[PATCH v8 xserver 6/7] xf86Cursor: Deal with rotation on GPU screens using a hw-cursor

[Michel Dänzer]

On 09/09/16 09:50 PM, Hans De Goede wrote:
> When a slave-output is rotated the transformation is done on the blit
> from master to slave GPU, so crtc->transform_in_use is not set, but we
> still need to adjust the mouse position for things to work.
> 
> This commit modifies xf86_crtc_transform_cursor_position to not rely
> on crtc->f_framebuffer_to_crtc, so that it can be used with GPU screens
> to and always calls it for cursors on GPU screens.
> 
> Note not using crtc->f_framebuffer_to_crtc means that crtc->transform
> will not be taken into account, that is ok, because when we've a transform
> active hw-cursors are not used and xf86_crtc_transform_cursor_position
> will never get called.
> 
> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
> ---
> Changes in v8:
> -Fix reflection on rotated outputs (use xf86_crtc_rotate_coord_back again)
> -Only call xf86_crtc_transform_cursor_position when rotating or reflecting
>  (instead of always calling it for GPU screens)

[...]

> +    rotation = crtc->rotation & 0xf;
> +    if (rotation == RR_Rotate_90 || rotation == RR_Rotate_270) {
> +        width = crtc->mode.VDisplay;
> +        height = crtc->mode.HDisplay;
> +    } else {
> +        width = crtc->mode.HDisplay;
> +        height = crtc->mode.VDisplay;
> +    }

[...]

> +    xf86_crtc_rotate_coord_back(crtc->rotation, width, height, *x, *y, x, y);

Instead of this, how about something like:

    xf86_crtc_rotate_coord(RR_Reflect_X - (crtc->rotation & 0xf),
			   width, height, *x, *y, x, y);

Though frankly, either of those seem a little dirty, shoehorning
xf86_crtc_rotate_coord(_back) into doing something they're not intended
for. But between two evils, I'd choose the simpler one. :)

The cleaner alternative would be not using xf86_crtc_rotate_coord(_back)
but open-coding the correct logic, basically like in v7 but with the
reflection handling moved after the rotation handling. You can have

Reviewed-by: Michel Dänzer <michel.daenzer at amd.com>

for that or

Acked-by: Michel Dänzer <michel.daenzer at amd.com>

for either of the dirty options.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer