[fix] minimap, common page bounds (#1770)

This PR fixes a bug that was introduced (by me) in #1751, where:
- the `commonBoundsOfAllShapesOnCurrentPage` would mutate the first
bounding box
- the render reactor would fire too often

### Change Type

- [x] `patch` — Bug fix

### Test Plan

1. Use the minimap

packages/editor/src/lib/editor/Editor.ts

@@ -4227,7 +4227,7 @@ export class Editor extends EventEmitter<TLEventMap> {
 			const bounds = this.getMaskedPageBounds(shapeId)
 			if (!bounds) return
 			if (!commonBounds) {
-				commonBounds = bounds
+				commonBounds = bounds.clone()
 			} else {
 				commonBounds = commonBounds.expand(bounds)
 			}

packages/tldraw/src/lib/ui/components/NavigationZone/Minimap.tsx

@@ -8,9 +8,9 @@ import {
 	intersectPolygonPolygon,
 	normalizeWheel,
 	setPointerCapture,
-	track,
-	useContainer,
+	useComputed,
 	useEditor,
+	useIsDarkMode,
 	useQuickReactor,
 } from '@tldraw/editor'
 import * as React from 'react'
@@ -22,30 +22,22 @@ export interface MinimapProps {
 	viewportFill: string
 }
 
-export const Minimap = track(function Minimap({
-	shapeFill,
-	selectFill,
-	viewportFill,
-}: MinimapProps) {
+export function Minimap({ shapeFill, selectFill, viewportFill }: MinimapProps) {
 	const editor = useEditor()
 
 	const rCanvas = React.useRef<HTMLCanvasElement>(null!)
-
-	const container = useContainer()
-
 	const rPointing = React.useRef(false)
 
-	const minimap = React.useMemo(
-		() => new MinimapManager(editor, editor.instanceState.devicePixelRatio),
-		[editor]
-	)
+	const isDarkMode = useIsDarkMode()
+	const devicePixelRatio = useComputed('dpr', () => editor.instanceState.devicePixelRatio, [editor])
+	const presences = React.useMemo(() => editor.store.query.records('instance_presence'), [editor])
 
-	const isDarkMode = editor.user.isDarkMode
+	const minimap = React.useMemo(() => new MinimapManager(editor), [editor])
 
 	React.useEffect(() => {
 		// Must check after render
 		const raf = requestAnimationFrame(() => {
-			const style = getComputedStyle(container)
+			const style = getComputedStyle(editor.getContainer())
 
 			minimap.colors = {
 				shapeFill: style.getPropertyValue(shapeFill).trim(),
@@ -58,7 +50,7 @@ export const Minimap = track(function Minimap({
 		return () => {
 			cancelAnimationFrame(raf)
 		}
-	}, [container, selectFill, shapeFill, viewportFill, minimap, isDarkMode])
+	}, [editor, selectFill, shapeFill, viewportFill, minimap, isDarkMode])
 
 	const onDoubleClick = React.useCallback(
 		(e: React.MouseEvent<HTMLCanvasElement>) => {
@@ -163,17 +155,15 @@ export const Minimap = track(function Minimap({
 
 	// Update the minimap's dpr when the dpr changes
 	useQuickReactor(
-		'update dpr',
+		'update when dpr changes',
 		() => {
-			const {
-				instanceState: { devicePixelRatio },
-			} = editor
-			minimap.setDpr(devicePixelRatio)
+			const dpr = devicePixelRatio.value
+			minimap.setDpr(dpr)
 
 			const canvas = rCanvas.current as HTMLCanvasElement
 			const rect = canvas.getBoundingClientRect()
-			const width = rect.width * devicePixelRatio
-			const height = rect.height * devicePixelRatio
+			const width = rect.width * dpr
+			const height = rect.height * dpr
 
 			// These must happen in order
 			canvas.width = width
@@ -182,26 +172,19 @@ export const Minimap = track(function Minimap({
 
 			minimap.cvs = rCanvas.current
 		},
-		[editor, minimap]
+		[devicePixelRatio, minimap]
 	)
 
-	const presences = React.useMemo(() => {
-		return editor.store.query.records('instance_presence')
-	}, [editor])
-
 	useQuickReactor(
 		'minimap render when pagebounds or collaborators changes',
 		() => {
-			const {
-				instanceState: { devicePixelRatio },
-				viewportPageBounds,
-				commonBoundsOfAllShapesOnCurrentPage: allShapesCommonBounds,
-			} = editor
+			const { shapeIdsOnCurrentPage, viewportPageBounds, commonBoundsOfAllShapesOnCurrentPage } =
+				editor
 
-			devicePixelRatio // dereference dpr so that it renders then, too
+			const _dpr = devicePixelRatio.value
 
-			minimap.contentPageBounds = allShapesCommonBounds
-				? Box2d.Expand(allShapesCommonBounds, viewportPageBounds)
+			minimap.contentPageBounds = commonBoundsOfAllShapesOnCurrentPage
+				? Box2d.Expand(commonBoundsOfAllShapesOnCurrentPage, viewportPageBounds)
 				: viewportPageBounds
 
 			minimap.updateContentScreenBounds()
@@ -210,8 +193,9 @@ export const Minimap = track(function Minimap({
 
 			const allShapeBounds = [] as (Box2d & { id: TLShapeId })[]
 
-			editor.shapeIdsOnCurrentPage.forEach((id) => {
-				let pageBounds = editor.getPageBounds(id)! as Box2d & { id: TLShapeId }
+			shapeIdsOnCurrentPage.forEach((id) => {
+				let pageBounds = editor.getPageBounds(id) as Box2d & { id: TLShapeId }
+				if (!pageBounds) return
 
 				const pageMask = editor.getPageMask(id)
 
@@ -230,11 +214,7 @@ export const Minimap = track(function Minimap({
 			})
 
 			minimap.pageBounds = allShapeBounds
-
-			// Collaborators
-
 			minimap.collaborators = presences.value
-
 			minimap.render()
 		},
 		[editor, minimap]
@@ -253,4 +233,4 @@ export const Minimap = track(function Minimap({
 			/>
 		</div>
 	)
-})
+}

packages/tldraw/src/lib/ui/components/NavigationZone/MinimapManager.ts

@@ -10,7 +10,9 @@ import {
 } from '@tldraw/editor'
 
 export class MinimapManager {
-	constructor(public editor: Editor, private dpr: number) {}
+	constructor(public editor: Editor) {}
+
+	dpr = 1
 
 	colors = {
 		shapeFill: 'rgba(144, 144, 144, .1)',
@@ -212,7 +214,6 @@ export class MinimapManager {
 		const by = ry / 4
 
 		// shapes
-
 		const shapesPath = new Path2D()
 		const selectedPath = new Path2D()
 
@@ -234,6 +235,7 @@ export class MinimapManager {
 				clamp(ry, ay, pb.height / by)
 			)
 		}
+
 		// Fill the shapes paths
 		ctx.fillStyle = shapeFill
 		ctx.fill(shapesPath)