[comp.lang.smalltalk] Color bitmaps

mcmullen@macado.cica.indiana.edu (Rick McMullen) (09/12/90)

Has anyone out there come up with a way to do color bitmaps? I am about to 
start on a project which requires the display of color bitmapped images
and want to do it using Objectworks-2.5. If there are existing UDPs for 
doing this on a Mac or Sun it would be a real time saver.

Thanks,
Rick

laukee@canon.co.uk (David Lau-Kee) (09/12/90)

mcmullen@macado.cica.indiana.edu (Rick McMullen) writes:
[ ... ]
>start on a project which requires the display of color bitmapped images
>and want to do it using Objectworks-2.5. If there are existing UDPs for 
>doing this on a Mac or Sun it would be a real time saver.
[ ... ]

This is sun specific (and I did it some time ago, so forgive memory lapses):

I did this under 2.4 by adding image handling/display primitives.  I haven't
tried them under 2.5, but I can see no problems with doing this.  If your
need for pixmaps is restricted to displaying data in a Smalltalk window then a
similar approach might be appropriate for you.  (Mail me and I'll give you
some pixrecty code for Suns).  You'll have to some colourmap frigging since I
guess St will install its fg/bg colours in pixwin fashion and Sunview will
insist on reinstalling the segment when the window has focus (e.g., the cursor
just flips the lsb, so you'll need to make every other colourmap entry black
if you want the cursor to display over colour images).

If you need to add a colour model to Smalltalk then you might have problems
with 2.5.  Under 2.3 you could use the methods:

displayForm:onFrameBufferAt:bitsPerPixel:
getMaxGunValue
setColorMapEntry:toRedValue:greenValue:blueValue:

to do colour work... in fact, some reckless souls even made it useful by
adding a ColorForm and ColorDisplayScreen using these primitives. 
I don't know why PPS removed these from 2.4+... ok they were a bit machine
specific, but anything is better than nothing.

-------------
David Lau-Kee
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