Hello Eddy!

Saturday September 21 1996 13:50, Eddy Thilleman wrote to All:

 ET> How does one query the current video mode in a OS/2 full screen
 ET> session and how does one set it at a specific video mode? I can't find
 ET> information on this. I want to set the OS/2 full screen video text
 ET> mode to 100 columns and 40 rows (which my ET4000 supports).

Ough! That is _TRUE_ FAQ, I guess :-)

-------------------------------8<------------------------------------
- OS2PROG (2:5020/620) ----------------------------------- OS2PROG -----
 Msg  : 265 of 528 From : Peter Fitzsimmons           1:259/414       Sat
15 Jul 95 20:25 To   : Paul Rider                                  Tue 18
Jul 95 02:02 Subj : Vio Screen Modes.
------------------------------------------------------------------------

 PR>         Is there a snippit or something with a very
 PR> small example of switching screen resolutions. I need
 PR> something to detect the current screen resolution,
 PR> then switch to 43/50 line mode (other resolutions
 PR> would also be nice, like 28, ... but *only* 80
 PR> columns). If this is WAY too easy to bother with than
 PR> don't. I am asking this question to save myself time.

Tip:  if you are writing a text mode app,  by default always be prepared to use
the video mode the user has set up.  Setting the mode under os/2 can be much
more than just setting the number of rows&cols;  the density of the font can
change too -- and a call to VioSetMode (even to set the same number of rows &
cols) can screw this up (especially if you are using bvhsvga.dll).

If you are using bvhsvga (look for this word in config.sys),  typing "mode
80,34" (my fav mode) will pick a crappy font,  whereas this little program will
select the  correct font (and the one that bvhVHA uses):

 // usage: "mode2 34"   (or 30, others).
 #define INCL_VIO
 #define INCL_NOPMAPI
 #include 
 #include 
 #include 
 #include 


 void main(int argc, char **argv)
 {
     VIOMODEINFO vi, om;
     USHORT rc;
     VioSetCurPos(0, 0, 0);

     memset(&vi, 0, sizeof(vi));
     vi.cb     = 12;
     vi.fbType = 1;
     vi.color  = 4;
     vi.col    = 80;
     vi.row    = atoi(argv[1]);
     vi.hres   = 720;
     vi.vres   = 480;
     rc = VioSetMode(&vi, 0);
     if(!rc)
         VioScrollUp(0, 0, -1, -1, -1, " \x7", 0);
     printf("mode2 rc = %d\n", rc);
 }

Moral of the story:  don't call VioSetMode unless you absolutely have to; call
VetGetMode() instead,  and use the size it returns.

Here is a program that will write a file named "out" with the
modes that your
adapter supports:

 #define INCL_VIO
 #define INCL_NOPM
 #include 
 #include 
 #include 
 #include 


 void main(void)
 {
     VIOMODEINFO vi, om;
     int r, c;
     USHORT rc;
     FILE *of = fopen("out", "wt");
     if(!of){
         perror("out");
         exit(3);
     }
     om.cb     = sizeof(om);
     VioGetMode(&om, 0);
     VioScrollUp(0, 0, -1, -1, -1, " \x1b", 0);
     VioSetCurPos(5, 0, 0);

     memset(&vi, 0, sizeof(vi));
     vi.cb     = 8;
     VioGetMode(&vi, 0);

     for(c=1; c<201; c++){
         for(r=1; r<66; r++){
             printf("\t\t\t\t\t%3d, %3d\r", c, r);
             vi.cb     = 8; /*sizeof(vb);*/
 /*          vi.fbType = VGMT_OTHER;
             vi.color  = COLORS_16;*/
             vi.col    = c;
             vi.row    = r;
             vi.hres   = 720;        // only seen if vi.cb == 12!!!
             vi.vres   = 480;
             rc = VioSetMode(&vi, 0);
             if(!rc){
                 vi.cb = sizeof(vi);
                 VioGetMode(&vi, 0);
                 fprintf(of, "%3d, %3d (%d x %d)\n", vi.col,
vi.row, vi.hres,
vi.vres);
             }
         }
     }
     VioSetMode(&om, 0);
     printf("om.cb              = %d\n", om.cb             );
     printf("om.fbType          = %d\n", om.fbType         );
     printf("om.color           = %d\n", om.color          );
     printf("om.col             = %d\n", om.col            );
     printf("om.row             = %d\n", om.row            );
     printf("om.hres            = %d\n", om.hres           );
     printf("om.vres            = %d\n", om.vres           );
     printf("om.fmt_ID          = %d\n", om.fmt_ID         );
     printf("om.attrib          = %d\n", om.attrib         );
     printf("om.buf_addr        = %Fp\n", om.buf_addr       );
     printf("om.buf_length      = %ld\n", om.buf_length     );
     printf("om.full_length     = %ld\n", om.full_length    );
     printf("om.partial_length  = %ld\n", om.partial_length );
     printf("om.ext_data_addr   = %Fp\n", om.ext_data_addr  );
 }

nb: the sample programs above were written for a 16bit compiler,  but I can't
see anything that would give you a problem for Watcom or Cset++.


--- Maximus/2 2.02p1