On 08/21/2012 03:56 PM, Lee Fallat wrote:
Alright, well I've decided to take another approach. I'm XGetImage()ing
the root window, then I darken my pixels, then, I go to store the data
in a Drawable via XPutImage, but this Drawable isn't retaining the data,
it's just white when I XCopyArea() over to what I want shown. Any
suggestions/reasons why this is happening?
Code sample:
static XImage *xi;
void XTintBG(Monitor *m, int x, int y, int w, int h) {
unsigned long new_color;
unsigned long r,g,b;
XCopyArea(dpy, root, m->barwin, dc.gc, x, y, w, h, x, y);
xi = XGetImage(dpy, m->barwin, x, y, w, h, AllPlanes, XYPixmap);
You almost certainly want ZPixmap rather than XYPixmap. ZPixmap is your
normal n-bits-per-pixel, pixels in scanline order image format.
XYPixmap is the oh-god-kill-me-now image format.
The rest of the code seems reasonable, so try fixing that first.
If you need better performance and are willing to make your code even
more complicated, you could bind the drawable in question using
GLX_EXT_texture_from_pixmap, either as a pixmap directly, or by using
the Composite extension to redirect the window you want and using its
backing pixmap. Then you can do much more complicated rendering using
it as an OpenGL texture. This unfortunately does not work on the root
window but you could copy the root window's contents into a pixmap and
then use that.
Adam's suggestion of using Render would be simpler if you can find a
blending op that does what you want.
-- Aaron
for(int pix_y = 0; pix_y < h; pix_y++) {
for(int pix_x = 0; pix_x < w; pix_x++) {
new_color = XGetPixel(xi, pix_x, pix_y);
r = g = b = 0x00000000;
r = (new_color & 0x00FF0000) >> 16;
g = (new_color & 0x0000FF00) >> 8;
b = (new_color & 0x000000FF) >> 0;
r -= 32;
g -= 32;
b -= 32;
if(r > 255) r = 255;
if(r < 0) r = 0;
if(g > 255) g = 255;
if(g < 0) g = 0;
if(b > 255) b = 255;
if(b < 0) b = 0;
new_color = r << 16;
new_color = new_color | (g << 8);
new_color = new_color | (b << 0);
XPutPixel(xi, pix_x, pix_y, new_color);
}
}
XPutImage(dpy, m->barwin, dc.gc, xi, 0, 0, 0, 0, m->ww, bh);
XCopyArea(dpy, m->barwin, dc.bg <http://dc.bg>, dc.gc, 0, 0, m->ww,
bh, 0, 0);
}
int ftime = 1;
void
drawbar(Monitor *m) {
int x;
unsigned int i, occ = 0, urg = 0;
XftColor *col;
Client *c;
if(ftime == 1) {
ftime = 0;
XTintBG(m, 0, 0, m->ww, bh);
}
XCopyArea(dpy, dc.bg <http://dc.bg>, dc.drawable, dc.gc, 0, 0, m->ww,
bh, 0, 0);
<More functions here but not relative to what I need>
}
On Mon, Aug 20, 2012 at 3:17 PM, Adam Jackson <a...@redhat.com
<mailto:a...@redhat.com>> wrote:
On 8/20/12 2:08 PM, Lee Fallat wrote:
Hey,
I'm trying to darken/lighten the image data in a
Drawable/XdbeBackBuffer.
Any ideas on how to get access to the data?...I've done an
XGetImage() on
Drawable but that really slows down the application I'm editing...
That is, in fact, how you do it. GetImage is not fast. ShmGetImage
is faster, and as fast as you're going to get, if you insist on
doing this by pulling all the pixels down to the client and then
pushing them back up.
You may instead wish to use the Render extension, which gives you
the usual set of Porter-Duff blend operations, and which runs in the
server so you're not copying all that data around.
- ajax
_______________________________________________
xorg@lists.x.org: X.Org support
Archives: http://lists.freedesktop.org/archives/xorg
Info: http://lists.x.org/mailman/listinfo/xorg
Your subscription address: arch...@mail-archive.com
