* * *

Author Topic: BGRABitmap 2DCanvas with scale  (Read 684 times)

hosune7845

  • Full Member
  • ***
  • Posts: 153
BGRABitmap 2DCanvas with scale
« on: March 23, 2017, 09:50:15 am »
Hello.

I drew vector images with TBGRABitmap.Canvas2D.FillText

It works fine. but TBGRABitmap.Canvas2D.scale function makes position error.

I attached two images with different scale.

Here's code

1. image 1.bmp
Code: Pascal  [Select]
  1.   with aBGRABitmap.Canvas2D do
  2.   begin
  3.     FontEmHeight := 30;
  4.     FontName     := 'Arial';
  5.     FontStyle    := [];
  6.     Antialiasing := True;
  7.     FillStyle(BGRABlack);
  8.     TextBaseline := 'top';
  9.  
  10.     FillText('123456', 100 ,50);
  11.   end;
  12.  

2. image 2.bmp
Code: Pascal  [Select]
  1.   with aBGRABitmap.Canvas2D do
  2.   begin
  3.     Scale(1/5, 5);
  4.     FontEmHeight := 30;
  5.     FontName     := 'Arial';
  6.     FontStyle    := [];
  7.     Antialiasing := True;
  8.     FillStyle(BGRABlack);
  9.     TextBaseline := 'top';
  10.  
  11.     FillText('123456', 100 ,50);
  12.     Scale(5, 1/5);
  13.   end;
  14.  

Anyone knows why the text position different?
« Last Edit: March 23, 2017, 09:56:23 am by hosune7845 »

circular

  • Hero Member
  • *****
  • Posts: 2594
    • Personal webpage
Re: BGRABitmap 2DCanvas with scale
« Reply #1 on: March 24, 2017, 06:17:12 am »
It is normal. The scaling applies to all coordinates. If you want the text to be at the pixel (100,50), then you need to do:
Code: Pascal  [Select]
  1. translate(100,50);
  2. scale(5,1/5); //for example
  3. FillText('123456', 0,0);
  4. resetTransform;
  5.  
Conscience is the debugger of the mind

hosune7845

  • Full Member
  • ***
  • Posts: 153
Re: BGRABitmap 2DCanvas with scale
« Reply #2 on: March 24, 2017, 08:52:05 am »
It is normal. The scaling applies to all coordinates. If you want the text to be at the pixel (100,50), then you need to do:
Code: Pascal  [Select]
  1. translate(100,50);
  2. scale(5,1/5); //for example
  3. FillText('123456', 0,0);
  4. resetTransform;
  5.  

Thank you.

That works fine for me.

circular

  • Hero Member
  • *****
  • Posts: 2594
    • Personal webpage
Re: BGRABitmap 2DCanvas with scale
« Reply #3 on: March 24, 2017, 09:21:41 am »
Cool.

You're welcome.
Conscience is the debugger of the mind

 

Recent

Get Lazarus at SourceForge.net. Fast, secure and Free Open Source software downloads Open Hub project report for Lazarus