1 files changed, 84 insertions, 0 deletions
diff --git a/modules/sksg/src/SkSGMerge.cpp b/modules/sksg/src/SkSGMerge.cpp
new file mode 100644
index 0000000000..be1ff4123a
--- /dev/null
+++ b/modules/sksg/src/SkSGMerge.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkSGMerge.h"
+
+#include "SkCanvas.h"
+#include "SkPathOps.h"
+
+namespace sksg {
+
+Merge::Merge(std::vector<sk_sp<GeometryNode>>&& geos, Mode mode)
+    : fGeos(std::move(geos))
+    , fMode(mode) {
+    for (const auto& geo : fGeos) {
+        this->observeInval(geo);
+    }
+}
+
+Merge::~Merge() {
+    for (const auto& geo : fGeos) {
+        this->unobserveInval(geo);
+    }
+}
+
+void Merge::onClip(SkCanvas* canvas, bool antiAlias) const {
+    canvas->clipPath(fMerged, SkClipOp::kIntersect, antiAlias);
+}
+
+void Merge::onDraw(SkCanvas* canvas, const SkPaint& paint) const {
+    canvas->drawPath(fMerged, paint);
+}
+
+SkPath Merge::onAsPath() const {
+    return fMerged;
+}
+
+static SkPathOp mode_to_op(Merge::Mode mode) {
+    switch (mode) {
+    case Merge::Mode::kUnion:
+        return kUnion_SkPathOp;
+    case Merge::Mode::kIntersect:
+        return kIntersect_SkPathOp;
+    case Merge::Mode::kDifference:
+        return kDifference_SkPathOp;
+    case Merge::Mode::kReverseDifference:
+        return kReverseDifference_SkPathOp;
+    case Merge::Mode::kXOR:
+        return kXOR_SkPathOp;
+    default:
+        break;
+    }
+
+    return kUnion_SkPathOp;
+}
+
+SkRect Merge::onRevalidate(InvalidationController* ic, const SkMatrix& ctm) {
+    SkASSERT(this->hasInval());
+
+    const auto op = mode_to_op(fMode);
+    SkOpBuilder builder;
+
+    fMerged.reset();
+
+    for (const auto& geo : fGeos) {
+        geo->revalidate(ic, ctm);
+        if (fMode == Mode::kMerge) {
+            fMerged.addPath(geo->asPath());
+        } else {
+            builder.add(geo->asPath(), geo == fGeos.front() ? kUnion_SkPathOp : op);
+        }
+    }
+
+    if (fMode != Mode::kMerge) {
+        builder.resolve(&fMerged);
+    }
+
+    return fMerged.computeTightBounds();
+}
+
+} // namespace sksg