Artifact on a certain glyph

bluebear94 commented 9 months ago

To reproduce: Save the following as shape.txt:

{
  26.3125, 9.5625;
  m;
  26.6875, 9.5625;
  c;
  26.6875, 4.8125;
  m;
  31.9375, 4.8125;
  y;
  31.9375, 27.8125;
  y(31.9375, 38.90625; 23.46875, 40.1875);
  19, 40.1875;
  y(13.75, 40.1875; 7.75, 38.34375);
  5, 32;
  m;
  10.125, 30.1875;
  c(11.28125, 32.71875; 14.09375, 35.4375);
  19.1875, 35.4375;
  c(24.125, 35.4375; 26.625, 32.84375);
  26.625, 28.375;
  c;
  26.625, 28.1875;
  c(26.625, 25.59375; 23.9375, 25.8125);
  17.5625, 25;
  c(11.09375, 24.15625; 4, 22.71875);
  4, 14.75;
  c(4, 7.90625; 9.28125, 4);
  15.9375, 4;
  c(22.03125, 4; 25.21875, 7.28125);
  #
}
{
  26.625, 22.375;
  m;
  26.625, 17.4375;
  m(26.625, 13.09375; 23.125, 8.8125);
  16.75, 8.8125;
  y(12.46875, 8.8125; 9.375, 10.71875);
  9.375, 14.4375;
  c(9.375, 18.53125; 13.125, 19.8125);
  17.3125, 20.375;
  c(19.5625, 20.625; 25.71875, 21.28125);
  #
}

(Taken from the a glyph in Inter. For various reasons, this isn’t reproducible by letting msdfgen load the glyph from the font file.)

Run:

./msdfgen msdf -shapedesc shape.txt -size 36 45 -testrender preview.png 360 450

When the resulting distance field is rendered, there is an artifact near the tail of the a:

rendered

The artifact is less pronounced when -scale 0.99 or -scale 1.01 is passed in.

MomoDeve commented 6 months ago

having similar issue with some letters Font: https://www.fontsquirrel.com/fonts/open-sans "OpenSans-Regular.ttf" Command: msdfgen.exe -font OpenSans-Regular.ttf 'M' -size 32 32 -testrender test.png 128 128 Output: output Render: test

AndrewPech6-dev commented 2 months ago

symbol.txt

I have also been having some rendering glitches on symbols. I have attached a shape file with the problematic symbol. I don't use Skia, so I use the flag -nopreprocess, although there are different artefacts when using Skia. I use a resolution of 126 by 126 to render this symbol. I also don't use -autoframe. There are limitations that prevent me from changing the resolution or from using -autoframe in my software environment.

msdfgen.exe -shapedesc shape_61498.shape -size 126 126 -testrender render.png 126 126 -testrendermulti output.png 126 126 -nopreprocess output render

Chlumsky commented 2 months ago

@AndrewPech6-dev If you don't use Skia preprocess, then you have to pass in a shape without self intersections:

self-intersect

But yes, distance fields can't deal very well with these angles:

angle

AndrewPech6-dev commented 2 months ago

Thank you, I did not see that intersection. I have other intersection tools that I can use to resolve this. Thanks for the quick response, I'll know what to look for next time I come across similar issues.

Chlumsky / msdfgen

Artifact on a certain glyph #193