Provided by: libsvga1-dev_1.4.3-31_i386 bug


       vga_getmodeinfo  -  returns pointer to mode information structure for a


       #include <vga.h>

       vga_modeinfo *vga_getmodeinfo(int mode );


       The function returns a pointer to a statical allocated mode information
       structure which is filled out with details for a video mode mode.

       #include <vga.h> defines vga_modeinfo as

       typedef struct {
            int width;
            int height;
            int bytesperpixel;
            int colors;
            int linewidth;
            int maxlogicalwidth;
            int startaddressrange;
            int maxpixels;
            int haveblit;
            int flags;
       /* Extended fields, not always available: */
            int chiptype;
            int memory;
            int linewidth_unit;
            char *linear_aperture;
            int aperture_size;
            void (*set_aperture_page) (int page);
            void *extensions;
       } vga_modeinfo;

       If the given mode is out of range, NULL is returned.  Beware, even when
       vga_getmodeinfo() returns details about a certain mode, you must  check
       if  it  is  currently  available  (may  depend on memory size and other
       details) with vga_hasmode (3).

       The fields meaning in detail:

   Basic mode details
       width  Width of mode in pixels.

       height Height of mode in pixel lines.

              Bytes per pixel. This is 1, 2, 3, or 4 (for 256, 32K & 64K, 16M,
              16M$ modes) and 0 for planar VGA modes.

              Logical  scanline  width  in  bytes.  This  is the memory offset
              between two pixels above  each  other  in  two  adjacent  screen
              lines.  It  is  not  valid  to  assume that linewidth == width *
              bytesperpixel in general!

       colors The number of colors which you can display simultaneously 2, 16,
              256,  32768, 65536, or 16777216.  Generally 16 and 256 mean that
              a color lookup table is used. 2 means that only  black/white  is
              used and the others use some high/true color mode.

   Possible modifications of the memory layout
              The  maximum logical scanline width (in bytes) which you can set
              for this mode with vga_setlogicalwidth(3) while still  expecting
              a perfect screen image.

              Mask  of  changeable bits of start address (in pixels). All bits
              zero in startaddressrange  must  also  be  zero  in  a  call  to
              vga_setdisplaystart(3)  when  you  want  to  avoid  noisy  video

   Memory size
              Maximum number of pixels that  will  fit  in  a  logical  screen
              (depends on video memory).

   Further, advanced capabilities
              Indicates whether the following bitblit functions are available.
              It is a logical or of the  following  predefined  values  (which
              each have only one bit set).

                     has vga_bitblt(3) old style accelerator function.

                     has vga_fillblt(3) old style accelerator function.

                     has vga_imageblt(3) old style accelerator function.

                     has vga_hlinelistblt(3) old style accelerator function.

                     has vga_blitwait(3) old style accelerator function.

       flags  Miscellaneous  flags.   It  is  a  logical  or  of the following
              predefined values (which each have only one bit set).

                     vga_setreadpage(3) and vga_setwritepage(3) are  available
                     in this mode.

                     Mode  is  interlaced, which means it will tend to flicker
                     and the user might be happier if the application  chooses
                     another mode.

                     Mode  user  mode  X like memory layout (planar 256 colors
                     VGA mode). See vga_setmodeX(3) for some explanations.

                     Dynamically  loaded  mode.  This  mode  was  defined   in
                     /etc/vga/libvga.conf by the user. He will probably prefer
                     its usage. However, usually this should be of no interest
                     to the user.

                     Mode    can    be   set   to   linear   addressing   with

                     Linear addressing is already enabled for this mode.

                     The extended fields in this information structure are set
                     to sensible information. If EXT_INFO_AVAILABLE is not set
                     you should even not access these fields as you might have
                     encountered  an  old  version  of  svgalib and the fields
                     migth actually not have been allocated at all.

                     For 16M4 modes it  means  that  the  4  bytes  per  pixel
                     actually  mean  0BGR rather than BGR0 as per default. For
                     16M mode it means that the  3  bytes  actually  mean  RGB
                     instead of BGR.

                     The  first  is a general limitation of Mach32, the latter
                     one of Mach32 with a ramdac of type 4. The  vga_  drawing
                     functions takes this into account.

                     A vga_ext_set(3) is available and can be called.

   Extended mode information
       You  must check for EXT_INFO_AVAILABLE in flags before trying to access
       these values.

              the chiptype that was detected/set. This specifies a subtype  of
              the current vga_getchipset(3) setting whose value depends on the
              chipset. It should be only used for debugging or internally.

       memory memory available on the SVGA card in KB.

              use only a multiple of this  value  for  set_logicalwidth(3)  or
              set_displaystart(3)  to  ensure graceful alignment of lines onto
              the vga memory in this mode and for noiseless video signals.

              ptr to a mmaped secondary linear framebuffer (not related to the
              use of vga_setlinearaddressing(3)) (NULL if unavailable)

              size of the secondary framebuffer in KB. 0 if unavailable.

              a  function  taking  an int as parameter to select a page in the
              framebuffer addressed by read/writes to  this  memory  arey  (if
              aperture_size < memory.

              pointer to additional, internal, chipset specific info (contents
              of the EEPROM for Mach32 driver.)

       The vgatest(6) demo displays most of this info for all supported modes.


       svgalib(7),  vgagl(7),  libvga.config(5),  vgatest(6),  vga_hasmode(3),
       vga_init(3),           vga_setmode(3),           vga_getcurrentmode(3),
       vga_getdefaultmode(3),    vga_lastmodenumber(3),    vga_getmodename(3),
       vga_getmodenumber(3),       vga_setlogicalwidth(3),      vga_bitblt(3),
       vga_fillblt(3), vga_imageblt(3), vga_hlinelistblt(3),  vga_blitwait(3),
       vga_setmodeX(3),           vga_getchipset(3),           vga_ext_set(3),


       This manual page was edited  by  Michael  Weller  <eowmob@exp-math.uni->.  The  exact  source of the referenced function as well as of
       the original documentation is unknown.

       It is very likely that both are at least to some extent are due to Harm
       Hanemaayer <>.

       Occasionally  this  might be wrong. I hereby asked to be excused by the
       original author and will happily accept any additions or corrections to
       this first version of the svgalib manual.