AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Fix GradientShaderBase4fContext::Interval fuzzer assert

Browse Source 
Although the iterator ensures v0 != v1, 2 - v0 may still be equal to
2 - v1 for very small values due to limited float precision.

We need to recheck the inequality to avoid triggering Interval asserts.

BUG=skia:5903
R=reed@google.com
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2474463002

Review-Url: https://codereview.chromium.org/2474463002
This commit is contained in:
fmalita 2016-11-02 13:10:51 -07:00 committed by Commit bot
parent e9215f0e24
commit cc34176c04
1 changed files with 10 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/effects/gradients/Sk4fGradientBase.cpp
View File

@ -125,7 +125,6 @@ Interval::Interval(const Sk4f& c0, SkScalar p0,
: fP0(p0)
, fP1(p1)
, fZeroRamp((c0 == c1).allTrue()) {
SkASSERT(p0 != p1);
// Either p0 or p1 can be (-)inf for synthetic clamp edge intervals.
SkASSERT(SkScalarIsFinite(p0) || SkScalarIsFinite(p1));
@ -274,10 +273,16 @@ GradientShaderBase4fContext::addMirrorIntervals(const SkGradientShaderBase& shad
iter.iterate([this, &componentScale] (SkColor c0, SkColor c1, SkScalar p0, SkScalar p1) {
SkASSERT(fIntervals.empty() || fIntervals.back().fP1 == 2 - p0);
fIntervals.emplace_back(pack_color(c0, fColorsArePremul, componentScale),
2 - p0,
pack_color(c1, fColorsArePremul, componentScale),
2 - p1);
const auto mirror_p0 = 2 - p0;
const auto mirror_p1 = 2 - p1;
// mirror_p1 & mirror_p1 may collapse for very small values - recheck to avoid
// triggering Interval asserts.
if (mirror_p0 != mirror_p1) {
fIntervals.emplace_back(pack_color(c0, fColorsArePremul, componentScale),
mirror_p0,
pack_color(c1, fColorsArePremul, componentScale),
mirror_p1);
}
});
}