[USDZ] Support autoPlay and playbackMode Stage metadataum.

src/ascii-parser.cc

@@ -231,6 +231,11 @@ static void RegisterStageMetas(
   // Type can be array. i.e. asset, asset[]
   metas["subLayers"] = AsciiParser::VariableDef(value::kAssetPath, "subLayers",
                                                 /* allow array type */ true);
+
+  // USDZ extension
+  metas["autoPlay"] = AsciiParser::VariableDef(value::kBool, "autoPlay");
+  metas["playbackMode"] = AsciiParser::VariableDef(value::kToken, "playbackMode");
+
 }
 
 static void RegisterPrimMetas(

src/ascii-parser.hh

@@ -112,6 +112,9 @@ class AsciiParser {
     nonstd::optional<double> endTimeCode;
     nonstd::optional<double> framesPerSecond;
 
+    nonstd::optional<bool> autoPlay;
+    nonstd::optional<value::token> playbackMode;  // 'none' or 'loop'
+
     std::map<std::string, MetaVariable> customLayerData;  // `customLayerData`.
     std::vector<StringData> strings;  // String only unregistered metadata.
   };

src/stage.cc

@@ -590,6 +590,20 @@ std::string Stage::ExportToString() const {
     ss << "  defaultPrim = " << tinyusdz::quote(stage_metas.defaultPrim.str())
        << "\n";
   }
+
+  if (!stage_metas.autoPlay.authored()) {
+    ss << "  autoPlay = " << to_string(stage_metas.autoPlay.get_value()) << "\n";
+  }
+
+  if (!stage_metas.playbackMode.authored()) {
+    auto v = stage_metas.playbackMode.get_value();
+    if (v == StageMetas::PlaybackMode::PlaybackModeLoop) {
+      ss << "  playbackMode = \"loop\"\n";
+    } else { // None
+      ss << "  playbackMode = \"none\"\n";
+    }
+  }
+
   if (!stage_metas.comment.value.empty()) {
     ss << "  comment = " << to_string(stage_metas.comment) << "\n";
   }

src/stage.hh

@@ -9,6 +9,11 @@
 namespace tinyusdz {
 
 struct StageMetas {
+  enum class PlaybackMode {
+    PlaybackModeNone,
+    PlaybackModeLoop,
+  };
+    
   // TODO: Support more predefined properties: reference = <pxrUSD>/pxr/usd/sdf/wrapLayer.cpp
   // Scene global setting
   TypedAttributeWithFallback<Axis> upAxis{Axis::Y}; // This can be changed by plugInfo.json in USD: https://graphics.pixar.com/usd/dev/api/group___usd_geom_up_axis__group.html#gaf16b05f297f696c58a086dacc1e288b5
@@ -24,6 +29,10 @@ struct StageMetas {
 
   CustomDataType customLayerData; // customLayerData
 
+  // USDZ extension
+  TypedAttributeWithFallback<bool> autoPlay{true}; // default(or not authored) = auto play
+  TypedAttributeWithFallback<PlaybackMode> playbackMode{PlaybackMode::PlaybackModeLoop};
+
   // String only metadataum.
   // TODO: Represent as `MetaVariable`?
   std::vector<StringData> stringData;

src/usda-reader.cc

@@ -610,6 +610,21 @@ class USDAReader::Impl {
             _stage.metas().framesPerSecond = metas.framesPerSecond.value();
           }
 
+          if (metas.autoPlay) {
+            _stage.metas().autoPlay = metas.autoPlay.value();
+          }
+
+          if (metas.playbackMode) {
+            value::token tok = metas.playbackMode.value();
+            if (tok.str() == "none") {
+              _stage.metas().playbackMode = StageMetas::PlaybackMode::PlaybackModeNone;
+            } else if (tok.str() == "loop") {
+              _stage.metas().playbackMode = StageMetas::PlaybackMode::PlaybackModeLoop;
+            } else {
+              PUSH_ERROR_AND_RETURN("Unsupported playbackMode: " + tok.str());
+            }
+          }
+
           _stage.metas().customLayerData = metas.customLayerData;
 
           _stage.metas().stringData = metas.strings;

src/usdc-reader.cc

@@ -1415,6 +1415,32 @@ bool USDCReader::Impl::ReconstrcutStageMeta(
             fv.second.type_name() + "'");
       }
       DCOUT("endTimeCode = " << metas->endTimeCode.get_value());
+    } else if (fv.first == "autoPlay") {
+      if (auto vf = fv.second.get_value<bool>()) {
+        metas->autoPlay = vf.value();
+      } else {
+        PUSH_ERROR_AND_RETURN(
+            "`autoPlay` value must be bool "
+            "type, but got '" +
+            fv.second.type_name() + "'");
+      }
+      DCOUT("autoPlay = " << metas->autoPlay.get_value());
+    } else if (fv.first == "playbackMode") {
+      if (auto vf = fv.second.get_value<value::token>()) {
+        if (vf.value().str() == "none") {
+          metas->playbackMode = StageMetas::PlaybackMode::PlaybackModeNone;
+        } else if (vf.value().str() == "loop") {
+          metas->playbackMode = StageMetas::PlaybackMode::PlaybackModeLoop;
+        } else {
+          PUSH_ERROR_AND_RETURN(
+              "Unsupported token value for `playbackMode`.");
+        }
+      } else {
+        PUSH_ERROR_AND_RETURN(
+            "`playbackMode` value must be token "
+            "type, but got '" +
+            fv.second.type_name() + "'");
+      }
     } else if ((fv.first == "defaultPrim")) {
       auto v = fv.second.get_value<value::token>();
       if (!v) {

tests/usda/usdz-schema-autoplay-001.usda

@@ -0,0 +1,4 @@
+#usda 1.0
+(
+  autoPlay = false
+)

tests/usda/usdz-schema-playbackmode-001.usda

@@ -0,0 +1,4 @@
+#usda 1.0
+(
+  playbackMode = "loop"
+)