WIP: Support in <Group /> for saveLayerFlags e.g. SaveLayerInitWithPrevious

Author: macksal

packages/skia/cpp/api/recorder/JsiRecorder.h

@@ -184,7 +184,7 @@ class JsiRecorder : public JsiSkWrappingSharedPtrHostObject<Recorder> {
   }
 
   JSI_HOST_FUNCTION(saveLayer) {
-    getObject()->saveLayer();
+    getObject()->saveLayer(runtime, arguments[0].asObject(runtime));
     return jsi::Value::undefined();
   }
 

packages/skia/cpp/api/recorder/Paint.h

@@ -8,6 +8,8 @@
 #include "Convertor.h"
 #include "DrawingCtx.h"
 
+#include "include/core/SkCanvas.h"
+
 namespace RNSkia {
 
 struct TransformProps {
@@ -38,7 +40,35 @@ SkMatrix processTransform(std::optional<SkMatrix> &matrix,
   return m3;
 }
 
-struct CTMCmdProps : TransformProps {
+struct SaveLayerProps {
+  std::optional<SkCanvas::SaveLayerFlags> saveLayerFlags;
+}
+
+class SaveLayerCmd : public Command {
+private:
+  SaveLayerProps props;
+
+public:
+  SaveLayerCmd(jsi::Runtime &runtime, const jsi::Object &object,
+               Variables &variables)
+      : Command(CommandType::SaveLayer) {
+    convertProperty(runtime, object, "saveLayerFlags", props.saveLayerFlags,
+                    variables);
+  }
+
+  void saveLayer(DrawingCtx *ctx) {
+    ctx->materializePaint();
+    auto paint = ctx->paintDeclarations.back();
+    ctx->paintDeclarations.pop_back();
+
+    SkCanvas::SaveLayerRec layerRec(nullptr, &paint, nullptr,
+                                    props.saveLayerFlags.value_or(0));
+    ctx->canvas->saveLayer(layerRec);
+  }
+}
+
+struct CTMCmdProps : TransformProps,
+                     SaveLayerProps {
   std::optional<ClipDef> clip;
   std::optional<bool> invertClip;
   std::optional<Layer> layer;
@@ -58,12 +88,15 @@ class SaveCTMCmd : public Command {
     convertProperty(runtime, object, "clip", props.clip, variables);
     convertProperty(runtime, object, "invertClip", props.invertClip, variables);
     convertProperty(runtime, object, "layer", props.layer, variables);
+    convertProperty(runtime, object, "saveLayerFlags", props.saveLayerFlags,
+                    variables);
   }
 
   void saveCTM(DrawingCtx *ctx) {
     auto clip = props.clip;
     auto invertClip = props.invertClip;
     auto layer = props.layer;
+    auto saveLayerFlags = props.saveLayerFlags;
     auto hasTransform = props.matrix.has_value() || props.transform.has_value();
     auto hasClip = clip.has_value();
     auto op = invertClip.has_value() && invertClip.value()
@@ -73,12 +106,12 @@ class SaveCTMCmd : public Command {
     SkMatrix m3 = processTransform(props.matrix, props.transform, props.origin);
     if (shouldSave) {
       if (layer.has_value()) {
-        if (std::holds_alternative<bool>(layer.value())) {
-          ctx->canvas->saveLayer(nullptr, nullptr);
-        } else {
-          auto paint = std::get<SkPaint>(layer.value());
-          ctx->canvas->saveLayer(nullptr, &paint);
+        SkCanvas::SaveLayerRec layerRec;
+        layerRec.fPaint = std::get_if<SkPaint>(layer.value());
+        if (saveLayerFlags.has_value()) {
+          layerRec.fSaveLayerFlags = saveLayerFlags.value();
         }
+        ctx->canvas->saveLayer(layerRec);
       } else {
         ctx->canvas->save();
       }

packages/skia/cpp/api/recorder/RNRecorder.h

@@ -355,8 +355,8 @@ class Recorder {
         std::make_unique<Command>(CommandType::RestorePaintDeclaration));
   }
 
-  void saveLayer() {
-    pushCommand(std::make_unique<Command>(CommandType::SaveLayer));
+  void saveLayer(jsi::Runtime &runtime, const jsi::Object &props) {
+    pushCommand(std::make_unique<SaveLayerCmd>(runtime, props, variables));
   }
 
   void saveBackdropFilter() {
@@ -418,10 +418,8 @@ inline void Recorder::playCommand(DrawingCtx *ctx, Command *cmd) {
     break;
   }
   case CommandType::SaveLayer: {
-    ctx->materializePaint();
-    auto paint = ctx->paintDeclarations.back();
-    ctx->paintDeclarations.pop_back();
-    ctx->canvas->saveLayer(SkCanvas::SaveLayerRec(nullptr, &paint, nullptr, 0));
+    auto *saveCTMCmd = static_cast<SaveCTMCmd *>(cmd);
+    saveCTMCmd->saveCTM(ctx);
     break;
   }
   case CommandType::MaterializePaint: {

packages/skia/src/dom/types/Common.ts

@@ -6,6 +6,7 @@ import type {
   InputMatrix,
   InputRRect,
   PaintStyle,
+  SaveLayerFlag,
   SkPaint,
   SkPath,
   SkRect,
@@ -70,7 +71,11 @@ export interface TransformProps {
   matrix?: InputMatrix;
 }
 
-export interface CTMProps extends TransformProps {
+export interface SaveLayerProps {
+  saveLayerFlags?: SaveLayerFlag;
+}
+
+export interface CTMProps extends TransformProps, SaveLayerProps {
   clip?: ClipDef;
   invertClip?: boolean;
   layer?: SkPaint | boolean;

packages/skia/src/renderer/components/Group.tsx

@@ -8,14 +8,25 @@ export interface PublicGroupProps extends Omit<GroupProps, "layer"> {
   layer?: GroupProps["layer"] | ChildrenProps["children"];
 }
 
-export const Group = ({ layer, ...props }: SkiaProps<PublicGroupProps>) => {
+export const Group = ({
+  layer,
+  saveLayerFlags,
+  ...props
+}: SkiaProps<PublicGroupProps>) => {
   if (isValidElement(layer) && typeof layer === "object") {
     return (
-      <skLayer>
+      // keep the saveLayerFlags on whichever node triggers saveLayer
+      <skLayer saveLayerFlags={saveLayerFlags}>
         {layer}
         <skGroup {...props} />
       </skLayer>
     );
   }
-  return <skGroup layer={layer as GroupProps["layer"]} {...props} />;
+  return (
+    <skGroup
+      layer={layer as GroupProps["layer"]}
+      saveLayerFlags={saveLayerFlags}
+      {...props}
+    />
+  );
 };

packages/skia/src/skia/types/Recorder.ts

@@ -28,6 +28,7 @@ import type {
   VerticesProps,
   SkottieProps,
   DrawingNodeProps,
+  SaveLayerProps,
 } from "../../dom/types";
 import type { AnimatedProps } from "../../renderer/processors/Animations/Animations";
 
@@ -61,7 +62,7 @@ export interface BaseRecorder {
   saveCTM(props: AnimatedProps<CTMProps>): void;
   restoreCTM(): void;
   drawPaint(): void;
-  saveLayer(): void;
+  saveLayer(props: AnimatedProps<SaveLayerProps>): void;
   saveBackdropFilter(): void;
   drawBox(
     boxProps: AnimatedProps<BoxProps>,

packages/skia/src/skia/types/RuntimeEffect/RuntimeEffectFactory.ts

@@ -9,4 +9,5 @@ export interface RuntimeEffectFactory {
    */
   Make: (sksl: string) => SkRuntimeEffect | null;
   //Make(sksl: string, callback?: (err: string) => void): RuntimeEffect | null;
+  MakeBlender: (sksl: string) => SkRuntimeEffect | null;
 }

packages/skia/src/skia/web/JsiSkRuntimeEffectFactory.ts

@@ -20,4 +20,12 @@ export class JsiSkRuntimeEffectFactory
     }
     return new JsiSkRuntimeEffect(this.CanvasKit, re, sksl);
   }
+
+  MakeBlender(sksl: string) {
+    const re = this.CanvasKit.RuntimeEffect.MakeForBlender(sksl);
+    if (re === null) {
+      return null;
+    }
+    return new JsiSkRuntimeEffect(this.CanvasKit, re, sksl);
+  }
 }

packages/skia/src/sksg/Elements.tsx

@@ -53,14 +53,15 @@ import type {
   BlendProps,
   SkottieProps,
   ImageFilterProps,
+  SaveLayerProps,
 } from "../dom/types";
 import type { SkiaProps } from "../renderer";
 
 declare module "react" {
   namespace JSX {
     interface IntrinsicElements {
       skGroup: SkiaProps<GroupProps>;
-      skLayer: SkiaProps<ChildrenProps>;
+      skLayer: SkiaProps<ChildrenProps & SaveLayerProps>;
       skPaint: SkiaProps<PaintProps>;
 
       // Drawings

packages/skia/src/sksg/Recorder/Core.ts

@@ -22,6 +22,7 @@ import type {
   AtlasProps,
   DrawingNodeProps,
   SkottieProps,
+  SaveLayerProps,
 } from "../../dom/types";
 
 export enum CommandType {
@@ -107,6 +108,7 @@ interface Props {
   [CommandType.DrawImage]: ImageProps;
   [CommandType.DrawCircle]: CircleProps;
   [CommandType.SaveCTM]: CTMProps;
+  [CommandType.SaveLayer]: SaveLayerProps;
   [CommandType.SavePaint]: DrawingNodeProps;
   [CommandType.PushBlurMaskFilter]: BlurMaskFilterProps;
   [CommandType.DrawPoints]: PointsProps;