRUSH_SIZE + this.blurSize;
var d = r * 2;
brushCanvas.width = d;
brushCanvas.height = d;
var ctx = brushCanvas.getContext('2d');
ctx.clearRect(0, 0, d, d);
// in order to render shadow without the distinct circle,
// draw the distinct circle in an invisible place,
// and use shadowOffset to draw shadow in the center of the canvas
ctx.shadowOffsetX = d;
ctx.shadowBlur = this.blurSize;
// draw the shadow in black, and use alpha and shadow blur to generate
// color in color map
ctx.shadowColor = '#000';
// draw circle in the left to the canvas
ctx.beginPath();
ctx.arc(-r, r, BRUSH_SIZE, 0, Math.PI * 2, true);
ctx.closePath();
ctx.fill();
return brushCanvas;
},
/**
* Heatmap Chart
*
* @class
*/
function Heatmap() {
var canvas = zrUtil.createCanvas();
this.canvas = canvas;
this.blurSize = 30;
this.opacity = 1;
this._gradientPixels = {};
}
/**
* Heatmap Chart
*
* @class
*/
function Heatmap() {
var canvas = zrUtil.createCanvas();
this.canvas = canvas;
this.blurSize = 30;
this.pointSize = 20;
this.maxOpacity = 1;
this.minOpacity = 0;
this._gradientPixels = {};
}
echartsProto.getConnectedDataURL = function (opts) {
if (!env.canvasSupported) {
return;
}
var groupId = this.group;
var mathMin = Math.min;
var mathMax = Math.max;
var MAX_NUMBER = Infinity;
if (connectedGroups[groupId]) {
var left = MAX_NUMBER;
var top = MAX_NUMBER;
var right = -MAX_NUMBER;
var bottom = -MAX_NUMBER;
var canvasList = [];
var dpr = (opts && opts.pixelRatio) || 1;
for (var id in instances) {
var chart = instances[id];
if (chart.group === groupId) {
var canvas = chart.getRenderedCanvas(
zrUtil.clone(opts)
);
var boundingRect = chart.getDom().getBoundingClientRect();
left = mathMin(boundingRect.left, left);
top = mathMin(boundingRect.top, top);
right = mathMax(boundingRect.right, right);
bottom = mathMax(boundingRect.bottom, bottom);
canvasList.push({
dom: canvas,
left: boundingRect.left,
top: boundingRect.top
});
}
}
left *= dpr;
top *= dpr;
right *= dpr;
bottom *= dpr;
var width = right - left;
var height = bottom - top;
var targetCanvas = zrUtil.createCanvas();
targetCanvas.width = width;
targetCanvas.height = height;
var zr = zrender.init(targetCanvas);
each(canvasList, function (item) {
var img = new graphic.Image({
style: {
x: item.left * dpr - left,
y: item.top * dpr - top,
image: item.dom
}
});
zr.add(img);
});
zr.refreshImmediately();
return targetCanvas.toDataURL('image/' + (opts && opts.type || 'png'));
}
else {
return this.getDataURL(opts);
}
};