Handle post-record-time clipPath scaling

bug:29547149

Change-Id: I268210b240d2d8e08638114715f9622840fc02f7

4 files changed, 89 insertions, 6 deletions

diff --git a/libs/hwui/ClipArea.cpp b/libs/hwui/ClipArea.cpp
index fe6823925083..39b8d3de9c75 100644
--- a/libs/hwui/ClipArea.cpp
+++ b/libs/hwui/ClipArea.cpp
@@ -464,10 +464,7 @@ const ClipBase* ClipArea::serializeIntersectedClip(LinearAllocator& allocator,
             }
             case ClipMode::Region:
                 other = getRegion(recordedClip);
-
-                // TODO: handle non-translate transforms properly!
-                other.translate(recordedClipTransform.getTranslateX(),
-                        recordedClipTransform.getTranslateY());
+                applyTransformToRegion(recordedClipTransform, &other);
             }
 
             ClipRegion* regionClip = allocator.create<ClipRegion>();
@@ -527,11 +524,29 @@ void ClipArea::applyClip(const ClipBase* clip, const Matrix4& transform) {
         }
     } else {
         SkRegion region(getRegion(clip));
-        // TODO: handle non-translate transforms properly!
-        region.translate(transform.getTranslateX(), transform.getTranslateY());
+        applyTransformToRegion(transform, &region);
         clipRegion(region, SkRegion::kIntersect_Op);
     }
 }
 
+void ClipArea::applyTransformToRegion(const Matrix4& transform, SkRegion* region) {
+    if (transform.isSimple() && !transform.isPureTranslate()) {
+        // handle matrices with scale manually by mapping each rect
+        SkRegion other;
+        SkRegion::Iterator it(*region);
+        while (!it.done()) {
+            Rect rect(it.rect());
+            transform.mapRect(rect);
+            rect.roundOut();
+            other.op(rect.left, rect.top, rect.right, rect.bottom, SkRegion::kUnion_Op);
+            it.next();
+        }
+        region->swap(other);
+    } else {
+        // TODO: handle non-translate transforms properly!
+        region->translate(transform.getTranslateX(), transform.getTranslateY());
+    }
+}
+
 } /* namespace uirenderer */
 } /* namespace android */
diff --git a/libs/hwui/ClipArea.h b/libs/hwui/ClipArea.h
index 6eb2eef5a5f9..53d9d03a3629 100644
--- a/libs/hwui/ClipArea.h
+++ b/libs/hwui/ClipArea.h
@@ -179,6 +179,8 @@ public:
             const ClipBase* recordedClip, const Matrix4& recordedClipTransform);
     void applyClip(const ClipBase* recordedClip, const Matrix4& recordedClipTransform);
 
+    static void applyTransformToRegion(const Matrix4& transform, SkRegion* region);
+
 private:
     void enterRectangleMode();
     void rectangleModeClipRectWithTransform(const Rect& r, const mat4* transform, SkRegion::Op op);
diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index de4fa55bb508..5786668addc5 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -73,6 +73,13 @@ public:
             bottom(height) {
     }
 
+    inline Rect(const SkIRect& rect):
+            left(rect.fLeft),
+            top(rect.fTop),
+            right(rect.fRight),
+            bottom(rect.fBottom) {
+    }
+
     inline Rect(const SkRect& rect):
             left(rect.fLeft),
             top(rect.fTop),
diff --git a/libs/hwui/tests/unit/ClipAreaTests.cpp b/libs/hwui/tests/unit/ClipAreaTests.cpp
index 54ca68d63dbe..afabd359ed45 100644
--- a/libs/hwui/tests/unit/ClipAreaTests.cpp
+++ b/libs/hwui/tests/unit/ClipAreaTests.cpp
@@ -275,5 +275,64 @@ TEST(ClipArea, serializeIntersectedClip_snap) {
     }
 }
 
+TEST(ClipArea, serializeIntersectedClip_scale) {
+    ClipArea area(createClipArea());
+    area.setClip(0, 0, 400, 400);
+    LinearAllocator allocator;
+
+    SkPath circlePath;
+    circlePath.addCircle(50, 50, 50);
+
+    ClipRegion recordedClip;
+    recordedClip.region.setPath(circlePath, SkRegion(SkIRect::MakeWH(100, 100)));
+    recordedClip.rect = Rect(100, 100);
+
+    Matrix4 translateScale;
+    translateScale.loadTranslate(100, 100, 0);
+    translateScale.scale(2, 2, 1);
+    auto resolvedClip = area.serializeIntersectedClip(allocator, &recordedClip, translateScale);
+
+    ASSERT_NE(nullptr, resolvedClip);
+    EXPECT_EQ(ClipMode::Region, resolvedClip->mode);
+    EXPECT_EQ(Rect(100, 100, 300, 300), resolvedClip->rect);
+    auto clipRegion = reinterpret_cast<const ClipRegion*>(resolvedClip);
+    EXPECT_EQ(SkIRect::MakeLTRB(100, 100, 300, 300), clipRegion->region.getBounds());
+}
+
+TEST(ClipArea, applyTransformToRegion_identity) {
+    SkRegion region(SkIRect::MakeLTRB(1, 2, 3, 4));
+    ClipArea::applyTransformToRegion(Matrix4::identity(), &region);
+    EXPECT_TRUE(region.isRect());
+    EXPECT_EQ(SkIRect::MakeLTRB(1, 2, 3, 4), region.getBounds());
+}
+
+TEST(ClipArea, applyTransformToRegion_translate) {
+    SkRegion region(SkIRect::MakeLTRB(1, 2, 3, 4));
+    Matrix4 transform;
+    transform.loadTranslate(10, 20, 0);
+    ClipArea::applyTransformToRegion(transform, &region);
+    EXPECT_TRUE(region.isRect());
+    EXPECT_EQ(SkIRect::MakeLTRB(11, 22, 13, 24), region.getBounds());
+}
+
+TEST(ClipArea, applyTransformToRegion_scale) {
+    SkRegion region(SkIRect::MakeLTRB(1, 2, 3, 4));
+    Matrix4 transform;
+    transform.loadScale(2, 3, 1);
+    ClipArea::applyTransformToRegion(transform, &region);
+    EXPECT_TRUE(region.isRect());
+    EXPECT_EQ(SkIRect::MakeLTRB(2, 6, 6, 12), region.getBounds());
+}
+
+TEST(ClipArea, applyTransformToRegion_translateScale) {
+    SkRegion region(SkIRect::MakeLTRB(1, 2, 3, 4));
+    Matrix4 transform;
+    transform.translate(10, 20);
+    transform.scale(2, 3, 1);
+    ClipArea::applyTransformToRegion(transform, &region);
+    EXPECT_TRUE(region.isRect());
+    EXPECT_EQ(SkIRect::MakeLTRB(12, 26, 16, 32), region.getBounds());
+}
+
 } // namespace uirenderer
 } // namespace android