Add option for max points per draw shape (#3900)

When a draw shape gets long, we split it into multiple shapes. This PR
gives the user the option to change how long a shape can be before it
needs to be split.

### Change Type

<!-- ❗ Please select a 'Scope' label ❗️ -->

- [x] `sdk` — Changes the tldraw SDK
- [ ] `dotcom` — Changes the tldraw.com web app
- [ ] `docs` — Changes to the documentation, examples, or templates.
- [ ] `vs code` — Changes to the vscode plugin
- [ ] `internal` — Does not affect user-facing stuff

<!-- ❗ Please select a 'Type' label ❗️ -->

- [ ] `bugfix` — Bug fix
- [x] `feature` — New feature
- [ ] `improvement` — Improving existing features
- [ ] `chore` — Updating dependencies, other boring stuff
- [ ] `galaxy brain` — Architectural changes
- [ ] `tests` — Changes to any test code
- [ ] `tools` — Changes to infrastructure, CI, internal scripts,
debugging tools, etc.
- [ ] `dunno` — I don't know


### Release Notes

- SDK: Add option for controlling max length of draw shapes

packages/editor/api-report.md

@@ -651,6 +651,7 @@ export const defaultTldrawOptions: {
     readonly hitTestMargin: 8;
     readonly longPressDurationMs: 500;
     readonly maxPages: 40;
+    readonly maxPointsPerDrawShape: 500;
     readonly maxShapesPerPage: 4000;
     readonly multiClickDurationMs: 200;
     readonly textShadowLod: 0.35;
@@ -2400,6 +2401,8 @@ export interface TldrawOptions {
     // (undocumented)
     readonly maxPages: number;
     // (undocumented)
+    readonly maxPointsPerDrawShape: number;
+    // (undocumented)
     readonly maxShapesPerPage: number;
     // (undocumented)
     readonly multiClickDurationMs: number;

packages/editor/src/lib/options.ts

@@ -26,6 +26,7 @@ export interface TldrawOptions {
 	readonly dragDistanceSquared: number
 	readonly defaultSvgPadding: number
 	readonly cameraSlideFriction: number
+	readonly maxPointsPerDrawShape: number
 	readonly gridSteps: readonly {
 		readonly min: number
 		readonly mid: number
@@ -58,6 +59,7 @@ export const defaultTldrawOptions = {
 	dragDistanceSquared: 16, // 4 squared
 	defaultSvgPadding: 32,
 	cameraSlideFriction: 0.09,
+	maxPointsPerDrawShape: 500,
 	gridSteps: [
 		{ min: -1, mid: 0.15, step: 64 },
 		{ min: 0.05, mid: 0.375, step: 16 },

packages/tldraw/src/lib/shapes/draw/toolStates/Drawing.ts

@@ -630,7 +630,7 @@ export class Drawing extends StateNode {
 				this.editor.updateShapes([shapePartial])
 
 				// Set a maximum length for the lines array; after 200 points, complete the line.
-				if (newPoints.length > 500) {
+				if (newPoints.length > this.editor.options.maxPointsPerDrawShape) {
 					this.editor.updateShapes([{ id, type: this.shapeType, props: { isComplete: true } }])
 
 					const newShapeId = createShapeId()