Check if the buffer is actually being scaled instead of only checking scaling mode

BufferStateLayers have a default scale to window scaling mode which
means the layers would be set use texture filtering regardless of
the buffer size. This was breaking some pixel by pixel screenshot
comparison tests. Instead check if the buffer size, after applying
any buffer transforms, matches the layer size.

Test: android.view.inputmethod.cts.FocusHandlingTest#testNonFocusablePopupWindowDoesNotAffectImeVisibility
Change-Id: I90b05187a2e22834a99d3690095293fa37118734

1 files changed, 25 insertions, 0 deletions

diff --git a/services/surfaceflinger/BufferStateLayer.cpp b/services/surfaceflinger/BufferStateLayer.cpp
index 6f344c721a..f85151449b 100644
--- a/services/surfaceflinger/BufferStateLayer.cpp
+++ b/services/surfaceflinger/BufferStateLayer.cpp
@@ -744,6 +744,31 @@ Layer::RoundedCornerState BufferStateLayer::getRoundedCornerState() const {
                                         static_cast<float>(s.active.transform.ty() + s.active.h)),
                               radius);
 }
+
+bool BufferStateLayer::bufferNeedsFiltering() const {
+    const State& s(getDrawingState());
+    if (!s.buffer) {
+        return false;
+    }
+
+    uint32_t bufferWidth = s.buffer->width;
+    uint32_t bufferHeight = s.buffer->height;
+
+    // Undo any transformations on the buffer and return the result.
+    if (s.transform & ui::Transform::ROT_90) {
+        std::swap(bufferWidth, bufferHeight);
+    }
+
+    if (s.transformToDisplayInverse) {
+        uint32_t invTransform = DisplayDevice::getPrimaryDisplayRotationFlags();
+        if (invTransform & ui::Transform::ROT_90) {
+            std::swap(bufferWidth, bufferHeight);
+        }
+    }
+
+    const Rect layerSize{getBounds()};
+    return layerSize.width() != bufferWidth || layerSize.height() != bufferHeight;
+}
 } // namespace android
 
 // TODO(b/129481165): remove the #pragma below and fix conversion issues