Drawing an SVG file on a HTML5 canvas

Applying advanced techniques

Here are some refined techniques and considerations to step up your SVG on canvas game.

More than just a path with Path2D

The Path2D() constructor allows us to work with complex paths, and paint them onto our canvas:

var svgPathData = "M10 10 h 80 v 80 h -80 Z"; // Swap this out for your SVG path data
var path = new Path2D(svgPathData);
ctx.fillStyle = 'blue';  // Make it blue, da ba dee da ba daa
ctx.fill(path);  // Blast that path onto the canvas!
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This example uses svgPathData, which represent your SVG path commands, obtained dynamically or hard-coded. It's key to convert from an SVG string to path commands.

Cross-browser compatibility: the canvg baller

To tackle those cross-browser quirks, canvg steps up to the plate:

canvg(canvas, svgXmlText);
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This handy library takes your svgXmlText, parses it and renders it directly onto the canvas. It's especially handy when dealing with that old friend of ours, IE.

Draw your SVGs, encode it like a spy

For some precise use cases, you might need to apply serialization and base64 encoding to handle SVG data:

var xml = new XMLSerializer().serializeToString(document.querySelector('svg')); // Utility belt: checked ✔
var svg64 = btoa(xml); // Our secret code message
var b64Start = 'data:image/svg+xml;base64,';
var image64 = b64Start + svg64; 

img.src = image64; // Replace existing src for drawImage
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The self-sustaining SVGs

For pure standalone use, ensure your SVG has all embedded images within itself, like a total survivalist:

<svg>
  <image href="data:image/png;base64,..."/> // In-line embedded images for the win!
</svg>
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Layout matters, so does loading

Remember to set the display property to block for svg, img, and canvas to keep the layout intact:

svg, img, canvas {
  display: block;  // Everybody in line now
}
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Attach an onload event to images to ensure it's fully loaded before the big show:

img.onload = function() { ctx.drawImage(img, 0, 0) };
img.src = image64; // previously encoded SVG data
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Keeping up with the Browsers

Always check for support before using specific methods of drawing SVG on canvas to avoid those browser blues:

if (canvas.getContext && canvas.toBlob) {
  // We're good to go! 🚀
}
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You can manually perform these checks, or you can use a library like Modernizr for a smoother cross-browser experience.

Enhanced SVG techniques for power users

Heading towards more demanding scenarios, let's explore some proficient methods and techniques for dealing with SVGs in high gear.

Performance tuning: off-screen drawing

For complex or dynamic SVGs, draw them off-screen onto a secondary canvas, then transfer to the main canvas. It's like rehearsals before the big show!

Ironing out console warnings

Browsers, like Chrome, are pretty vocal about their issues. Take heed and ensure to dress your SVG data in proper formatting and encoding to please the browser lords.

Maximizing the canvg potential

For intricate SVGs, canvg is your secret sauce. It simplifies and ensures a more uniform rendering of SVGs. Using the drawSvg() method with SVG XML data is a real crowd pleaser.

Digging through documentation

If you hit a snag, fear not! The extensive documentation by browsers, and archived resources like Mozilla's, provide vital clues about drawing DOM objects on canvas.