[skottie] Add support for round-corners geometry effects

TBR=
Change-Id: I5505561df28d5953526662d60fe2300cb112bc37
Reviewed-on: https://skia-review.googlesource.com/124769
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

1 files changed, 56 insertions, 0 deletions

diff --git a/experimental/sksg/geometry/SkSGRoundEffect.cpp b/experimental/sksg/geometry/SkSGRoundEffect.cpp
new file mode 100644
index 0000000000..8cf9068f65
--- /dev/null
+++ b/experimental/sksg/geometry/SkSGRoundEffect.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkSGRoundEffect.h"
+
+#include "SkCanvas.h"
+#include "SkCornerPathEffect.h"
+#include "SkStrokeRec.h"
+
+namespace sksg {
+
+RoundEffect::RoundEffect(sk_sp<GeometryNode> child)
+    : fChild(std::move(child)) {
+    this->observeInval(fChild);
+}
+
+RoundEffect::~RoundEffect() {
+    this->unobserveInval(fChild);
+}
+
+void RoundEffect::onClip(SkCanvas* canvas, bool antiAlias) const {
+    canvas->clipPath(fRoundedPath, SkClipOp::kIntersect, antiAlias);
+}
+
+void RoundEffect::onDraw(SkCanvas* canvas, const SkPaint& paint) const {
+    SkASSERT(!paint.getPathEffect());
+
+    canvas->drawPath(fRoundedPath, paint);
+}
+
+SkPath RoundEffect::onAsPath() const {
+    return fRoundedPath;
+}
+
+SkRect RoundEffect::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
+    SkASSERT(this->hasInval());
+
+    const auto childbounds = fChild->revalidate(ic, ctm);
+    const auto path        = fChild->asPath();
+
+    if (auto round = SkCornerPathEffect::Make(fRadius)) {
+        fRoundedPath.reset();
+        SkStrokeRec rec(SkStrokeRec::kHairline_InitStyle);
+        SkAssertResult(round->filterPath(&fRoundedPath, path, &rec, &childbounds));
+    } else {
+        fRoundedPath = path;
+    }
+
+    return fRoundedPath.computeTightBounds();
+}
+
+} // namespace sksg