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

[Paolo Bonzini <pbonzini@redhat.com>]

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
>
>