1 files changed, 48 insertions, 25 deletions

diff --git a/libs/hwui/pipeline/skia/LayerDrawable.cpp b/libs/hwui/pipeline/skia/LayerDrawable.cpp
index eed19420a78a..96b17e1d7975 100644
--- a/libs/hwui/pipeline/skia/LayerDrawable.cpp
+++ b/libs/hwui/pipeline/skia/LayerDrawable.cpp
@@ -33,21 +33,47 @@ void LayerDrawable::onDraw(SkCanvas* canvas) {
     }
 }
 
-// This is a less-strict matrix.isTranslate() that will still report being translate-only
-// on imperceptibly small scaleX & scaleY values.
-static bool isBasicallyTranslate(const SkMatrix& matrix) {
-    if (!matrix.isScaleTranslate()) return false;
-    return MathUtils::isOne(matrix.getScaleX()) && MathUtils::isOne(matrix.getScaleY());
-}
-
-static bool shouldFilter(const SkMatrix& matrix) {
-    if (!matrix.isScaleTranslate()) return true;
-
-    // We only care about meaningful scale here
-    bool noScale = MathUtils::isOne(matrix.getScaleX()) && MathUtils::isOne(matrix.getScaleY());
-    bool pixelAligned =
-            SkScalarIsInt(matrix.getTranslateX()) && SkScalarIsInt(matrix.getTranslateY());
-    return !(noScale && pixelAligned);
+// Disable filtering when there is no scaling in screen coordinates and the corners have the same
+// fraction (for translate) or zero fraction (for any other rect-to-rect transform).
+static bool shouldFilterRect(const SkMatrix& matrix, const SkRect& srcRect, const SkRect& dstRect) {
+    if (!matrix.rectStaysRect()) return true;
+    SkRect dstDevRect = matrix.mapRect(dstRect);
+    float dstW, dstH;
+    bool requiresIntegerTranslate = false;
+    if (MathUtils::isZero(matrix.getScaleX()) && MathUtils::isZero(matrix.getScaleY())) {
+        // Has a 90 or 270 degree rotation, although total matrix may also have scale factors
+        // in m10 and m01. Those scalings are automatically handled by mapRect so comparing
+        // dimensions is sufficient, but swap width and height comparison.
+        dstW = dstDevRect.height();
+        dstH = dstDevRect.width();
+        requiresIntegerTranslate = true;
+    } else {
+        // Handle H/V flips or 180 rotation matrices. Axes may have been mirrored, but
+        // dimensions are still safe to compare directly.
+        dstW = dstDevRect.width();
+        dstH = dstDevRect.height();
+        requiresIntegerTranslate =
+                matrix.getScaleX() < -NON_ZERO_EPSILON || matrix.getScaleY() < -NON_ZERO_EPSILON;
+    }
+    if (!(MathUtils::areEqual(dstW, srcRect.width()) &&
+          MathUtils::areEqual(dstH, srcRect.height()))) {
+        return true;
+    }
+    if (requiresIntegerTranslate) {
+        // Device rect and source rect should be integer aligned to ensure there's no difference
+        // in how nearest-neighbor sampling is resolved.
+        return !(MathUtils::isZero(SkScalarFraction(srcRect.x())) &&
+                 MathUtils::isZero(SkScalarFraction(srcRect.y())) &&
+                 MathUtils::isZero(SkScalarFraction(dstDevRect.x())) &&
+                 MathUtils::isZero(SkScalarFraction(dstDevRect.y())));
+    } else {
+        // As long as src and device rects are translated by the same fractional amount,
+        // filtering won't be needed
+        return !(MathUtils::areEqual(SkScalarFraction(srcRect.x()),
+                                     SkScalarFraction(dstDevRect.x())) &&
+                 MathUtils::areEqual(SkScalarFraction(srcRect.y()),
+                                     SkScalarFraction(dstDevRect.y())));
+    }
 }
 
 bool LayerDrawable::DrawLayer(GrContext* context, SkCanvas* canvas, Layer* layer,
@@ -114,24 +140,21 @@ bool LayerDrawable::DrawLayer(GrContext* context, SkCanvas* canvas, Layer* layer
                 skiaDestRect = SkRect::MakeIWH(layerWidth, layerHeight);
             }
             matrixInv.mapRect(&skiaDestRect);
-            // If (matrix is identity or an integer translation) and (src/dst buffers size match),
+            // If (matrix is a rect-to-rect transform)
+            // and (src/dst buffers size match in screen coordinates)
+            // and (src/dst corners align fractionally),
             // then use nearest neighbor, otherwise use bilerp sampling.
-            // Integer translation is defined as when src rect and dst rect align fractionally.
             // Skia TextureOp has the above logic build-in, but not NonAAFillRectOp. TextureOp works
             // only for SrcOver blending and without color filter (readback uses Src blending).
-            bool isIntegerTranslate =
-                    isBasicallyTranslate(totalMatrix) &&
-                    SkScalarFraction(skiaDestRect.fLeft + totalMatrix[SkMatrix::kMTransX]) ==
-                            SkScalarFraction(skiaSrcRect.fLeft) &&
-                    SkScalarFraction(skiaDestRect.fTop + totalMatrix[SkMatrix::kMTransY]) ==
-                            SkScalarFraction(skiaSrcRect.fTop);
-            if (layer->getForceFilter() || !isIntegerTranslate) {
+            if (layer->getForceFilter() ||
+                shouldFilterRect(totalMatrix, skiaSrcRect, skiaDestRect)) {
                 paint.setFilterQuality(kLow_SkFilterQuality);
             }
             canvas->drawImageRect(layerImage.get(), skiaSrcRect, skiaDestRect, &paint,
                                   SkCanvas::kFast_SrcRectConstraint);
         } else {
-            if (layer->getForceFilter() || shouldFilter(totalMatrix)) {
+            SkRect imageRect = SkRect::MakeIWH(layerImage->width(), layerImage->height());
+            if (layer->getForceFilter() || shouldFilterRect(totalMatrix, imageRect, imageRect)) {
                 paint.setFilterQuality(kLow_SkFilterQuality);
             }
             canvas->drawImage(layerImage.get(), 0, 0, &paint);