Compatibility problems

[lidongsevenlee]

https://github.com/mapbox/tiny-sdf/blob/5bd130204f341acfd974081a791be9397fb10c39/index.js#L58C27-L58C133

const {
width: glyphAdvance,
actualBoundingBoxAscent,
actualBoundingBoxDescent,
actualBoundingBoxLeft,
actualBoundingBoxRight
} = this.ctx.measureText(char);
const glyphWidth = Math.max(0, Math.min(this.size - this.buffer, Math.ceil(actualBoundingBoxRight - actualBoundingBoxLeft)));
const glyphHeight = Math.min(this.size - this.buffer, glyphTop + Math.ceil(actualBoundingBoxDescent));

const imgData = ctx.getImageData(buffer, buffer, glyphWidth, glyphHeight);

actualBoundingBoxRight, actualBoundingBoxLeft, actualBoundingBoxDescent
These values ​​may be undefined in low-end machine environments, which will cause the glyphWidth and glyphHeight to be calculated as NaN, which will cause the ctx.getImageData method to throw a DOMException error.

[mourner]

As of v2, tiny-sdf no longer supports legacy browser environments (IE11 and such), and full TextMetrics API is universally supported: https://caniuse.com/mdn-api_textmetrics_actualboundingboxleft

Perhaps we should throw a more meaningful error when this happens, but I don't think we should go back to supporting this case.

[lidongsevenlee]

I understand, thank you for the reply, but you still need to avoid the situation where the glyphWidth and glyphHeight are calculated as NaN, because this will cause ctx.getImageData to throw an error and hinder subsequent logic.