[skotty] Refactor paint opacity

Promote to a PaintNode attribute, drop color composite.

TBR=
Change-Id: Ia79d5f7e193a472d53ac4ff8beb7234d4dc26cef
Reviewed-on: https://skia-review.googlesource.com/94280
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>

5 files changed, 15 insertions, 40 deletions

diff --git a/experimental/skotty/Skotty.cpp b/experimental/skotty/Skotty.cpp
index ce2644ea51..72d12d6ac4 100644
--- a/experimental/skotty/Skotty.cpp
+++ b/experimental/skotty/Skotty.cpp
@@ -298,17 +298,12 @@ sk_sp<sksg::Color> AttachColor(const Json::Value& obj, AttachContext* ctx) {
     SkASSERT(obj.isObject());
 
     auto color_node = sksg::Color::Make(SK_ColorBLACK);
-    auto composite  = sk_make_sp<CompositeColor>(color_node);
-    auto color_attached = BindProperty<VectorValue>(obj["c"], ctx, composite,
-        [](CompositeColor* node, const VectorValue& c) {
+    auto color_attached = BindProperty<VectorValue>(obj["c"], ctx, color_node,
+        [](sksg::Color* node, const VectorValue& c) {
             node->setColor(ValueTraits<VectorValue>::As<SkColor>(c));
         });
-    auto opacity_attached = BindProperty<ScalarValue>(obj["o"], ctx, composite,
-        [](CompositeColor* node, const ScalarValue& o) {
-            node->setOpacity(o);
-        });
 
-    return (color_attached || opacity_attached) ? color_node : nullptr;
+    return color_attached ? color_node : nullptr;
 }
 
 sk_sp<sksg::Gradient> AttachGradient(const Json::Value& obj, AttachContext* ctx) {
@@ -353,12 +348,16 @@ sk_sp<sksg::Gradient> AttachGradient(const Json::Value& obj, AttachContext* ctx)
     return gradient_node;
 }
 
-sk_sp<sksg::PaintNode> AttachPaint(const Json::Value& jfill, AttachContext* ctx,
+sk_sp<sksg::PaintNode> AttachPaint(const Json::Value& jpaint, AttachContext* ctx,
                                    sk_sp<sksg::PaintNode> paint_node) {
     if (paint_node) {
         paint_node->setAntiAlias(true);
 
-        // TODO: refactor opacity
+        BindProperty<ScalarValue>(jpaint["o"], ctx, paint_node,
+            [](sksg::PaintNode* node, const ScalarValue& o) {
+                // BM opacity is [0..100]
+                node->setOpacity(o * 0.01f);
+        });
     }
 
     return paint_node;
diff --git a/experimental/skotty/SkottyProperties.cpp b/experimental/skotty/SkottyProperties.cpp
index e962a7d538..6be2eebfa3 100644
--- a/experimental/skotty/SkottyProperties.cpp
+++ b/experimental/skotty/SkottyProperties.cpp
@@ -183,20 +183,6 @@ SkPath ValueTraits<ShapeValue>::As<SkPath>(const ShapeValue& path) {
     return path;
 }
 
-CompositeColor::CompositeColor(sk_sp<sksg::Color> wrapped_node)
-    : fColorNode(std::move(wrapped_node)) {
-    SkASSERT(fColorNode);
-}
-
-void CompositeColor::apply() {
-    // 'opacity' is [0..100]
-    const auto a = SkScalarRoundToInt(SkTPin<float>(fOpacity * .01f, 0, 1) * SkColorGetA(fColor));
-    fColorNode->setColor(SkColorSetARGB(a,
-                                        SkColorGetR(fColor),
-                                        SkColorGetG(fColor),
-                                        SkColorGetB(fColor)));
-}
-
 CompositeRRect::CompositeRRect(sk_sp<sksg::RRect> wrapped_node)
     : fRRectNode(std::move(wrapped_node)) {}
 
diff --git a/experimental/skotty/SkottyProperties.h b/experimental/skotty/SkottyProperties.h
index cd22810c2e..177ba35873 100644
--- a/experimental/skotty/SkottyProperties.h
+++ b/experimental/skotty/SkottyProperties.h
@@ -58,21 +58,6 @@ using ShapeValue  = SkPath;
     p_type f##p_name = p_default;                     \
   public:
 
-class CompositeColor final : public SkRefCnt {
-public:
-    explicit CompositeColor(sk_sp<sksg::Color>);
-
-     COMPOSITE_PROPERTY(Color  , SkColor , SK_ColorBLACK)
-     COMPOSITE_PROPERTY(Opacity, SkScalar, 100          )
-
-private:
-    void apply();
-
-    sk_sp<sksg::Color> fColorNode;
-
-    using INHERITED = SkRefCnt;
-};
-
 class CompositeRRect final : public SkRefCnt {
 public:
     explicit CompositeRRect(sk_sp<sksg::RRect>);
diff --git a/experimental/sksg/SkSGPaintNode.cpp b/experimental/sksg/SkSGPaintNode.cpp
index 146d248b8e..bb5b714030 100644
--- a/experimental/sksg/SkSGPaintNode.cpp
+++ b/experimental/sksg/SkSGPaintNode.cpp
@@ -31,6 +31,9 @@ SkRect PaintNode::onRevalidate(InvalidationController*, const SkMatrix&) {
 
     this->onApplyToPaint(&fPaint);
 
+    // Compose opacity on top of the subclass value.
+    fPaint.setAlpha(SkScalarRoundToInt(fPaint.getAlpha() * SkTPin<SkScalar>(fOpacity, 0, 1)));
+
     return SkRect::MakeEmpty();
 }
 
diff --git a/experimental/sksg/SkSGPaintNode.h b/experimental/sksg/SkSGPaintNode.h
index a2fbada065..1085e27c0f 100644
--- a/experimental/sksg/SkSGPaintNode.h
+++ b/experimental/sksg/SkSGPaintNode.h
@@ -25,6 +25,7 @@ public:
     const SkPaint& makePaint();
 
     SG_ATTRIBUTE(AntiAlias  , bool          , fAntiAlias  )
+    SG_ATTRIBUTE(Opacity    , SkScalar      , fOpacity    )
     SG_ATTRIBUTE(StrokeWidth, SkScalar      , fStrokeWidth)
     SG_ATTRIBUTE(StrokeMiter, SkScalar      , fStrokeMiter)
     SG_ATTRIBUTE(Style      , SkPaint::Style, fStyle      )
@@ -41,7 +42,8 @@ protected:
 private:
     SkPaint        fPaint;
 
-    SkScalar       fStrokeWidth = 1,
+    SkScalar       fOpacity     = 1,
+                   fStrokeWidth = 1,
                    fStrokeMiter = 4;
     bool           fAntiAlias   = false;
     SkPaint::Style fStyle       = SkPaint::kFill_Style;