[Pixman] [PATCH 3/4] Speed up pixman_region{, 32}_contains_rectangle()

[Soeren Sandmann]

Andrea Canciani <ranma42 at gmail.com> writes:

>> @@ -2137,12 +2170,13 @@ PIXMAN_EXPORT PREFIX (_contains_rectangle) (region_type_t *  region,
>>     x = prect->x1;
>>     y = prect->y1;
>>
>> +    pbox = PIXREGION_BOXPTR (region);
>> +    pbox_end = pbox + numRects;
>> +
>> +    pbox = find_box_for_y (pbox, pbox_end, y);
>>     /* can stop when both part_out and part_in are TRUE, or we reach prect->y2 */
>> -    for (pbox = PIXREGION_BOXPTR (region), pbox_end = pbox + numRects;
>> -         pbox != pbox_end;
>> -         pbox++)
>> +    for (; pbox != pbox_end; pbox++)
>>     {
>> -
>>         if (pbox->y2 <= y)
>>            continue;   /* getting up to speed or skipping remainder of band */
>
> If this test is not needed anymore, I think it should be deleted,
> otherwise the documentation of find_box_for_y should be modified.
>
> The same objection applies to patch 4/4.

*Some* kind of test is needed because y is not constant. However, we may
as well use the binary search here too, for some additional speed-up
when skipping the remainder of bands with many boxes.

I'll send an updated series that takes care of your other comments.


Thanks for the review,
Soren