Mattias Gaertner napsal(a):
On Fri, 31 Mar 2006 12:36:27 +0200
Tomas Gregorovic <[EMAIL PROTECTED]> wrote:
Mattias Gaertner napsal(a):
On Thu, 30 Mar 2006 15:23:08 +0200
Tomas Gregorovic <[EMAIL PROTECTED]> wrote:
Tomas Gregorovic napsal(a):
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?
I got the bad feeling there is a misunderstanding.
At the moment the LCL only provides 1 bit transparency. For the LCL it
does not matter if the alpha channel is separated in a MaskHandle or
contained in the Handle. The gtk interface uses a combo Handle, while
the >>win32 interface uses a separate MaskHandle.
Of course we want alpha transparency, i.e. >1 bit, which is typically 8
or 16 bit alpha channel.
AFAIK the gtk1 does not support 8 bit masks (at least not without
tricks), but the gtk2 supports them.
The only missing part is to add 8 bit transparency support to the gtk2
interface and some properties to TBitmap, so the user can select the
alpha depth.
I thought, your patch is starting the latter. But maybe you meant
something different?
Maybe. I wanted to implement bitmap color transparency, which is
adjusted through TransparentColor porperty...
Huh? This already works. What exactly are you trying to implement?
But from my point of view it doesn't work. I have tested it on several
various lazarus versions including the latest svn snapshot with attached
small project and it simply does not function!
Therefore I had thought it's not implemented and created that patch.
Maybe it's only some bug occuring on my system.
Thanks. The bitmap is loaded transparent.
I could not test the := Image1.Picture.Bitmap.Canvas.Pixels[X, Y];, as this
does is not yet implemented under gtk1 interface.
You want to switch the transparentcolor, when the image is already loaded,
right?
I implemented that.
Aboslutely right.
It works but there is a problem with xpm images - when you set some
transparent color, strange stripes appear (see screenshot 1).
There is another issue: when the bitmap is loaded with default
transparency (the left-bottom pixel color is transparent) then all
pixels with this color appear to be black if transparent color is
changed and the original color is lost (e.g. clFuchsia on sceenshot2).
tombo
