mirror of https://github.com/Comfy-Org/ComfyUI_frontend.git synced 2026-05-24 14:45:36 +00:00

Files

Christian Byrne 79d0e6dc69 fix: cache ctx.measureText results to avoid redundant calls in draw loop (#9404 )

## What
Add a per-frame text measurement cache for all hot-path
ctx.measureText() calls.

## Why
drawTruncatingText() in BaseWidget calls ctx.measureText() per widget
per frame with zero caching. For a 50-node workflow at 60fps:
~78,000-243,000 measureText calls/sec. Text labels rarely change between
frames.

## How
Global Map<string, number> cache keyed by font+text, cleared once per
frame at the start of drawFrontCanvas(). Replaces direct
ctx.measureText() calls in BaseWidget.drawTruncatingText, draw.ts
truncateTextToWidth/drawTextInArea, LGraphBadge.getWidth,
LGraphButton.getWidth, and textUtils.truncateText.

## Perf Impact
Expected: ~95% reduction in measureText calls (only cache misses on
first frame and value changes). Firefox has slower measureText than
Chrome, so this disproportionately benefits Firefox.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9404-fix-cache-ctx-measureText-results-to-avoid-redundant-calls-in-draw-loop-31a6d73d3650814e9cdac16949c55cb7)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>

2026-03-13 08:16:53 -07:00

imgs

Add 'src/lib/litegraph/' from commit '1b58bf4966e9cdaa04bfaa40f5650b6c6680ab97'

2025-08-03 14:55:05 -04:00

public/css

Chore: Oxfmt formatting pass (#8341 )

2026-01-27 17:59:19 -08:00

src

fix: cache ctx.measureText results to avoid redundant calls in draw loop (#9404 )

2026-03-13 08:16:53 -07:00

AGENTS.md

docs: add widget serialization reference (widget.serialize vs widget.options.serialize) (#9102 )

2026-02-22 16:40:43 -08:00

API.md

docs: audit and update litegraph documentation (#8588 )

2026-02-03 15:07:43 -08:00

CLAUDE.md

Chore: Oxfmt formatting pass (#8341 )

2026-01-27 17:59:19 -08:00

LICENSE

Add 'src/lib/litegraph/' from commit '1b58bf4966e9cdaa04bfaa40f5650b6c6680ab97'

2025-08-03 14:55:05 -04:00

README.md

docs: audit and update litegraph documentation (#8588 )

2026-02-03 15:07:43 -08:00

README.md

@ComfyOrg/litegraph

This is the litegraph version used in ComfyUI_frontend.

It is a fork of the original litegraph.js. Some APIs may by unchanged, however it is largely incompatible with the original.

Some early highlights:

Accumulated comfyUI custom changes (2024-01 ~ 2024-05) (https://github.com/Comfy-Org/litegraph.js/pull/1)
Type schema change for ComfyUI_frontend TS migration (https://github.com/Comfy-Org/litegraph.js/pull/3)
Zoom fix (https://github.com/Comfy-Org/litegraph.js/pull/7)
Emit search box triggering custom events (https://github.com/Comfy-Org/litegraph.js/pull/10)
Truncate overflowing combo widget text (https://github.com/Comfy-Org/litegraph.js/pull/17)
Sort node based on ID on graph serialization (https://github.com/Comfy-Org/litegraph.js/pull/21)
Fix empty input not used when connecting links (https://github.com/Comfy-Org/litegraph.js/pull/24)
Batch output connection move/disconnect (https://github.com/Comfy-Org/litegraph.js/pull/39)
And now with hundreds more...

Usage

This library is included as a git subtree in the ComfyUI frontend project at src/lib/litegraph.

litegraph.js

A TypeScript library to create graphs in the browser similar to Unreal Blueprints.

Description of the original litegraph.js

A library in Javascript to create graphs in the browser similar to Unreal Blueprints. Nodes can be programmed easily and it includes an editor to construct and tests the graphs.

It can be integrated easily in any existing web applications and graphs can be run without the need of the editor.

Features

Renders on Canvas2D (zoom in/out and panning, easy to render complex interfaces, can be used inside a WebGLTexture)
Easy to use editor (searchbox, keyboard shortcuts, multiple selection, context menu, ...)
Optimized to support hundreds of nodes per graph (on editor but also on execution)
Customizable theme (colors, shapes, background)
Callbacks to personalize every action/drawing/event of nodes
Graphs can be executed in NodeJS
Highly customizable nodes (color, shape, widgets, custom rendering)
Easy to integrate in any JS application (one single file, no dependencies)
Typescript support

Integration

This library is integrated as a git subtree in the ComfyUI frontend project. To use it in your code:

import { LGraph, LGraphNode, LiteGraph } from '@/lib/litegraph'

How to code a new Node type

Here is an example of how to build a node that sums two inputs:

import { LiteGraph, LGraphNode } from './litegraph'

class MyAddNode extends LGraphNode {
  // Name to show
  title = 'Sum'

  constructor() {
    this.addInput('A', 'number')
    this.addInput('B', 'number')
    this.addOutput('A+B', 'number')
    this.properties.precision = 1
  }

  // Function to call when the node is executed
  onExecute() {
    var A = this.getInputData(0)
    if (A === undefined) A = 0
    var B = this.getInputData(1)
    if (B === undefined) B = 0
    this.setOutputData(0, A + B)
  }
}

// Register the node type
LiteGraph.registerNodeType('basic/sum', MyAddNode)

Server side

It also works server-side using NodeJS although some nodes do not work in server (audio, graphics, input, etc).

import { LiteGraph, LGraph } from './litegraph.js'

const graph = new LGraph()

const firstNode = LiteGraph.createNode('basic/sum')
graph.add(firstNode)

const secondNode = LiteGraph.createNode('basic/sum')
graph.add(secondNode)

firstNode.connect(0, secondNode, 1)

graph.start()