LoadFromIntfImage - don't work?
lazarus / 39-Graphics

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konung · 2012-12-24 00:06

I do the following:
Code: [Select]...
graphtype, intfgraphics, lazcanvas, fpImage;  
...
var
  AImage : TLazIntfImage;
  lRawImage: TRawImage;
  i,j:integer;
begin
lRawImage.Init;
  lRawImage.Description.Init_BPP32_A8R8G8B8_BIO_TTB(100, 100);
  lRawImage.CreateData(true);
  AImage := TLazIntfImage.Create(0, 0);
  AImage.SetRawImage(lRawImage);
  for i:=0 to AImage.Width-1 do
    for j:=0 to AImage.Height-1 do
      AImage.Colors[i,j]:=FPColor(200, 0, 0, 255);

  Image1.Picture.Bitmap.LoadFromIntfImage(AImage);
...
but Image1 is black. what wrong?

winXP 32 bit, Lazarus 1.0.2

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taazz · 2012-12-24 02:07

Depending on the widget set you are using the alpha value is backwards
reversed.
Windows and QT use the same values for opaque and transparent (if I
remember correctly 0 = transparent 255 opaque) gtk works the other way
around (255 transparent 0 opaque)
I'm not sure about the actual value so you need to test it for your
self.

At least that was my problem a few months back when I was porting a
color component suit.

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User137 · 2012-12-24 06:36

You are trying to load it into bitmap (special BMP format).

Can you do something like either of these?
Code: [Select]Image1.Picture.LoadFromIntfImage(AImage);
Image1.Picture.Assign(AImage);

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konung · 2012-12-24 10:07

Quote from: taazz on December 24, 2012, 03:07:43 am... alpha value ...
I try different vlaues for Alpha. Result is same.

Quote from: User137 on December 24, 2012, 07:36:33 amYou are trying to
load it into bitmap (special BMP format).
Yeah. 'couse it's manual example:
http://wiki.lazarus.freepascal.org/Developing_with_Graphics#Working_wi
th_TLazIntfImage.2C_TRawImage_and_TLazCanvas
Topic: "Working with TLazIntfImage, TRawImage and TLazCanvas" and
"Loading a TLazIntfImage into a TImage".

Quote from: User137 on December 24, 2012, 07:36:33 amCan you do
something like either of these?

No. First - impossible. Second - the same result.

Does some one try the same code? Or it's unusable feature?
May be there is some another way? I need to do some manipulation with
image. And then - show them in some TImage. As i understand - there
isn't fast access to pixels in bitmap. And I mast use the way, that I
write above.

In win7 64 bit - the same. in Linux (ubuntu 64 bit, lazarus 1.0) -
nothing (blackbox is'n too)...

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konung · 2012-12-24 13:44

hum... problem solved.
I miss that R G B A is World type... 

however there is one more problem. if i fill by pixel image with
32-bit mode - it does not work correct. it use image like 24-bit. but
it's another problem.

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User137 · 2012-12-24 23:34

Like i said, you are loading image to bitmap. BMP does not support
alpha channel.