diff options
Diffstat (limited to 'services/surfaceflinger/Layer.cpp')
| -rw-r--r-- | services/surfaceflinger/Layer.cpp | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp index 6ed4a94f25..be16942d40 100644 --- a/services/surfaceflinger/Layer.cpp +++ b/services/surfaceflinger/Layer.cpp @@ -2194,6 +2194,37 @@ Rect Layer::getInputBounds() const { return getCroppedBufferSize(getDrawingState()); } +// Applies the given transform to the region, while protecting against overflows caused by any +// offsets. If applying the offset in the transform to any of the Rects in the region would result +// in an overflow, they are not added to the output Region. +static Region transformTouchableRegionSafely(const ui::Transform& t, const Region& r, + const std::string& debugWindowName) { + // Round the translation using the same rounding strategy used by ui::Transform. + const auto tx = static_cast<int32_t>(t.tx() + 0.5); + const auto ty = static_cast<int32_t>(t.ty() + 0.5); + + ui::Transform transformWithoutOffset = t; + transformWithoutOffset.set(0.f, 0.f); + + const Region transformed = transformWithoutOffset.transform(r); + + // Apply the translation to each of the Rects in the region while discarding any that overflow. + Region ret; + for (const auto& rect : transformed) { + Rect newRect; + if (__builtin_add_overflow(rect.left, tx, &newRect.left) || + __builtin_add_overflow(rect.top, ty, &newRect.top) || + __builtin_add_overflow(rect.right, tx, &newRect.right) || + __builtin_add_overflow(rect.bottom, ty, &newRect.bottom)) { + ALOGE("Applying transform to touchable region of window '%s' resulted in an overflow.", + debugWindowName.c_str()); + continue; + } + ret.orSelf(newRect); + } + return ret; +} + void Layer::fillInputFrameInfo(WindowInfo& info, const ui::Transform& screenToDisplay) { Rect tmpBounds = getInputBounds(); if (!tmpBounds.isValid()) { @@ -2256,7 +2287,8 @@ void Layer::fillInputFrameInfo(WindowInfo& info, const ui::Transform& screenToDi info.transform = inputToDisplay.inverse(); // The touchable region is specified in the input coordinate space. Change it to display space. - info.touchableRegion = inputToDisplay.transform(info.touchableRegion); + info.touchableRegion = + transformTouchableRegionSafely(inputToDisplay, info.touchableRegion, mName); } void Layer::fillTouchOcclusionMode(WindowInfo& info) { |