From 7ea6dda14aaf3ebcea554d59586a00cdd7ece0f8 Mon Sep 17 00:00:00 2001
From: wp <wp.no-reply@lazarus-ide-org>
Date: Thu, 7 Feb 2019 15:38:55 +0000
Subject: [PATCH] TAChart: Fix stacked bar series containing missing values
 (NaN).

git-svn-id: trunk@60355 -
---
 components/tachart/tacustomseries.pas | 36 +++++++++++++++------------
 components/tachart/taseries.pas       |  5 ++--
 components/tachart/tasources.pas      | 18 +++++++++++---
 3 files changed, 36 insertions(+), 23 deletions(-)

diff --git a/components/tachart/tacustomseries.pas b/components/tachart/tacustomseries.pas
index 4262369c04..21947e7688 100644
--- a/components/tachart/tacustomseries.pas
+++ b/components/tachart/tacustomseries.pas
@@ -1265,6 +1265,7 @@ var
   lfont: TFont;
   curr, prev: Double;
   ext: TDoubleRect;
+  yIsNaN: Boolean;
 begin
   if not Marks.IsMarkLabelsVisible then exit;
 
@@ -1275,29 +1276,24 @@ begin
     ext := Extent;
 
     for i := FLoBound to FUpBound do begin
-      if IsNan(Source[i]^.Point) then
+      if IsNan(Source[i]^.X) then
         continue;
-      y := Source[i]^.Y;
-      ysum := y;
       if FSupportsZeroLevel then
         prev := GetZeroLevel
       else
         prev := TDoublePointBoolArr(ext.a)[not IsRotated];
+      y := Source[i]^.Y;
+      yIsNaN := IsNaN(y);
+      ysum := IfThen(yIsNaN, prev, y);
       ld := GetLabelDirection(i);
       for si := 0 to Source.YCount - 1 do begin
-        if Styles <> nil then begin
-          style := Styles.StyleByIndex(si);
-          if style.UseFont then
-            Marks.LabelFont.Assign(style.Font)
-          else
-            Marks.LabelFont.Assign(lfont);
-        end;
         g := GetLabelDataPoint(i, si);
         if si > 0 then begin
-          y := NumberOr(Source[i]^.YList[si-1], 0);
-          if IsNaN(y) then Continue;
+          y := Source[i]^.YList[si-1];
+          yIsNaN := IsNaN(y);
+          if yIsNaN then y := 0.0;
           if Stacked then begin
-            if IsNaN(ysum) then ysum := y else ysum += y;
+            ysum += y;
             y := ysum;
           end;
         end;
@@ -1319,9 +1315,17 @@ begin
         with ParentChart do
           if
             ((Marks.YIndex = MARKS_YINDEX_ALL) or (Marks.YIndex = si)) and
-            IsPointInViewPort(g)
-          then
+            IsPointInViewPort(g) and (not yIsNaN)
+          then begin
+            if Styles <> nil then begin
+              style := Styles.StyleByIndex(si);
+              if style.UseFont then
+                Marks.LabelFont.Assign(style.Font)
+              else
+                Marks.LabelFont.Assign(lfont);
+            end;
             DrawLabel(FormattedMark(i, '', si), GraphToImage(g), ld);
+          end;
       end;
     end;
 
@@ -1413,7 +1417,7 @@ end;
 
 function TBasicPointSeries.GetLabelDataPoint(AIndex, AYIndex: Integer): TDoublePoint;
 begin
-  Result := GetGraphPoint(AIndex);
+  Result := GetGraphPoint(AIndex, 0, AYIndex);
 end;
 
 function TBasicPointSeries.GetLabelDirection(AIndex: Integer): TLabelDirection;
diff --git a/components/tachart/taseries.pas b/components/tachart/taseries.pas
index cf3f8c8f25..196fb04c5d 100644
--- a/components/tachart/taseries.pas
+++ b/components/tachart/taseries.pas
@@ -1190,9 +1190,8 @@ begin
     if FStacked then begin
       heights[1] := NumberOr(p.Y, zero);
       for stackIndex := 1 to Source.YCount - 1 do begin
-        y := Source[pointIndex]^.YList[stackIndex - 1];
-        if not IsNan(y) then
-          heights[stackIndex + 1] := heights[stackIndex] + y;
+        y := NumberOr(Source[pointIndex]^.YList[stackIndex - 1], 0);
+        heights[stackIndex + 1] := heights[stackIndex] + y;
       end;
       for stackIndex := 0 to High(heights) do
         heights[stackindex] := AxisToGraphY(heights[stackindex]);
diff --git a/components/tachart/tasources.pas b/components/tachart/tasources.pas
index c79e9b1408..d9de974206 100644
--- a/components/tachart/tasources.pas
+++ b/components/tachart/tasources.pas
@@ -688,6 +688,18 @@ begin
   Notify;
 end;
 
+function CompareFloat(x1, x2: Double): Integer;
+begin
+  if IsNaN(x1) and IsNaN(x2) then
+    Result := 0
+  else if IsNaN(x1) then
+    Result := +1
+  else if IsNaN(x2) then
+    Result := -1
+  else
+    Result := CompareValue(x1, x2);
+end;
+
 function CompareDataItemX(AItem1, AItem2: Pointer): Integer;
 var
   i: Integer;
@@ -695,13 +707,11 @@ var
 begin
   item1 := PChartDataItem(AItem1);
   item2 := PChartDataItem(AItem2);
-  Result := Sign(item1^.X - item2^.X);          // wp: why "sign" ???
-
-//  Result := Sign(PChartDataItem(AItem1)^.X - PChartDataItem(AItem2)^.X);
 
+  Result := CompareFloat(item1^.X, item2^.X);
   if Result = 0 then
     for i := 0 to Min(High(item1^.XList), High(item2^.XList)) do begin
-      Result := Sign(item1^.XList[i] - item2^.XList[i]);
+      Result := CompareFloat(item1^.XList[i], item2^.XList[i]);
       if Result <> 0 then
         exit;
     end;