"threshold" code add int cast

Meter.c

@@ -871,7 +871,7 @@ static void GraphMeterMode_computeColors(Meter* this, const GraphDrawContext* co
          if (hasThresholdRange && nCellsPaintedLow < nCellsPaintedHigh) {
             // Linear interpolation
             assert(nCellsPaintedLow <= nCellsToPaint);
-            threshold -= ((thresholdHigh - thresholdLow) * (nCellsToPaint - nCellsPaintedLow) / (nCellsPaintedHigh - nCellsPaintedLow));
+            threshold -= ((thresholdHigh - thresholdLow) * (double)(int)(nCellsToPaint - nCellsPaintedLow) / (double)(int)(nCellsPaintedHigh - nCellsPaintedLow));
             if (threshold < nextThresholdLow) {
                threshold = nextThresholdLow;
             }