diff --git a/components/tachart/tadraweraggpas.pas b/components/tachart/tadraweraggpas.pas
index d4429b5ccb..61965917f9 100644
--- a/components/tachart/tadraweraggpas.pas
+++ b/components/tachart/tadraweraggpas.pas
@@ -51,11 +51,10 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
+      AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
@@ -147,8 +146,6 @@ procedure TAggPasDrawer.Polygon(
 begin
   FCanvas.Polygon(APoints, false, AStartIndex, ANumPts);
   FCanvas.Polyline(APoints, AStartIndex, ANumPts);
-  if ANumPts < 0 then
-    ANumPts := Length(APoints);
   FCanvas.Line(APoints[ANumPts - 1], APoints[0])
 end;
 
diff --git a/components/tachart/tadrawerbgra.pas b/components/tachart/tadrawerbgra.pas
index 604410b2fa..9f342d3171 100644
--- a/components/tachart/tadrawerbgra.pas
+++ b/components/tachart/tadrawerbgra.pas
@@ -58,11 +58,10 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
+      AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
@@ -84,8 +83,7 @@ function PointsToPointsF(
 var
   i: Integer;
 begin
-  if ANumPts = -1 then
-    ANumPts := Length(APoints) - AStartIndex;
+  Assert(ANumPts >= 0);
   SetLength(Result, ANumPts);
   for i := 0 to ANumPts - 1 do
     with APoints[i + AStartIndex] do
@@ -180,7 +178,7 @@ begin
 end;
 
 procedure TBGRABitmapDrawer.Polygon(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer);
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer);
 var
   bt: TBGRACustomBitmap;
 begin
@@ -201,7 +199,7 @@ end;
 
 procedure TBGRABitmapDrawer.Polyline(
   const APoints: array of TPoint;
-  AStartIndex: Integer; ANumPts: Integer; AEndPoint: Boolean);
+  AStartIndex, ANumPts: Integer; AEndPoint: Boolean);
 begin
   Unused(AEndPoint);
   FCanvas.DrawPolyLineAntialias(
diff --git a/components/tachart/tadrawercanvas.pas b/components/tachart/tadrawercanvas.pas
index e45f261687..5779ec3f22 100644
--- a/components/tachart/tadrawercanvas.pas
+++ b/components/tachart/tadrawercanvas.pas
@@ -58,11 +58,10 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint;
+      AStartIndex, ANumPts: Integer; AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
diff --git a/components/tachart/tadrawerfpcanvas.pas b/components/tachart/tadrawerfpcanvas.pas
index 4a903c3e7f..b07a77bc67 100644
--- a/components/tachart/tadrawerfpcanvas.pas
+++ b/components/tachart/tadrawerfpcanvas.pas
@@ -61,11 +61,10 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
+      AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
@@ -187,9 +186,9 @@ begin
 end;
 
 procedure TFPCanvasDrawer.Polygon(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer);
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer);
 begin
-  if (ANumPts < 0) and (AStartIndex = 0) then
+  if (ANumPts = Length(APoints)) and (AStartIndex = 0) then
     FCanvas.Polygon(APoints)
   else
     FCanvas.Polygon(CopyPoints(APoints, AStartIndex, ANumPts));
@@ -197,10 +196,10 @@ end;
 
 procedure TFPCanvasDrawer.Polyline(
   const APoints: array of TPoint;
-  AStartIndex: Integer; ANumPts: Integer; AEndPoint: Boolean);
+  AStartIndex, ANumPts: Integer; AEndPoint: Boolean);
 begin
   Unused(AEndPoint);
-  if (ANumPts < 0) and (AStartIndex = 0) then
+  if (ANumPts = Length(APoints)) and (AStartIndex = 0) then
     FCanvas.Polyline(APoints)
   else
     FCanvas.Polyline(CopyPoints(APoints, AStartIndex, ANumPts));
diff --git a/components/tachart/tadraweropengl.pas b/components/tachart/tadraweropengl.pas
index 7bfd36ee22..edccde4b21 100644
--- a/components/tachart/tadraweropengl.pas
+++ b/components/tachart/tadraweropengl.pas
@@ -55,8 +55,7 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
       const APoints: array of TPoint; AStartIndex: Integer = 0;
       ANumPts: Integer = -1; AEndPoint: Boolean = false);
@@ -155,13 +154,11 @@ procedure TOpenGLDrawer.InternalPolyline(
 var
   i: Integer;
 begin
-  if ANumPts < 0 then
-    ANumPts := Length(APoints);
   glBegin(AMode);
   ChartGLColor(FPenColor);
   glLineWidth(FPenWidth);
   for i := AStartIndex to AStartIndex + ANumPts - 1 do
-    glVertex2i(APoints[i].X, APoints[i].Y);
+    glVertex2iv(@APoints[i]);
   glEnd();
 end;
 
@@ -191,22 +188,20 @@ begin
 end;
 
 procedure TOpenGLDrawer.Polygon(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer);
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer);
 var
   i: Integer;
 begin
-  if ANumPts < 0 then
-    ANumPts := Length(APoints);
   glBegin(GL_POLYGON);
   ChartGLColor(FBrushColor);
   for i := AStartIndex to AStartIndex + ANumPts - 1 do
-    glVertex2i(APoints[i].X, APoints[i].Y);
+    glVertex2iv(@APoints[i]);
   glEnd();
   InternalPolyline(APoints, AStartIndex, ANumPts, GL_LINE_LOOP);
 end;
 
 procedure TOpenGLDrawer.Polyline(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer;
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
   AEndPoint: Boolean);
 begin
   Unused(AEndPoint);
diff --git a/components/tachart/tadrawersvg.pas b/components/tachart/tadrawersvg.pas
index 444b55dfc6..f7a9a78b2b 100644
--- a/components/tachart/tadrawersvg.pas
+++ b/components/tachart/tadrawersvg.pas
@@ -71,11 +71,10 @@ type
     procedure LineTo(AX, AY: Integer); override;
     procedure MoveTo(AX, AY: Integer); override;
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); override;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); override;
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
+      AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
@@ -235,7 +234,7 @@ begin
 end;
 
 procedure TSVGDrawer.Polygon(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer);
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer);
 begin
   WriteFmt(
     '<polygon points="%s" style="%s"/>',
@@ -243,7 +242,7 @@ begin
 end;
 
 procedure TSVGDrawer.Polyline(
-  const APoints: array of TPoint; AStartIndex: Integer; ANumPts: Integer;
+  const APoints: array of TPoint; AStartIndex, ANumPts: Integer;
   AEndPoint: Boolean);
 begin
   Unused(AEndPoint);
diff --git a/components/tachart/tadrawutils.pas b/components/tachart/tadrawutils.pas
index 0ff8d20709..2b3de60077 100644
--- a/components/tachart/tadrawutils.pas
+++ b/components/tachart/tadrawutils.pas
@@ -84,11 +84,10 @@ type
     procedure MoveTo(AX, AY: Integer);
     procedure MoveTo(const AP: TPoint);
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1);
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer);
     procedure Polyline(
-      const APoints: array of TPoint; AStartIndex: Integer = 0;
-      ANumPts: Integer = -1; AEndPoint: Boolean = false);
+      const APoints: array of TPoint;
+      AStartIndex, ANumPts: Integer; AEndPoint: Boolean = false);
     procedure PrepareSimplePen(AColor: TChartColor);
     procedure RadialPie(
       AX1, AY1, AX2, AY2: Integer;
@@ -137,8 +136,7 @@ type
     procedure MoveTo(AX, AY: Integer); virtual; abstract;
     procedure MoveTo(const AP: TPoint);
     procedure Polygon(
-      const APoints: array of TPoint;
-      AStartIndex: Integer = 0; ANumPts: Integer = -1); virtual; abstract;
+      const APoints: array of TPoint; AStartIndex, ANumPts: Integer); virtual; abstract;
     function Scale(ADistance: Integer): Integer; virtual;
     procedure SetDoChartColorToFPColorFunc(AValue: TChartColorToFPColorFunc);
     procedure SetGetFontOrientationFunc(AValue: TGetFontOrientationFunc);
@@ -300,7 +298,7 @@ var
   d: TPoint;
 begin
   d := Point(ADepth, -ADepth);
-  Polygon([AP1, AP1 + d, AP2 + d, AP2]);
+  Polygon([AP1, AP1 + d, AP2 + d, AP2], 0, 4);
 end;
 
 procedure TBasicDrawer.LineTo(const AP: TPoint);
diff --git a/components/tachart/tageometry.pas b/components/tachart/tageometry.pas
index a33b7e3bc1..a7171654f6 100644
--- a/components/tachart/tageometry.pas
+++ b/components/tachart/tageometry.pas
@@ -96,8 +96,7 @@ function CopyPoints(
 var
   i: Integer;
 begin
-  if ANumPts = -1 then
-    ANumPts := Length(APoints) - AStartIndex;
+  Assert(ANumPts >= 0);
   SetLength(Result, ANumPts);
   for i := 0 to ANumPts - 1 do
     Result[i] := APoints[i + AStartIndex];
diff --git a/components/tachart/taradialseries.pas b/components/tachart/taradialseries.pas
index f4cdfb0ef1..bde6ffc03a 100644
--- a/components/tachart/taradialseries.pas
+++ b/components/tachart/taradialseries.pas
@@ -401,7 +401,7 @@ begin
     pts[i] := FChart.GraphToImage(GraphPoint(i));
   ADrawer.Pen := LinePen;
   ADrawer.SetBrushParams(bsClear, clTAColor);
-  ADrawer.Polygon(pts);
+  ADrawer.Polygon(pts, 0, Length(pts));
 end;
 
 function TPolarSeries.Extent: TDoubleRect;
diff --git a/components/tachart/tatypes.pas b/components/tachart/tatypes.pas
index 41bb76468a..48491f599e 100644
--- a/components/tachart/tatypes.pas
+++ b/components/tachart/tatypes.pas
@@ -580,7 +580,7 @@ begin
   ADrawer.Brush := LabelBrush;
   if IsMarginRequired then begin
     ADrawer.Pen := Frame;
-    ADrawer.Polygon(labelPoly);
+    ADrawer.Polygon(labelPoly, 0, Length(labelPoly));
   end;
 
   ptText := RotatePoint(-ptText div 2, LabelAngle) + ALabelCenter;