feat(paint): match brush cursor to selected segment color

Author: PaulHax

src/components/tools/paint/PaintWidget2D.vue

@@ -24,6 +24,7 @@ import { VtkViewContext } from '@/src/components/vtk/context';
 import { Maybe } from '@/src/types';
 import { PaintMode } from '@/src/core/tools/paint';
 import { usePaintInteractionMode } from '@/src/segmentation/composables/usePaintInteractionMode';
+import { useSegmentStore } from '@/src/segmentation/segments';
 import eyedropperCursor from '@/src/assets/eyedropper-cursor.svg?url';
 import { useActionHeld } from '@/src/composables/useKeyboardShortcuts';
 
@@ -70,6 +71,14 @@ export default defineComponent({
 
     // --- widget representation config --- //
 
+    const { segments } = useSegmentStore();
+    watchEffect(() => {
+      const [r, g, b] = segments.appearanceOf(
+        segments.selectedSegmentId.value
+      ).color;
+      widgetState.getBrush().setColor3([r, g, b]);
+    });
+
     // Every mask uses the parent voxel grid. Selection and mask growth do not
     // change the brush's world-space footprint.
     watchEffect(() => {

src/vtk/PaintBrushContextRepresentation/index.js

@@ -122,7 +122,6 @@ function vtkPaintBrushContextRepresentation(publicAPI, model) {
 
   const actorProperty = model.pipelines.brush.actor.getProperty();
   actorProperty.setLineWidth(2);
-  actorProperty.setColor([1, 0, 0]);
   actorProperty.setDisplayLocation(DisplayLocation.FOREGROUND);
   actorProperty.setRepresentation(Representation.SURFACE);
 
@@ -135,6 +134,7 @@ function vtkPaintBrushContextRepresentation(publicAPI, model) {
 
     const stencil = widgetState.getStencil();
     const brush = widgetState.getBrush();
+    actorProperty.setColor(brush.getColor3().map((channel) => channel / 255));
     const { indexToWorld, worldToIndex } = model;
 
     if (stencil && brush.getOrigin()) {

src/vtk/PaintWidget/state.ts

@@ -10,8 +10,8 @@ export interface PaintPointWidgetState extends vtkWidgetState {
   getScale1(): number;
   setVisible(visible: boolean): boolean;
   getVisible(): boolean;
-  setColor(color: number): boolean;
-  getColor(): number;
+  setColor3(color: Vector3): boolean;
+  getColor3(): Vector3;
 }
 
 export interface PaintWidgetState extends vtkWidgetState {
@@ -26,7 +26,7 @@ export default function generateState() {
     .addStateFromMixin({
       labels: ['brush'],
       name: 'brush',
-      mixins: ['origin', 'scale1', 'visible', 'color'],
+      mixins: ['origin', 'scale1', 'visible', 'color3'],
       initialValues: {
         scale1: 1,
         origin: null,