On Sun, May 23, 2021 at 7:06 AM Sarthak Bhardwaj <[email protected]> wrote: > > Hello Suzuki, > > I believe you misunderstood me, I meant I have a program for highlighting > differences in images, I wanted to test what would happen in a regression > scenario, so wanted to know how to create a regression/difference in > freetype's rendering output. > > Thanks > Sarthak >
There are so many places: rounding errors in scaling, multiple hinting algorithms, curve flattening during rendering to name few. Here is one line in the code to mess things up: https://gitlab.freedesktop.org/freetype/freetype/-/blob/master/src/smooth/ftgrays.c#L1041 Change that to ONE_PIXEL / 3, and all TrueType curves will look slightly different, slightly worse. Alexei
