Rotating text in BGRA

[wp]

Currently I am extending the LazMapViewer to handle rotated text. I thought it would be convenient to rotate the text around its center and implemented this feature in this way for the default drawer based on LazIntfImage.

There is also a drawing engine using BGRABitmap. And when I rotate the text here, I see that the rotation center is in the upper left text corner. Is there a way to set parameters such that rotation occurs around the center here, too?

[DomingoGP]

Hi wp

I guess You can use this property of bgrabitmap.

  Bitmap.FontVerticalAnchor := fvaCenter;

To draw text along lines like roads, streets and rivers I would use  Bitmap.TextOutCurved like this sample code.

Code: Pascal  [Select][+][-]

1.  
2. uses
3.   BGRABitmap,BGRABitmapTypes,BGRAPath;
4.  
5. var
6.   polyline:Array [0..3]Of TPointF=((x:10;y:60),(x:70;y:30),(x:200;y:30),(x:260;y:50));
7.  
8. procedure TForm1.Button1Click(Sender: TObject);
9. var
10.   bitmap:TBGRABitmap;
11.   path2:TBGRAPath;
12. begin
13.   bitmap:=TBGRABitmap.Create(600,180,BGRA(255,255,255));
14.   path2 := TBGRAPath.Create;
15.   bitmap.DrawPolyLineAntialias(polyline,BGRA(0,0,0),2);
16.   path2.polyline(polyline);
17.   Bitmap.FontVerticalAnchor := fvaCenter;
18.   Bitmap.TextOutCurved(path2, 'Sample rotated text', BGRA(255,0,0), taLeftJustify, 0);
19.  
20.   //bitmap.DrawLine(280,5,340,65,BGRA(0,0,0),true);
21.   //bitmap.TextOutAngle(280,5, -450, 'Hello', BGRA(0,0,255), taLeftJustify);
22.  
23.   bitmap.FontVerticalAnchor := fvaTop;
24.   path2.Free;
25.   bitmap.Draw(Canvas,0,50);
26.   bitmap.Free;
27. end;    
28.  

Regards
Domingo

[wp]

I found it: I need Bitmap.FontVerticalAnchor := fvaCenter, and taCenter as Align parameter in the Bitmap.TextOut call.