[Gmsh] Antialiasing gmsh2

[Christophe Geuzaine]

Kubicek Bernhard wrote:
> Hello!
> 
> While playing around with the gmsh-2.0.0-nightly-20070117 source, I
> found that at least on my system (Ubuntu-x86 dapper, nvidia) enabling
> antialiasing leads to nicer/smoother look in the gmsh-OpenGL window. A
> drawback might be slower rendering time. Attached are two PNGs showing
> the difference. 

Nice! I've merged a modified patch in cvs (with a button to control the
behavior in the gui).

Thanks,

Christophe

> 
> To do so, one needs to change the sourcecode and recompile.
> 
> In the file Fltk/GUI.cpp, after line 1445, change the code to (basically
> just inserting FL_MULTISAMPLE): 
> ----
>   // opengl window
> 
>   g_opengl_window = new Opengl_Window(0, 0, width, glheight);
> 	g_opengl_window->mode(FL_RGB | FL_DEPTH | FL_MULTISAMPLE |
> FL_DOUBLE ); //enable antialiasing
>   if(!opt_general_double_buffer(0, GMSH_GET, 0)) {
>     Msg(INFO, "Setting OpenGL visual to single buffered");
>     g_opengl_window->mode(FL_RGB | FL_DEPTH | FL_MULTISAMPLE | FL_SINGLE
> ); //enable antialiasing
>   }
> ----
> 
> However for being able to switch between single and double buffered
> display without loosing the antialiasing, also Common/Options.cpp needs
> to changed similarly:
> ----
> double opt_general_double_buffer(OPT_ARGS_NUM)
> {
>   if(action & GMSH_SET) {
>     CTX.db = (int)val;
> #if defined(HAVE_FLTK)
>     if(WID) {
>       if(CTX.db) {
>         Msg(INFO, "Setting OpenGL visual to double buffered");
>         WID->g_opengl_window->mode(FL_RGB | FL_DEPTH | FL_MULTISAMPLE |
> FL_DOUBLE); //enable antialiasing
>       }
>       else {
>         Msg(INFO, "Setting OpenGL visual to single buffered");
>         WID->g_opengl_window->mode(FL_RGB | FL_DEPTH | FL_MULTISAMPLE |
> FL_SINGLE);//enable antialiasing
>       }
>     }
> #endif
>   }
> #if defined(HAVE_FLTK)
>   if(WID && (action & GMSH_GUI))
>     WID->gen_butt[3]->value(CTX.db);
> #endif
>   return CTX.db;
> }
> ----
> For productive usage, one probably could include a preprocessor switch
> or a GUI element similar to the double-buffering switch.
> 
> Nice greetings,
>  Bernhard
> 
> 
> /------
> | freelancer at Arsenal Research, Vienna, Austria http://arsenal.ac.at/ 
> | PhD at Vienna University of Technology, Austria 
> | http://www.phdcomics.com/comics/archive.php?comicid=180
> \------
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> gmsh mailing list
> gmsh at geuz.org
> http://www.geuz.org/mailman/listinfo/gmsh


-- 
Prof. Christophe Geuzaine
University of Liege, Electrical Engineering and Computer Science
http://www.montefiore.ulg.ac.be/~geuzaine