l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
January 6: Social gathering
Next Installfest:
TBD
Latest News:
Nov. 18: Club officer elections
Page last updated:
2005 Jan 30 07:05

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] opengl: lines and points
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] opengl: lines and points



On Sun, 30 Jan 2005 00:49:56 -0500
p@dirac.org (Peter Jay Salzman) wrote:

>    #include <GL/glut.h>
> 
>    void display(void)
>    {
>       glClear (GL_COLOR_BUFFER_BIT);
> 
>       glBegin( GL_LINES );
>          glColor3f( 1.0, 0.0, 0.0 );     // *1*
>          glVertex2f( 400.0f, 50.0f );    // *1*
>          glVertex2f( 400.0f, 550.0f );   // *1*
> 
>          glColor3f( 1.0, 1.0, 1.0 );     // *2*
>          glVertex2f( 50.0f, 300.0f );    // *2*
>          glVertex2f( 750.0f, 300.0f );   // *2*
>       glEnd();
> 
>       glFlush();
>    }
> 
>    int main(int argc, char *argv[])
>    {
>       glutInit(&argc, argv);
>       glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
>       glutInitWindowSize (800, 600); 
>       glutInitWindowPosition (100, 100);
>       glutCreateWindow (argv[0]);
> 
>       glClearColor (0.0, 0.0, 0.0, 0.0);
>       glShadeModel (GL_FLAT);
> 
>       glutDisplayFunc(display); 
> 
>       glutMainLoop();
>       return 0;
>    }

I'm not sure why it shows up for you when you deleted one of the lines,
but when I ran your code as written, the lines were outside the
(-1.0,-1.0) to (1.0,1.0) clipping box, so they weren't getting drawn.
Changing the coordinates helped, and they were both drawn. The second
one was white though (use glColor3f( 0.0, 0.0, 1.0 ); if you want blue).

--Ken Bloom

-- 
I usually have a GPG digital signature included as an attachment.
See http://www.gnupg.org/ for info about these digital signatures.

Attachment: pgp00030.pgp
Description: PGP signature

_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech


LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Appahost Applications
For a significant contribution towards our projector, and a generous donation to allow us to continue meeting at the Davis Library.