1 files changed, 86 insertions, 0 deletions
diff --git a/libs/hwui/Layer.cpp b/libs/hwui/Layer.cpp
index c174c240ff22..f4c633fbe58f 100644
--- a/libs/hwui/Layer.cpp
+++ b/libs/hwui/Layer.cpp
@@ -18,6 +18,7 @@
 
 #include "renderstate/RenderState.h"
 #include "utils/Color.h"
+#include "utils/MathUtils.h"
 
 namespace android {
 namespace uirenderer {
@@ -52,5 +53,90 @@ SkBlendMode Layer::getMode() const {
     }
 }
 
+static inline SkScalar isIntegerAligned(SkScalar x) {
+    return fabsf(roundf(x) - x) <= NON_ZERO_EPSILON;
+}
+
+// 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;
+    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();
+    } 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();
+    }
+    if (!(MathUtils::areEqual(dstW, srcRect.width()) &&
+          MathUtils::areEqual(dstH, srcRect.height()))) {
+        return true;
+    }
+    // Device rect and source rect should be integer aligned to ensure there's no difference
+    // in how nearest-neighbor sampling is resolved.
+    return !(isIntegerAligned(srcRect.x()) &&
+             isIntegerAligned(srcRect.y()) &&
+             isIntegerAligned(dstDevRect.x()) &&
+             isIntegerAligned(dstDevRect.y()));
+}
+
+void Layer::draw(SkCanvas* canvas) {
+    GrRecordingContext* context = canvas->recordingContext();
+    if (context == nullptr) {
+        SkDEBUGF(("Attempting to draw LayerDrawable into an unsupported surface"));
+        return;
+    }
+    SkMatrix layerTransform = getTransform();
+    //sk_sp<SkImage> layerImage = getImage();
+    const int layerWidth = getWidth();
+    const int layerHeight = getHeight();
+    if (layerImage) {
+        SkMatrix textureMatrixInv;
+        textureMatrixInv = getTexTransform();
+        // TODO: after skia bug https://bugs.chromium.org/p/skia/issues/detail?id=7075 is fixed
+        // use bottom left origin and remove flipV and invert transformations.
+        SkMatrix flipV;
+        flipV.setAll(1, 0, 0, 0, -1, 1, 0, 0, 1);
+        textureMatrixInv.preConcat(flipV);
+        textureMatrixInv.preScale(1.0f / layerWidth, 1.0f / layerHeight);
+        textureMatrixInv.postScale(layerImage->width(), layerImage->height());
+        SkMatrix textureMatrix;
+        if (!textureMatrixInv.invert(&textureMatrix)) {
+            textureMatrix = textureMatrixInv;
+        }
+
+        SkMatrix matrix;
+        matrix = SkMatrix::Concat(layerTransform, textureMatrix);
+
+        SkPaint paint;
+        paint.setAlpha(getAlpha());
+        paint.setBlendMode(getMode());
+        paint.setColorFilter(getColorFilter());
+        const bool nonIdentityMatrix = !matrix.isIdentity();
+        if (nonIdentityMatrix) {
+            canvas->save();
+            canvas->concat(matrix);
+        }
+        const SkMatrix& totalMatrix = canvas->getTotalMatrix();
+
+        SkRect imageRect = SkRect::MakeIWH(layerImage->width(), layerImage->height());
+        if (getForceFilter() || shouldFilterRect(totalMatrix, imageRect, imageRect)) {
+            paint.setFilterQuality(kLow_SkFilterQuality);
+        }
+        canvas->drawImage(layerImage.get(), 0, 0, &paint);
+        // restore the original matrix
+        if (nonIdentityMatrix) {
+            canvas->restore();
+        }
+    }
+}
+
 }  // namespace uirenderer
 }  // namespace android