FLTK draw pixmap gives segfault

Question

I'm trying to draw a xpm file in a C++ program with FLTK.

Here's the code

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include "image.xpm"
#include <FL/Fl_Pixmap.H>
#include <FL/fl_draw.H>
#include <FL/Fl_Image.H>
int main(int argc, char ** argv)
{
  Fl_Window *window = new Fl_Window(800,650);
  Fl_Pixmap pix(XFACE);
  pix.draw(200,200);
  window->end();
  window->show(argc,argv);
  return Fl::run();
}

XFACE is a valid xpm object inside "image.xpm"

But I'm getting a segmentation fault at the pix.draw() line.
What causes this?

Everything? Nothing? Honestly, it's impossible to answer your question as of now. At least edit your question to include `XPM`, or at least the beginning and end of `XPM`. — Some programmer dude, Jun 15 '12 at 05:32
Write a SSCCE please ( http://sscce.org/ ) or at least make a web-paste somewhere that contains complete error output... My first guess is - you either do not have a valid FLTK context, so Fl_Pixmap does not know where to render itself to, or the XPM is invalid... — DejanLekic, Jun 15 '12 at 13:19

score 3 · Accepted Answer · answered Jun 18 '12 at 10:25

/* Try this - this works for me, and I guess is what you meant! */

#include <FL/Fl.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Pixmap.H>

#include "image.xpm"

int main(int argc, char ** argv)
{
    Fl_Window *window = new Fl_Window(800,650);
    Fl_Box *image_box = new Fl_Box(5, 5, 790, 640);
    Fl_Pixmap pix(XFACE);
    window->end();
    image_box->image(pix);
    window->show(argc,argv);
    return Fl::run();
}

/* end of file */

score 0 · Answer 2 · answered Jun 18 '12 at 10:11

To be honest, that doesn't even look like valid fltk code; you are calling the draw() method directly, and AFAIK that is seldom valid in fltk.

You probably want to ask over on their mailing list - they are pretty responsive.

Also, did you look at the pixmap demo in the "test" folder of the tarball - see what it does, then copy it!

FLTK draw pixmap gives segfault

2 Answers2