Adam Jackson <a...@redhat.com> writes: > On Fri, 2016-09-30 at 22:44 -0700, Keith Packard wrote: > >> + /* copy mode for the first plane to clear all of the other bits */ >> + gcv[0].val = GXcopy; >> + gcv[1].val = gc->fgPixel; >> + gcv[2].val = gc->bgPixel; >> + ChangeGC(NullClient, temp_gc, GCFunction|GCForeground|GCBackground, >> gcv); > > You don't need to set GCFunction here, the scratch gc already has > GXcopy set. > > You _do_ need to copy GCPlanemask from the source gc, because for > XYPixmap PutImage that determines how many planes of data were given; > if you let it stay as FB_ALLONES when it should only be, say, 0x3, > you'll read in 30 planes of garbage.
That's true for GetImage, but the protocol doc is rather unclear about
PutImage. The only mention of 'plane-mask' in the PutImage spec is as a
relevant component in the GC. Xlib doesn't look at the plane mask; the
request length is computed with:
bytes_per_dest = (unsigned long)ROUNDUP((long)req->width + req->leftPad,
dpy->bitmap_pad) >> 3;
bytes_per_dest_plane = bytes_per_dest * req->height;
length = bytes_per_dest_plane * image->depth;
req->length += (length + 3) >> 2;
Looks like fb has a bug.
--
-keith
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