Provided by: libsvga1-dev_1.4.3-29_i386
vga_bitblt - copy pixmap on screen using an accelerator
void vga_bitblt(int srcaddr, int destaddr, int w, int h, int pitch);
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)
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.
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)
This manual page was edited by Michael Weller <email@example.com-
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
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.