This is the mail archive of the
cygwin-xfree
mailing list for the Cygwin XFree86 project.
Re: glwDrawingAreaWidgetClass
- From: Chris Carlson <cwcarlsonc at cox dot net>
- To: cygwin-xfree at cygwin dot com
- Date: Sun, 12 Oct 2014 18:48:19 -0700
- Subject: Re: glwDrawingAreaWidgetClass
- Authentication-results: sourceware.org; auth=none
- Authentication-results: cox.net; auth=pass (CRAM-MD5) smtp dot auth=cwcarlsonc at cox dot net
- References: <5433509B dot 8050805 at cox dot net> <0DqF1p0240YP9AS01DqG2B>
- Reply-to: cygwin-xfree at cygwin dot com
I apologize for being so vague.
I have a fairly large program that I developed on Fedora Linux. It uses
glwDrawingAreaClassRec to create a GL window. I attempted to compile
and run it on Cygwin, and I got the failure.
I added a print statement just before calling XtCreateManagedWidget()
and discovered the value was 0 on Cygwin and an address on Linux. I
presumed that meant there was an issue.
To get around the problem, I downloaded the source from Mesa and
compiled it myself. The .a that was generated identifies the following
(using nm):
0000000000000640 D glwDrawingAreaClassRec
0000000000000728 D glwDrawingAreaWidgetClass
I then compared it to /lib/libGLw.dll.a and got this:
nm /lib/libGLw.dll.a | grep DrawingAreaClass
0000000000000000 I __imp_glwMDrawingAreaClassRec
0000000000000000 I __nm_glwMDrawingAreaClassRec
0000000000000000 I __imp_glwDrawingAreaClassRec
0000000000000000 I __nm_glwDrawingAreaClassRec
Now I tried compiling your test program and found that it did work as
you showed, but I then added the include of GLwDrawA.h, and it fails.
This doesn't make a whole lot of sense to me, and it doesn't seem right.
What do you think? If I want to use the GLwDrawingAreaWidgetClass, I
would presume that I should include the corresponding header file and
the class would be defined.
Thanks for your time, and I really do appreciate you and Cygwin.
Chris Carlson
On 10/7/2014 6:50 AM, Jon TURNEY wrote:
On 07/10/2014 03:31, Chris Carlson wrote:
I've discovered that the constant glwDrawingAreaWidgetClass is set to
0. It's supposed to be defined as:
WidgetClass
glwDrawingAreaWidgetClass=(WidgetClass)&glwDrawingAreaClassRec;
Can I ask you to please provide some more details as to how you made
this discovery?
If you do this:
$ cat glw-test.c
#include <Xm/Xm.h>
#include <GL/GLwDrawA.h>
#include <stdio.h>
int main()
{
printf("glwDrawingAreaWidgetClass %p", glwDrawingAreaWidgetClass);
}
then you could reach that conclusion:
$ gcc glw-test.c ; ./a
glwDrawingAreaWidgetClass 0x0
but this isn't testing correctly as glwDrawingAreaWidgetClass isn't
marked as extern in GLwDrawA.h
$ cat glw-test.c
#include <Xm/Xm.h>
#include <stdio.h>
extern WidgetClass glwDrawingAreaWidgetClass;
int main()
{
printf("glwDrawingAreaWidgetClass %p", glwDrawingAreaWidgetClass);
}
$ gcc glw-test.c -lGLw ; ./a
glwDrawingAreaWidgetClass 0x5bd8e3640
Is it broken?
I don't know.
--
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
Problem reports: http://cygwin.com/problems.html
Documentation: http://x.cygwin.com/docs/
FAQ: http://x.cygwin.com/docs/faq/