[pdf] TTF font displayed as dots on iOS and Adobe Reader (OTF equivalent is fine) about canvas HOT 2 CLOSED

Someone e-mailed me personally with the same issue, this was my response:

It looks like dots are displayed when the font file cannot be found or the character is not defined in the PDF. This is strange as it loads fine in a variety of applications on my Linux computer. It might be related to the use of UTF-8 characters in the text (the double quotes in this case). To be fair, text embedding in PDFs could be improved in general as there is a bug of copy pasting text from the PDF not representing the written text. The latter might be related to your issue.

Can you output a PDF of https://github.com/tdewolff/canvas/tree/master/examples/document and see what happens? That is, does this happen when there is a UTF-8 character used, or also when just using ASCII. In general, at https://github.com/tdewolff/canvas/blob/master/pdf/renderer.go#L490 I'm wrapping the font program in a couple of layers which seems to be unnecessary and might be part of the problem. For example, output from Inkscape is much more concise.

In particular, this could be fixed with a GID to codepoint table as defined in the PDF specification, but I think it could be simpler by more directly embedding the font program and specifying the right encoding. In the future it would be desireable to create the TTF/OTF font (instead of copying the original font file) so that we can tweak the GID=>codepoint table to match one of PDFs encodings and so we can subset the file and remove unnecessary tables.

from canvas.

This should be fixed in the develop branch, see the roadmap for more information: #74

from canvas.