[plt-scheme] still got a little probleme with transparency

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Tue Apr 1 09:01:58 EST 2003

At Tue, 1 Apr 2003 13:49:54 +0200 (CEST), Berticolas Copimasso wrote:
> We've installed Win2k instead of Win98 and now the
> transparency works well,but we've got a little
> problem.We tryed to use transparent bitmap in
> snip-image%(we need to move the .GIF image)but it
> doesn't works,the background is white.

I see lots of problems:

 1. The documentation is wrong. The initialization mode that accepts a
    bitmap% also accepts a second optional argument, which is a mask

      (define bm (make-object bitmap% <some-file> 'gif/mask))
      (make-object image-snip% bm (send bm get-loaded-mask))

    Hopefully this will solve your problem. Meanwhile, I'll fix the

 2. When image-snip% is given a filename, it doesn't use any mask that
    might be in the file.

       ; doesn't use he mask:
      (make-object image-snip% <some-file> 'gif/mask)

    I'll fix this.

 3. When the snip is saved to a file, any mask it might have is lost.

    I'll fix this, though it will likely require a
    backward-incompatible extention of the WXME format.


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