diff --git a/lcl/include/shape.inc b/lcl/include/shape.inc
index 381f0fe3aa..75109de950 100644
--- a/lcl/include/shape.inc
+++ b/lcl/include/shape.inc
@@ -57,13 +57,16 @@ begin
     if PaintRect.Top = PaintRect.Bottom then
       PaintRect.Bottom := PaintRect.Bottom + 1;
 
-    MinSize := Min(PaintRect.Right - PaintRect.Left, PaintRect.Bottom - PaintRect.Top);
-    if FShape in [stSquare, stRoundSquare, stCircle, stSquaredDiamond] then
+    with PaintRect do
     begin
-      PaintRect.Left := PaintRect.Left + ((PaintRect.Right - PaintRect.Left) - MinSize) div 2;
-      PaintRect.Top := PaintRect.Top + ((PaintRect.Bottom - PaintRect.Top) - MinSize) div 2;
-      PaintRect.Right := PaintRect.Left + MinSize;
-      PaintRect.Bottom := PaintRect.Top + MinSize;
+      MinSize := Min(Right - Left, Bottom - Top);
+      if FShape in [stSquare, stRoundSquare, stCircle, stSquaredDiamond] then
+      begin
+        Left := Left + ((Right - Left) - MinSize) div 2;
+        Top := Top + ((Bottom - Top) - MinSize) div 2;
+        Right := Left + MinSize;
+        Bottom := Top + MinSize;
+      end;
     end;
 
     case FShape of
@@ -75,99 +78,117 @@ begin
         Ellipse(PaintRect);
       stSquaredDiamond, stDiamond:
       begin
-        P[0].x := PaintRect.Left;
-        P[0].y := (PaintRect.Top + PaintRect.Bottom) div 2;
-        P[1].x := (PaintRect.Left + PaintRect.Right) div 2;
-        P[1].y := PaintRect.Top;
-        P[2].x := PaintRect.Right - 1;
-        P[2].y := P[0].y;
-        P[3].x := P[1].x;
-        P[3].y := PaintRect.Bottom - 1;
-        Polygon(P);
+        with PaintRect do
+        begin
+          P[0].x := Left;
+          P[0].y := (Top + Bottom) div 2;
+          P[1].x := (Left + Right) div 2;
+          P[1].y := Top;
+          P[2].x := Right - 1;
+          P[2].y := P[0].y;
+          P[3].x := P[1].x;
+          P[3].y := Bottom - 1;
+          Polygon(P);
+        end;
       end;
       stTriangle:
       begin
-        P[0].x := (Width - 1) div 2;
-        P[0].y := PenInc;
-        P[1].x := Width - PenInc - 1;
-        P[1].y := Height - PenInc - 1;
-        P[2].x := PenInc;
-        P[2].y := Height - PenInc - 1;
-        P[3].x := P[0].x;
-        P[3].y := P[0].y;
-        Polygon(P);
+        with Self do
+        begin
+          P[0].x := (Width - 1) div 2;
+          P[0].y := PenInc;
+          P[1].x := Width - PenInc - 1;
+          P[1].y := Height - PenInc - 1;
+          P[2].x := PenInc;
+          P[2].y := Height - PenInc - 1;
+          P[3].x := P[0].x;
+          P[3].y := P[0].y;
+          Polygon(P);
+        end;
       end;
       stTriangleDown:
       begin
-        P[0].x := (Width - 1) div 2;
-        P[0].y := Height - PenInc - 1;
-        P[1].x := Width - PenInc - 1;
-        P[1].y := PenInc;
-        P[2].x := PenInc;
-        P[2].y := PenInc;
-        P[3].x := P[0].x;
-        P[3].y := P[0].y;
-        Polygon(P);
+        with Self do
+        begin
+          P[0].x := (Width - 1) div 2;
+          P[0].y := Height - PenInc - 1;
+          P[1].x := Width - PenInc - 1;
+          P[1].y := PenInc;
+          P[2].x := PenInc;
+          P[2].y := PenInc;
+          P[3].x := P[0].x;
+          P[3].y := P[0].y;
+          Polygon(P);
+        end;
       end;
       stTriangleLeft:
       begin
-        P[0].x := PenInc;
-        P[0].y := Height div 2;
-        P[1].x := Width - PenInc - 1;
-        P[1].y := PenInc;
-        P[2].x := Width - PenInc - 1;
-        P[2].y := Height - PenInc - 1;
-        P[3].x := P[0].x;
-        P[3].y := P[0].y;
-        Polygon(P);
+        with Self do
+        begin
+          P[0].x := PenInc;
+          P[0].y := Height div 2;
+          P[1].x := Width - PenInc - 1;
+          P[1].y := PenInc;
+          P[2].x := Width - PenInc - 1;
+          P[2].y := Height - PenInc - 1;
+          P[3].x := P[0].x;
+          P[3].y := P[0].y;
+          Polygon(P);
+        end;
       end;
       stTriangleRight:
       begin
-        P[0].x := Width - PenInc - 1;
-        P[0].y := Height div 2;
-        P[1].x := PenInc;
-        P[1].y := PenInc;
-        P[2].x := PenInc;
-        P[2].y := Height - PenInc - 1;
-        P[3].x := P[0].x;
-        P[3].y := P[0].y;
-        Polygon(P);
+        with Self do
+        begin
+          P[0].x := Width - PenInc - 1;
+          P[0].y := Height div 2;
+          P[1].x := PenInc;
+          P[1].y := PenInc;
+          P[2].x := PenInc;
+          P[2].y := Height - PenInc - 1;
+          P[3].x := P[0].x;
+          P[3].y := P[0].y;
+          Polygon(P);
+        end;
       end;
       stStar,
       stStarDown:
       begin
-        //radius if star scaled by height
-        RadiusBig := Trunc((Height-Pen.Width) / (1+cos(pi/5)));
-        //radius if star scaled by width
-        RadiusBig2 := Trunc((Width-Pen.Width) / (2*sin(pi*2/5)));
-
-        if RadiusBig<=RadiusBig2 then
+        with Self do
         begin
-          if FShape=stStar then
-            PCenter.Y := RadiusBig+PenDec
+          //radius if star scaled by height
+          RadiusBig := Trunc((Height-Pen.Width) / (1+cos(pi/5)));
+          //radius if star scaled by width
+          RadiusBig2 := Trunc((Width-Pen.Width) / (2*sin(pi*2/5)));
+
+          if RadiusBig<=RadiusBig2 then
+          begin
+            if FShape=stStar then
+              PCenter.Y := RadiusBig+PenDec
+            else
+              PCenter.Y := Height-RadiusBig-PenDec;
+          end
           else
-            PCenter.Y := Height-RadiusBig-PenDec;
-        end
-        else
-        begin
-          RadiusBig := RadiusBig2;
-          PCenter.Y := Height div 2;
-        end;
-        PCenter.X := Width div 2;
-        RadiusSm := RadiusBig * 57 div 150;
+          begin
+            RadiusBig := RadiusBig2;
+            PCenter.Y := Height div 2;
+          end;
+          PCenter.X := Width div 2;
+          RadiusSm := RadiusBig * 57 div 150;
 
-        for i := 0 to 4 do
-        begin
-          Alfa := GetStarAngle(i*2, FShape=stStarDown);
-          PStar[i*2].x := PCenter.X + Round(RadiusBig*cos(Alfa));
-          PStar[i*2].y := PCenter.Y - Round(RadiusBig*sin(Alfa));
-          Alfa:= GetStarAngle(i*2+1, FShape=stStarDown);
-          PStar[i*2+1].x := PCenter.X + Round(RadiusSm*cos(Alfa));
-          PStar[i*2+1].y := PCenter.Y - Round(RadiusSm*sin(Alfa));
-        end;
+          for i := 0 to 4 do
+          begin
+            Alfa := GetStarAngle(i*2, FShape=stStarDown);
+            PStar[i*2].x := PCenter.X + Round(RadiusBig*cos(Alfa));
+            PStar[i*2].y := PCenter.Y - Round(RadiusBig*sin(Alfa));
+            Alfa:= GetStarAngle(i*2+1, FShape=stStarDown);
+            PStar[i*2+1].x := PCenter.X + Round(RadiusSm*cos(Alfa));
+            PStar[i*2+1].y := PCenter.Y - Round(RadiusSm*sin(Alfa));
+          end;
 
-        PStar[10] := PStar[0];
-        Polygon(PStar);
+          PStar[10] := PStar[0];
+          Polygon(PStar);
+        end;
       end;
     end;
   end;