大规模散点图

src/chart/line.js

@@ -589,6 +589,8 @@ define(function (require) {
             var seriesPL;
             var singlePL;
             
+            var isLarge;
+            
             // 堆叠层叠需求，反顺序构建
             for (var seriesIndex = series.length - 1;
                 seriesIndex >= 0;
@@ -622,6 +624,8 @@ define(function (require) {
 
                     for (var i = 0, l = seriesPL.length; i < l; i++) {
                         singlePL = seriesPL[i];
+                        isLarge = this._isLarge(orient, singlePL);
+                        if (!isLarge) { // 非大数据模式才显示拐点symbol
                             for (var j = 0, k = singlePL.length; j < k; j++) {
                                 data = serie.data[singlePL[j][2]];
                                 if (this.deepQuery(
@@ -646,8 +650,13 @@ define(function (require) {
                                         orient
                                     ));
                                 }
-
                             }
+                        }
+                        else {
+                            // 大数据模式截取pointList
+                            singlePL = this._getLargePointList(orient, singlePL);
+                        }
+                        
                         // 折线图
                         this.shapeList.push(new BrokenLineShape({
                             zlevel : this._zlevelBase,
@@ -715,6 +724,38 @@ define(function (require) {
             }
         },
         
+        _isLarge : function(orient, singlePL) {
+            var len = singlePL.length;
+            if (orient == 'horizontal') {
+                var width = this.component.grid.getWidth();
+                return width * 2 < len;
+            }
+            else {
+                var height = this.component.grid.getHeight();
+                return height * 2 < len;
+            }
+        },
+        
+        /**
+         * 大规模pointList优化 
+         */
+        _getLargePointList : function(orient, singlePL) {
+            var total;
+            if (orient == 'horizontal') {
+                total = this.component.grid.getWidth();
+            }
+            else {
+                total = this.component.grid.getHeight();
+            }
+            
+            var len = singlePL.length;
+            var newList = [];
+            for (var i = 0; i < total; i++) {
+                newList[i] = singlePL[Math.floor(len / total * i)];
+            }
+            return newList;
+        },
+        
         _getSmooth : function (isSmooth/*, pointList, orient*/) {
             if (isSmooth) {
                 /* 不科学啊，发现0.3通用了