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vga_imageblt(3) 	       Svgalib User Manual		 vga_imageblt(3)

NAME
     vga_imageblt - copy a rectangular pixmap from system memory to video memory

SYNOPSIS
     #include <vga.h>

     void vga_imageblt(void *srcaddr, int destaddr, int w, int h, int pitch);

DESCRIPTION
     Write a rectangular pixmap from system memory to video memory.  destaddr is
     an  offset  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!

     It  fills the given box with the data in memory area *srcaddr.  The  memory
     buffer  must   contain the pixels in the same representation as used in the
     vga memory, starting at the top left corner, from left to right, and  then,
     line  by  line,  from  up	 to   down,   without  any  gaps  and  interline
     spaces.

     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)  in-
     stead.

     The  old  vga_bitblt(3),  vga_blitwait(3),  vga_fillblt(3),  vga_hlinelist-
     blt(3), and vga_imageblt(3) interface was originally designed for the  Cir-
     rus  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 inter-
     face.

     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_bitblt(3),   vga_blitwait(3),	 vga_fillblt(3),    vga_hlinelistblt(3),
     vga_getmodeinfo(3), vga_lockvc(3), vga_unlockvc(3)

AUTHOR
     This  manual  page  was  edited  by Michael Weller <eowmob@exp-math.uni-es-
     sen.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 orig-
     inal author and will happily accept any additions or  corrections	to  this
     first version of the svgalib manual.

Svgalib (>= 1.2.11)		  27 July 1997			 vga_imageblt(3)

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