findTopCellItem() handle underflow (f11-2)

Explorer09 · Feb 7, 2024 · 837b61b · 837b61b
1 parent 1409533
commit 837b61b
Showing 1 changed file with 7 additions and 9 deletions.
diff --git a/Meter.c b/Meter.c
@@ -386,7 +386,7 @@ static uint8_t GraphMeterMode_findTopCellItem(const Meter* this, double scaledTo
    assert(topCell < graphHeight);
 
    double valueSum = 0.0;
-   bool hasPrevArea = false;
+   bool maxValueIsArea = false;
    double maxValue = 0.0;
    uint8_t topCellItem = this->curItems - 1;
    for (uint8_t i = 0; i < this->curItems && valueSum < DBL_MAX; i++) {
@@ -411,30 +411,28 @@ static uint8_t GraphMeterMode_findTopCellItem(const Meter* this, double scaledTo
       // Favor item with higher index in case of a tie.
 
       double area = (value / scaledTotal) * (double)(int)graphHeight;
+      assert(area >= 0.0);
 
       if (topCellItem > i) {
-         assert(!hasPrevArea);
+         assert(!maxValueIsArea);
          assert(maxValue <= 0.0);
 
          double topPoint = (valueSum / scaledTotal) * (double)(int)graphHeight;
          assert(topPoint >= 0.0);
 
-         if (topCell > 0 && !(topPoint > (double)(int)topCell)) {
+         if (topCell > 0 && !(topPoint > (double)(int)topCell))
             continue;
-         }
-         // If (topCell == 0), permit the cases where the division underflows,
-         // i.e. "topPoint" and "area" both round to 0.0.
 
          if (area > topPoint - (double)(int)topCell) {
-            hasPrevArea = true;
+            maxValueIsArea = true;
             maxValue = topPoint - (double)(int)topCell;
          } else {
             maxValue = value;
          }
          topCellItem = i;
-      } else if (hasPrevArea) {
+      } else if (maxValueIsArea) {
          if (area >= maxValue) {
-            hasPrevArea = false;
+            maxValueIsArea = false;
             maxValue = value;
             topCellItem = i;
          }