How to position Path2D SVG element in canvas?

问题

I'm drawing a path2D SVG shape on canvas. The problem is that the moveTo function does not seem to work when using SVG data.

The problem is illustrated in this codepen. https://codepen.io/grasmachien/pen/rNaJeBN

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

let p = new Path2D('M10 10 h 80 v 80 h -80 Z');
p.moveTo(100,100)
ctx.fill(p);

Is there a way to move the path without moving the canvas?

回答1:

Use the transform to move the path

Using CanvasRenderingContext2D.translate

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

let p = new Path2D('M10 10 h 80 v 80 h -80 Z');
ctx.translate(100, 100);
ctx.fill(p);

or using CanvasRenderingContext2D.setTransform

let p = new Path2D('M10 10 h 80 v 80 h -80 Z');
ctx.setTransform(1, 0, 0, 1, 100, 100);  // Also resets the transform before applying
ctx.fill(p);

or using CanvasRenderingContext2D.transform

let p = new Path2D('M10 10 h 80 v 80 h -80 Z');
ctx.transform(1, 0, 0, 1, 100, 100);  
ctx.fill(p);

来源：https://stackoverflow.com/questions/59631446/how-to-position-path2d-svg-element-in-canvas