Mail Archives: djgpp/1997/11/28/23:02:52
> Sorry to ask such an obvious question, but I've new to C/DJGPP and just
> starting graphics work. But, Anyway does anyone know how to :
> 1 .Switch from text to graphics mode using DJGPP
> 2. Change a single pixel from "OFF" to "ON"
> Thanks in advance
To switch from text to graphics mode. I'm assuming you're meaning VGA
320x200x256
__dpmi_regs r;
r.ax = 0x0013;
__dpmi_int ( 0x10, &r );
// if you get an error, you are either missing a header file, or there is
one too many, or too little _ , you can
// look it up in LIBC.INF out of C:/DJGPP/INFO directory to make sure.
To place a single pixel ( in that same mode)
int x, y, c;
x = 3; // x
y = 5; // y
c = 15; // color value
_farpokeb ( _dos_ds, 0xA0000 + x + (y*320), c );
That requires an odd header file, it might be <sys\farptr.h>, but you
should look it up in LIBC.INF as well. That's the second fastest way I
know how to. (The fastest way I know how, requires disabling protected
memory, and is more complicated to get started)
Hope that helps! But I recommend you do try getting the Allegro library.
It has many of the functions and more, and is pretty fast for a library.
Here's the address to Allegro home page
http://www.talula.demon.co.uk/allegro/
-Steve
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