> Anyone can tell me how do I create a pixmap inside the code of the
> program.
> Let me explain. A pixmap is a const char **matrix, isn't it?
No, it is not.
The problem here is a confusion of terms: The `data' referred to in
the function fl_set_pixmap_data() is an array of char strings in the
XPM format, which is translated to a real server Pixmap object by the
libXpm functions. I really wish the developers of XPM had picked some
other term than "Pixmap" to describe their format. Here is an example
of an XPM data structure from the `eye.xpm' file supplied with XForms:
/* XPM */
static char * eye[] = {
/* eye pixmap
* width height ncolors chars_per_pixel */
"32 32 4 2 ",
" c #FFFFFFFFFFFF s s_#FFFFFFFFFFFF ",
". c #000 s s_#000 ",
"X c #FFFFB0B0B0B0 s s_#FFFFB0B0B0B0 ",
"o c #32329999CCCC s s_#32329999CCCC ",
/* pixels */
" ",
" ",
" . . . . . . . ",
" . . . X X X X X X X . . . ",
" . . X X X X X X X X X X X X X . . ",
" . X X X X X X X X X X X X X X X X X . ",
" . X X X X X X X X X X X X X X X X X X X . ",
" . X X X X X X X X X X X X X X X X X X X X X . ",
" . X X X X X X X X X X X X X X X X . X . X . X X . ",
" . X X X X X X X X X X X X X X X . . . . X . ",
" . X X X X X X X X X X X X X X X . . o . . X . ",
" . X X X X X X . X X X X X X X . . o o o o o . . ",
" . X X X X X . X X . X X X X . . o o o o o o . ",
" . X X X X . X X . X X X X X X . o o o o o o o . . ",
" . X X X . X X . X X X X X X . . o o o o o o o . ",
" . X X . X X . X X X X X X X X . o o o o o o o o . . ",
" . X X X . X X . X X X X X X . . o o o o o o o . ",
" . X X X X . X X . . . X X X X . . o o o o o . . ",
" . X X X X . X X X X . X X X X . . o . . . ",
" . X X X X X . X X X X . X X X X . . . . X . ",
" . X X X X . . X X X . X X X X X . X . X . X . ",
" . X X . X X X X . X X X X X X X X X X X . ",
" . X X . X X . X X X X X X X X X X X . ",
" . . X . . X X X X X X X X X X . . ",
" . X X X X X X X X X . . . ",
" . X X X X . . . . ",
" . X X . X X . ",
" . X X . X X . ",
" . X X . . . . . . . ",
" . X . X X X X X . . X . . ",
" . X X X X X X X X X X . X X . ",
" . . . . . . . . . . . . . X . . "
} ;
It consists of an introducer line giving the size of the image, the
number of colors and the number of bytes (characters) per color,
followed by the color map, finally followed by the image data itself.
In the above case, your call would look like
fl_set_pixmap_data( obj, eye );
XPM is mostly useful for small icons and other graphic objects which
are generally static in nature. It is *not* an appropriate format for
real useful image data (such as satellite images, etc.) given the high
overhead in translating from the XPM format to the XImage structure
and Pixmap server object, not to mention various bits of colormap
fiddling.
If you want to display an image of any significant size you really,
really, really *must* use the Canvas object with raw Xlib XImage and
Pixmap objects or use another API. For information on how to deal
with this data you should refer to a good Xlib reference, such as the
O'Reilly book I recommended in an earlier posting or the other book
referred to by another poster to this list. You may also want to look
at my color quantization library (available at
ftp://ncmir.ucsd.edu/pub/quantize -- refer to
ftp://ncmir.ucsd.edu/pub/quantize/libquantize.html for documentation.
See the README file in the same location for downloading details, etc.).
If you have OpenGL on your system, use the GLCanvas object. The
glDrawPixels() function will allow you to write images to a GLCanvas
The next release of XForms will have support for images built in but
I'm not certain when that will be out -- Real Soon Now, I suppose,
depending upon how busy they keep TC at MERL. :-)
spl
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