Does Lazarus Suuport transparency with PNG

[BenJones]

Hi, I was wondering does lazarus support the saving of Transparent png files. I tryed loading in a Bitmap with the transparent color set at RGB 255,0,255, the png file saves but no transparency. any ideas of how to get around this?

Here is a sniplet of code I use maybe you guys can see if I gone wrong anywere.
Thanks

Code: [Select]

var
  png : TPortableNetworkGraphic;
  bmp : TBitmap;
begin
  png := TPortableNetworkGraphic.Create;
  bmp := TBitmap.Create;
  bmp.LoadFromFile('c:\out\ben.bmp');
  png.PixelFormat := pf32bit;
  png.Transparent := True;
  png.TransparentColor := RGBToColor(255,0,255);
  png.Assign(bmp);
  png.SaveToFile('c:\out\hello.png');

[User137]

That didn't seem to work, but changing it a little did:

Code: [Select]

var
  png : TPortableNetworkGraphic;
  bmp : TBitmap;
begin
  png := TPortableNetworkGraphic.Create;
  png.PixelFormat := pf32bit;
  bmp := TBitmap.Create;
  bmp.PixelFormat := pf32bit;
  bmp.Transparent := True;
  bmp.TransparentColor := RGBToColor(255,0,255);
  bmp.LoadFromFile('d:\netti\temp.bmp');
  png.SetSize(bmp.Width, bmp.Height);
  png.Canvas.Draw(0, 0, bmp);
  png.SaveToFile('d:\netti\temp.png');
  bmp.Free;
  png.Free;I got rid of assign(), and made the bmp transparent instead.

[Dibo]

Try with BGRABitmap. It has full support for PNG. http://wiki.freepascal.org/BGRABitmap

[BenJones]

Thanks User137 seems to work that now.
Dibo I also take a look at BGRABitmap
thanks agian.