[SLOF PATCH 2/2] fbuffer: Use a smaller cursor

[Alexey Kardashevskiy]

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 at 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
>


-- 
Alexey