Fix volume annotation tool availability on datasets with rotation transforms (#8432)

* make volume annotation tools properly available for datasets with rotation transforms where the dataset rotation is turned off but not the active volume layer is the selected "nativelyRenderedLayerName"

* add changelog entry

* ensure reference to identity transform is also returned when transform for skeleton layer is calculated

* rename function

---------

Co-authored-by: Michael Büßemeyer <frameworklinux+MichaelBuessemeyer@users.noreply.github.com>

Author: MichaelBuessemeyer

CHANGELOG.unreleased.md

@@ -20,6 +20,7 @@ For upgrade instructions, please check the [migration guide](MIGRATIONS.released
 ### Fixed
 - Fixed a bug that would lock a non-existing mapping to an empty segmentation layer under certain conditions. [#8401](https://github.com/scalableminds/webknossos/pull/8401)
 - Fixed the alignment of the button that allows restricting floodfill operations to a bounding box. [#8388](https://github.com/scalableminds/webknossos/pull/8388) 
+- Fixed a bug for rotated dataset where volume tools were disabled although the dataset was rendered untransformed. [#8432](https://github.com/scalableminds/webknossos/pull/8432)
 - Fixed rare bug where saving got stuck. [#8409](https://github.com/scalableminds/webknossos/pull/8409)
 - Fixed a bug where reverting annotations could get stuck if some of its layers had been deleted in the meantime. [#8405](https://github.com/scalableminds/webknossos/pull/8405)
 - Fixed a bug where newly added remote datasets would always appear in root folder, regardless of actual selected folder. [#8425](https://github.com/scalableminds/webknossos/pull/8425)

frontend/javascripts/oxalis/model/accessors/dataset_layer_transformation_accessor.ts

@@ -191,6 +191,10 @@ export function isLayerWithoutTransformationConfigSupport(layer: APIDataLayer |
   );
 }
 
+function toIdentityTransformMaybe(transform: Transform | null): Transform {
+  return transform && !equalsIdentityTransform(transform) ? transform : IdentityTransform;
+}
+
 function _getTransformsForLayerOrNull(
   dataset: APIDataset,
   layer: APIDataLayer | APISkeletonLayer,
@@ -210,7 +214,7 @@ function _getTransformsForLayerOrNull(
   const layerTransforms = getOriginalTransformsForLayerOrNull(dataset, layer as APIDataLayer);
   if (nativelyRenderedLayerName == null) {
     // No layer is requested to be rendered natively. -> We can use the layer's transforms as is.
-    return layerTransforms;
+    return toIdentityTransformMaybe(layerTransforms);
   }
 
   // Apply the inverse of the layer that should be rendered natively
@@ -221,11 +225,11 @@ function _getTransformsForLayerOrNull(
   if (transformsOfNativeLayer == null) {
     // The inverse of no transforms, are no transforms. Leave the layer
     // transforms untouched.
-    return layerTransforms;
+    return toIdentityTransformMaybe(layerTransforms);
   }
 
   const inverseNativeTransforms = invertTransform(transformsOfNativeLayer);
-  return chainTransforms(layerTransforms, inverseNativeTransforms);
+  return toIdentityTransformMaybe(chainTransforms(layerTransforms, inverseNativeTransforms));
 }
 
 export const getTransformsForLayerOrNull = memoizeWithThreeKeys(_getTransformsForLayerOrNull);
@@ -239,7 +243,7 @@ export function getTransformsForLayer(
   );
 }
 
-export function isIdentityTransform(transform: Transform) {
+function equalsIdentityTransform(transform: Transform) {
   return transform.type === "affine" && _.isEqual(transform.affineMatrix, Identity4x4);
 }
 
@@ -266,7 +270,7 @@ function _getTransformsForLayerThatDoesNotSupportTransformationConfigOrNull(
     const someLayersTransformsMaybe = usableReferenceLayer
       ? getTransformsForLayerOrNull(dataset, usableReferenceLayer, nativelyRenderedLayerName)
       : null;
-    return someLayersTransformsMaybe;
+    return toIdentityTransformMaybe(someLayersTransformsMaybe);
   } else if (nativelyRenderedLayerName != null && allLayersSameRotation) {
     // If all layers have the same transformations and at least one is rendered natively, this means that all layer should be rendered natively.
     return null;
@@ -281,7 +285,7 @@ function _getTransformsForLayerThatDoesNotSupportTransformationConfigOrNull(
     return null;
   }
 
-  return invertTransform(transformsOfNativeLayer);
+  return toIdentityTransformMaybe(invertTransform(transformsOfNativeLayer));
 }
 
 export const getTransformsForLayerThatDoesNotSupportTransformationConfigOrNull = memoizeOne(

frontend/javascripts/oxalis/view/left-border-tabs/layer_settings_tab.tsx

@@ -40,7 +40,7 @@ import {
   settingsTooltips,
 } from "messages";
 import type { Vector3 } from "oxalis/constants";
-import Constants, { ControlModeEnum, MappingStatusEnum } from "oxalis/constants";
+import Constants, { ControlModeEnum, IdentityTransform, MappingStatusEnum } from "oxalis/constants";
 import defaultState from "oxalis/default_state";
 import {
   getDefaultValueRangeOfLayer,
@@ -55,7 +55,6 @@ import {
   getTransformsForLayer,
   getTransformsForLayerOrNull,
   hasDatasetTransforms,
-  isIdentityTransform,
   isLayerWithoutTransformationConfigSupport,
 } from "oxalis/model/accessors/dataset_layer_transformation_accessor";
 import {
@@ -208,7 +207,7 @@ function TransformationIcon({ layer }: { layer: APIDataLayer | APISkeletonLayer
   if (!showIcon) {
     return null;
   }
-  const isRenderedNatively = transform == null || isIdentityTransform(transform);
+  const isRenderedNatively = transform == null || transform === IdentityTransform;
 
   const typeToLabel = {
     affine: "an affine",