[A89] Re: ellipses again

To: <assembly-89@lists.ticalc.org>
Subject: [A89] Re: ellipses again
From: "Scott Noveck" <noveck@pluto.njcc.com>
Date: Mon, 16 Jul 2001 19:37:49 -0400
References: <20010716221719.171091802C@mx-1.sollentuna.net>
Reply-To: assembly-89@lists.ticalc.org


> This should work:
> (looks a lot like Scotts, but he forgot that he needs to do the draw
before
> the x and y changes)

Thank you Olle!  I realized when you corrected me that XOR should be able to
work, but I couldn't figure out what I did wrong the other day -- stupid me
=)


FYI, I wrote some VS XOR'ing code here the other day, but it seems to have
been overlooked.  However, I think Brensenham should be an optimal solution,
so I suggest trying that first.

void xorScreens(void *VS)                    // I think this should work
{
    unsigned long *VSptr = (unsigned long *)VS;
    unsigned long *screenptr = (unsigned long *)LCD_MEM;
    int i;

    for (i=0; i < (240/8*128)/sizeof(unsigned long); ++i)
        *(VSptr++) ^= *(screenptr++);
}

    -Scott

Follow-Ups:

[A89] Re: ellipses again

From: jeff <jefromi42@yahoo.com>