[skottie] Inverted matte support

TBR=

Change-Id: I761d80d27d9a737710123a183af37135c270b8a7
Reviewed-on: https://skia-review.googlesource.com/112162
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

3 files changed, 30 insertions, 10 deletions

diff --git a/experimental/skottie/Skottie.cpp b/experimental/skottie/Skottie.cpp
index 5b0e836997..ad513fdc75 100644
--- a/experimental/skottie/Skottie.cpp
+++ b/experimental/skottie/Skottie.cpp
@@ -1095,8 +1095,18 @@ sk_sp<sksg::RenderNode> AttachLayer(const Json::Value& jlayer,
 
     if (layerCtx->fCurrentMatte) {
         // There is a pending matte. Apply and reset.
-        return sksg::MaskEffect::Make(std::move(controller_node),
-                                      std::move(layerCtx->fCurrentMatte));
+        static constexpr sksg::MaskEffect::Mode gMaskModes[] = {
+            sksg::MaskEffect::Mode::kNormal, // tt: 1
+            sksg::MaskEffect::Mode::kInvert, // tt: 2
+        };
+        const auto matteType = ParseDefault(jlayer["tt"], 1) - 1;
+
+        if (matteType >= 0 && matteType < SkTo<int>(SK_ARRAY_COUNT(gMaskModes))) {
+            return sksg::MaskEffect::Make(std::move(controller_node),
+                                          std::move(layerCtx->fCurrentMatte),
+                                          gMaskModes[matteType]);
+        }
+        layerCtx->fCurrentMatte.reset();
     }
 
     return controller_node;
diff --git a/experimental/sksg/effects/SkSGMaskEffect.cpp b/experimental/sksg/effects/SkSGMaskEffect.cpp
index 17b4da7037..16e4c0dd8d 100644
--- a/experimental/sksg/effects/SkSGMaskEffect.cpp
+++ b/experimental/sksg/effects/SkSGMaskEffect.cpp
@@ -11,9 +11,10 @@
 
 namespace sksg {
 
-MaskEffect::MaskEffect(sk_sp<RenderNode> child, sk_sp<RenderNode> mask)
+MaskEffect::MaskEffect(sk_sp<RenderNode> child, sk_sp<RenderNode> mask, Mode mode)
     : INHERITED(std::move(child))
-    , fMaskNode(std::move(mask)) {
+    , fMaskNode(std::move(mask))
+    , fMaskMode(mode) {
     this->observeInval(fMaskNode);
 }
 
@@ -32,7 +33,7 @@ void MaskEffect::onRender(SkCanvas* canvas) const {
 
 
     SkPaint p;
-    p.setBlendMode(SkBlendMode::kSrcIn);
+    p.setBlendMode(fMaskMode == Mode::kNormal ? SkBlendMode::kSrcIn : SkBlendMode::kSrcOut);
     canvas->saveLayer(this->bounds(), &p);
 
     this->INHERITED::onRender(canvas);
@@ -45,7 +46,9 @@ SkRect MaskEffect::onRevalidate(InvalidationController* ic, const SkMatrix& ctm)
     const auto maskBounds = fMaskNode->revalidate(ic, ctm);
     auto childBounds = this->INHERITED::onRevalidate(ic, ctm);
 
-    return childBounds.intersect(maskBounds) ? childBounds : SkRect::MakeEmpty();
+    return (fMaskMode == Mode::kInvert || childBounds.intersect(maskBounds))
+        ? childBounds
+        : SkRect::MakeEmpty();
 }
 
 } // namespace sksg
diff --git a/experimental/sksg/effects/SkSGMaskEffect.h b/experimental/sksg/effects/SkSGMaskEffect.h
index aef82b4ef6..c4fd0120e5 100644
--- a/experimental/sksg/effects/SkSGMaskEffect.h
+++ b/experimental/sksg/effects/SkSGMaskEffect.h
@@ -18,23 +18,30 @@ namespace sksg {
  */
 class MaskEffect final : public EffectNode {
 public:
-    static sk_sp<MaskEffect> Make(sk_sp<RenderNode> child, sk_sp<RenderNode> mask) {
+    enum class Mode {
+        kNormal,
+        kInvert
+    };
+
+    static sk_sp<MaskEffect> Make(sk_sp<RenderNode> child, sk_sp<RenderNode> mask,
+                                  Mode mode = Mode::kNormal) {
         return (child && mask)
-            ? sk_sp<MaskEffect>(new MaskEffect(std::move(child), std::move(mask)))
+            ? sk_sp<MaskEffect>(new MaskEffect(std::move(child), std::move(mask), mode))
             : nullptr;
     }
 
     ~MaskEffect() override;
 
 protected:
-    MaskEffect(sk_sp<RenderNode>, sk_sp<RenderNode> mask);
+    MaskEffect(sk_sp<RenderNode>, sk_sp<RenderNode> mask, Mode);
 
     void onRender(SkCanvas*) const override;
 
     SkRect onRevalidate(InvalidationController*, const SkMatrix&) override;
 
 private:
-    sk_sp<RenderNode> fMaskNode;
+    const sk_sp<RenderNode> fMaskNode;
+    const Mode              fMaskMode;
 
     typedef EffectNode INHERITED;
 };