diff options
| author | Siarhei Siamashka <siarhei.siamashka@nokia.com> | 2011-05-22 22:51:00 +0300 |
|---|---|---|
| committer | Søren Sandmann Pedersen <ssp@redhat.com> | 2011-09-21 18:55:25 -0400 |
| commit | 9126f36b964c71b83c69235df4c3a46ab81ab5d5 (patch) | |
| tree | 48905913c4d7e90e2974d58abe447c798a9fe3b5 | |
| parent | ad5c6bbb36c1c5e72313f7c7bc7c6e6b7e79daba (diff) | |
BILINEAR->NEAREST filter optimization for simple rotation and translation
Simple rotation and translation are the additional cases when BILINEAR
filter can be safely reduced to NEAREST.
| -rw-r--r-- | pixman/pixman-image.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/pixman/pixman-image.c b/pixman/pixman-image.c index 88262f7..a3bb9b6 100644 --- a/pixman/pixman-image.c +++ b/pixman/pixman-image.c @@ -251,9 +251,46 @@ compute_image_info (pixman_image_t *image) case PIXMAN_FILTER_BEST: flags |= (FAST_PATH_BILINEAR_FILTER | FAST_PATH_NO_CONVOLUTION_FILTER); - /* Reduce BILINEAR to NEAREST for identity transforms */ + /* Here we have a chance to optimize BILINEAR filter to NEAREST if + * they are equivalent for the currently used transformation matrix. + */ if (flags & FAST_PATH_ID_TRANSFORM) + { flags |= FAST_PATH_NEAREST_FILTER; + } + else if ( + /* affine and integer translation components in matrix ... */ + ((flags & FAST_PATH_AFFINE_TRANSFORM) && + !pixman_fixed_frac (image->common.transform->matrix[0][2] | + image->common.transform->matrix[1][2])) && + ( + /* ... combined with a simple rotation */ + (flags & (FAST_PATH_ROTATE_90_TRANSFORM | + FAST_PATH_ROTATE_180_TRANSFORM | + FAST_PATH_ROTATE_270_TRANSFORM)) || + /* ... or combined with a simple non-rotated translation */ + (image->common.transform->matrix[0][0] == pixman_fixed_1 && + image->common.transform->matrix[1][1] == pixman_fixed_1 && + image->common.transform->matrix[0][1] == 0 && + image->common.transform->matrix[1][0] == 0) + ) + ) + { + /* FIXME: there are some affine-test failures, showing that + * handling of BILINEAR and NEAREST filter is not quite + * equivalent when getting close to 32K for the translation + * components of the matrix. That's likely some bug, but for + * now just skip BILINEAR->NEAREST optimization in this case. + */ + pixman_fixed_t magic_limit = pixman_int_to_fixed (30000); + if (image->common.transform->matrix[0][2] <= magic_limit && + image->common.transform->matrix[1][2] <= magic_limit && + image->common.transform->matrix[0][2] >= -magic_limit && + image->common.transform->matrix[1][2] >= -magic_limit) + { + flags |= FAST_PATH_NEAREST_FILTER; + } + } break; case PIXMAN_FILTER_CONVOLUTION: |