Came up against a problem wherein a font with some rather complex glyphs wouldn’t fully display - either in Test Font or in MS Word.
Symptom: the line the large character was on wouldn’t display, but the lines before and after were ok. The other characters would show when they were on a line by themselves. When these very large characters were unmapped, things cleared up of course.
A font would show at 30k points and not at 35k points, so I trimmed the 35k down to the point at which it would. Magically 32,768 points was the dividing line. It was an easy test to add a point and have it go away.
32,768 is 2^15 and is the maximum value of a signed 32 bits integer so perhaps this is being used along the way.
Interesting, FC wouldn’t show the letter, but MT did not have the same limit. I added a thousand points of dark … and MT was still showing the glyph, but it wouldn’t display the 57k glyph so there is a stopping point someplace..
There were no problems printing when the glyphs could be seen on the screen. These images were silhouettes yet still had so many points – largest was 57k points and was simple picture of a man in white tie tuxedo(!) drinking Martini Cocktails from a bottle(!) and smoking a cigar(!). The designer had drawn the smoke as thousands of tiny particles.