Eclipse Community Forums: Standard Widget Toolkit (SWT)

Help

Home

Home » Eclipse Projects » Standard Widget Toolkit (SWT) » Alpha Data

Show: Today's Messages :: Show Polls :: Message Navigator

Alpha Data [message #437478]

Fri, 04 June 2004 16:18

Ryan

Messages: 34
Registered: July 2009

Member

Hi!

In the ImageData class, there is a byte array called alphaData. This array
contains the alpha blending values for each pixel of the image. The
javadoc says that the values in this array range from 0-255. However, I
looked at the alphaData for a png file I had and the array consisted of 0s
and -1s.

What does -1 mean?

Thanks!

Ryan

Report message to a moderator

Re: Alpha Data [message #437491 is a reply to message #437478]

Sat, 05 June 2004 09:03

Eclipse User

Originally posted by: wikiz.centras.lt

Ryan wrote:
> javadoc says that the values in this array range from 0-255. However, I
> looked at the alphaData for a png file I had and the array consisted of 0s
> and -1s.
>
> What does -1 mean?

:) I think "-1" means "255", as it's the same byte value "0xFF"

--

Viktoras M.
wikiz@centras.lt

Report message to a moderator

Re: Alpha Data [message #437519 is a reply to message #437478]

Mon, 07 June 2004 07:25

Jean Couillaud

Messages: 184
Registered: July 2009

Senior Member

Ryan a écrit :
> Hi!
>
> In the ImageData class, there is a byte array called alphaData. This array
> contains the alpha blending values for each pixel of the image. The
> javadoc says that the values in this array range from 0-255. However, I
> looked at the alphaData for a png file I had and the array consisted of 0s
> and -1s.
>
> What does -1 mean?

I have not looked at the class you mentionned, but my guess is it is
just the representation of a signed byte with value 255.

> Thanks!
>
> Ryan
>

Report message to a moderator

Previous Topic:	SashForm and listener
Next Topic:	MenuManager

Goto Forum:

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

]

Current Time: Thu Apr 25 01:26:49 GMT 2024

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter