migrate some animation helper classes

lib/animations/csv_animation.dart

@@ -0,0 +1,113 @@
+import 'dart:convert';
+import 'dart:io';
+import 'dart:typed_data';
+import 'package:tuple/tuple.dart';
+import 'package:polyvox_filament/animations/bone_animation_data.dart';
+import 'package:polyvox_filament/animations/bone_driver.dart';
+import 'package:polyvox_filament/animations/morph_animation_data.dart';
+import 'package:vector_math/vector_math.dart';
+
+///
+/// A class for loading animation data from a single CSV and allocating between morph/bone animation with help.
+///
+class DynamicAnimation {
+  final MorphAnimationData morphAnimation;
+  final List<BoneAnimationData> boneAnimation;
+
+  factory DynamicAnimation.load(String meshName, String csvPath,
+      {String? boneDriverConfigPath}) {
+    // create a MorphAnimationData instance from the given CSV
+    var llf = _loadLiveLinkFaceCSV(csvPath);
+    var morphNames = llf
+        .item1; //.where((name) => !boneDrivers.any((element) => element.blendshape == name));
+    var morphAnimationData = MorphAnimationData(
+      meshName,
+      llf.item2,
+      morphNames,
+      1000 / 60.0,
+    );
+
+    final boneAnimations = <BoneAnimationData>[];
+
+    // if applicable, load the bone driver config
+    if (boneDriverConfigPath != null) {
+      var boneData = json.decode(File(boneDriverConfigPath).readAsStringSync());
+      // for each driver
+      for (var key in boneData.keys()) {
+        var driver = BoneDriver.fromJsonObject(boneData[key]);
+
+        // get all frames for the single the blendshape
+        var morphFrameData =
+            morphAnimationData.getData(driver.blendshape).toList();
+
+        // apply the driver to the blendshape weight
+        var transformedQ = driver.transform(morphFrameData).toList();
+
+        // transform the quaternion to a Float32List
+        var transformedF = _quaternionToFloatList(transformedQ);
+
+        // add to the list of boneAnimations
+        boneAnimations.add(BoneAnimationData(
+            driver.bone, meshName, transformedF, 1000.0 / 60.0));
+      }
+    }
+
+    return DynamicAnimation(morphAnimationData, boneAnimations);
+  }
+
+  static Float32List _quaternionToFloatList(List<Quaternion> quats) {
+    var data = Float32List(quats.length * 4);
+    for (var quat in quats) {
+      data.addAll([0, 0, 0, quat.w, quat.x, quat.y, quat.z]);
+    }
+    return data;
+  }
+
+  DynamicAnimation(this.morphAnimation, this.boneAnimation);
+
+  ///
+  /// Load visemes fom a CSV file formatted according to the following header:
+  /// "Timecode,BlendShapeCount,EyeBlinkLeft,EyeLookDownLeft,EyeLookInLeft,EyeLookOutLeft,EyeLookUpLeft,EyeSquintLeft,EyeWideLeft,EyeBlinkRight,EyeLookDownRight,EyeLookInRight,EyeLookOutRight,EyeLookUpRight,EyeSquintRight,EyeWideRight,JawForward,JawRight,JawLeft,JawOpen,MouthClose,MouthFunnel,MouthPucker,MouthRight,MouthLeft,MouthSmileLeft,MouthSmileRight,MouthFrownLeft,MouthFrownRight,MouthDimpleLeft,MouthDimpleRight,MouthStretchLeft,MouthStretchRight,MouthRollLower,MouthRollUpper,MouthShrugLower,MouthShrugUpper,MouthPressLeft,MouthPressRight,MouthLowerDownLeft,MouthLowerDownRight,MouthUpperUpLeft,MouthUpperUpRight,BrowDownLeft,BrowDownRight,BrowInnerUp,BrowOuterUpLeft,BrowOuterUpRight,CheekPuff,CheekSquintLeft,CheekSquintRight,NoseSneerLeft,NoseSneerRight,TongueOut,HeadYaw,HeadPitch,HeadRoll,LeftEyeYaw,LeftEyePitch,LeftEyeRoll,RightEyeYaw,RightEyePitch,RightEyeRoll"
+  /// Returns only those specified by [targetNames].
+  ///
+  static Tuple2<List<String>, Float32List> _loadLiveLinkFaceCSV(String path) {
+    final data = File(path)
+        .readAsLinesSync()
+        .where((l) => l.length > 1)
+        .map((l) => l.split(","));
+
+    final header = data.first;
+    final numBlendShapes = header.length - 2;
+
+    final _data = <double>[];
+
+    for (var frame in data.skip(1)) {
+      int numFrameWeights = frame.length - 2;
+      // CSVs may contain rows where the "BlendShapeCount" column is set to "0" and/or the weight columns are simply missing.
+      // This can happen when something went wrong while recording via an app (e.g. LiveLinkFace)
+      // Whenever we encounter this type of row, we consider that all weights should be set to zero for that frame.
+      if (numFrameWeights == int.parse(frame[1])) {
+        _data.addAll(List<double>.filled(numBlendShapes, 0.0));
+        continue;
+      }
+
+      //
+      // Now, we check that the actual number of weight columns matches the header
+      // we ignore the "BlendShapeCount" column (and just count the number of columns)
+      // This is due to some legacy issues where we generated CSVs that had 61 weight columns, but accidentally left the "BlendShapeCount" column at 55
+      // This is probably fine as we always have either zero weights (handled above), or all weights (handled below).
+      // In other words, if this throws, we have a serious problem.
+      if (numFrameWeights != numBlendShapes) {
+        throw Exception(
+            "Malformed CSV, header specifies ${numBlendShapes} columns but frame specified only $numFrameWeights weights");
+      }
+
+      _data.addAll(frame
+          .skip(2)
+          .map((weight) => double.parse(weight))
+          .cast<double>()
+          .toList());
+    }
+    return Tuple2(header.skip(2).toList(), Float32List.fromList(_data));
+  }
+}