vga_setreadpage(3) [mojave man page]

vga_setreadpage(3)						Svgalib User Manual						vga_setreadpage(3)

NAME

       vga_setreadpage - set the 64K SVGA page number

SYNOPSIS

       #include <vga.h>

       void vga_setreadpage(int page);

DESCRIPTION

       Usually	SVGA  cards  have  more than the 64K memory which suffice for an ordinary VGA.	However, the memory window mapped at vga_getgraph-
       mem(3) is only 64K bytes large.	vga_setreadpage() selects the page-th 64K memory chunk to be visible for reads at  position  vga_getgraph-
       mem(3).

       vga_setwritepage(3)  allows  a different 64K memory chunk to be modified by writes to this memory window. This is a very useful feature for
       screen to screen pixmap copies. However, not all cards support this in all graphics mode. Check vga_modeinfo(3) for availability.  Esp.	as
       this feature can also not be used when in background mode.

       Of course, this function must be used in conjunction with vga_setwritepage(3) but may not be used in conjunction with vga_setpage(3).

SEE ALSO

       svgalib(7),  vgagl(7),  libvga.config(5), fun(6), vgatest(6), vga_claimvideomemory(3), vga_getgraphmem(3), vga_modeinfo(3), vga_setpage(3),
       vga_setwritepage(3), vga_setlinearaddressing(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.

Svgalib (>;= 1.2.11)						   27 July 1997 						vga_setreadpage(3)

vga_setlinearaddressing(3)					Svgalib User Manual					vga_setlinearaddressing(3)

NAME

       vga_setlinearaddressing - switch to linear addressing mode

SYNOPSIS

       #include <vga.h>

       int vga_setlinearaddressing(void);

DESCRIPTION

       Switch  to  linear  addressing  mode. This maps all (or most) of the SVGA memory at the position returned by vga_getgraphmem(3) (which will
       probably change by the call to vga_setlinearaddressing()).  The vga_set*page(3) calls are no longer required. This ensures optimal  perfor-
       mance, however the drawing functions of svgalib do not support this memory layout and not all cards support it (and not in all modes).

       Use vga_modeinfo(3) to check for availability of the function in a given mode.

       Furthermore,  some cards (Cirrus) just enable this buffer at a fixed hardware address.  For Cirrus it is mapped at 14MB so you should never
       used it if you have more than 14MB of memory (But how does an application know?).  The Mach32 support for this is smarter.  It  makes  this
       feature only available when it is safe to be used.

       To avoid all this problems you can use

       nolinear
	      Inhibit use of a linear mmaped frame buffer.

       linear Allow (not enforce!) use of a linear mmaped frame buffer.

       in the /etc/vga/libvga.config file to disable the linear frame buffer if it cannot be used.

       Returns the size of the mapped framebuffer if successful (can be less than total video memory), -1 if not.

       The testlinear(6) demo shows the use of this feature (and if it works for you).

SEE ALSO

       svgalib(7),   vgagl(7),	 libvga.config(5),   testlinear(6),   vga_modeinfo(3),	 vga_getgraphmem(3),  vga_setpage(3),  vga_setreadpage(3),
       vga_setwritepage(3), vga_setlinearaddressing(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.

Svgalib (>;= 1.2.11)						   27 July 1997 					vga_setlinearaddressing(3)