Mattias Gaertner napsal(a):
On Mon, 27 Mar 2006 15:29:44 +0200
Tomas Gregorovic <[EMAIL PROTECTED]> wrote:
Mattias Gaertner napsal(a):
On Mon, 13 Mar 2006 11:09:19 +0100
Tomas Gregorovic <[EMAIL PROTECTED]> wrote:
Mattias Gaertner napsal(a):
On Fri, 10 Mar 2006 14:15:44 +0100
Tomas Gregorovic <[EMAIL PROTECTED]> wrote:
Hi,
finally I have finished my long battle around bitmap masks.
I have implemented method CreateBitmapMask, which creates mask
according >>>
to transparent color. The white pixels stand for opacity and black for
transperency (I have found out that this is in contrary to Delphi). I
hope this routine will function under all supported OSes - I have
tested >>>
it on win only.
Next, I had to change btimap and image transparent* properties to
behave >>>
like Delphi equivalents.
The difficult problem was how to keep transparency built in source of
bitmaps such as *.xpm. This I have solved by creating new seperate
mask >>>accessible throught AlphaMaskHandle, which stores alpha channel
data >>>that were previously stored in MaskHandle object.
I have attached small test project, which nicely illustrates right
mask >>>functioning.
You added an AlphaMaskHandle, but I don't see when we need both
MaskHandle and AlphaMaskHandle.
Why not use the MaskHandle for the Mask?
And btw: Not all widgetsets use separate Handle and MaskHandle.
Mattias
Sorry, my fault. Now when I have better looked into code I see it.
Therefore I have moved into using only MaskHandle and added flag
FAlphaMasked, which says whether the MaskHandle is source bitmap alpha
mask and then the transparent color is not used.
I took a closer look at the patch:
You rewrote TBitmap.InitFPImageReader to not use for the transparentcolor
the left, bottom pixel of the coming stream. Why?
Because under Windows with bmp picture all pixels with the same color as
the left bottom pixel are black (maybe clNone) and I haven't found any
way how to get theirs original color.
Canvas.Pixels[0,Height-1] does not work under gtk, so
TBitmap.GetTransparentColor does not work this way.
That's really pitty. Is it not implemented yet or is it impossible?
Not implemented. I don't how to implement it.
And where do you actually create the alpha mask?
I create the aplha mask in function CreateBitmapMask. I draw source
bitmap to monochromatic mask bitmap using a trick which changes the
transparent color to white in the mask bitmap. I am not sure if it is
multiplatform.
And where is the 8 or 16 bit alpha mask created?
I don't know what you are actually asking about. The CreateBitmapMask
function creates only 1 bit mask, because it is enough to make one color
transparent.
Is there some need to create any bit-depth masks?
tombo
_________________________________________________________________
To unsubscribe: mail [EMAIL PROTECTED] with
"unsubscribe" as the Subject
archives at http://www.lazarus.freepascal.org/mailarchives
