My apologies if you've seen this message before: my previous two attempts
to send it (apparently) disappeared into the void and left no mark on the
mailing list archives.
My further apologies if these questions are blindingly obvious faqs. I'm
somewhat new to X-windows programming: please point me toward the
appropriate documents.
Ok, so I've installed xforms 0.86, built the demos, built "hello world"
type programs, used fdesign and everything works fine. Now I'm trying to
port an old svgalib (256-color) application to xforms (under linux/x86).
Question 1: How to set the Palette ...
I have a description of the 256-color palette used under svgalib: I know
the red, green and blue components (on a 0-63 scale) for each color.
I was thinking of leaving the first 64 colors untouched (for xforms
decorations) and mapping my palette into the next 256 colors, like so:
for (c=0; c<256 ;c++)
fl_mapcolor(c+64, red[c], green[c], blue[c]);
Am I on the right track with this?
Question 2: Displaying Linear Bitmaps ...
The old application made extensive use of linear bitmaps. Briefly, a
linear bitmap is a two-dimensional array (of externally known height and
width) where each element represents a pixel colors for a picture. In
8-bit mode a 12x10 lbm would be 120 bytes long and the first 12 would hold
the colors for the pixels in the top row, etc. Thus, if you were forced
to display on one the screen by hand you might code something like this:
unsighed char lbm[120]; /* our linear bitmap */
for (y=0; y<10 ;y++)
for (x=0; x<12 ;x++)
set_pixel_color(x+x_offset,y+y_offset,/ *color = */ lbm[(y*12)+x]);
How can I display an lbm (or even paint a pixel) at an arbitrary location
within an xforms window? Would a "canvas" be the best object for
something like this?
If push truly comes to shove, I could convert all of the lbms to xpms
(dramatically increasing their size, though): if there is no way to draw
arbitrary points to an xforms window, is there a way to draw arbitrary
xpms (outside of the pixmapbutton)? I would much prefer to use them as
lbms, however: I don't know the xpm format as well.
Thanks!
-Wes Weimer
wrw3@cornell.edu
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