SF: fix off-by one in luma mean calculation
There was an off by one error in luma mean calculation that could
lead to segfault. Flaw was figured out in writing the 5 attached
unit tests for the function. Condition would be obscure in the wild,
but an exactly half-white, half-another-color in the sampled region
could present condition.
Fixes: 129858549
Test: libsurfaceflinger_unittest (5 new tests)
Change-Id: I920cd9cac15122178ec9258e33c9bc35b1bb9357
diff --git a/services/surfaceflinger/RegionSamplingThread.h b/services/surfaceflinger/RegionSamplingThread.h
index d4e57bf..9796429 100644
--- a/services/surfaceflinger/RegionSamplingThread.h
+++ b/services/surfaceflinger/RegionSamplingThread.h
@@ -37,6 +37,8 @@
class SurfaceFlinger;
struct SamplingOffsetCallback;
+float sampleArea(const uint32_t* data, int32_t stride, const Rect& area);
+
class RegionSamplingThread : public IBinder::DeathRecipient {
public:
struct TimingTunables {