Sunday, November 9, 2014

Even more progress on proportional fonts

Hot on the heals of the earlier fixes of the evening, descenders (the bits of characters that hang below the base-line) and bits poking out the top are now correctly draw as can be seen in the screen-shot below.

Along the way I have fixed bugs in my unicode printing programme, and also a couple of bugs in my true-type font rasteriser (the top pixel of characters could be chopped off, and character tiles were being written to the file in the wrong order).

As with the other screen-shots, the Matrix-like green tint is an artefact of the image capture process I am using, and the bad kerning is pending a patch to the FPGA so that it stops ignoring the least significant bit of the kerning field of each character.

Once the horizontal kerning has been fixed, that just leaves the vertical spacing to fix.  This will probably require both FPGA and more font-file format tweaking.


The above image is captured the same way as the one in the previous post. Then I realised that my VNC viewer was scaling the image, so below is the same image really without any scaling:




Just for further fun and to prove that it works for larger font sizes, I produced a 24 point version of the same font to try out:


This revealed a few new glitches, like why is the "t" in jupiter mostly missing.  There are also some other issues, like the width of the right vertical of "H", Alef (the right-most Hebrew character) that I will have to look into.

The disappearing "t" turned out to be a quick fix, so the final result for the night is as follows:


 Note also that with a big font the suppression of the spare blank raster lines becomes less important.  I still intend to fix it, however.

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