Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!mit-eddie!bloom-beacon!eru!hagbard!sunic!mcsun!ukc!icdoc!syma!jonm
From: jonm@syma.sussex.ac.uk (Jonathan Meyer)
Newsgroups: comp.windows.x
Subject: X11R5 Dreams
Message-ID: <3355@syma.sussex.ac.uk>
Date: 29 Aug 90 12:39:25 GMT
Organization: University of Sussex
Lines: 41

I'm sure that many people would agree with me if I said that one of the most
unpleasant part of X is handling color images. I'd love someone to rationalise
the situation for constructing new colors. Whoever named the following two
procedures must have been a little tired:

	XAllocColor      - allocate single READ ONLY color cell
	XAllocColorCells - allocate multiple READ WRITE color cells

What happened to multiple read-only color cells, or a single read write color
cell? It seems our memory is once again left to do the work, rather than an
explicit naming system. I would love something like:

	XAllocReadWriteColor
	XAllocReadWriteColors
and
	XAllocReadOnlyColor
	XAllocReadOnlyColors

Which take a color or array of colors and allocate them corrospondingly,
returning 1 on success.

Another thing I miss is the ability to determine whether a pixel value is a
valid allocated color, an unallocated color, and whether it is read-write
or read-only for a specific display connection. It would also be very useful
to see if an RGB value is named in the color database for a display, so that I
can take a pixel value and determine what named color it corrosponds to. Maybe
XQueryColor could be extended to do something like this.

Next, I would love a hook on XImage structures for XGetImage/XPutImage so that
I could perform normalization on the pixel values on the fly as they go
up/down the socket. This way, I can write a conversion procedure that maps
between image data and colormap pixel values (and visa-versa) which work
invisibly. Specifying normalization procedures of NULL would result
in optimized performance using no normalization. This system would be much more
useful than writing coercion procedures that I call before an XPutImage and
after an XGetImage. Since just about every image goes through this conversion
procedure, I think that all of us would benifit from such a feature.

Of course, a standard image format would help (and XPM is a start), but can
people remember that some of us are performing image processing; 1/2 or 1 MB
grayscale images are commonplace - an ASCII format such as XPM would be
unsuitable for such images. Personally, I'm happy with sun rasterfiles, and
support converting between pixmaps and rasterfiles would be wonderful!

Now, I could go on to talk about the Xt (especially things like resource
conversion dependancy trees), but then again...

Jon