| Message ID | 1438078795-14360-3-git-send-email-thuth@redhat.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 07/28/2015 08:19 PM, Thomas Huth wrote: > Drawing the cursor in the frame buffer memory is a very, very > slow operation. So let's simply switch to a "underscore" cursor > instead of the full block cursor to save some precious cycles. > > Signed-off-by: Thomas Huth <thuth@redhat.com> > --- > slof/fs/fbuffer.fs | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/slof/fs/fbuffer.fs b/slof/fs/fbuffer.fs > index 0128c07..542c431 100644 > --- a/slof/fs/fbuffer.fs > +++ b/slof/fs/fbuffer.fs > @@ -98,7 +98,8 @@ CREATE bitmap-buffer 400 4 * allot > > : fb8-toggle-cursor ( -- ) > line# fb8-line2addr column# fb8-columns2bytes + > - char-height 0 ?DO > + char-height 3 - screen-width screen-depth * * + > + 3 0 ?DO Why not just: - char-height 0 ?DO + 1 0 ?DO ? What is this magic with screen-width about? > dup char-width screen-depth * invert-region > screen-width screen-depth * + > LOOP drop >
On Wed, Jul 29, 2015 at 01:05:48PM +1000, Alexey Kardashevskiy wrote: > > : fb8-toggle-cursor ( -- ) > > line# fb8-line2addr column# fb8-columns2bytes + > >- char-height 0 ?DO > >+ char-height 3 - screen-width screen-depth * * + > >+ 3 0 ?DO > > Why not just: > > - char-height 0 ?DO > + 1 0 ?DO > > ? What is this magic with screen-width about? Thomas' patch draws the cursor as the bottom three lines of a character cell; your suggestion would draw it as the top one line. But indeed it could be char-height dup 3 - ?DO ... Segher
On 29/07/15 05:42, Segher Boessenkool wrote: > On Wed, Jul 29, 2015 at 01:05:48PM +1000, Alexey Kardashevskiy wrote: >>> : fb8-toggle-cursor ( -- ) >>> line# fb8-line2addr column# fb8-columns2bytes + >>> - char-height 0 ?DO >>> + char-height 3 - screen-width screen-depth * * + >>> + 3 0 ?DO >> >> Why not just: >> >> - char-height 0 ?DO >> + 1 0 ?DO >> >> ? What is this magic with screen-width about? > > Thomas' patch draws the cursor as the bottom three lines of a > character cell; your suggestion would draw it as the top one line. Right. > But indeed it could be > > char-height dup 3 - ?DO ... Since the loop body expects the framebuffer address on the stack, the loop boundaries are just used to count the iterations ... so "3 0" sounds like the easiest and most readable way to specify this IMHO. Thomas
diff --git a/slof/fs/fbuffer.fs b/slof/fs/fbuffer.fs index 0128c07..542c431 100644 --- a/slof/fs/fbuffer.fs +++ b/slof/fs/fbuffer.fs @@ -98,7 +98,8 @@ CREATE bitmap-buffer 400 4 * allot : fb8-toggle-cursor ( -- ) line# fb8-line2addr column# fb8-columns2bytes + - char-height 0 ?DO + char-height 3 - screen-width screen-depth * * + + 3 0 ?DO dup char-width screen-depth * invert-region screen-width screen-depth * + LOOP drop
Drawing the cursor in the frame buffer memory is a very, very slow operation. So let's simply switch to a "underscore" cursor instead of the full block cursor to save some precious cycles. Signed-off-by: Thomas Huth <thuth@redhat.com> --- slof/fs/fbuffer.fs | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)