Re: [Qemu-devel] [PATCH 20/42] input: mouse: add graphic_rotate support

[Paolo Bonzini]

Il 03/02/2014 10:42, Gerd Hoffmann ha scritto:
>   Hi,
>
> > > +    switch (graphic_rotate) {
> > > +    case 90:
> > > +        if (evt->abs->axis == INPUT_AXIS_X) {
> > > +            evt->abs->axis = INPUT_AXIS_Y;
> > > +        }
> > > +        if (evt->abs->axis == INPUT_AXIS_Y) {
> >
> > Need else here, same for "case 270".
>
> Why?

Because otherwise both axes become X.  When the first if triggers the 
axis changes to Y, and then it becomes X again. :)

> > > +            evt->abs->axis = INPUT_AXIS_X;
> > > +            evt->abs->axis = INPUT_EVENT_ABS_SIZE - 1 - evt->abs->axis;
> >
> > ->value here, not ->axis.
>
> Oops, indeed.
>
> > It looks like doing it right for relative is easy:
>
> But what is the point when this isn't used anyway?

In what sense it is not used?  Because you do not have e.g. a USB 
controller in the only machines that support graphic_rotate?

Paolo

> >      if (graphic_rotate == 0) {
> >          return;
> >      }
> >      if (move->axis != INPUT_AXIS_X && move->axis != INPUT_AXIS_Y) {
> >          return;
> >      }
> >      if ((graphic_rotate <= 180 && move->axis == INPUT_AXIS_X) ||
> >          (graphic_rotate >= 180 && move->axis == INPUT_AXIS_Y)) {
> >           if (kind == INPUT_EVENT_KIND_ABS) {
> >               move->value = INPUT_EVENT_ABS_SIZE - 1 - move->value;
> >           } else {
> >               move->value = -move->value;
> >           }
> >      }
> >      if (graphic_rotate == 90 || graphic_rotate == 270) {
> >          move->axis ^= INPUT_AXIS_X ^ INPUT_AXIS_Y;
> >      }
>
> Saves a few lines but it's a bit harder to figure what is going on ...
>
> cheers,
>   Gerd