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Bug 1961

Summary:	Donut series chart displays values incorrectly (GDI rendering), v. 2017.23.171221 VCL
Product:	VCL TeeChart	Reporter:	trubetskov
Component:	Chart	Assignee:	Steema Issue Manager <issuemanager>
Status:	RESOLVED WORKSFORME
Severity:	critical	CC:	marc, sandra, trubetskov
Priority:	High
Version:	23.171221
Target Milestone:	---
Hardware:	PC
OS:	Windows
Chart Series:	Donut	Delphi / C++ Builder RAD IDE Version:	RAD 10.2 Tokyo
Attachments:	Screenshots of the demo with GDI+ ON and OFF

Description trubetskov 2018-01-02 08:44:08 EST

Donut chart represents values incorrectly (GDI rendering only!) due to extra transformation from Degrees to Radians.

In the function TTeeCanvas3D.Donut in version 23.171221 you introduced an additional transformation from Degrees to Radians: 

  CalcPoint(DegToRad(StartAngle),x3,y3);
  CalcPoint(DegToRad(EndAngle),x4,y4);

In the previous version in this place we had:

  CalcPoint(StartAngle,x3,y3);
  CalcPoint(EndAngle,x4,y4);

As the result in GDI case rendering donut charts are very strangely looking!

Regards,
   Michael

Comment 1 trubetskov 2018-01-02 08:46:00 EST

I cannot enter the most recent version number in Bugzilla! This selection is unavailable!

Comment 2 sandra pazos 2018-02-22 10:46:59 EST

Hello Michael, 

Could you attached a simple code because we can reproduce the problem? Also, would be helpful if you can attach images to see the different behaviour between versions. 

Thanks for your colaboration,
Regards.

Comment 3 trubetskov 2018-02-22 13:08:23 EST

Created attachment 815 [details]
Screenshots of the demo with GDI+ ON and OFF

I attached 2 screenshots from your demo. Please, pay special attention to GDI+ setting and 3D = OFF. When GDI+ = OFF, the transformation from Degrees to Radians is obviously applied one extra time!

Regards,
   Michael

Comment 4 sandra pazos 2018-02-23 05:03:28 EST

Hello Michael,

Many thanks for the information. Finally, we can reproduce the problem turning off the 3D View as you have indicated. I have added a simple code to reproduce in easy way the problem: 

 uses TeCanvas;
procedure TForm3.FormCreate(Sender: TObject);
begin
   Chart1.View3D := false;
   Series1.FillSampleValues(4);
   gdi.Checked := True;
end;
procedure TForm3.GDIClick(Sender: TObject);
begin
       if gdi.Checked then
          Chart1.Canvas := TGDIPlusCanvas.Create
        else
          Chart1.Canvas:=TTeeCanvas3D.Create;
end;

Comment 5 trubetskov 2018-03-31 05:37:25 EDT

This bug is not fixed in the new release v.2018.24.180321

Very strange and disappointing! 

-Michael

Comment 6 marc meumann 2021-04-20 11:11:02 EDT

Not reproducible in latest version.