adjust ex tooltip.order, rename vars / calc stack util

Author: sjcobb

src/component/tooltip/seriesFormatTooltip.ts

@@ -75,8 +75,8 @@ export function defaultSeriesFormatTooltip(opt: {
             // Difference between the cumulative sum including this series and the cumulative sum before
             // this series gives its individual contribution.
             if (!isNaN(stackTop) && !isNaN(stackBottom)) {
-                const percentVal = stackTop - stackBottom;
-                inlineValue = `${inlineValue} (${percentVal.toFixed(1)}%)`;
+                const percentValue = stackTop - stackBottom;
+                inlineValue = `${inlineValue} (${percentValue.toFixed(1)}%)`;
             }
         }
     }

src/layout/barGrid.ts

@@ -525,9 +525,13 @@ export function createProgressiveLayout(seriesType: string): StageHandler {
                         // stackResultDimension directly.
                         if (stacked) {
                             if (isPercentStack) {
+                                // For 'percent' stackStrategy, use the normalized bottom edge (stackedOverDimension)
+                                // as the start value of the bar segment.
                                 stackStartValue = store.get(stackedOverDimIdx, dataIndex);
                             }
                             else {
+                                // For standard (non-percent) stackStrategy, subtract the original value from the
+                                // stacked total to compute the bar segment's start value.
                                 stackStartValue = +value - (store.get(valueDimIdx, dataIndex) as number);
                             }
                         }

src/processor/dataStack.ts

@@ -71,12 +71,12 @@ export default function dataStack(ecModel: GlobalModel) {
             calculatePercentStack(stackInfoList);
         }
         else {
-            calculateStack(stackInfoList);
+            calculateStandardStack(stackInfoList);
         }
     });
 }
 
-function calculateStack(stackInfoList: StackInfo[]) {
+function calculateStandardStack(stackInfoList: StackInfo[]) {
     each(stackInfoList, function (targetStackInfo, idxInStack) {
         const resultVal: number[] = [];
         const resultNaN = [NaN, NaN];