4 ms·

It's a good thought, and it does seem a much better way to go at face value. However, I strongly suspect there are good technical reasons why you basically need

by benhoyt 12y ago

It's a good thought, and it does seem a much better way to go at face value. However, I strongly suspect there are good technical reasons why you basically need to use canvas, to get the complete, pixel-perfect control over the layout and font rendering that you'd need for PDFs.

userbinator 12y ago
to get the complete, pixel-perfect control over the layout and font rendering that you'd need for PDFs. I suspect this is part of the problem too - the desire to render every pixel of fonts the same as the native application. But honestly, 99.9% of the time I'm reading a PDF, I don't care if each pixel is in exactly the same place as it would be in some other reader application so long as I can read the content, and would be willing to sacrifice that if it meant a drastic decrease in memory consumption (and possibly better performance.) That doesn't mean a "precise mode" is a bad idea, so maybe make this an option - you can either have pixel-perfect rendering but use more memory and CPU, or have a "close enough" rendering that doesn't.
- masklinn 12y ago
  If you don't care you should feel free to replace pdf.js with a degraded version, but I'd expect something which claims to render PDFs to actually do that.
- mhaymo 12y ago
  Seems to me that the development time spent maintaining two different modes might be better spent simply improving the efficiency of the one correct version.
- jerf 12y ago
  "But honestly, 99.9% of the time I'm reading a PDF, I don't care if each pixel is in exactly the same place as it would be in some other reader application so long as I can read the content" No, you don't actually want that. I've seen this in Linux where a PDF gets rendered with the wrong font because the correct one wasn't on my system or embedded in the PDF. It becomes illegible. PDFs are deeply pixel perfect in specification; you can't just decide to not worry about that anymore and expect anything legible to come out the other side. It is not HTML under the hood; it's a printer format under the hood.
  - nnethercote 12y ago
    Spot on. Pixel-perfection is probably the single most compelling thing about PDF, and it certainly is a fundamental design goal of pdf.js.

by benhoyt 12y ago

userbinator 12y ago

to get the complete, pixel-perfect control over the layout and font rendering that you'd need for PDFs. I suspect this is part of the problem too - the desire to render every pixel of fonts the same as the native application. But honestly, 99.9% of the time I'm reading a PDF, I don't care if each pixel is in exactly the same place as it would be in some other reader application so long as I can read the content, and would be willing to sacrifice that if it meant a drastic decrease in memory consumption (and possibly better performance.) That doesn't mean a "precise mode" is a bad idea, so maybe make this an option - you can either have pixel-perfect rendering but use more memory and CPU, or have a "close enough" rendering that doesn't.

masklinn 12y ago
If you don't care you should feel free to replace pdf.js with a degraded version, but I'd expect something which claims to render PDFs to actually do that.
mhaymo 12y ago
Seems to me that the development time spent maintaining two different modes might be better spent simply improving the efficiency of the one correct version.
jerf 12y ago
"But honestly, 99.9% of the time I'm reading a PDF, I don't care if each pixel is in exactly the same place as it would be in some other reader application so long as I can read the content" No, you don't actually want that. I've seen this in Linux where a PDF gets rendered with the wrong font because the correct one wasn't on my system or embedded in the PDF. It becomes illegible. PDFs are deeply pixel perfect in specification; you can't just decide to not worry about that anymore and expect anything legible to come out the other side. It is not HTML under the hood; it's a printer format under the hood.
- nnethercote 12y ago
  Spot on. Pixel-perfection is probably the single most compelling thing about PDF, and it certainly is a fundamental design goal of pdf.js.