Add full support for KHR_animation_pointer validation

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ### New Features
 
+* Added full support for `KHR_animation_pointer` extension.
+  * Added new `KHR_ANIMATION_POINTER_CANNOT_VALIDATE_EXTRAS`, `KHR_ANIMATION_POINTER_INVALID_POINTER`, `KHR_ANIMATION_POINTER_INTEGER_NON_STEP_INTERPOLATION`, `KHR_ANIMATION_POINTER_COMPONENT_TYPE_MISMATCH`, and `KHR_ANIMATION_POINTER_VECTOR_SIZE_MISMATCH` validation errors.
+  * The `INCOMPLETE_EXTENSION_SUPPORT` validation info will now be reported far less often, only for unknown extensions.
+  * Extensions can define validation for their own pointer targets by implementing the `validateExtensionPointer` method in their extension class.
+
 * Added support for the `KHR_node_visibility` extension.
 
 * Added new `NODE_SKINNED_MESH_PARENT_TRANSFORMS` validation warning.

ISSUES.md

@@ -43,6 +43,11 @@
 |INVALID_GL_VALUE|Invalid value `%1` for GL type '`%2`'.|Error|
 |KHR_ANIMATION_POINTER_ANIMATION_CHANNEL_TARGET_NODE|This extension requires the animation channel target node to be undefined.|Error|
 |KHR_ANIMATION_POINTER_ANIMATION_CHANNEL_TARGET_PATH|This extension requires the animation channel target path to be 'pointer'. Found '`%1`' instead.|Error|
+|KHR_ANIMATION_POINTER_INTEGER_NON_STEP_INTERPOLATION|Animation samplers used with int or bool Object Model Data Types MUST use STEP interpolation. Pointer: '`%1`', expected: '`%2`', found: '`%3`'.|Error|
+|KHR_ANIMATION_POINTER_CANNOT_VALIDATE_EXTRAS|Cannot validate pointers into non-standardized extras.|Hint|
+|KHR_ANIMATION_POINTER_INVALID_POINTER|The pointer '`%1`' does not point to a valid property in the glTF JSON. Animated properties must be defined in the JSON document.|Error|
+|KHR_ANIMATION_POINTER_COMPONENT_TYPE_MISMATCH|The output component type of the accessor does not match the required type of the glTF Object Model property being targeted by the pointer '`%1`'. Expected type: '`%2`', found type: '`%3`'.|Error|
+|KHR_ANIMATION_POINTER_VECTOR_SIZE_MISMATCH|The output vector size of the accessor does not match the required vector size of the glTF Object Model property being targeted by the pointer '`%1`'. Expected size: `%2`, found size: `%3`.|Error|
 |KHR_LIGHTS_PUNCTUAL_LIGHT_SPOT_ANGLES|outerConeAngle (`%2`) is less than or equal to innerConeAngle (`%1`).|Error|
 |KHR_MATERIALS_ANISOTROPY_ANISOTROPY_TEXTURE_TEXCOORD|Normal and anisotropy textures should use the same texture coords.|Warning|
 |KHR_MATERIALS_CLEARCOAT_CLEARCOAT_NORMAL_TEXTURE_TEXCOORD|Normal and clearcoat normal textures should use the same texture coords.|Warning|

lib/src/base/animation.dart

@@ -311,14 +311,13 @@ class AnimationChannel extends GltfProperty {
     if (context.validate) {
       checkMembers(map, ANIMATION_CHANNEL_MEMBERS, context);
     }
-
-    return AnimationChannel._(
-        getIndex(map, SAMPLER, context),
-        getObjectFromInnerMap<AnimationChannelTarget>(
-            map, TARGET, context, AnimationChannelTarget.fromMap,
-            req: true),
-        getExtensions(map, AnimationChannel, context),
-        getExtras(map, context));
+    final target = getObjectFromInnerMap<AnimationChannelTarget>(
+        map, TARGET, context, AnimationChannelTarget.fromMap,
+        req: true);
+    final channel = AnimationChannel._(getIndex(map, SAMPLER, context), target,
+        getExtensions(map, AnimationChannel, context), getExtras(map, context));
+    context.registerObjectsOwner(channel, [target]);
+    return channel;
   }
 }
 

lib/src/context.dart

@@ -54,6 +54,29 @@ class Context {
   static Iterable<String> get defaultExtensionNames =>
       kDefaultExtensions.map((e) => e.name);
 
+  static PointerValidity validateExtensionPointer(Context context,
+      List<String> pointer, GltfProperty prop, int inPropDepth) {
+    for (final extension in context._userExtensions) {
+      final func = extension.validateExtensionPointer;
+      if (func != null) {
+        final result = func(context, pointer, prop, inPropDepth);
+        if (result != PointerValidity.unknown) {
+          return result;
+        }
+      }
+    }
+    for (final extension in kDefaultExtensions) {
+      final func = extension.validateExtensionPointer;
+      if (func != null) {
+        final result = func(context, pointer, prop, inPropDepth);
+        if (result != PointerValidity.unknown) {
+          return result;
+        }
+      }
+    }
+    return PointerValidity.unknown;
+  }
+
   Context({this.validate = true, ValidationOptions options})
       : options = options ?? ValidationOptions() {
     _extensionsLoadedView = UnmodifiableListView(_extensionsLoaded);

lib/src/errors.dart

@@ -502,6 +502,43 @@ class SemanticError extends IssueType {
           (args) => 'This extension requires the animation channel target path '
               "to be 'pointer'. Found ${_q(args[0])} instead.");
 
+  static final SemanticError khrAnimationPointerCannotValidateExtras =
+      SemanticError._(
+          'KHR_ANIMATION_POINTER_CANNOT_VALIDATE_EXTRAS',
+          (args) => 'Cannot validate pointers into non-standardized extras.',
+          Severity.Hint);
+
+  static final SemanticError khrAnimationPointerInvalidPointer =
+      SemanticError._(
+          'KHR_ANIMATION_POINTER_INVALID_POINTER',
+          (args) => 'The pointer ${_q(args[0])} does not point to a valid '
+              'property in the glTF JSON. Animated properties must be '
+              'defined in the JSON document.');
+
+  static final SemanticError khrAnimationPointerIntegerNonStepInterpolation =
+      SemanticError._(
+          'KHR_ANIMATION_POINTER_INTEGER_NON_STEP_INTERPOLATION',
+          (args) => 'Animation samplers used with int or bool Object Model '
+              'Data Types MUST use STEP interpolation. '
+              'Pointer: ${_q(args[0])}, expected: ${_q(args[1])}, '
+              'found: ${_q(args[2])}.');
+
+  static final SemanticError khrAnimationPointerComponentTypeMismatch =
+      SemanticError._(
+          'KHR_ANIMATION_POINTER_COMPONENT_TYPE_MISMATCH',
+          (args) => 'The output component type of the accessor does not '
+              'match the required type of the glTF Object Model property '
+              'being targeted by the pointer ${_q(args[0])}. '
+              'Expected type: ${_q(args[1])}, found type: ${_q(args[2])}.');
+
+  static final SemanticError khrAnimationPointerVectorSizeMismatch =
+      SemanticError._(
+          'KHR_ANIMATION_POINTER_VECTOR_SIZE_MISMATCH',
+          (args) => 'The output vector size of the accessor does not match '
+              'the required vector size of the glTF Object Model property '
+              'being targeted by the pointer ${_q(args[0])}. '
+              'Expected size: ${args[1]}, found size: ${args[2]}.');
+
   static final SemanticError khrLightsPunctualLightSpotAngles = SemanticError._(
       'KHR_LIGHTS_PUNCTUAL_LIGHT_SPOT_ANGLES',
       (args) => 'outerConeAngle (${args[1]}) is less than or equal to '