Automattic/node-canvas

RGB functions do not support real numbers

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#2,339 opened on Jan 18, 2024

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Description

Issue

RGB colors that contain a real number are not supported, while in browsers this works. The official spec defines real numbers as a valid argument for the modern spec and browsers have supported this for several years so it would be nice to have consistency.

Steps to Reproduce

const { Canvas } = require('canvas');
const canvas = new Canvas();
const ctx = canvas.getContext('2d');

ctx.fillStyle = 'rgb(127,127.0,255)';
console.log(ctx.fillStyle); // output: #000000

ctx.fillStyle = 'rgb(127,127,255)';
console.log(ctx.fillStyle); // output: #7f7fff

I think this parsing may just have to be changed to floats?

Your Environment

  • Version of node-canvas: canvas@2.11.2
  • Environment: node v20.2.0 on macOS 14.2.1 (e.g. node 20.9.0 on macOS 14.1.1):

Contributor guide

Research direction
Inspect the color parsing function in src/color.cc and modify it to accept real numbers (floats) for RGB components. Ensure the parsing matches the CSS Color specification and test with the provided reproduction case.
Tech stack
javascriptnodejscpp
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C++
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
75