[Mesa-dev] [PATCH] swrast: Fix the coordinates passed to _mesa_regions_overlap()

[Anuj Phogat]

On Mon, Nov 23, 2015 at 8:29 PM, Matt Turner <mattst88 at gmail.com> wrote:
> On Mon, Nov 23, 2015 at 5:35 PM, Anuj Phogat <anuj.phogat at gmail.com> wrote:
>> Cc: "11.1" <mesa-stable at lists.freedesktop.org>
>> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
>> ---
>>  src/mesa/swrast/s_copypix.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/swrast/s_copypix.c b/src/mesa/swrast/s_copypix.c
>> index 0dbccc0..31e1d3d 100644
>> --- a/src/mesa/swrast/s_copypix.c
>> +++ b/src/mesa/swrast/s_copypix.c
>> @@ -53,8 +53,10 @@ regions_overlap(GLint srcx, GLint srcy,
>>                  GLfloat zoomX, GLfloat zoomY)
>>  {
>>     if (zoomX == 1.0F && zoomY == 1.0F) {
>> -      return _mesa_regions_overlap(srcx, srcy, srcx + width, srcy + height,
>> -                                   dstx, dsty, dstx + width, dsty + height);
>> +      return _mesa_regions_overlap(srcx, srcy,
>> +                                   srcx + width - 1, srcy + height - 1,
>> +                                   dstx, dsty,
>> +                                   dstx + width - 1, dsty + height - 1);
>>     }
>
> What problem is this fixing? Reading the implementation of
> _mesa_regions_overlap(), it seems that the arguments are inclusive, so
> subtracting 1 shouldn't be necessary (or correct).
>
I realized the mistake. Dropping this patch. The problem is in
the implementation of _mesa_regions_overlap() which returns true
for the rectangles with shared edges. It makes the driver fall back to
slower paths.

> The other two call sites (src/mesa/drivers/dri/i965/intel_blit.c and
> src/mesa/state_tracker/st_cb_drawpixels.c) also don't seem to subtract
> 1.