NAME

       vga_bitblt - copy pixmap on screen using an accelerator

SYNOPSIS

       #include <vga.h>

       void vga_bitblt(int srcaddr, int destaddr, int w, int h, int pitch);

DESCRIPTION

       Bitblit  (copy  rectangular area in video memory), addresses are offsets into video memory
       (up to 2M). The pitch is the logical width of the screen. Height h is in Pixels,  Width  w
       is in BYTES!

       This is an old style function to access the accelerator of an SVGA card. Before calling it
       you  should  check  for  availability  of  the  function  in  the  mode   you   use   with
       vga_getmodeinfo(3).

       For new applications you might be better of trying to use vga_accel(3) instead.

       The   old   vga_bitblt(3),   vga_blitwait(3),   vga_fillblt(3),  vga_hlinelistblt(3),  and
       vga_imageblt(3) interface was originally designed for the  Cirrus  chipsets.  Then  Mach32
       added  support  too  but  has  problems to resemble the unintuitive Cirrus interface. Then
       these new ideas were reinjected and vga_accel(3) was designed.  Now  Cirrus  and  Chips  &
       Technologies  chipset  give  limited  vga_accel(3)  support  but  no longer this old style
       support.  Mach32 is left to use the unintuitive Cirrus interface. At some future point the
       functions  might  be  added  for  Mach32  too  (which  should  be  rather  simple), so new
       applications should use the newer and probably more efficient interface.

       It would be fatal if the accelerator would be used while the  console  is  switched  away.
       You   should   use   vga_lockvc(3)  and  vga_unlockvc(3)  to  avoid  this,  although  good
       implementations of the accelerator functions (like Mach32) will already ensure that.

       The testaccel(6) demo utilizes the old style accelerator functions.

SEE ALSO

       svgalib(7),  vgagl(7),  libvga.config(5),  testaccel(6),  vga_accel(3),   vga_blitwait(3),
       vga_fillblt(3),  vga_hlinelistblt(3),  vga_imageblt(3), vga_getmodeinfo(3), vga_lockvc(3),
       vga_unlockvc(3)

AUTHOR

       This manual page was edited by Michael Weller  <eowmob@exp-math.uni-essen.de>.  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
       <H.Hanemaayer@inter.nl.net>.

       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.