From: Siarhei Siamashka <siarhei.siamas...@nokia.com> Without this fix, setting PAD repeat on a source image prevents the use of any nonscaled standard fast paths, affecting performance a lot. But as long as no pixels outside the source image boundaries are touched by the compositing operation, all the repeat types behave the same and can take the same fast paths.
This is important because setting PAD repeat instead of NONE is more hardware acceleration friendly (for the drivers implementing RENDER extension) and does not inhibit OVER->SRC operator optimization in pixman. --- We discussed this problem and the related code with Soeren on IRC the other day, and it may be that the code dealing with FAST_PATH_COVERS_CLIP and FAST_PATH_SAMPLES_COVER_CLIP would better to be changed a bit. Along with the selection of fast path functions dealing with SOLID sources or masks (for example, any transformation set on a SOLID source image does not actually make any difference for end result, so it can be ignored). And there is a special optimization for NORMAL repeat in walk_region_internal() function which is also somehow related. Well, I guess this all stuff carried us away from the original problem :) But now returning back to this issue. Ideally, PAD repeat would be a better default instead of NONE. Just because NONE repeat is a bit strange and hard to accelerate in hardware. This is one example from freedesktop.org bugzilla (and there are more similar reports): https://bugs.freedesktop.org/show_bug.cgi?id=27954 But right now setting PAD repeat for everying will cause serious performance problems for pixman, because it will stop using simple non-transformed fast paths. This patch tries to address the problem. It passes current pixman tests and I think that it is most likely fine. But I'm still not totally sure if it is really safe in all possible cases. pixman/pixman-image.c | 6 ++---- pixman/pixman-private.h | 2 -- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c index 8397f6a..14a2219 100644 --- a/pixman/pixman-image.c +++ b/pixman/pixman-image.c @@ -363,16 +363,14 @@ compute_image_info (pixman_image_t *image) flags |= FAST_PATH_NO_PAD_REPEAT | FAST_PATH_NO_NONE_REPEAT | - FAST_PATH_NO_NORMAL_REPEAT | - FAST_PATH_COVERS_CLIP; + FAST_PATH_NO_NORMAL_REPEAT; break; case PIXMAN_REPEAT_PAD: flags |= FAST_PATH_NO_REFLECT_REPEAT | FAST_PATH_NO_NONE_REPEAT | - FAST_PATH_NO_NORMAL_REPEAT | - FAST_PATH_COVERS_CLIP; + FAST_PATH_NO_NORMAL_REPEAT; break; default: diff --git a/pixman/pixman-private.h b/pixman/pixman-private.h index d85868f..80b1ed3 100644 --- a/pixman/pixman-private.h +++ b/pixman/pixman-private.h @@ -597,8 +597,6 @@ _pixman_choose_implementation (void); (FAST_PATH_ID_TRANSFORM | \ FAST_PATH_NO_ALPHA_MAP | \ FAST_PATH_NO_CONVOLUTION_FILTER | \ - FAST_PATH_NO_PAD_REPEAT | \ - FAST_PATH_NO_REFLECT_REPEAT | \ FAST_PATH_NO_ACCESSORS | \ FAST_PATH_NARROW_FORMAT | \ FAST_PATH_COVERS_CLIP) -- 1.7.2.2 _______________________________________________ Pixman mailing list Pixman@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/pixman
