improvements in barRect height calculation

Source/Charts/Components/YAxis.swift

@@ -150,6 +150,17 @@ open class YAxis: AxisBase
         var min = _customAxisMin ? _axisMinimum : dataMin
         var max = _customAxisMax ? _axisMaximum : dataMax
 
+        // Make sure max is greater than min
+        if min > max {
+            if _customAxisMax && _customAxisMin {
+                (min, max) = (max, min)
+            } else if _customAxisMax && !_customAxisMin {
+                min = max - 1
+            } else if !_customAxisMax && _customAxisMin {
+                max = min + 1
+            }
+        }
+
         // temporary range (before calculations)
         let range = abs(max - min)
 

Source/Charts/Renderers/BarChartRenderer.swift

@@ -108,6 +108,30 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
         var barRect = CGRect()
         var x: Double
         var y: Double
+
+
+
+        // When drawing with an auto calculated y-axis minimum, the renderer actually draws each bar from 0
+        // to the required value. This drawn bar is then clipped to the visible chart rect in BarLineChartViewBase's draw(rect:) using clipDataToContent.
+        // While this works fine when calculating the bar rects for drawing, it causes the accessibilityFrames to be oversized in some cases.
+        // This offset attempts to undo that unnecessary drawing when calculating barRects, particularly when not using custom axis minima.
+        // This allows the minimum to still be visually non zero, but the rects are only drawn where necessary.
+        // This offset calculation is not necessary when bars won't be clipped (when y-axis minimum <= 0  and y-axis maximum  >= 0)
+        var heightOffset: CGFloat = 0.0
+        var originYOffset: CGFloat = 0.0
+        if let offsetView = dataProvider as? BarChartView {
+            let offsetAxis = offsetView.leftAxis.isEnabled ? offsetView.leftAxis : offsetView.rightAxis
+            if !offsetAxis._customAxisMin {
+                if barData.yMin > 0 {
+                    heightOffset = CGFloat(offsetAxis.axisMinimum)
+                }
+            }
+            if !offsetAxis._customAxisMax {
+                if barData.yMax < 0 {
+                    originYOffset = CGFloat(offsetAxis.axisMaximum)
+                }
+            }
+        }
 
         for i in stride(from: 0, to: min(Int(ceil(Double(dataSet.entryCount) * animator.phaseX)), dataSet.entryCount), by: 1)
         {
@@ -139,28 +163,10 @@ open class BarChartRenderer: BarLineScatterCandleBubbleRenderer
                     bottom *= CGFloat(phaseY)
                 }
 
-                // When drawing with an auto calculated y-axis minimum, the renderer actually draws each bar from 0
-                // to the required value. This drawn bar is then clipped to the visible chart rect in BarLineChartViewBase's draw(rect:) using clipDataToContent.
-                // While this works fine when calculating the bar rects for drawing, it causes the accessibilityFrames to be oversized in some cases.
-                // This offset attempts to undo that unnecessary drawing when calculating barRects, particularly when not using custom axis minima.
-                // This allows the minimum to still be visually non zero, but the rects are only drawn where necessary.
-                // This offset calculation also avoids cases where there are positive/negative values mixed, since those won't need this offset.
-                var offset: CGFloat = 0.0
-                if let offsetView = dataProvider as? BarChartView {
-
-                    let offsetAxis = offsetView.leftAxis.isEnabled ? offsetView.leftAxis : offsetView.rightAxis
-
-                    if barData.yMin.sign != barData.yMax.sign { offset = 0.0 }
-                    else if !offsetAxis._customAxisMin {
-                        offset = CGFloat(offsetAxis.axisMinimum)
-                    }
-                }
-
                 barRect.origin.x = left
+                barRect.origin.y = top + originYOffset
                 barRect.size.width = right - left
-                barRect.origin.y = top
-                barRect.size.height = bottom == top ? 0 : bottom - top + offset
-
+                barRect.size.height = bottom - top + heightOffset - originYOffset
                 buffer.rects[bufferIndex] = barRect
                 bufferIndex += 1
             }