Re: gamegrid.el and some games

[Richard Stallman]

    > * Use a PBM form of the same image.  How hard is that?  Does it have
    > drawbacks?

    You mean, if a package provides only XPM we should calculate a PBM/XBM
    image from that XPM via manipulation of the data strings?

I was thinking that the programmer would supply the image in PBM
format.  This could be in addition to XPM, or instead of XPM.  How
hard is that?

    It is a pity that Emacs does not provide any means to create and
    change an image in the image cache directly. This could make this task
    (and some others) much easier.

I guess so.  It would be nice if all image formats (or at least more
of them) supported getting the image from Lisp data rather than from
a file.  Does someone want to work on that?

    > * Change gamegrid so that it can check for support for a specific
    > bitmap type before deciding to use a bitmap of that type.
    [...]

    I am not sure. Depending on how it is done it could either introduce
    incompatibilities to the former version of gamegrid or it could make
    gamegrid's interface even less clear.

Incompatibilities with the former version of gamegrid are not terribly
important.  Most of the programs that use gamegrid are included in Emacs.
We would change them too.

I doubt the interface will be much less clear.

    I guess, instead of applying `find-image' we could introduce new
    environment types for Emacsen compiled with and without support for
    XPM. Then we could fix pong.el, tetris.el and snake.el to be aware of
    that distinction. The keyword would then be 'glyph for an Emacs with
    support for XPM (for the sake of compatibility) and 'xbm-glyph or
    'simple-glyph or whatever for an Emacs that support nothing but the
    image types not relying on external libraries.

That seems like a good method.