Draw svg with dynamic value on canvas-CodePudding

I want to be able to draw svg with dynamic value (color) to the canvas. I'd tried making the svg react component, so I could pass the color to the svg, but I'm then confused how to draw the react svg component to the canvas.

P.S. Best would be if the svg would be stored in seperate file.

Working static svg example:

import ant_skin_url from '../../assets/AntSkin.svg';

const ant_skin = new Image();
ant_skin.src = ant_skin_url;

context.drawImage(
  ant_skin,
  i * width_cell,
  ii * height_cell,
  width_cell,
  height_cell,
);

React svg component, but confused how to handle the output (draw this in the canvas):

export const AntSkin = (color) => 
  <svg>
    ...
  </svg>

CodePudding user response：

Since you don't want to render the svg but take it into a canvas, importing from .svg won't be much helpful.

You can create a component that:

Receives a color as prop
Has the svg content as string

On mount, it combines the svg string and the color, converts it to base64 (this is what webpack does when importing from .svg) and feed the canvas the same way you do.

This is how it looks

import { useEffect, useMemo, useRef } from "react";

export const Icon = ({ color }) => {
  const ref = useRef();
  const svg = useMemo(
    () => `<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" id="Layer_1" x="0px" y="0px" viewBox="0 0 100 100" enable-background="new 0 0 100 100" xml:space="preserve" height="100px" width="100px">
    <g>
      <path color="${color}" d="M28.1,36.6c4.6,1.9,12.2,1.6,20.9,1.1c8.9-0.4,19-0.9,28.9,0.9c6.3,1.2,11.9,3.1,16.8,6c-1.5-12.2-7.9-23.7-18.6-31.3   c-4.9-0.2-9.9,0.3-14.8,1.4C47.8,17.9,36.2,25.6,28.1,36.6z"/>
      <path color="${color}" d="M70.3,9.8C57.5,3.4,42.8,3.6,30.5,9.5c-3,6-8.4,19.6-5.3,24.9c8.6-11.7,20.9-19.8,35.2-23.1C63.7,10.5,67,10,70.3,9.8z"/>
      <path color="${color}" d="M16.5,51.3c0.6-1.7,1.2-3.4,2-5.1c-3.8-3.4-7.5-7-11-10.8c-2.1,6.1-2.8,12.5-2.3,18.7C9.6,51.1,13.4,50.2,16.5,51.3z"/>
      <path color="${color}" d="M9,31.6c3.5,3.9,7.2,7.6,11.1,11.1c0.8-1.6,1.7-3.1,2.6-4.6c0.1-0.2,0.3-0.4,0.4-0.6c-2.9-3.3-3.1-9.2-0.6-17.6   c0.8-2.7,1.8-5.3,2.7-7.4c-5.2,3.4-9.8,8-13.3,13.7C10.8,27.9,9.8,29.7,9,31.6z"/>
      <path color="${color}" d="M15.4,54.7c-2.6-1-6.1,0.7-9.7,3.4c1.2,6.6,3.9,13,8,18.5C13,69.3,13.5,61.8,15.4,54.7z"/>
      <path color="${color}" d="M39.8,57.6C54.3,66.7,70,73,86.5,76.4c0.6-0.8,1.1-1.6,1.7-2.5c4.8-7.7,7-16.3,6.8-24.8c-13.8-9.3-31.3-8.4-45.8-7.7   c-9.5,0.5-17.8,0.9-23.2-1.7c-0.1,0.1-0.2,0.3-0.3,0.4c-1,1.7-2,3.4-2.9,5.1C28.2,49.7,33.8,53.9,39.8,57.6z"/>
      <path color="${color}" d="M26.2,88.2c3.3,2,6.7,3.6,10.2,4.7c-3.5-6.2-6.3-12.6-8.8-18.5c-3.1-7.2-5.8-13.5-9-17.2c-1.9,8-2,16.4-0.3,24.7   C20.6,84.2,23.2,86.3,26.2,88.2z"/>
      <path color="${color}" d="M30.9,73c2.9,6.8,6.1,14.4,10.5,21.2c15.6,3,32-2.3,42.6-14.6C67.7,76,52.2,69.6,37.9,60.7C32,57,26.5,53,21.3,48.6   c-0.6,1.5-1.2,3-1.7,4.6C24.1,57.1,27.3,64.5,30.9,73z"/>
    </g>
    </svg>`,
    [color]
  );

  useEffect(() => {
    const image = new Image();
    const context = ref.current.getContext("2d");

    image.src = `data:image/svg xml;base64,${window.btoa(svg)}`;
    image.onload = () => {
      context.drawImage(image, 0, 0);
    };
  }, [svg]);

  return <canvas ref={ref} width="200" height="200" />;
};

Demo