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author | Jonas Ådahl <jadahl@gmail.com> | 2015-09-10 16:12:51 +0800 |
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committer | Jonas Ådahl <jadahl@gmail.com> | 2015-09-11 10:36:52 +0800 |
commit | 5d83260b19c06f216cfdb21a57f256ebee1affef (patch) | |
tree | f71a7749f5e2da49751f95a50c911dac6d9b6ef3 /clutter | |
parent | 63813ad398a38d5d7f304c497a1c3f0fda92bdd7 (diff) | |
download | clutter-5d83260b19c06f216cfdb21a57f256ebee1affef.tar.gz |
actor: Fix transforming stage point when scale is less than 1
The commit 6cd24faaa54de3246ca45d1c7426d8b7a74f71db (actor: Clean up
transform_stage_point()) changed the validation of the transformation
matrix to ignore the fraction part of the determinant. This caused
clutter_actor_transform_stage_point() to fail and return FALSE for
actors which scale was less than 1.
Previously the validation was ('det' being a float):
det = (RQ[0][0] * ST[0][0])
+ (RQ[0][1] * ST[0][1])
+ (RQ[0][2] * ST[0][2]);
if (!det)
return FALSE;
Semantically, the if statement expression '!det' is equivalent to
'det == 0', i.e. 'det == 0.0f'. Post cleanup patches, 'det' was turned
into a double, and the if statement was changed to:
if (CLUTTER_NEARBYINT (det) == 0)
return FALSE;
which, different from before, rounds the determinant to the nearest
integer value, meaning determinant in the range (-0.5, 0.5) would be
considered invalid.
This patch reverts this part to the old behavior, while, because of the
inexact nature of floating point arithmetics, allowing a bit more liberal
meaning of "equals to 0" than '== 0.0'.
https://bugzilla.gnome.org/show_bug.cgi?id=754766
Diffstat (limited to 'clutter')
-rw-r--r-- | clutter/clutter-actor.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/clutter/clutter-actor.c b/clutter/clutter-actor.c index 1cbbd5c5f..ad106c452 100644 --- a/clutter/clutter-actor.c +++ b/clutter/clutter-actor.c @@ -15190,8 +15190,8 @@ clutter_actor_transform_stage_point (ClutterActor *self, dy2 = v[2].y - v[3].y; det = DET (dx1, dx2, dy1, dy2); - if (CLUTTER_NEARBYINT (det) == 0) - return FALSE; + if (fabs (det) <= DBL_EPSILON) + return FALSE; RQ[0][2] = DET (px, dx2, py, dy2) / det; RQ[1][2] = DET (dx1, px, dy1, py) / det; @@ -15236,7 +15236,7 @@ clutter_actor_transform_stage_point (ClutterActor *self, det = (RQ[0][0] * ST[0][0]) + (RQ[0][1] * ST[0][1]) + (RQ[0][2] * ST[0][2]); - if (CLUTTER_NEARBYINT (det) == 0) + if (fabs (det) <= DBL_EPSILON) return FALSE; /* |