Function stb::easy_font::stb_easy_font_spacing

pub fn stb_easy_font_spacing(spacing: f32)

Use positive values to expand the space between characters, and small negative values (no smaller than -1.5) to contract the space between characters. E.g. spacing = 1 adds one "pixel" of spacing between the characters. spacing = -1 is reasonable but feels a bit too compact to me; -0.5 is a reasonable compromise as long as you're scaling the font up.