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Bug 562

Summary:	Bad shadow rendering with Metafile export in GDI+
Product:	VCL TeeChart	Reporter:	narcís calvet <narcis>
Component:	Canvas	Assignee:	Steema Issue Manager <issuemanager>
Status:	IN_PROGRESS ---
Severity:	normal	CC:	david
Priority:	High
Version:	131119
Target Milestone:	---
Hardware:	PC
OS:	Windows
Chart Series:	---	Delphi / C++ Builder RAD IDE Version:

Description narcís calvet 2014-02-06 11:17:16 EST

Shadows are not rendered correctly when exporting to a Metafile image in GDI+ canvas. Works fine in GDI. To reproduce drop a TImage and TChart components to a form and use this code:

uses Series, TeCanvas;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Chart1.AddSeries(TPieSeries.Create(Self)).FillSampleValues;
  //Chart1.Canvas:=TTeeCanvas3D.Create; //GDI canvas works fine
  Image1.Picture.Graphic := Chart1.TeeCreateMetafile(True, Rect(0, 0, Chart1.Width, Chart1.Height));
end;

Comment 1 david berneda 2014-02-06 12:34:41 EST

Fixed. The problem is GDI+ draws shadows are displayed using semi-transparent colors to obtain a "smooth" shadow effect.  This semi-transparent colors are converted to Metafiles as "brush patterns".

Pending to investigate how to convert our metafiles from Enhanced to Enhanced Plus.

Enhanced Plus (GDI+ only) metafiles should support both antialiasing and semi-transparent colors without patterns.

Comment 2 narcís calvet 2014-02-07 03:00:52 EST

Workaround are either using the GDI canvas for the export:

uses VCLTee.TeCanvas;

procedure TForm1.Button1Click(Sender: TObject); begin
  Chart1.Canvas:=TTeeCanvas3D.Create;
  Image1.Picture.Graphic := Chart1.TeeCreateMetafile(True, Rect(0, 0, Chart1.Width, Chart1.Height));
  Chart1.Canvas:=TGDIPlusCanvas.Create;
end;

Or hiding all shadows:

procedure TForm1.Button1Click(Sender: TObject); begin
  Series1.Shadow.Visible:=False;
  Series1.Marks.Shadow.Visible:=False;
  Chart1.Legend.Shadow.Visible:=False;
  Chart1.Legend.Symbol.Shadow.Visible:=False;

  Image1.Picture.Graphic := Chart1.TeeCreateMetafile(True, Rect(0, 0, Chart1.Width, Chart1.Height)); end;