Fix drawing session, avoids expensive iterations if we can

packages/tldraw/src/shape/shapes/arrow/arrow.tsx

@@ -72,7 +72,7 @@ export class Arrow extends TLDrawShapeUtil<ArrowShape, SVGGElement> {
   }
 
   render = React.forwardRef<SVGGElement, TLShapeProps<ArrowShape, SVGGElement>>(
-    ({ shape, meta, events }) => {
+    ({ shape, meta, events }, ref) => {
       const {
         handles: { start, bend, end },
         decorations = {},
@@ -220,7 +220,7 @@ export class Arrow extends TLDrawShapeUtil<ArrowShape, SVGGElement> {
       const sw = strokeWidth * 1.618
 
       return (
-        <g {...events}>
+        <g ref={ref} {...events}>
           <g pointerEvents="none">
             {shaftPath}
             {startArrowHead && (

packages/tldraw/src/shape/shapes/draw/draw.tsx

@@ -31,7 +31,7 @@ export class Draw extends TLDrawShapeUtil<DrawShape, SVGGElement> {
   }
 
   render = React.forwardRef<SVGGElement, TLShapeProps<DrawShape, SVGGElement>>(
-    ({ shape, meta, events, isEditing }) => {
+    ({ shape, meta, events, isEditing }, ref) => {
       const { points, style } = shape
 
       const styles = getShapeStyle(style, meta.isDarkMode)
@@ -47,7 +47,7 @@ export class Draw extends TLDrawShapeUtil<DrawShape, SVGGElement> {
         const sw = strokeWidth * 0.618
 
         return (
-          <g {...events}>
+          <g ref={ref} {...events}>
             <circle
               r={strokeWidth * 0.618}
               fill={styles.stroke}
@@ -76,7 +76,7 @@ export class Draw extends TLDrawShapeUtil<DrawShape, SVGGElement> {
           : Utils.getFromCache(this.drawPathCache, points, () => getDrawStrokePath(shape, false))
 
         return (
-          <g {...events}>
+          <g ref={ref} {...events}>
             {shouldFill && (
               <path
                 d={polygonPathData}
@@ -121,7 +121,7 @@ export class Draw extends TLDrawShapeUtil<DrawShape, SVGGElement> {
       const sw = strokeWidth * 1.618
 
       return (
-        <g {...events}>
+        <g ref={ref} {...events}>
           <path
             d={path}
             fill={shouldFill ? styles.fill : 'none'}
@@ -260,19 +260,6 @@ export class Draw extends TLDrawShapeUtil<DrawShape, SVGGElement> {
   ): Partial<DrawShape> {
     return this.transform(shape, bounds, info)
   }
-
-  onSessionComplete(shape: DrawShape): Partial<DrawShape> {
-    const bounds = this.getBounds(shape)
-
-    const [x1, y1] = Vec.round(Vec.sub([bounds.minX, bounds.minY], shape.point))
-
-    const points = shape.points.map(([x0, y0, p]) => Vec.round([x0 - x1, y0 - y1]).concat(p))
-
-    return {
-      points,
-      point: Vec.add(shape.point, [x1, y1]),
-    }
-  }
 }
 
 const simulatePressureSettings = {

packages/tldraw/src/shape/shapes/ellipse/ellipse.tsx

@@ -38,7 +38,7 @@ export class Ellipse extends TLDrawShapeUtil<EllipseShape, SVGGElement> {
   }
 
   render = React.forwardRef<SVGGElement, TLShapeProps<EllipseShape, SVGGElement>>(
-    ({ shape, meta, isBinding, events }) => {
+    ({ shape, meta, isBinding, events }, ref) => {
       const {
         radius: [radiusX, radiusY],
         style,
@@ -56,7 +56,7 @@ export class Ellipse extends TLDrawShapeUtil<EllipseShape, SVGGElement> {
         )
 
         return (
-          <g {...events}>
+          <g ref={ref} {...events}>
             {isBinding && (
               <ellipse
                 className="tl-binding-indicator"
@@ -102,7 +102,7 @@ export class Ellipse extends TLDrawShapeUtil<EllipseShape, SVGGElement> {
       const sw = strokeWidth * 1.618
 
       return (
-        <g {...events}>
+        <g ref={ref} {...events}>
           {isBinding && (
             <ellipse
               className="tl-binding-indicator"

packages/tldraw/src/shape/shapes/group/group.tsx

@@ -39,7 +39,7 @@ export class Group extends TLDrawShapeUtil<GroupShape, SVGGElement> {
   }
 
   render = React.forwardRef<SVGGElement, TLShapeProps<GroupShape, SVGGElement>>(
-    ({ shape, isBinding, isHovered, isSelected, events }) => {
+    ({ shape, isBinding, isHovered, isSelected, events }, ref) => {
       const { id, size } = shape
 
       const sw = 2
@@ -77,7 +77,7 @@ export class Group extends TLDrawShapeUtil<GroupShape, SVGGElement> {
       })
 
       return (
-        <g {...events}>
+        <g ref={ref} {...events}>
           {isBinding && (
             <rect
               className="tl-binding-indicator"

packages/tldraw/src/shape/shapes/rectangle/rectangle.tsx

@@ -42,10 +42,6 @@ export class Rectangle extends TLDrawShapeUtil<RectangleShape, SVGGElement> {
       const styles = getShapeStyle(style, meta.isDarkMode)
       const strokeWidth = +styles.strokeWidth
 
-      React.useEffect(() => {
-        console.log(this.refMap.get(shape.id))
-      }, [])
-
       if (style.dash === DashStyle.Draw) {
         const pathData = Utils.getFromCache(this.pathCache, shape.size, () => renderPath(shape))
 
@@ -166,7 +162,6 @@ export class Rectangle extends TLDrawShapeUtil<RectangleShape, SVGGElement> {
   }
 
   getBounds(shape: RectangleShape) {
-    console.log(this.refMap.get(shape.id))
     const bounds = Utils.getFromCache(this.boundsCache, shape, () => {
       const [width, height] = shape.size
       return {

packages/tldraw/src/state/session/sessions/draw/draw.session.ts

@@ -8,10 +8,12 @@ import { TLDR } from '~state/tldr'
 export class DrawSession implements Session {
   id = 'draw'
   status = TLDrawStatus.Creating
+  topLeft: number[]
   origin: number[]
   previous: number[]
   last: number[]
   points: number[][]
+  shiftedPoints: number[][] = []
   snapshot: DrawSnapshot
   isLocked?: boolean
   lockedDirection?: 'horizontal' | 'vertical'
@@ -20,6 +22,7 @@ export class DrawSession implements Session {
     this.origin = point
     this.previous = point
     this.last = point
+    this.topLeft = point
 
     this.snapshot = getDrawSnapshot(data, id)
 
@@ -79,6 +82,12 @@ export class DrawSession implements Session {
     // The previous input (not adjusted) point
     this.previous = point
 
+    const prevTopLeft = [...this.topLeft]
+
+    this.topLeft = [Math.min(this.topLeft[0], point[0]), Math.min(this.topLeft[1], point[1])]
+
+    const delta = Vec.sub(this.topLeft, this.origin)
+
     // The new adjusted point
     const newPoint = Vec.round(Vec.sub(this.previous, this.origin)).concat(pressure)
 
@@ -89,16 +98,35 @@ export class DrawSession implements Session {
     // The new adjusted point is now the previous adjusted point.
     this.last = newPoint
 
+    let points: number[][]
+
     // Add the new adjusted point to the points array
     this.points.push(newPoint)
 
+    // Time to shift some points!
+
+    if (Vec.isEqual(prevTopLeft, this.topLeft)) {
+      // If the new top left is the same as the previous top left,
+      // we don't need to shift anything: we just shift the new point
+      // and add it to the shifted points array.
+      points = [...this.shiftedPoints, Vec.sub(newPoint, delta)]
+    } else {
+      // If we have a new top left, then we need to iterate through
+      // the "unshifted" points array and shift them based on the
+      // offset between the new top left and the original top left.
+      points = this.points.map((pt) => Vec.sub(pt, delta))
+    }
+
+    this.shiftedPoints = points
+
     return {
       document: {
         pages: {
           [data.appState.currentPageId]: {
             shapes: {
               [snapshot.id]: {
-                points: [...this.points], // Set to a new array here
+                point: this.topLeft,
+                points,
               },
             },
           },
@@ -163,11 +191,7 @@ export class DrawSession implements Session {
           pages: {
             [pageId]: {
               shapes: {
-                [snapshot.id]: TLDR.onSessionComplete(
-                  data,
-                  { ...TLDR.getShape(data, snapshot.id, pageId), points: [...this.points] },
-                  pageId
-                ),
+                [snapshot.id]: TLDR.getShape(data, snapshot.id, pageId),
               },
             },
           },