nanogui: nanox double buffering
Subject:
nanox double buffering
From:
Junior ####@####.####
Date:
6 Jun 2007 17:22:55 +0100
Message-Id: <62AFB10DF1A.000002F6ejr@inbox.com>
Hi all,
I'm a bit baffled by a problem I have with double buffering.
I borrowed some code from Jordan's patch for double buffering and
those who use it before may have some ideas. I'll appreciate it.
fliping the buffer essentially does what the code below shows.
To me it looks like when the buffer is flipped, the order is
"flip then draw" instead of "draw then flip". I say this because the screen
shows what looks like a background drawing flicker.
I don't see how this could happen but surely I'm missing something.
Does anyone know where this occurs and how to change it?
void
GdPanScreen(PSD psd, int xoffset, int yoffset) {
if (!psd->PanScreen) return;
if ((psd->xvisible != psd->xvirtres)) {
/* Bound it */
if (xoffset < 0) xoffset = 0;
if (xoffset + psd->xvisible > psd->xvirtres)
xoffset = psd->xvirtres - psd->xvisible;
}
else
xoffset = 0;
if ((psd->yvisible != psd->yvirtres)) {
/* Bound it */
if (yoffset < 0) yoffset = 0;
if (yoffset + psd->yvisible > psd->yvirtres)
yoffset = psd->yvirtres - psd->yvisible;
}
else
yoffset = 0;
if (xoffset != psd->xoffset || yoffset != psd->yoffset) {
psd->yoffset = yoffset;
psd->xoffset = xoffset;
fb_var.xoffset = xoffset;
fb_var.yoffset = yoffset;
ioctl(fb, FBIOPAN_DISPLAY, &fb_var);
}
Thank you.
